Article

Risk of Travel-Associated Typhoid and Paratyphoid Fevers in Various Regions

Article

Risk of Travel-Associated Typhoid and Paratyphoid Fevers in Various Regions

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Abstract

Although enteric fever (typhoid and paratyphoid fevers) is a major global public health problem, comparable data on the risks of contracting travel-associated enteric fever in various regions of the world are scarce. From the Swedish database on notifiable communicable diseases, we retrieved all case records from 1997 to 2003 on typhoid and paratyphoid fevers. The data set was compared with data on travel patterns obtained from a comprehensive travel database with information from interviews with more than 16,000 Swedish residents with recent overnight travel outside Sweden. The overall risk of being notified with enteric fever after travel was 0.42 in 100,000 travelers. The highest risk for typhoid fever was seen in travelers from India and neighboring countries (41.7 in 100,000), the Middle East (5.91 in 100,000), and Central Africa (3.33 in 100,000), whereas the risk was comparatively low in East Asia (0.24 in 100,000). Almost the same risk areas stood out for paratyphoid fever: India and neighbors (37.5 in 100,000), the Middle East (3.64 in 100,000), and East Africa (3.33 in 100,000). The epidemiology of paratyphoid fever was considerably affected by a large outbreak of paratyphoid B in a Turkish tourist resort in 1999. The youngest children were at highest risk for typhoid fever (odds ratio 44.2), whereas youths ages 7 to 18 years were at highest risk for paratyphoid fever (odds ratio 9.7). Detailed risk data for enteric fever after travel could form the basis for travel advice. Vaccination against typhoid fever should always be considered for travelers to the Indian subcontinent, the Middle East, and Africa but should not routinely be given to travelers to the Malay Peninsula.

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... The publication year of the 136 articles selected ranged from 1985 to 2017, with the largest number of articles (n = 17) published in 2016 (Table 2). In the 20 years following the publication by Rvachev and Longini in 1985, the oldest article relevant to this review, only seven relevant articles were published [13][14][15][16][17][18][19]. ...
... According to the set of standards we had established to determine an article's reproducibility (see Table 1, part B), no article was considered fully reproducible. Eight (6%) articles were deemed partially reproducible (score of 3 or above), where some information regarding the description and use of passenger data was reported [13,[50][51][52][53][54][55][56]. Of the 45 total data sources identified, 26 were open source, 11 were closed source, and 8 were not publicly available. ...
... Icelandic Tourist Board 1 [56] Singapore Tourism Board 1 [144] Turism.se (Swedish tourist and travel commercial database) 1 [13] World Tourism Organization (UNWTO) 5 [95,107,134,150,155] United States Office of Travel and Tourism Industries 1 [41] National passenger surveys (n = 4; 2%) ...
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BackgroundA variety of airline passenger data sources are used for modelling the international spread of infectious diseases. Questions exist regarding the suitability and validity of these sources.AimWe conducted a systematic review to identify the sources of airline passenger data used for these purposes and to assess validation of the data and reproducibility of the methodology.Methods Articles matching our search criteria and describing a model of the international spread of human infectious disease, parameterised with airline passenger data, were identified. Information regarding type and source of airline passenger data used was collated and the studies' reproducibility assessed.ResultsWe identified 136 articles. The majority (n = 96) sourced data primarily used by the airline industry. Governmental data sources were used in 30 studies and data published by individual airports in four studies. Validation of passenger data was conducted in only seven studies. No study was found to be fully reproducible, although eight were partially reproducible.LimitationsBy limiting the articles to international spread, articles focussed on within-country transmission even if they used relevant data sources were excluded. Authors were not contacted to clarify their methods. Searches were limited to articles in PubMed, Web of Science and Scopus.Conclusion We recommend greater efforts to assess validity and biases of airline passenger data used for modelling studies, particularly when model outputs are to inform national and international public health policies. We also recommend improving reporting standards and more detailed studies on biases in commercial and open-access data to assess their reproducibility.
... 19,20 Those aged 20 to 29 years showed a higher incidence of travelers' diarrhea than other age groups, a finding consistent with other reports. 3,5,6,9,21 This may reflect the relatively more adventurous and careless behavior 6,22 or larger appetite in this age group. 1 Differences in disease incidence between sexes might be ascribed to hygiene behavior, destination, and purpose of travel. For instance, young men are more adventurous and thus show higher incidence of travelers' diarrhea than young women in general. ...
... However, many studies have not shown any significant differences in travelers' diarrhea by gender. 6,13,22 In contrast, our results indicate that the difference in incidence between sexes largely varies by age. Additional studies will be needed to determine the reasons behind our findings. ...
... Studies in other countries have also found that these regions are associated with travelers' diarrhea, 6,13,23 salmonellosis, 11 shigellosis, 10 and enteric fever. 22 In contrast to the age-month analysis, age distribution of travelers to specific destinations was not available (Table 1). However, information regarding the increased possibility of contracting various diseases in specific countries should be given to all travelers going to these regions. ...
Article
Background. Although travelers' diarrhea is one of the most common health problems among international travelers, current findings depend largely on hospital and clinic-based information. To better understand the disease epidemiology and to identify specific subpopulations with increased risks, denominator data covering a large traveler population are needed. Methods. We conducted a questionnaire survey of all travelers at the quarantine station, Narita International Airport, and retrospectively reviewed records from January 2001 to December 2005. The Immigration Bureau database was used as denominator data on travel patterns during the same period. To elucidate the risks of contracting diarrhea, we estimated incidence according to age, sex, month of travel, and travel destination. Results. A total of 7,937,654 people voluntarily submitted questionnaires; 9,836 had travelers' diarrhea. Travelers of both sexes aged 20 to 29 years reported the disease most frequently. Men aged 20 to 24 had the highest estimated incidence compared with any other age and sex group. The incidence was higher in March, August, and September than other months, mainly due to the influx of young adult travelers. Travel to south-central Asia, Southeast Asia, and North Africa was associated with higher risks than that to other areas. Conclusions. Risks of contracting travelers' diarrhea are dependent on age, sex, season, and destination of travel. Incidence of diarrhea in all four seasons varies with age. Some destinations are associated with increased risks regardless of age. To prevent travelers from contracting diarrhea, adequate measures should focus on specific subpopulations.
... Dentre os instrumentos de coleta de dados empíricos, foi predominante a utilização de questionários, tanto fechados quanto abertos, aplicados pessoalmente, por telefone ou por meio de carta (16,18,20,22,23,25,28,39,42,43). A entrevista semiestruturada apareceu em menor escala (22,39). ...
... Alguns estudos consideram que o melhor local para atingir os turistas com informações de saúde seria a agência de viagens (38,40), enquanto que outros consideram que as companhias aéreas e as autoridades deveriam ser responsáveis pelo aconselhamento aos passageiros para minimizar riscos de saúde relacionados ao meio de transporte (37). A falta de dados específicos a respeito da saúde de turistas é mencionada como causa da dificuldade de relacionar doenças específicas com as atividades de turismo (12,13,15,16). ...
... In travellers to destinations in South Asia, typhoid fever is the third most commonly contracted disease, after traveler's diarrhea and influenza (Steffen et al., 2015a). In a study from the Swedish database on notifiable communicable diseases, including all cases recorded of typhoid and paratyphoid fevers from 1997 to 2003, Ekdahl et al. reported an overall risk of enteric fever after travel of 0.42 per 100,000 travellers (Ekdahl et al., 2005). The highest risk was observed in travellers returning from India and neighboring countries (41.7 per 100,000), the Middle East (5.91 per 100,000), and Central Africa (3.33 per 100,000), while the risk was comparatively lower in East Asia (0.24 per 100,000) (Ekdahl et al., 2005). ...
... In a study from the Swedish database on notifiable communicable diseases, including all cases recorded of typhoid and paratyphoid fevers from 1997 to 2003, Ekdahl et al. reported an overall risk of enteric fever after travel of 0.42 per 100,000 travellers (Ekdahl et al., 2005). The highest risk was observed in travellers returning from India and neighboring countries (41.7 per 100,000), the Middle East (5.91 per 100,000), and Central Africa (3.33 per 100,000), while the risk was comparatively lower in East Asia (0.24 per 100,000) (Ekdahl et al., 2005). ...
Article
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Background: International tourist travel has been increasingly steadily in recent years, and looks set to reach unprecedented levels in the coming decades. Among these travellers, an increasing proportion is aged over 60 years, and is healthy and wealthy enough to be able to travel. However, senior travellers have specific risks linked to their age, health and travel patterns, as compared to their younger counterparts. Methods: We review here the risk of major vaccine-preventable travel-associated infectious diseases, and forms and efficacy of vaccination for these diseases. Results: Routine vaccinations are recommended for older persons, regardless of whether they travel or not (e.g., influenza, pneumococcal vaccines). Older individuals should be advised about the vaccines that are recommended for their age group in the framework of the national vaccination schedule. Travel-specific vaccines must be discussed in detail on a case-by-case basis, and the risk associated with the vaccine should be carefully weighed against the risk of contracting the disease during travel. Travel-specific vaccines reviewed here include yellow fever, hepatitis, meningococcal meningitis, typhoid fever, cholera, poliomyelitis, rabies, Japanese encephalitis, tick-borne encephalitis and dengue. Conclusion: The number of older people who have the good health and financial resources to travel is rising dramatically. Older travellers should be advised appropriately about routine and travel-specific vaccines, taking into account the destination, duration and purpose of the trip, the activities planned, the type of accommodation, as well as patient-specific characteristics, such as health status and current medications.
... Typhoid fever is endemic in developing countries, particularly in South Asia, and the risk of acquiring typhoid fever among travelers to South Asia is greater than in travelers to other areas (1,2). More than 16 million Japanese travel abroad annually, and travel to tropical areas (e.g., South Asia) endemic for hepatitis A and typhoid fever (3,4), has increased (5). ...
... typhoid patients have traveled to India, followed by other South Asian countries (Pakistan and Bangladesh) (2). Other surveillance studies have also established a high risk for travel to India and South Asian countries (1,15). Our study indicated that most clients traveling to South Asia (75.8%) tended to be vaccinated with typhoid vaccine. ...
Article
Full-text available
Objective In 2010, candid advice concerning the low rate of typhoid vaccination among Japanese travelers was received from Nepal. Recently, progressive Japanese travel clinics have encouraged Japanese travelers to be vaccinated against typhoid fever in conjunction with officially approved vaccines, such as hepatitis A vaccine. We herein report the status of typhoid vaccinations for Japanese travelers to the most endemic area (South Asia) and describe the factors associated with compliance. Methods In the travel clinic at Kurume University Hospital, we used the following criteria to retrospectively extract the records of new pre-travel Japanese clients between January 2011 and March 2015: hepatitis A vaccine administered, traveling to South Asian countries, and ≥2 years of age. We first summarized the participants and then divided them into typhoid-vaccinated and typhoid non-vaccinated groups for a comparative analysis. Results This study included 160 clients. A majority (70.0%) of these clients traveled for business. The duration of trips was long (≥1 month) (75.0%), and India was a popular destination (90.6%). A comparative study between the vaccinated group (n=122) and the non-vaccinated group (n=38) revealed that the two factors most positively associated with typhoid vaccination were business trips [adjusted odds ratio (aOR) 3.59, 95% confidence interval (CI) 1.42-9.06] and coverage by a company/organization payment plan (aOR 7.14, 95% CI 2.67-20.3). Conclusion The trend toward typhoid vaccination among Japanese travelers to South Asia with pre-travel consultation is correlated with business trips and coverage by a company/organization payment plan. If problems concerning the cost of vaccines were resolved, more travelers would request typhoid vaccination.
... The high-incidence estimate for south Asia is consistent with studies of travellers from high-income countries. [67][68][69][70] However, the high incidence fi gures for Africa, to which one Kenyan study contributes heavily, 25 need careful interpretation. The south African datapoint is decades old, whereas a recent review of communityacquired bloodstream infections in Africa showed fewer than 10% of isolates were S typhi. ...
Article
Full-text available
Background: No access to safe water is an important risk factor for typhoid fever, yet risk-level heterogeneity is unaccounted for in previous global burden estimates. Since WHO has recommended risk-based use of typhoid polysaccharide vaccine, we revisited the burden of typhoid fever in low-income and middle-income countries (LMICs) after adjusting for water-related risk. Methods: We estimated the typhoid disease burden from studies done in LMICs based on blood-culture-confirmed incidence rates applied to the 2010 population, after correcting for operational issues related to surveillance, limitations of diagnostic tests, and water-related risk. We derived incidence estimates, correction factors, and mortality estimates from systematic literature reviews. We did scenario analyses for risk factors, diagnostic sensitivity, and case fatality rates, accounting for the uncertainty in these estimates and we compared them with previous disease burden estimates. Findings: The estimated number of typhoid fever cases in LMICs in 2010 after adjusting for water-related risk was 11·9 million (95% CI 9·9-14·7) cases with 129 000 (75 000-208 000) deaths. By comparison, the estimated risk-unadjusted burden was 20·6 million (17·5-24·2) cases and 223 000 (131 000-344 000) deaths. Scenario analyses indicated that the risk-factor adjustment and updated diagnostic test correction factor derived from systematic literature reviews were the drivers of differences between the current estimate and past estimates. Interpretation: The risk-adjusted typhoid fever burden estimate was more conservative than previous estimates. However, by distinguishing the risk differences, it will allow assessment of the effect at the population level and will facilitate cost-effectiveness calculations for risk-based vaccination strategies for future typhoid conjugate vaccine.
... Paratyphi cases, which are not prevented by current typhoid fever vaccines. Our results showing that two thirds of cases were among ill travelers returning from south-central Asia and that enteric fever PM is increasing (+10/1,000, p = 0.013) are consistent with global trends (19,20). ...
Article
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Longitudinal data examining travel-associated illness patterns are lacking. To address this need and determine trends and clusters in travel-related illness, we examined data for 2000-2010, prospectively collected for 42,223 ill travelers by 18 GeoSentinel sites. The most common destinations from which ill travelers returned were sub-Saharan Africa (26%), Southeast Asia (17%), south-central Asia (15%), and South America (10%). The proportion who traveled for tourism decreased significantly, and the proportion who traveled to visit friends and relatives increased. Among travelers returning from malaria-endemic regions, the proportionate morbidity (PM) for malaria decreased; in contrast, the PM trends for enteric fever and dengue (excluding a 2002 peak) increased. Case clustering was detected for malaria (Africa 2000, 2007), dengue (Thailand 2002, India 2003), and enteric fever (Nepal 2009). This multisite longitudinal analysis highlights the utility of sentinel surveillance of travelers for contributing information on disease activity trends and an evidence base for travel medicine recommendations.
... Risk of typhoid fever was highest for destinations in the Indian subcontinent 2008 France Caumes et al. (2001) ST, SPT 17/38 1/2 MDR from IND 2006 Sweden Ekdahl et al. (2005) ST, SPT ...
Article
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Abstract The human race owes a debt of gratitude to antimicrobial agents, penicillin and its successors that have saved people from tremendous pain and suffering in the last several decades. Unfortunately, this consideration is no more true, as millions of people are prone to the challenging threat of emergence of antimicrobial resistance worldwide and the menace is more distressing in developing countries. Comparable with other bacterial species, Salmonella enterica serovar Typhi (S. typhi) and Paratyphi (S. paratyphi) have been evolving multidrug resistance (MDR) against a wide array of antibiotics, including chloramphenicol, ampicillin and co-trimoxazole, and globally affecting 21 million people with 220 000 deaths each year. S. typhi and S. paratyphi infections are also endemic in South Asia and a series of antibiotics used to treat these infections, have been losing efficacy against enteric fever. Currently, quinolones are regarded as a choice to treat MDR Salmonella in these regions. Travel-related cases of enteric fever, especially from South Asian countries are the harbinger of the magnitude of MDR Salmonella in that region. Conclusively, the MDR will continue to grow and the available antimicrobial agents would become obsolete. Therefore, a radical and aggressive approach in terms of rational use of antibiotics during treating infections is essentially needed.
... Risk of typhoid fever was highest for destinations in the Indian subcontinent 2008 France Caumes et al. (2001) ST, SPT 17/38 1/2 MDR from IND 2006 Sweden Ekdahl et al. (2005) ST, SPT ...
Article
Full-text available
The human race owes a debt of gratitude to antimicrobial agents, penicillin and its successors that have saved people from tremendous pain and suffering in the last several decades. Unfortunately, this consideration is no more true, as millions of people are prone to the challenging threat of emergence of antimicrobial resistance worldwide and the menace is more distressing in developing countries. Comparable with other bacterial species, Salmonella enterica serovar Typhi (S. typhi) and Paratyphi (S. paratyphi) have been evolving multidrug resistance (MDR) against a wide array of antibiotics, including chloramphenicol, ampicillin and co-trimoxazole, and globally affecting 21 million people with 220 000 deaths each year. S. typhi and S. paratyphi infections are also endemic in South Asia and a series of antibiotics used to treat these infections, have been losing efficacy against enteric fever. Currently, quinolones are regarded as a choice to treat MDR Salmonella in these regions. Travel-related cases of enteric fever, especially from South Asian countries are the harbinger of the magnitude of MDR Salmonella in that region. Conclusively, the MDR will continue to grow and the available antimicrobial agents would become obsolete. Therefore, a radical and aggressive approach in terms of rational use of antibiotics during treating infections is essentially needed.
... The increased incidence of S. Paratyphi A is reflected in statistics of travel-related EF. Case registries from several countries have consistently shown an increase in the importance of S. Paratyphi A [3,161718. This increase may, in part, be due to the partial protection against S. Typhi offered by vaccines or it may reflect the increase in S. Paratyphi A infection seen in many parts of Asia [19]. Treatment of EF has been complicated in recent decades by the rise of multidrug-resistant strains including quinolone/nalidixic acid–resistant Salmonella (NARS). ...
Article
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Background: In Asia, Salmonella Paratyphi A is an emerging infection, and travelers are increasingly at risk. During October 2009-November 2009, an outbreak in S. Paratyphi A infection was noted in Israeli travelers returning from Nepal. Methods: An outbreak investigation included a standardized exposure questionnaire admitted to all patients and medical chart abstraction. Isolates were tested for antimicrobial susceptibility and pulsed-field gel electrophoresis (PFGE). Results: During 1 October 2009-30 November 2009, 37 Israeli travelers returning from Nepal were diagnosed with S. Paratyphi A bacteremia. All 37 case isolates had an identical pattern on PFGE, and all were nalidixic acid resistant. Only 1 food venue was frequented by all the outbreak cases, with the largest number of exposures occurring around the Jewish New Year. All patients recovered without complications. Time to defervescence in 17 patients treated with ceftriaxone and azithromycin combination was 3.2 days (± 1.7), whereas in 13 cases treated with ceftriaxone monotherapy, the time to defervescence was 6.6 days (± 1.8; P < .001). Conclusions: A point-source, "Paratyphoid Mary"-like outbreak was identified among Israeli travelers to Nepal. Combination Ceftriaxone-Azithromycin therapy may provide a therapeutic advantage over monotherapy, and merits further clinical trials.
... The increased incidence of S. Paratyphi A is reflected in statistics of travel-related EF. Case registries from several countries have consistently shown an increase in the importance of S. Paratyphi A [3,161718. This increase may, in part, be due to the partial protection against S. Typhi offered by vaccines or it may reflect the increase in S. Paratyphi A infection seen in many parts of Asia [19]. Treatment of EF has been complicated in recent decades by the rise of multidrug-resistant strains including quinolone/nalidixic acid–resistant Salmonella (NARS). ...
Article
Current guidelines recommend continuation of atovaquone-proguanil (AP) malaria prophylaxis for 7 days after leaving Plasmodium falciparum endemic areas. Evidence from clinical studies suggests that discontinuation of AP 1 day after exposure ends may be safe and effective. Our objective was to assess the effectiveness of short-course AP prophylaxis among travelers to sub-Saharan Africa. To detect prophylactic failures associated with short-course AP prophylaxis discontinued 1 day after return, we conducted active surveillance during the years 2010 and 2011, by a retrospective telephone survey 1 to 6 months after travelers' return. Passive surveillance data were obtained from the Israel Ministry of Health (MOH) malaria registry. Among 485 travelers to sub-Saharan Africa (cumulative exposure of 4,979 days), 421 (87%) discontinued AP 1 day after leaving the endemic region (cumulative exposure of 4,337 days). None of the 485 travelers reported malaria infection. The MOH malaria registry survey included 363 P. falciparum-infected patients during the years 2003 to 2011. The majority (n = 305; 84%) did not use any malaria prophylaxis. None of the patients had used AP (neither regular nor short course AP) for malaria prophylaxis. We did not detect prophylaxis failures among a group of travelers who discontinued AP prophylaxis 1 day after leaving malaria-endemic areas. Passive surveillance in Israel did not detect any P. falciparum cases among AP users. We recommend further validation of our findings by clinical trials, prospective studies, and active surveillance in larger cohorts to assess the effectiveness of short-course AP prophylaxis in travelers.
... Although the most common cause of enteric fever worldwide is S. typhi, S. paratyphi may be a more common cause of this illness in travellers, which may be explained by a growing number of tourists vaccinated against S. typhi [25]. A study conducted on case records from a Swedish database of notifiable and communicable diseases [26] concludes that the highest risk of being infected with enteric fever is connected with travel to India and neighbouring countries (41.7/100,000 people for S. typhi infection and 37.5/100,000 for S. paratyphi), followed by Middle East (5.91/100,000 and 3.64/100,000, respectively) and Africa (3.33/100,000 for both typhoid and paratyphoid fever). Other studies show that travel to Indian subcontinent might be associated with an even 18 times higher risk of contracting enteric fever than to any other region [25]. ...
Article
Full-text available
The aim of the article is to discuss issues associated with the occurrence of febrile illnesses in leisure and business travellers, with a particular emphasis on fevers of unknown origin (FUO). FUO, apart from diarrhoeas, respiratory tract infections and skin lesions, are one of the most common health problems in travellers to tropical and subtropical countries. FUO are manifestations of various diseases, typically of infectious or invasive aetiology. In one out of 3 cases, the cause of a fever in travellers returning from the hot climate zone is malaria, and therefore diagnostic tests should first aim at ruling out this specific disease entity. Other illnesses with persistent fever include dengue, enteric fever, viral hepatitis A, bacterial diarrhoeas and rickettsioses. Fever may also occur in travellers suffering from diseases of non-tropical origin, e.g. cosmopolitan respiratory tract or urinary tract infections, also, fever may coexist with other illnesses or injuries (skin rashes, bites, burns).
... Additional data from Pakistan, Bangladesh and Nepal indicate that cases of paratyphoid fever are increasing[5,6], consistent with other reports from China, where S. Paratyphi A infection is responsible for up to 64% of enteric fever cases[7][8][9][10]. The apparent increase in S. Paratyphi A infections was also consistent with an increasing proportion of S. Paratyphi A infections found among returning travelers from endemic regions[11][12][13]. Additionally, the true prevalence of enteric fever caused by S. Paratyphi A is underestimated due to the lack of reliable diagnostic tools. ...
Article
Full-text available
Enteric fevers remain a common and serious disease, affecting mainly children and adolescents in developing countries. Salmonella enterica serovar Typhi was believed to cause most enteric fever episodes, but several recent reports have shown an increasing incidence of S. Paratyphi A, encouraging the development of a bivalent vaccine to protect against both serovars, especially considering that at present there is no vaccine against S. Paratyphi A. The O-specific polysaccharide (O:2) of S. Paratyphi A is a protective antigen and clinical data have previously demonstrated the potential of using O:2 conjugate vaccines. Here we describe a new conjugation chemistry to link O:2 and the carrier protein CRM(197), using the terminus 3-deoxy-D-manno-octulosonic acid (KDO), thus leaving the O:2 chain unmodified. The new conjugates were tested in mice and compared with other O:2-antigen conjugates, synthesized adopting previously described methods that use CRM(197) as carrier protein. The newly developed conjugation chemistry yielded immunogenic conjugates with strong serum bactericidal activity against S. Paratyphi A.
... The surveillance of Legionnaires' disease associated with international travel might, at least partly, overcome this limitation. A similar approach has been used in pre-vious studies to estimate and compare the risks for foodborne and waterborne diseases in Europe (12,13). Tourism is a massive industry in Europe, and its summer peak coincides with the peak of Legionnaires' disease. ...
Article
Full-text available
Legionnaires' disease is underreported in Europe; notification rates differ substantially among countries. Approximately 20% of reported cases are travel-associated. To assess the risk for travel-associated Legionnaires' disease (TALD) associated with travel patterns in European countries, we retrieved TALD surveillance data for 2009 from the European Surveillance System, and tourism denominator data from the Statistical Office of the European Union. Risk (number cases reported/number nights spent) was calculated by travel country. In 2009, the network reported 607 cases among European travelers, possibly associated with 825 accommodation sites in European Union countries. The overall risk associated with travel abroad was 0.3 cases/million nights. We observed an increasing trend in risk from northwestern to southeastern Europe; Greece had the highest risk (1.7). Our findings underscore the need for countries with high TALD risks to improve prevention and control of legionellosis; and for countries with high TALD risks, but low notification rates of Legionnaires' disease to improve diagnostics and reporting.
... Paratyphoid fever, caused by Salmonella enterica serovar Paratyphi A and B (Salmonella Paratyphi A and B) and, albeit rarely, Salmonella enterica serovar Paratyphi C (Salmonella Paratyphi C), is a systemic disease with clinical features indistinguishable from typhoid fever [1][2][3][4][5][6]. Globally, it has been estimated that there are 5.4 million cases of paratyphoid fever annually [6], with incidence on the increase both in endemic areas [5,[7][8][9][10] and among travelers [5,10,11]. The major burden of enteric fever (both typhoid and paratyphoid fever) is in Africa, Asia, and Latin America [6,12,13], with the highest incidence in the Indian subcontinent and in South-East Asia [6,[12][13][14]. ...
Article
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Background: There are no vaccines against paratyphoid fever in clinical use. The disease has become more wide-spread and there is a growing problem of antibiotic resistance among the strains. Previous reports suggest that the oral live Salmonella Typhi Ty21a-vaccine confers protection against paratyphoid B fever. Data on efficacy against paratyphoid A fever are somewhat contentious. The present study investigated the immunological basis for such efficacy reports at a single-cell level: plasmablasts (identified as antibody-secreting cells, ASC) were studied for secretion of antibodies cross-reactive with Salmonella Paratyphi in the circulation of patients with enteric fever and of volunteers vaccinated with Ty21a. Materials and methods: Thirty volunteers immunized with Ty21a and five patients with enteric fever were investigated for Salmonella Typhi and Salmonella Paratyphi A/B/C-specific circulating plasmablasts. PBMC were sorted by their expression of homing receptors (HR) for the intestine (α4β7), peripheral lymph node (l-selectin) and skin (CLA) and typhoid- and paratyphoid-specific plasmablasts were enumerated with ELISPOT. Results: Before vaccination, no cross-reactive ASC were found in the volunteers. In addition to the Salmonella Typhi-specific response, a significant cross-reactive immune response was mounted against Salmonella Paratyphi A and B both in the patients and the vaccinees. The magnitude of the response increased in the order Salmonella Paratyphi A (median 30 ASC/10(6) PBMC)→Salmonella Paratyphi B (median 81)→Salmonella Typhi (median 301) in the vaccinees. Both in patients and in vaccinees, the homing receptor (HR) selection favored homing to the gut, indicating a humoral intestinal immune response. Conclusions: These immunological data provide evidence consistent with previous reports describing certain levels of cross-protective efficacy of Ty21a against paratyphoid fever. Controlled studies are needed to evaluate cross-protective efficacy. In the current situation where paratyphoid fever is emerging and no vaccines are available, any level of cross-protective capacity is valuable.
... As a consequence there is increasing attention to the exposure to parasitic and viral infections including malaria, hepatitis, dengue fever, and HIV-infection2345. Among travel-related bacterial infections, typhoid and paratyphoid fevers have been addressed in a number of studies678. Less information is available concerning invasive infections with non-typhoidal Salmonella enterica serovars (henceforth Salmonella) although they are common causes of gastrointestinal infections in travellers. ...
Article
Full-text available
Information is sparse regarding the association between international travel and hospitalization with non-typhoidal Salmonella bacteremia. The aim of this study was to determine the proportion, risk factors and outcomes of travel-related non-typhoidal Salmonella bacteremia. We conducted a 10-year population-based cohort study of all patients hospitalized with non-typhoidal Salmonella bacteremia in three Danish counties (population 1.6 million). We used denominator data on Danish travellers to assess the risk per 100,000 travellers according to age and travel destination. We used patients contemporaneously diagnosed with travel-related Salmonella gastroenteritis as reference patients to estimate the relative risk of presenting with travel-related bacteremia as compared with gastroenteritis. To evaluate clinical outcomes, we compared patients with travel-related bacteremia and patients with domestically acquired bacteremia in terms of length of hospital stay, number of extraintestinal focal infections and mortality after 30 and 90 days. We identified 311 patients hospitalized with non-typhoidal Salmonella bacteremia of whom 76 (24.4%) had a history of international travel. The risk of travel-related bacteremia per traveller was highest in the age groups 15-24 years (0.8/100,000 travellers) and 65 years and above (1.2/100,000 travellers). The sex- and age-adjusted relative risk of presenting with bacteremia was associated with travel to Sub-Saharan Africa (odds ratio 18.4; 95% confidence interval [6.9-49.5]), the Middle East (10.6; [2.1-53.2]) and South East Asia (4.0; [2.2-7.5]). We found high-risk countries in the same three regions when estimating the risk per traveller according to travel destination. Patients hospitalized with travel-related bacteremia had better clinical outcomes than patients with domestically acquired bacteremia, they had a shorter length of hospital stay (8 vs. 11 days), less extraintestinal focal infections (5 vs. 31 patients) and a lower risk of death within both 30 days (relative risk 0.2; [0.1-0.7]) and 90 days (0.3; [0.1-0.7]). A healthy traveller effect was a plausible explanation for the observed differences in outcomes. International travel is a notable risk factor for being hospitalized with non-typhoidal Salmonella bacteremia and the risk differs between age groups and travel destinations. Healthy travellers hospitalized with bacteremia are less likely to have poor outcomes than patients with domestically acquired bacteremia.
... The high-incidence estimate for south Asia is consistent with studies of travellers from high-income countries. [67][68][69][70] However, the high incidence fi gures for Africa, to which one Kenyan study contributes heavily, 25 need careful interpretation. The south African datapoint is decades old, whereas a recent review of communityacquired bloodstream infections in Africa showed fewer than 10% of isolates were S typhi. ...
Article
Full-text available
Background No access to safe water is an important risk factor for typhoid fever, yet risk-level heterogeneity is unaccounted for in previous global burden estimates. Since WHO has recommended risk-based use of typhoid polysaccharide vaccine, we revisited the burden of typhoid fever in low-income and middle-income countries (LMICs) after adjusting for water-related risk.
... This could be explained by two different short-and long-transmission modes. For typhoid fever, the dose of infectious bacteria required is low (about 100 bacteria), 73 and is common transmitted from person-toperson. 4 A higher dose of infectious bacteria is required for paratyphoid fever (about 1,000), 74 and food (in which Salmonella bacteria can multiply) is considered as the major vehicle for transmission. Furthermore, for paratyphoid fever, in high rainfall surroundings, the water reservoirs in the broader environment combined with the shorter incubation period can further promote the survival and reproduction of pathogens. ...
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The impact of temperature and rainfall on the occurrence of typhoid/paratyphoid fever are not fully understood. This study aimed to characterize the effect of daily ambient temperature and total rainfall on the incidence of typhoid/paratyphoid in a sub-tropical climate city of China and to identify the vulnerable groups for disease prevention. Daily notified typhoid/paratyphoid fever cases and meteorological data for Taizhou from 2005 to 2013 were extracted from the National Notifiable Disease Surveillance System and the Meteorological Data Sharing Service System, respectively. Distributed lag nonlinear model was used to quantify the association between daily mean temperature, total rainfall, and typhoid/paratyphoid fever. Subgroup analyses by gender, age, and occupation were conducted to identify the vulnerable groups. A total of 625 typhoid fever cases and 1,353 paratyphoid fever cases were reported during the study period. An increased risk of typhoid fever was detected with the increase of temperature (Each 2°C rise resulted in 6%, 95% [confidence interval] CI: 2–10 increase in typhoid cases), while the increased risk was associated with the higher temperature for paratyphoid (the highest cumulative risk of temperature was 33.40 [95% CI: 12.23–91.19] at 33°C). After the onset of mild precipitation, the relative risk of typhoid fever increased in a short-lasting and with a 13–26 days delay, and the risk was no significant after the continuous increase of precipitation (the highest cumulative risk of rainfall was 24.96 [95% CI: 4.54–87.21] at 100 mm). Whereas the risk of paratyphoid fever was immediate and long lasting, and increase rapidly with the increase of rainfall (each 100 mm increase was associated with 26% increase in paratyphoid fever cases). Significant temperature-typhoid/paratyphoid fever and rainfall-typhoid/paratyphoid fever associations were found in both genders and those aged 0–4 years old, 15–60 years old, farmers, and children. Characterized with a lagged, nonlinear, and cumulative effect, high temperature and rainfall could increase the risk of typhoid/paratyphoid fever in regions with a subtropical climate. Public health interventions such as early warning and community health education should be taken to prevent the increased risk of typhoid/paratyphoid fever, especially for the vulnerable groups.
... Since 1989, in Sweden, a database, mostly used by travel agencies etc., that contains data on number and duration of trips to each country is available, making it possible to estimate also the incidence of travel-associated infections. This database has previously been used to study the incidence and risk for Swedish international travellers for malaria, dengue, hepatitis A, campylobacteriosis, salmonellosis and shigellosis [7][8][9][10][11][12][13]. In this study we, rather than study one pathogen at a time as had been done in previous studies, we grouped notifiable pathogens by their mode of transmission (also including one group with diseases vaccinated against in the Swedish childhood vaccination programme), since the mode of transmission is often more relevant than pathogen when providing recommendations to international travellers. ...
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We studied food and water-borne diseases (FWDs), sexually transmitted diseases (STDs), vector-borne diseases (VBDs) and diseases vaccinated against in the Swedish childhood vaccination programme among Swedish international travellers, in order to identify countries associated with a high number of infections. We used the national database for notifiable infections to estimate the number of FWDs (campylobacteriosis, salmonellosis, giardiasis, shigellosis, EHEC, Entamoeba histolytica, yersinosis, hepatitis A, paratyphoid fever, typhoid fever, hepatitis E, listeriosis, cholera), STIs (chlamydia, gonorrhoea and acute hepatitis B), VBDs (dengue fever, malaria, West Nile fever, Japanese encephalitis and yellow fever) and diseases vaccinated against in the Swedish childhood vaccination programme (pertussis, measles, mumps, rubella, diphtheria) acquired abroad 2009–2013. We obtained number and duration of trips to each country from a database that monthly collects travel data from a randomly selected proportion of the Swedish population. We calculated number of infections per country 2009–2013 and incidence/million travel days for the five countries with the highest number of infections. Thailand had the highest number of FWDs (7,697, incidence 191/million travel days), STIs (1,388, incidence 34/million travel days) and VBDs (358, incidence 9/million travel days). France had the highest number of cases of diseases vaccinated against in the Swedish childhood vaccination programme (8, 0.4/million travel days). Swedish travellers contracted most infections in Thailand. Special focus should be placed on giving advice to travellers to this destination. © 2017 Dahl, Wallensten. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
... Typhoid has the likelihood of resulting in death without prompt treatment. Untreated enteric fever has a case fatality rate of 10% or higher [4], while typhoid fever has a case fatality rate of 10%-30% [5] without effective treatment. Again, it is important to mention that some Salmonella serovars are host-specific. ...
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Background: Typhoid and paratyphoid fever remain a global public health burden, yet annual estimates of prevalence vary. Estimates have ranged between 9.9 and 24.2 million cases annually. Similar differences in estimates are seen within countries but point to a serious health challenge. In Ghana, for instance, typhoid fever has been ranked among the top twenty causes of outpatient morbidity and constituted 1.2%, 1.7% and 1.3% of hospital admissions in 2017, 2016 and 2015 respectively. Objective: The objective of the study was to determine the prevalence of Salmonella Typhi and Salmonella Paratyphi in the Hohoe Municipality. Methods: Data on all reported cases of typhoid fever in the Hohoe municipality as entered into the District Health Information Management System 2 (DHIMS 2) database between January 2012 and December 2016 were extracted. A time-trend analysis was conducted to establish the relationship between typhoid fever prevalence and factors such as age, gender, and season. Stata was used to analyse data and to measure rates, associations, and their significance. Findings: The results showed that a total of 6282 individuals suffered from typhoid fever during the five-year period. Of these numbers, 2080 (33.1%) were males, and 4202 (66.9%) were females, representing a P-value 0.0222, and 95% CI. The 25–29 age group were the most affected. High prevalence was observed during the wet months, although cases occurred throughout the year. Trend analysis showed growing cases of typhoid over the period. Prevalence for the various years were found as follows: 2012 – 148 per 100,000, 2013 – 135 per 100,000, 2014 – 396 per 100,000 and in 2015 – 943 per 100,000. Conclusions: Typhoid fever remains and continues to be a major public health challenge in the municipality. This calls for health authorities and service providers to educate the public about the disease if the challenge is to be addressed.
... Traditionally, the clinical features of paratyphoid fever were thought to be similar or milder than those of typhoid fever. With increasing incidence and more data now available, studies have started to demonstrate an equivalent or even increased rate of complications with paratyphoid infections (Ekdahl et al., 2005;Vollaard et al., 2005;Woods et al., 2006). S. Paratyphi A, B or C may present with either systemic (Lee et al., 2000;Rajagopal et al., 2002;Mohanty et al., 2003) or localised infection (Fangtham et al., 2008). ...
... A study of Swedish returning travellers showed that the incidence of EF acquisition in Asia was highest, at about 0.5 cases/10 6 days of travel (or 18.25/100 000 travel-years, a rate which is similar to the range in the local population). 30 Being born in India and visiting friends and relatives (VFRs) as the reason for travel were also strongly associated with EF. 31 In parallel with reports of declining rates of EF in many endemic countries, some data suggest a decline in the risk of travel-related EF. A Dutch study, for example, shows that rates of EF in non-immunized travellers outside South Asia are very low and falling. ...
Article
Rationale for review Enteric fever (EF) caused by Salmonella enterica subspecies enterica serovar Typhi (Salmonella Typhi) & S. Paratyphi (Salmonella Paratyphi) remains an important cause of infectious morbidity and mortality in many low-income countries, and therefore still poses a major infectious risk for travelers to endemic countries. Main findings Although the global burden of EF has decreased over the past two decades, prevalence of EF remains high in Asia and Africa, with the highest prevalence reported from the Indian subcontinent. These statistics are mirrored by data on travel-related EF. Widespread and increasing antimicrobial resistance has narrowed treatment options for travel-related EF. Ceftriaxone and azithromycin-based therapies are commonly used, even with the emergence of extremely drug resistant (XDR) typhoid in Pakistan. Preventive measures among locals and travelers include provision of safe food and water and vaccination. Food and water precautions offer limited protection and the efficacy of Salmonella Typhi vaccines are only moderate signifying the need for travelers to be extra cautious. Recommendations Improvement in the diagnosis of typhoid with high degree of clinical suspicion, better diagnostic assays, early and accurate detection of resistance, therapy with appropriate drugs, improvements in hygiene and sanitation with provision of safe drinking water in endemic areas and vaccination among travellers as well as in the endemic population are keys to controlling typhoid. While typhoid vaccines are recommended for travellers to high risk areas, moderate efficacy and inability to protect against Salmonella Paratyphi are limitations to bear in mind. Improved Salmonella Typhi vaccines and vaccines against Salmonella Paratyphi A are required.
... Food was identified as the source of paratyphoid A infection following an outbreak among travellers returning from Nepal (Woods et al., 2006;Bakers et al., 2011;Meltzer et al., 2014). To explain the higher incidence of paratyphoid in returned travellers, authors of a Swedish study of enteric fever (typhoid fever or paratyphoid fever) surmised that travellers are more likely to be exposed to food from street vendors infected by S. Paratyphi than to persons carrying S. Typhi (Ekdahl et al., 2005). Imported foods (sauerkraut, ham, sausage, broiler chicken, eggs) have also been associated with outbreaks of typhoid (Katz et al., 2002). ...
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This study deals with Salmonella enterica serovar Typhi and Paratyphi responsible of typhoid and paratyphoid fevers transmitted by environment and foods. Typhoid and paratyphoid fevers are systemic diseases caused by the bacteria Salmonella Typhi and Salmonella Paratyphi, respectively. Humans are the only reservoir for Salmonella Typhi (which is the most serious), whereas Salmonella Paratyphi also has animal reservoirs. Humans can carry the bacteria in the gut for very long times (chronic carriers), and transmit the bacteria to other persons (either directly or via food or water contamination). Although S. Typhi and S. Paratyphi are strictly adapted to humans, both serovars can remain viable in the environment, surviving in water and underlying sediment for days to weeks. Foods are susceptible to be contaminated and transport Salmonella include vegetable products such as lettuce. In developping countries, typhoid and paratyphoide fever were generally treat with using antimicrobial such as quinolones, and cephalosporin. Patients were not responding to the most available antibiotics of choice. Some patients, because of ignorance and lack of financial means, prefer street drugs, so they practice self-medication. Those practices can enhance the antibiotics resistances genes. As the ultimate solution for the prevention and eradication of paratyphoid fever, it is essential to improve sanitation such as the provision of safe water and food as well as enhanced public health awareness.
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Serotyping is not sufficient to differentiate between Salmonella species that cause paratyphoid fever from the strains that cause milder gastroenteritis as these organisms share the same serotype Salmonella Paratyphi B (S. Paratyphi B). Strains causing paratyphoid fever do not ferment d-tartrate and this key feature was used in this study to determine the prevalence of these strains among the collection of S. Paratyphi B strains isolated from patients in Malaysia. A total of 105 isolates of S. Paratyphi B were discriminated into d-tartrate positive (dT+) and d-tartrate negative (dT) variants by two lead acetate test protocols and multiplex PCR. The lead acetate test protocol 1 differed from protocol 2 by a lower inoculum size and different incubation conditions while the multiplex PCR utilized 2 sets of primers targeting the ATG start codon of the gene STM3356. Lead acetate protocol 1 discriminated 97.1% of the isolates as S. Paratyphi B dT+ and 2.9% as dT while test protocol 2 discriminated all the isolates as S. Paratyphi B dT+. The multiplex PCR test identified all 105 isolates as S. Paratyphi B dT+ strains. The concordance of the lead acetate test relative to that of multiplex PCR was 97.7% and 100% for protocol 1 and 2 respectively. This study showed that S. Paratyphi B dT+ is a common causative agent of gastroenteritis in Malaysia while paratyphoid fever appears to be relatively uncommon. Multiplex PCR was shown to be a simpler, more rapid and reliable method to discriminate S. Paratyphi B than the phenotypic lead acetate test.
Article
Typhoid fever is a bacterial infection caused by the Gram-negative bacterium Salmonella enterica subspecies enterica serovar Typhi (S. Typhi), prevalent in many low- and middle-income countries. In high-income territories, typhoid fever is predominantly travel-related, consequent to travel in typhoid-endemic regions; however, data show that the level of typhoid vaccination in travellers is low. Successful management of typhoid fever using antibiotics is becoming increasingly difficult due to drug resistance; emerging resistance has spread geographically due to factors such as increasing travel connectivity, affecting those in endemic regions and travellers alike. This review provides an overview of: the epidemiology and diagnosis of typhoid fever; the emergence of drug-resistant typhoid strains in the endemic setting; drug resistance observed in travellers; vaccines currently available to prevent typhoid fever; vaccine recommendations for people living in typhoid-endemic regions; strategies for the introduction of typhoid vaccines and stakeholders in vaccination programmes; and travel recommendations for a selection of destinations with a medium or high incidence of typhoid fever.
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OBJECTIVE: To identify relationships between tourism and health as well as the methods employed in studies about this topic. METHODS: The PubMed and SciELO databases were searched in March of 2008 using the following strategy: traveler or traveller or tourism or tourist AND risk or hazard or vulnerability AND health or surveillance. The following were excluded: articles on animal health, conceptual and review articles, articles about non-tourist travel, and articles written in languages other than Portuguese, English, Italian, and Spanish. Of 153 articles identified, 112 were excluded, and 41 articles were examined. RESULTS: The number of articles on tourism and health increased from one in the 1970s to 34 in the 2000s. Most studies were carried out in Europe, followed by the Americas, and most covered insect-borne diseases, respiratory diseases transmitted from person to person, and gastrointestinal diseases. Mail, telephone, or face-to-face questionnaires were generally used for data collection. In terms of location, 21 studies were performed at the place of departure, 17 at the destination, and in 3 this information was not specified. Four studies were carried out before the trip, 9 during the trip, 24 after the trip, and 3 did not specify this information. Most studies focus on the tourist as a likely victim of health problems, unprepared to face situations of exposure during the trip. CONCLUSIONS: The need to implement health care policies aimed at the tourist population is evident, with emphasis on infectious diseases and emergency actions to detect outbreaks involving tourists. A tourist-specific surveillance and notification system is also necessary, together with measures to prepare health care institutions to meet the individual demands of this population.
Chapter
Typhoid fever is an acute generalized infection of the reticuloendothelial system, intestinal lymphoid tissue, and gallbladder caused by Salmonella enterica serovar Typhi (S. Typhi). This communicable disease is restricted to human hosts and humans (chronic carriers) serve as the reservoir of infection. A broad spectrum of clinical illness can ensue, with more severe forms being characterized by persisting high fever, abdominal discomfort, malaise, and headache. In the preantibiotic era, the disease ran its course over several weeks, resulting in a case fatality rate of approximately 10–20%.(1,2) The protracted, debilitating nature of this febrile illness in untreated (or improperly treated) patients is accompanied by mental cloudiness or stupor, which gave rise to the term “typhoid,” meaning stuporlike. Paratyphoid fever is the clinically similar febrile infection caused by S. Paratyphi A or B (or more rarely C). Typhoid and paratyphoid fevers are also referred to as enteric fevers. In most endemic areas, typhoid comprises approximately 80% of enteric fever.
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Typhoid fever continues to be an important concern for travelers visiting many parts of the world. This communication provides updated guidance for pre-travel typhoid vaccination from the US Centers for Disease Control and Prevention (CDC) and describes the methodology for assigning country-specific recommendations.
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The purpose of this study was to estimate the incidence density and prevalence of dengue virus infection in Australian travellers to Asia. We conducted a multi-centre prospective cohort study of Australian travellers over a 32-month period. We recruited 467 travellers (≥ 16 years of age) from three travel clinics who intended to travel Asia, and 387 (82.9%) of those travellers completed questionnaires and provide samples pre- and post-travel for serological testing for dengue virus infection. Demographic data, destination countries and history of vaccinations and flavivirus infections were obtained. Serological testing for dengue IgG and IgM by enzyme-linked immunosorbent assay (ELISA) (PanBio assay) was performed. Acute seroconversion for dengue infection was demonstrated in 1.0% of travellers, representing an incidence of 3.4 infections per 10,000 days of travel (95% confidence interval [CI]: 0.9-8.7). The seroprevalence of dengue infection was 4.4% and a greater number of prior trips to Asia was a predictor for dengue seroprevalence (p = 0.019). All travellers experienced subclinical dengue infections and had travelled to India (n = 3) and China (n = 1). This significant attack rate of dengue infection can be used to advise prospective travellers to dengue-endemic countries.
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Objective Travel-related enteric infections likely represent a large proportion of all enteric infections in British Columbia (BC). The objective of this study was to assess the proportion of enteric infections in BC reported in 2008 associated with international travel in order to understand trends in infections so that targeted interventions can be implemented. Methods Travel information for all reported cases of salmonellosis, verotoxigenic E. coli (VTEC) infection, shigellosis, Vibrio parahemolyticus infection, botulism, cholera, listeriosis, typhoid fever, paratyphoid fever, hepatitis A infection, cryptosporidiosis, cyclosporiasis and a representative proportion of campylobacteriosis was collected. Temporal, demographic and geographic analysis was conducted comparing locally-acquired infections to infections acquired during international travel. Travel destination was compared between cases of enteric infections and the BC population. Results Of the 3,120 enteric infections reported in 2008, 60% were classified as locally-acquired and 40% were associated with international travel. The proportion of infections associated with international travel was highest among 30 to 39 year olds. Locally-acquired infections were highest in the summer months and international travel-related infections were highest in the winter. Asia and Mexico were the most common destinations in relation to enteric infections acquired internationally. The proportion of enteric infections was significantly higher than the proportion of the BC population travelling to these areas. Conclusions The proportion of enteric infections in BC associated with international travel is significant. Identification and assessment of locally-acquired infections separately from those associated with international travel will improve assessment of trends and rates for enteric infections in B. and lead to more targeted public health actions.
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Enteric fever caused by Salmonella enterica serovar Typhi and Salmonella enterica serovar Paratyphi is still a major disease burden mainly in developing countries. Previously, S. Typhi was believed to be the major cause of enteric fever. The real situation is now becoming clear with reports emerging from many Asian countries of S. Paratyphi, mostly S. Paratyphi A, causing a substantial number of cases of enteric fever. Although there have been advances in the use of the currently available typhoid vaccines and in the development of newer typhoid vaccines, paratyphoid vaccine development is lagging behind. Since the disease caused by S. Typhi and S. Paratyphi are clinically indistinguishable and are commonly termed 'enteric' fever, it will be necessary to have a vaccine available against both S. Typhi and S. Paratyphi A as a bivalent 'enteric fever vaccine'.
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The West Asia and the Middle East region are both ethnically and geographically diverse area. The region stretches from arid deserts in its south to mountainous and temperate areas in the northern part. Nations in this area are characterized by a wide range of cultural backgrounds and religious history. Socioeconomic disparity is wide including industrialized affluent economies and developing economies. As in most of the destinations, the most common infections in travelers are gastrointestinal infections. In a key GeoSentinel study published by Wilson et al. in 2007, the common causes of fever from this region were respiratory and diarrheal illnesses (16% each), while 31% of travelers with fever after traveling to the region remained undiagnosed [1]. Several specific infections that are endemic in this region including leishmaniasis, brucellosis, rickettsiosis, relapsing fever, and endemic viral diseases such as West Nile Fever will be discussed further. Chronic and latent infections which should be considered in immigrants from this region include echinococcosis and neurocysticercosis [2].
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On October 2, 2014, the Government of India launched the Swachh Bharat Mission (SBM) throughout the country as a national movement. The aim of this campaign was to achieve the vision of ‘Clean India’ by October 2, 2019. This mission, apart from being a cleanliness drive, was expected to give a boost to the Indian economy if planned and executed properly. Health, tourism, and rural development were some of the sectors expected to be positively impacted by this campaign. The estimated cost of this campaign was estimated at Rs.1.96 trillion. India could channelize investment under SBM and reap its potential economic benefits. These impacts would bring positive change in GDP and employment in India. This paper mainly analyzed the Central government’s contribution in funding SBM. The study found that the development under the mission was not able to meet its expectations. It is observed that there was a lack of effort on part of Central and State governments. Even after 3 years of the SBM campaign, the Central government funding has been inadequate. Not even half of the funds have been allocated. The state governments have not utilized the funds allocated to them. The government’s expenditure in information and communication is abysmally low. The study found that the state governments were unable to mobilize funds from corporate businesses under CSR. However, the available statistics on physical progress of SBM certainly appeared promising to achieve its vision.
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Immunisation has traditionally played an important role in travel medicine practice and unlike routine immunisations; vaccines for travel are sought by and often paid for by the traveller. A convenient way of looking at vaccines for travel is by grouping them into those that are: Required, Routine, or Recommended, although this classification is not always consistent. Prioritising the use of vaccines classed as “Recommended” has proved the most controversial. There are a number of factors that influence both the traveller and health professional in this decision making process. The incidence rate and impact of a disease are thought by many to be the two most important factors to consider when prioritising vaccines. For travellers, the efficacy and adverse events associated with vaccines may also be important. This article reviews the role of immunisation in travel health with the aim of assisting travel health professionals prioritise their use of vaccines. It also highlights the need for travel medicine advisors worldwide to be aware of the differences between Japan and other nations with regard to national immunisation programmes, vaccine availability and vaccine uptake.
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There are no vaccines in clinical use against paratyphoid fever, caused by Salmonella Paratyphi A and B, or, rarely, C. Oral Salmonella Typhi Ty21a typhoid vaccine elicits a significant cross-reactive immune response against S. Paratyphi A and B, and some reports suggest cross-protective efficacy against the disease. These findings are ascribed to the O-12 antigen shared between the strains. The Vi capsular polysaccharide vaccine has been shown to elicit antibodies reactive with O-9,12. 25 volunteers immunized with the parenteral Vi vaccine (Typherix®) were explored for plasmablasts cross-reactive with paratyphoid strains; the responses were compared to those in 25 age- and gender-matched volunteers immunised with Ty21a (Vivotif®). Before vaccination, 48/50 vaccinees had no plasmablasts reactive with the antigens. Seven days after vaccination, 15/25 and 22/25 Vi- and Ty21a-vaccinated volunteers had circulating plasmablasts producing antibodies cross-reactive with S. Paratyphi A, 18/25 and 23/25 with S. Paratyphi B and 16/25 and 9/25 with Paratyphi C, respectively. Compared to the Ty21a group, the Vi group showed significantly lower responses to S. Paratyphi A and B, and higher to S. Paratyphi C. To conclude, the Vi vaccine elicited a cross-reactive plasmablast response to S. Paratyphi C (Vi antigen in common), and less marked responses to S. Paratyphi A and B than the Ty21a preparation. S. Paratyphi A and B both being Vi negative, the result can be explained by trace amounts of bacterial cell wall O-12 antigen in the Vi preparation, despite purification. The clinical significance of this finding remains to be determined. This article is protected by copyright. All rights reserved.
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Obwohl über 90% der Malaria-Erkrankungen und -Todesfälle in Afrika vorkommen, müssen auch Sie diesbezüglich auf dem Laufenden bleiben. Bei unklarem Fieber, insbesondere bei Reiserückkehrern und Migranten, sollten Sie eine Malaria zwingend mit in Betracht ziehen.
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Chapter
Gastrointestinal infections are common in community and hospitalized patients. In older adults, the presentation of such infections, which typically includes fever, abdominal pain, and leukocytosis, may be subclinical or even asymptomatic. Treatment of intra-abdominal infections requires swift diagnoses, source control, and empiric treatment with antibiotics effective against common pathogen associated with each infectious syndrome. Targeted treatment with a narrow spectrum agent may be initiated based upon culture and susceptibly data of the infecting pathogens, when available. Antibiotic choice is driven by disease process (local versus systemic), place of acquisition (community acquired, hospital acquired, and healthcare associated), disease severity, patient characteristics such as renal or hepatic insufficiency, and microbial resistant patterns, as well as local and regional epidemiology.
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This study aimed at exploring pomegranate peel (PoP) for its potential as an ingredient of choice in baked products primarily to stabilize lipids and inhibit microbiological spoilage. Pomegranate peel extracts (PoPx) and pomegranate peel bagasse (Pbg) were supplemented to wheat flour cookies at 0.25–1.0% and 1.5–7.5%, respectively. Cookies supplemented with 7.5% Pbg reduced caloric contents and significantly (P < 0.05) enhanced dietary fiber and inorganic residues of the product. Positive correlation was observed for cookies phenolics contents with 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power assay. Total phenolics recovery from Pbg and PoPx was shown to range from 78.35 to 315.7 mg GAE/100g), respectively. PoPx supplemented cookies, holding significant antioxidant properties, inhibited thiobarbituric acid number by 67% and reduced growth of aerobic counts (2.04–1.30 log10 cfu/g) and yeasts/molds (1.70–1.05 log10 cfu/g). Sensory evaluation of Pbg supplemented cookies indicated relatively lower score for texture and crispiness while other treatment combinations were ranked acceptable at 9-point hedonic scale for all sensory parameters.
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Typhoid fever and other systemic Salmonella infections are severe diseases responsible for more than a hundred thousand deaths each year. Poverty and inadequate hygiene facilitate massive outbreaks, lack of medical support results in severe courses of the disease leading to complications and death. Furthermore the general situation in the areas mainly affected means that the data collection is poor, neither the diagnoses nor the reporting system are trustworthy. Never-theless even the rudimentary data available provide a serious basis for some conclusions. The Indian subcontinent is a proven high risk area for these infections. The emergence of (multi-)resistant strains has made efficacious treatment more difficult; most of the patients have no access to modern medicine. Whereas the number of reported cases of typhoid fever was rather stable in recent years, the number of S. paratyphi A infections has steadily increased and in some areas has reached the levels of typhoid fever. Vaccines with acceptable efficacy are available against typhoid fever (S. Typhi), only. Thus improvement of prophylaxis on the basis of food hygiene, drinking water quality and sanitation remains very important.
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The medical history of a patient returning from Bangladesh with enteric fever caused by Salmonella Paratyphi A is reported. The isolate revealed decreased fluoroquinolone susceptibility. The changing epidemiology and the new antibiotic treatment options of enteric fever caused by Salmonella spp. with decreased fluoroquinolone susceptibility are described.
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Travel medicine is the medical subspecialty which promotes healthy and safe travel. Numerous studies have been published that provide evidence for the practice of travel medicine, but gaps exist. The Research Committee of the International Society of Travel Medicine (ISTM) established a Writing Group which reviewed the existing evidence base and identified an initial list of research priorities through an interactive process that included e-mails, phone calls, and smaller meetings. The list was presented to a broader group of travel medicine experts, then was presented and discussed at the Annual ISTM Meeting, and further revised by the Writing Group. Each research question was then subject to literature search to ensure that adequate research had not already been conducted. Twenty-five research priorities were identified and categorized as intended to inform pre-travel encounters, safety during travel, and post-travel management. We have described the research priorities that will help to expand the evidence base in travel medicine. This discussion of research priorities serves to highlight the commitment that the ISTM has in promoting quality travel-related research.
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Calculation of the incidence of typhoid fever during preschool years is important to define the optimum age of immunisation and the choice of vaccines for public-health programmes in developing countries. Hospital-based studies have suggested that children younger than 5 years do not need vaccination against typhoid fever, but this view needs to be re-examined in community-based longitudinal studies. We undertook a prospective follow-up study of residents of a low-income urban area of Delhi, India, with active surveillance for case detection. A baseline census was undertaken in 1995. Between Nov 1, 1995, and Oct 31, 1996, we visited 8172 residents of 1820 households in Kalkaji, Delhi, twice weekly to detect febrile cases. Blood samples were obtained from febrile patients, and those who tested positive for Salmonella typhi were treated with ciprofloxacin. 63 culture-positive typhoid fever cases were detected. Of these, 28 (44%) were in children aged under 5 years. The incidence rate of typhoid per 1000 person-years was 27.3 at age under 5 years, 11.7 at 5-19 years, and 1.1 between 19 and 40 years. The difference in the incidence of typhoid fever between those under 5 years and those aged 5-19 years (15.6 per 1000 person-years [95% CI 4.7-26.5]), and those aged 19-40 years (26.2 [16.0-36.3]) was significant (p<0.001 for both). The difference between the incidence of typhoid at 5-19 years and the incidence at 19-40 years was also significant (10.6 [6.3-14.8], p<0.001). Morbidity in those under 5 and in older people was similar in terms of duration of fever, signs and symptoms, and need for hospital admission. Our findings challenge the common view that typhoid fever is a disorder of school-age children and of adults. Typhoid is a common and significant cause of morbidity between 1 and 5 years of age. The optimum age of typhoid immunisation and the choice of vaccines needs to be reassessed.
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Notification records of typhoid and paratyphoid cases among residents of south-eastern Sydney during 1992-1997 were reviewed, with particular attention paid to identifying a source of infection and to completeness of follow up. Notifications comprised 30 cases of Salmonella Typhi, nine of S. Paratyphi A and five of S. Paratyphi B. These 44 cases had a median age of 20 years (range 2-62). Of the 39 cases with known country of birth, 30 were born overseas, predominantly in Asian countries. Of 39 cases with a known travel history, 33 were cases of overseas-acquired acute infection and two cases were asymptomatic chronic carriers. A source was identified in only one of four domestically acquired infections. Of eight household contacts in occupations posing a public health risk (seven food-handlers and one health-care worker), complete follow-up information was available for only five. Most cases were in overseas-born individuals who may have been infected when returning to their country of birth. Explicit follow-up protocols need to cover appropriate clinical management (including treatment of chronic carriage) and monitoring of those cases and contacts who could pose a public health risk.
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Stools from tourists from Europe and North America who acquired diarrhea in Mombasa (Kenya), Goa (India), or Montego Bay (Jamaica) were examined for enteric pathogens. Enterotoxigenic Escherichia coli (ETEC) was the most common pathogen (25%) identified in the 3 locations. Isolation of Shigella species was more frequent in Goa and Mombasa than in Montego Bay (10%, 9%, and 0.3%, respectively; P < .005). Viruses (rotaviruses and enteric adenoviruses) were found in 9% of travelers to the 3 areas. Of 275 ETEC isolates in this study, 158 (57%) produced a defined colonization factor antigen (CFA). Coli surface 6 (CS6) was the most frequent and was found in 41%–52% of CFA/CS-positive ETEC isolates. The frequency of resistance among bacterial enteropathogens to traditional antimicrobial agents was particularly high throughout the study period in all 3 regions. Quinolones were active against the bacterial enteropathogens in the 3 sites.
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Dengue fever (DF) has become common in western travelers to the tropics. To improve the basis for travel advice, risk factors and dengue manifestations were assessed in 107 Swedish patients for whom DF was diagnosed after return from travel in 1998 and 1999. Patient data were compared with data on a sample of all Swedish travelers to dengue-endemic countries in the same years. Only three of the patients had received pretravel advice concerning DF from their physicians. Hemorrhagic manifestations were common (21 of 74 patients) but caused no deaths. Risk factors for a DF diagnosis were travel to the Malay Peninsula (odds ratio [OR] 4.95; confidence interval [CI] 2.92 to 8.46), age 15-29 years (OR 3.03; CI 1.87 to 4.92), and travel duration >25 days (OR 8.75; CI 4.79 to 16.06). Pretravel advice should be given to all travelers to DF-endemic areas, but young persons traveling to southern and Southeast Asia for >3 weeks (who constituted 31% of the patients in our study) may be more likely to benefit by adhering to it.
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The proportion of paratyphoid fever cases to typhoid fever cases may change due to urbanization and increased dependency on food purchased from street vendors. For containment of paratyphoid a different strategy may be needed than for typhoid, because risk factors for disease may not coincide and current typhoid vaccines do not protect against paratyphoid fever. To determine risk factors for typhoid and paratyphoid fever in an endemic area. Community-based case-control study conducted from June 2001 to February 2003 in hospitals and outpatient health centers in Jatinegara district, Jakarta, Indonesia. Enrolled participants were 1019 consecutive patients with fever lasting 3 or more days, from which 69 blood culture-confirmed typhoid cases, 24 confirmed paratyphoid cases, and 289 control patients with fever but without Salmonella bacteremia were interviewed, plus 378 randomly selected community controls. Blood culture-confirmed typhoid or paratyphoid fever; risk factors for both diseases. In 1019 fever patients we identified 88 (9%) Salmonella typhi and 26 (3%) Salmonella paratyphi A infections. Paratyphoid fever among cases was independently associated with consumption of food from street vendors (comparison with community controls: odds ratio [OR], 3.34; 95% confidence interval [CI], 1.41-7.91; with fever controls: OR, 5.17; 95% CI, 2.12-12.60) and flooding (comparison with community controls: OR, 4.52; 95% CI, 1.90-10.73; with fever controls: OR, 3.25; 95% CI, 1.31-8.02). By contrast, independent risk factors for typhoid fever using the community control group were mostly related to the household, ie, to recent typhoid fever in the household (OR, 2.38; 95% CI, 1.03-5.48); no use of soap for handwashing (OR, 1.91; 95% CI, 1.06-3.46); sharing food from the same plate (OR, 1.93; 95% CI, 1.10-3.37), and no toilet in the household (OR, 2.20; 95% CI, 1.06-4.55). Also, typhoid fever was associated with young age in years (OR, 0.96; 95% CI, 0.94-0.98). In comparison with fever controls, risk factors for typhoid fever were use of ice cubes (OR, 2.27; 95% CI, 1.31-3.93) and female sex (OR, 1.79; 95% CI, 1.04-3.06). Fecal contamination of drinking water was not associated with typhoid or paratyphoid fever. We did not detect fecal carriers among food handlers in the households. In Jakarta, typhoid and paratyphoid fever are associated with distinct routes of transmission, with the risk factors for disease either mainly within the household (typhoid) or outside the household (paratyphoid).
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To use new data to make a revised estimate of the global burden of typhoid fever, an accurate understanding of which is necessary to guide public health decisions for disease control and prevention efforts. Population-based studies using confirmation by blood culture of typhoid fever cases were sought by computer search of the multilingual scientific literature. Where there were no eligible studies, data were extrapolated from neighbouring countries and regions. Age-incidence curves were used to model rates measured among narrow age cohorts to the general population. One-way sensitivity analysis was performed to explore the sensitivity of the estimate to the assumptions. The burden of paratyphoid fever was derived by a proportional method. A total of 22 eligible studies were identified. Regions with high incidence of typhoid fever (>100/100,000 cases/year) include south-central Asia and south-eastAsia. Regions of medium incidence (10-100/100,000 cases/year) include the rest of Asia, Africa, Latin America and the Caribbean, and Oceania, except for Australia and New Zealand. Europe, North America, and the rest of the developed world have low incidence of typhoid fever (<10/100,000 cases/year). We estimate that typhoid fever caused 21,650,974 illnesses and 216,510 deaths during 2000 and that paratyphoid fever caused 5,412,744 illnesses. New data and improved understanding of typhoid fever epidemiology enabled us to refine the global typhoid burden estimate, which remains considerable. More detailed incidence studies in selected countries and regions, particularly Africa, are needed to further improve the estimate.
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The epidemiology of travel-associated campylobacteriosis is still largely unclear, and various known risk factors could only explain limited proportions of the recorded cases. Using data from 28,704 notifications of travel-associated campylobacteriosis in Sweden 1997 to 2003 and travel patterns of 16,255 Swedish residents with overnight travel abroad in the same years, we analysed risks for travel-associated campylobacteriosis in 19 regions of the world, and looked into the seasonality of the disease in each of these regions. The highest risk was seen in returning travellers from the Indian subcontinent (1,253/100,000 travellers), and the lowest in travellers from the other Nordic countries (3/100,000 travellers). In Africa, large differences in risk between regions were noted, with 502 /100,000 in travellers from East Africa, compared to 76/100,00 from West Africa and 50/100,000 from Central Africa. A distinct seasonal pattern was seen in all temperate regions with peaks in the summer, while no or less distinct seasonality was seen in tropical regions. In travellers to the tropics, the highest risk was seen in children below the age of six. Data on infections in returning travellers together with good denominator data could provide comparable data on travel risks in various regions of the world.
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Salmonella enterica serotype Paratyphi A has been reported less frequently as a causative agent of enteric fever. Reports on the antimicrobial susceptibility of this pathogen are few and varied. An unusually high occurrence of S. Paratyphi A was noted in a tertiary care hospital at Nagpur, Maharashtra during April 2001-September 2002. An effort was made to study the antimicrobial susceptibility pattern and phage types of the isolates. Blood cultures of patients suspected to have enteric fever admitted to the Indira Gandhi Medical College and Hospital, Nagpur were processed by conventional methods. Antimicrobial susceptibility was tested by Kirby-Bauer disc diffusion method and the minimum inhibitory concentration (MIC) to chloramphenicol was determined. Eighteen (46.15%) of 39 Salmonella isolates were S. Paratyphi A and all were sensitive to ciprofloxacin and cephotaxime. Twelve (66.67%) strains were sensitive to ampicillin and 13 (72.22 %) to chloramphenicol. Two strains (11.11%) were resistant to three drugs (ampicillin, chloramphenicol and cotrimoxazole) simultaneously. The prevalent phage type in the local population was phage type I. The high occurrence of S. Paratyphi A found in the present study indicated the emergence of this rare pathogen of enteric fever in the local population. Though some degree of resistance was encountered with ampicillin and chloramphenicol, all the isolates were sensitive to ciprofloxacin, currently a drug of choice for enteric fever. Multidrug resistance was rare.
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Article
Strains of Salmonella Typhi resistant to multiple antimicrobial agents have been reported worldwide with increasing frequency, but comprehensive data on the incidence of antimicrobial-resistant S. Typhi strains in the U.S. are lacking. On June 1, 1996, we initiated a 1-year survey to determine the incidence of antimicrobial-resistant S. Typhi infections and identify risk factors for infection. States and territories were asked to submit all laboratory-confirmed isolates of S. Typhi from symptomatic patients for antimicrobial susceptibility testing at CDC. Patients were interviewed with a standard form. As of April 1, 1997, 34 sites had submitted 285 isolates and 209 forms, including 200 matched pairs. The median age of patients was 21 years (range, 1-83 years); 56% were male. One hundred fifty-six patients (81%) were hospitalized, and 2 died. In the 6 weeks before illness onset, 81% of patients had traveled abroad; 4 (3%) reported receiving the oral typhoid vaccine before travel. Forty-three (22%) isolates were resistant to ≥ 1 agent, and 30 (15%) were resistant to ≥ 6 agents, including chloramphenicol, trimethoprim-sulfamethoxazole, and ampicillin (multidrug-resistant). No resistance to ciprofloxacin or ceftriaxone was observed. Third-generation cephalosporins (52%), fluoroquinolones (36%), and ampicillin (12%) were the most frequent agents used for initial treatment of multidrug-resistant strains. Patients with multidrug-resistant strains were more likely to have traveled to Bangladesh, India, Pakistan, or Vietnam, (p<0.00001) and to have longer durations of hospitalization, (p<0.05). S. Typhi is often resistant to multiple antimicrobial agents and causes significant morbidity. At present, ciprofloxacin and ceftriaxone remain appropriate choices for empiric therapy for suspected typhoid fever. Continued monitoring of antimicrobial resistance among S. Typhi strains will help inform vaccination and treatment policies.
Article
In the 16-year period 1975–90, there were 267 cases of acute infection with typhoidal salmonellae reported in Scotland, in addition to which 32 chronic carriers were identified. The overall incidence of disease changed little over this period, but there was a fall in indigenously acquired paratyphoid B and typhoid, and a rise in imported paratyphoid A. The majority, 215 (81%), had a history of recent travel and were considered to have acquired infection overseas. Only six of the indigenously acquired infections were traced to acutely infected persons, illustrating the low risk of transmission associated with acute enteric fever in the UK. Only one death was definitely ascribed to enteric fever, and one person with S. paratyphi B became a chronic carrier. Significant illness was observed in five chronically infected individuals, including one with carcinoma of the gallbladder. UK residents of ‘Asian’ ethnicity returning from the Indian subcontinent accounted for 63 (46%) of the 137 cases of typhoid, and 34 (64%) of the 53 cases of paratyphoid A. People of ‘Asian’ ethnicity were more likely to have acquired infection overseas than ‘non-Asians’: 110 (89%) of 123 persons compared with 105 (73%) of 144 (odds ratio 3.1, 95% confidence interval 1.5–6.6, P = 0.001). Although there seems to be limited scope for preventing indigenously acquired infection, immunisation of travellers could contribute significantly to reducing the incidence of typhoid.
Article
To identify risk factors for typhoid fever in Semarang city and its surroundings, 75 culture-proven typhoid fever patients discharged 2 weeks earlier from hospital and 75 controls were studied. Control subjects were neighbours of cases with no history of typhoid fever, not family members, randomly selected and matched for gender and age. Both cases and controls were interviewed at home by the same trained interviewer using a standardized questionnaire. A structured observation of their living environment inside and outside the house was performed during the visit and home drinking water samples were tested bacteriologically. Univariate analysis showed the following risk factors for typhoid fever: never or rarely washing hands before eating (OR=3.28; 95% CI=1.41–7.65); eating outdoors at least once a week (OR=3.00; 95% CI=1.09–8.25); eating outdoors at a street food stall or mobile food vendor (OR=3.86; 95% CI=1.30–11.48); consuming ice cubes in beverage in the 2-week period before getting ill (OR=3.00, 95% CI=1.09–8.25) and buying ice cubes from a street vendor (OR=5.82; 95% CI=1.69–20.12). Water quality and living environment of cases were worse than that of controls, e.g. cases less often used clean water for taking a bath (OR=6.50; 95% CI= 1.47–28.80), for brushing teeth (OR=4.33; 95% CI=1.25–15.20) and for drinking (OR=3.67; 95% CI=1.02–13.14). Cases tended to live in houses without water supply from the municipal network (OR=11.00; 95% CI=1.42–85.2), with open sewers (OR=2.80; 95% CI=1.0–7.77) and without tiles in the kitchen (OR=2.67; 95% CI=1.04–6.81). Multivariate analysis showed that living in a house without water supply from the municipal network (OR=29.18; 95% CI=2.12–400.8) and with open sewers (OR=7.19; 95% CI=1.33–38.82) was associated with typhoid fever. Never or rarely washing hands before eating (OR=3.97; 95% CI=1.22–12.93) and being unemployed or having a part-time job (OR=31.3; 95% CI=3.08–317.4) also were risk factors. In this population typhoid fever was associated with poor housing and inadequate food and personal hygiene.
Article
Typhoid fever is a potentially fatal illness common in the less industrialized world. In the United States, the majority of cases occur in travelers to other countries. We reviewed surveillance forms submitted to the Centers for Disease Control and Prevention, Atlanta, Ga, for patients with culture-confirmed typhoid fever between 1985 and 1994. The Centers for Disease Control and Prevention received report forms for 2445 cases of typhoid fever. Median age of patients was 24 years (range, 0-89 years). Ten (0.4%) died. Seventy-two percent reported international travel within the 30 days before onset of illness. Six countries accounted for 80% of cases: Mexico (28%), India (25%), the Philippines (10%), Pakistan (8%), El Salvador (5%), and Haiti (4%). The percentage of cases associated with visiting Mexico decreased from 46% in 1985 to 23% in 1994, while the percentage of cases associated with visiting the Indian subcontinent increased from 25% in 1985 to 37% in 1994. The incidence of typhoid fever in US citizens traveling to the Indian subcontinent was at least 18 times higher than for any other geographic region. Complete data on antimicrobial susceptibility to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole were reported for 330 (13%) Salmonella Typhi isolates. Isolates from 1990 to 1994 were more likely than isolates from 1985 to 1989 to be resistant to any of these antimicrobial agents (30% vs 12%; P<.001) and to be resistant to all 3 agents (12% vs 0.6%; P<.001). American travelers to less industrialized countries, especially those traveling to the Indian subcontinent, continue to be at risk for typhoid fever. Antimicrobial resistance has increased, and a quinolone or third-generation cephalosporin may be the best choice for empirical treatment of typhoid fever.
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Travellers from temperate climates to the tropics of the Third World face a high risk of acquiring traveller's diarrhea. Epidemiology plays a major role in the exact description of this syndrome. This paper describes the epidemiology of traveller's diarrhea in 3696 Austrian tourists and the influence of various epidemiologic parameters on incidence is evaluated. Destination and season of travel influences attack rates, in particular in the sub-tropics. High (up to app. 60% incidence) and low risk (below 35% incidence) regions can be described, exhibiting risk differences of nearly 100%. Individual parameters, like age and body weight, can influence the risk in an evident manner and, or course, the duration of stay plays a major role. It is pointed out that accommodation and travel characteristics are important factors for risk evaluation, as well as dietary hygiene.
Article
A retrospective survey of all notified cases of typhoid and paratyphoid fever in Denmark 1986-1990 was carried out by extracting epidemiological data from the mandatory notification forms; laboratory results of diagnostic and follow-up bacteriological investigations of the patients were also obtained. A total of 161 patients were identified, corresponding to a mean incidence of 0.6 per 100,000 inhabitants per year. Salmonella typhi was isolated in 107 cases and S. paratyphi A and S. paratyphi B in 27 cases each. Median age was 21 years, range 2 months to 74 years. All but six patients probably contracted the infection abroad, most often in Pakistan or other Asian countries. Of six cases with no travel history, two were laboratory associated and two had had relevant foreign contacts. Forty percent of the patients were immigrants now resident in Denmark but infected while visiting their home countries. Only one third of the patients strictly fulfilled the recommendations for follow-up laboratory screenings. It is concluded that the incidence of typhoid and paratyphoid fever is low in Denmark and that nearly all cases are imported; secondary cases are uncommon. There is a need for simplification and modernization of the present recommendations for follow-up laboratory screenings, which date from 1943.
Article
We conducted a study to evaluate risk factors for developing typhoid fever in a setting where the disease is endemic in Karachi, Pakistan. We enrolled 100 cases with blood culture-confirmed Salmonella typhi between July and October 1994 and 200 age-matched neighbourhood controls. Cases had a median age of 5.8 years. In a conditional logistic regression model, eating ice cream (Odds ratio [OR] = 2.3; 95% confidence interval [CI] 1.2-4.2, attributable risk [AR] = 36%), eating food from a roadside cabin during the summer months (OR = 4.6, 95% CI 1.6-13.0; AR = 18%), taking antimicrobials in the 2 weeks preceding the onset of symptoms (OR = 5.7, 95% CI 2.3-13.9, AR = 21%), and drinking water at the work-site (OR = 44.0, 95% CI 2.8-680, AR = 8%) were all independently associated with typhoid fever. There was no difference in the microbiological water quality of home drinking water between cases and controls. Typhoid fever in Karachi resulted from high-dose exposures from multiple sources with individual susceptibility increased by young age and prior antimicrobial use. Improving commercial food hygiene and decreasing unnecessary antimicrobial use would be expected to decrease the burden of typhoid fever.
Article
Cases of enteric fever in the north west of England who acquired infection abroad between April 1996 and March 1998 were surveyed to determine the workload associated with the follow up of contacts of cases and the yield from their investigation. No asymptomatic secondary cases were detected, and it is argued that low risk asymptomatic contacts of cases of enteric fever acquired abroad do not need to be screened.
Article
In this review we will briefly consider the important aetiological agents and clinical expressions in travellers' diarrhoea, then we will review the prevention and therapy of the illness.
Article
Multidrug-resistant Salmonella serotype Typhi infections have been reported worldwide, but data on the incidence of resistant strains in the United States are lacking. To determine the incidence of antimicrobial-resistant Salmonella Typhi infections and to identify risk factors for infection. Cross-sectional laboratory-based surveillance study. A total of 293 persons with symptomatic typhoid fever who had Salmonella Typhi isolates and epidemiological information submitted to US public health departments and laboratories from June 1, 1996, to May 31, 1997. Proportion of Salmonella Typhi isolates demonstrating resistance to 12 antimicrobial agents; patient epidemiological factors associated with drug-resistant infections. Median age was 21 years (range, 3 months to 84 years); 56% were male. Two hundred twenty-eight (80%) were hospitalized; 2 died. In the 6 weeks before illness onset, 81% of patients had traveled abroad. Seventy-four Salmonella Typhi isolates (25%) were resistant to 1 or more antimicrobial agent, and 51 (17%) were resistant to 5 or more agents, including ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole (multidrug-resistant Salmonella Typhi [MDRST]). Although no resistance to ciprofloxacin or ceftriaxone was observed, 20 isolates (7%) were nalidixic acid-resistant (NARST). Patients with MDRST and NARST infections were more likely to report travel outside the United States, particularly to the Indian subcontinent (Bangladesh, India, and Pakistan) (odds ratio [OR], 29.3; 95% confidence interval [CI], 6.8-126.7; P<.001 and OR, 35.9; 95% CI, 3.4-377.3; P<.001, respectively). Our data suggest that ciprofloxacin and ceftriaxone are appropriate empirical therapy for suspected typhoid fever; however, resistance may be anticipated. Continued monitoring of antimicrobial resistance among Salmonella Typhi strains will help determine vaccination and treatment policies. JAMA. 2000;283:2668-2673.
Article
Increasing numbers of imported cases of malaria have been reported from several European countries. By analysing data from the Norwegian Surveillance System for Communicable Diseases (MSIS) from 1989 to 1998, the incidence of imported malaria and the most important risk groups for acquiring the disease in endemic areas are assessed. In the ten-year period a total of 744 cases of malaria imported into Norway were reported. An increase in incidence has been observed during the period. Since 1992 Plasmodium falciparum has been the most common reported parasite. 58% of the cases were among people of non-Norwegian origin, and 41% among people of Norwegian origin. Immigrants from Pakistan, India and Sri Lanka constitute 26% of all imported cases. During the five year period from 1994 to 1998, 60% of patients of non-Norwegian origin, and 19% of patients of Norwegian origin took no chemoprophylaxis prior to their illness. From 1994 to 1998, 23% of the patients developed malaria despite taking recommended chemoprophylaxis. The majority of these patients used chloroquine and proguanil and developed falciparum malaria after visiting sub-Saharan Africa. Increased emphasis should be put on avoiding exposure to mosquitoes while in endemic areas. Mefloquine should be recommended as prophylaxis to the majority of travellers visiting regions with chloroquine-resistant malaria.
Article
Almost two of three tourists developed traveller's diarrhoea during 2-week stays at high-risk destinations. Large differences in infection rates between hotels were seen. Patients with milder forms of diarrhoea show a similar chronology to those more severely affected. Although enterotoxigenic Escherichia coil was the most frequent cause, viral pathogens were detected more often than in other studies.
Article
Vaccination of populations throughout the world has led to dramatic decreases in morbidity and mortality from many infectious diseases, including poliomyelitis and measles. In the United States, for example, morbidity and mortality from invasive disease from Haemophilus influenzae type b has decreased more than 99%. International travelers should ensure that they are up-to-date on their routine immunizations and then consider vaccination against other diseases based on risk. This article reviews new vaccines such as those against rotavirus, Lyme disease, and enterotoxigenic Escherichia coli and provides updated information on the risk of typhoid fever and the efficacy of vaccination against it. The use of hepatitis A vaccine in outbreak control, the safety of yellow fever vaccine, and the importance of protecting travelers against rabies exposure are also discussed. Vaccination is an important way for travelers to maintain their health before, during, and after travel.
Article
A population-based surveillance for typhoid fever was conducted in three rural communes of Dong Thap Province in southern Vietnam (population 28,329) for a 12-month-period starting on December 4, 1995. Cases of typhoid fever were detected by obtaining blood for culture from residents with fever > or = 3 days. Among 658 blood cultures, 56 (8.5%) were positive for Salmonella typhi with an overall incidence of 198 per 10(5) population per year. The peak occurrence was at the end of the dry season in March and April. The attack rate was highest among 5-9 year-olds (531/10(5)/year), and lowest in > 30 year-olds (39/10(5)/year). The attack rate was 358/10(5)/year in 2-4 year-olds. The isolation of S. typhi from blood cultures was highest (17.4%) in patients with 5 to 6 days of fever. Typhoid fever is highly endemic in Vietnam and is a significant disease in both preschool and school-aged children.
Article
To describe the age-specific distribution of typhoid fever including the degree of Salmonella typhi bacteremia among patients evaluated at a large private diagnostic center in Bangladesh, a highly endemic area. We conducted a prospective-, passive- and laboratory-based study to identify patients with S. typhi bacteremia. Subjects (n = 4,650) from whom blood cultures were obtained during 16-month period were enrolled from private clinics and hospitals throughout Dhaka. Isolation and quantification of S. typhi from blood cultures were performed by the lysis direct plating/ centrifugation method. Bacterial pathogens were recovered from blood of 538 of 4,650 patients (11.6%) evaluated. S. typhi was the single most common pathogen recovered, comprising nearly three-fourths of isolates (72.7%; 391 of 538). Isolation rate of S. typhi was highest in monsoon and summer seasons and lowest in winter months. The majority (54.5%; 213 of 391) of S. typhi isolates were from children who were younger than 5 years, and 27% (105 of 391) were from children in the first 2 years of life. The isolation rate was highest (17.4%, 68 of 486) in the second year of life. The number of bacteria in blood on the basis of colony-forming units per ml of blood by age group was inversely related to age. Detection of S. typhi bacteremia in young children in Dhaka, Bangladesh, was considerably higher than previously appreciated, with a peak detection rate in children < or =2 years of age, indicating the need to reassess the age-specific burden of typhoid fever in the community on a regional basis. Contrary to current recommendations this study suggests that development of new vaccines should target infants and young children.
Article
Enteric fever remains a major cause of fever in travelers. We evaluated new trends in enteric fever. We reviewed the epidemiological, clinical, biological, bacteriological data, and outcome of all cases of typhoid and paratyphoid fever seen in our department over the last decade. The inclusion criteria were the presence of signs compatible with enteric fever and isolation of Salmonella typhi or Salmonella paratyphi A, B, or C from blood or stool cultures or any other site. Among the 41 patients, 38 (93%) had travel-associated enteric fever. The main geographic source of contamination was the Indian subcontinent. One patient had been vaccinated with parenteral Vi vaccine 1 year previously. Fever and headaches were the only signs which were present in more than 80% of patients. The Widal test at inclusion was positive in 27%, and a second serological test was found to be positive in 50% of evaluated cases. Blood cultures and stool cultures were positive in 34 cases and 10 cases, respectively. Salmonellae spp were isolated in both hemocultures and stool cultures in 4 cases and in urine in 1 case. Two strains of S. typhi were resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole. One strain of S. typhi and one of S. paratyphi B were nalidixic acid resistant. All evaluable patients were cured with the exception of 2 patients (1 failure, 1 relapse). We observed 3 toxic reactions. No patients died. The diagnosis and outcome of enteric fever are hampered by the lack of specificity of clinical and biological signs, the increasing rates of antimicrobial resistance, and the occurrence of toxic reactions during treatment.
Article
During the summer of 1999, several Norwegian tourists returning from Turkey became ill as a result of Salmonella enterica serovar paratyphi B (S. paratyphi B) infection. We examined the S. paratyphi B isolates from 14 of these patients (10 from blood cultures, 4 from stool specimens) who were admitted to 2 hospitals in Bergen, Norway during August and September 1999. Moreover, during the same period, a laboratory technician working at 1 of these hospitals was admitted with S. paratyphi B septicemia and was included in the study. Using repetitive-sequence-based PCR (rep-PCR) with 2 primer pairs (ERIC and REP), pulsed-field gel electrophoresis and phage typing we found that the laboratory technician was infected with the same S. paratyphi B clone as the 14 tourists. The discriminatory capacity of the rep-PCR method and pulsed-field gel electrophoresis was examined using S. paratyphi B strains from the outbreak and from other geographical locations. We conclude that a combination of rep-PCR with the ERIC primer pair and phage typing was useful in discriminating between the epidemic isolates and epidemiologically unrelated isolates from S. paratyphi B infections and that the laboratory technician was most likely infected while handling patient samples or bacterial cultures from the Turkish tourists.
Article
Vacations in the home country are important and positive events in the lives of immigrants, events that allow them to maintain contact with their culture, relatives and friends. However, vacations also carry certain health risks, though these risks can to some degree be prevented. Infectious disease is the greatest risk. Some children and adolescents also run the risk of female genital mutilation, forced marriage, and the risk og being left behind in the home country against their will. Among the notifiable diseases registered with the Norwegian Surveillance System for Communicable Diseases (MSIS), five stand out as having a higher incidence in people of foreign background than in people of Norwegian origin: malaria, hepatitis A, shigella infection, typhoid and paratyphoid fever. This higher incidence is partly the result of less use of pre-travel vaccines and malaria prophylaxis. Immigrants as a group are exposed to varied risks and should be given high priority in relation to vaccines and malaria prophylaxis for travel abroad. High priority should also be given to preventive health measures designed to reduce the risk of female genital mutilation and other violations against children and young people on visit to their country of origin.
Article
From laboratory records, information was collected on all 77 cases of rickettsioses diagnosed in Sweden during 1997-2001, 14 of which were diagnosed as belonging to the typhus group and 63 to the spotted fever group. Signs of hepatic involvement occurred more frequently in the typhus group. Denominators for the number of journeys to different parts of the world were retrieved from a commercial Swedish tourist database. The estimated risk of rickettsioses in destinations outside Europe varied from 1 case in 140,000 travellers to south-east Asia to 1 in 1600 travellers to southern Africa. The risk of infection in southern Africa increased over the 5 y period and is now 4-5 times higher than the risk of acquiring malaria in the same region. Rickettsiosis is an important differential diagnosis to consider in the febrile traveller, especially from South Africa. It should be remembered that the serological response may be considerably delayed and in patients with a negative first serology, serological testing should be repeated. Where there is a strong suspicion of rickettsiosis treatment may have to be started without a confirmed diagnosis.
Article
Typhoid fever, a systemic infection caused by Salmonella enterica serotype typhi, remains an important worldwide cause of morbidity and mortality. Endemic cases in the United States are unusual, with most following foreign travel to the Indian subcontinent, Africa, Asia, or Latin America. The classic findings of typhoid fever include rose spots, relative bradycardia, and stepwise fevers, but unfortunately these signs are frequently absent. Gastrointestinal manifestations may include diffuse abdominal pain, bleeding, perforation, cholecystitis, and cholangitis. The diagnosis should be suspected after collection of the appropriate clinical and travel history with confirmation by blood or bone marrow culture. Novel methods are in development to establish the diagnosis when cultures are negative or unavailable. Multidrug resistance has increased worldwide, and decisions on antimicrobial therapy must take such resistance into account. The empiric treatment of choice is a fluoroquinolone drug; ceftriaxone and azithromycin are alternatives. Preventive strategies include good sanitation and food handling practices along with vaccination of selected groups.
Article
In order to have a rational approach to necessary preventive measures it is essential to know the health risks. The 80 million travellers each year with destinations in Africa, Asia, Latin America, Pacific Islands and remote areas in Eastern Europe are exposed to a broad range of pathogens that are rarely encountered at home. The risk depends on the degree of endemicity in the area visited, the duration of stay, the individual behaviour and the preventive measures taken. Travellers' diarrhoea (TD) is the most frequent ailment of visitors to countries with poor hygiene. The incidence rate is 25-90% in the first 2 weeks abroad. The risk of TD is far less in travellers originating in a high risk country, as some immunity develops. Malaria is an important risk for travellers going to endemic areas. Without chemoprophylaxis, the monthly incidence is high in some destinations, among them frequently visited tropical Africa where 80-95% of the infections are due to Plasmodium falciparum. The incidence rates are lower in most endemic areas of Asia and Latin America where Plasmodium vivax predominates. The risk is nil in all capital cities of South America and SE Asia, as well as in many frequently visited tourist destinations. The diseases preventable by immunization will be discussed in a separate paper (Vaccination priorities; page 175). Sexually transmitted diseases occur frequently, as some travellers (5% of Europeans) engage in casual sex, approximately half of them without being protected by a condom. The prevalence for HIV-infection, syphilis, gonorrhoea, etc. often exceeds 50% in prostitutes. In some European countries, a major proportion of heterosexuals with newly acquired HIV-infection have acquired it while abroad.
Article
The Swedish database on notifiable communicable diseases was used to identify 24 803 cases of travel-associated non-typhoidal salmonellosis from the period 1997-2003. Serotype data were available for 24 358 (98.2%) of these cases, which were compared with a data set from the same period of 16 255 randomly selected Swedish residents with a history of recent overnight travel outside Sweden. The highest risk of disease was seen in travellers returning from East Africa (471/100 000 travellers; 95% CI 294-755), or the Indian subcontinent (474/100 000; 95% CI 330-681). Children aged 0-6 years were at higher risk than travellers of other ages (OR 2.4; 95% CI 2.1-2.8). Some distinct seasonal patterns could be distinguished, with highest (adjusted) risk in December in East Asia, and in August in Europe. Marked geographical differences in serotype distribution were noted. Salmonella Enteritidis was especially dominant in Europe, but was much less common in Africa, Asia and America, where the variety of circulating serotypes was greater. Overall, the two data sets provided important information on travel risks which are also likely to apply to travellers from other western countries.
Article
To give a detailed risk estimate of contracting travel-associated shigellosis in various regions of the world. Data on notifications of travel-associated shigellosis in Sweden 1997-2003 were compared with information on recent travel abroad from a comprehensive database based on telephone interviews with more than 160,000 Swedish travellers. From the national notification database 2678 patients with travel-associated shigellosis were retrieved. The highest risk of being notified with shigellosis was seen in returning travellers from India and neighbouring countries (318/100,000 travellers), East Africa (219/100,000), West Africa (120/100,000), and North Africa (76/100,000). Data on serogroup was available for 2529 isolates. Shigella sonnei was the most common serogroup (67%), followed by Shigella flexneri (26%), Shigella boydii (5%), and Shigella dysenteriae (3%). A higher risk was seen in children below the age of six, compared to older children and adults and in women compared to men. A distinct seasonal pattern was noted with the highest risk of shigellosis in July-October and the lowest in May. Denominator based data on reported travel-associated infections are well suited to give risk estimates per region of infection, that could be used to target high-risk groups for pre-travel advice.
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Saudi Arabia, Syria, United Arab Emirates,Yemen; India with neighbors = Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, Sri Lanka The Gambia,Togo; East Africa = Burundi Democratic Republic of the Congo, São Tomé and Principe
  • For
  • Denmark
  • Finland
  • Iceland
  • Norway
  • Austria
  • Belgium
  • France
  • Germany
  • Ireland
  • The Luxembourg
  • Netherlands
  • United Switzerland
  • Kingdom
  • Southern
  • Europe
  • Italy
  • Malta
  • Monaco
  • Portugal
  • Spain
  • Czech Bulgaria
  • Republic
  • Estonia
  • Hungary
  • Latvia
  • Lithuania
  • Poland
  • Romania
  • Slovakia
  • Albania
  • Cyprus
  • Yugoslavia
  • Greece
  • Israel
  • Ussr And
  • Armenia
  • Azerbaijan
  • Belarus
  • Georgia
  • Kazakhstan
  • Kyrgyzstan
  • Russia
  • Tajikistan
  • Turkmenistan
  • Ukraine
  • Uzbekistan
  • East
  • Bahrain
  • Iraq
  • Iran
  • Jordan
  • Kuwait
  • Lebanon
  • Qatar Oman
  • Asia
  • Brunei
  • Burma
  • Cambodia
  • Hong China
  • Kong
  • Indonesia
  • Japan
  • Laos
  • Malaysia
  • North Mongolia
  • Korea
  • Philippines
  • South
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*For comparisons, estimated regional incidences of typhoid fever obtained, with data adapted from Crump et al, 2 are included. † Nordic countries = Denmark, Finland, Iceland, Norway;Western Europe = Austria, Belgium, France, Germany, Ireland, Luxembourg,The Netherlands, Switzerland, United Kingdom; Southern Europe = Italy, Malta, Monaco, Portugal, Spain; Eastern Europe = Bulgaria, Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Romania, Slovakia; Eastern Mediterranean = Albania, Cyprus, former Yugoslavia, Greece, Israel,Turkey; Russia and former USSR = Armenia, Azerbaijan, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Russia,Tajikistan,Turkmenistan, Ukraine, Uzbekistan; Middle East = Bahrain, Iraq, Iran, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, Syria, United Arab Emirates,Yemen; India with neighbors = Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, Sri Lanka; East Asia = Brunei, Burma, Cambodia, China, Hong Kong, Indonesia, Japan, Laos, Malaysia, Mongolia, North Korea, Philippines, South Korea, Singapore,Taiwan,Thailand,Tibet,Vietnam; Australia, New Zealand, and the Pacific = American Samoa, Australia, Cook Islands, Fiji, French Polynesia, Guam, Kiribati, Marshall Islands, Micronesia, Nauru, New Caledonia, New Zealand, Niue, Palau, Papua New Guinea, Samoa,Tokelau,Tonga,Tuvalu,Vanuatu,Wallis and Futuna; North Africa = Algeria, Egypt, Libya, Morocco, Tunisia;West Africa = Benin, Burkina Faso, Cape Verde, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, Mali, Mauritania, Senegal, Sierra Leone, The Gambia,Togo; East Africa = Burundi, Djibouti, Eritrea, Ethiopia, Kenya, Rwanda, Seychelles, Somalia, Sudan,Tanzania, Uganda; Central Africa = Congo (Brazzaville), Cameroon, Central African Republic, Chad, Equatorial Guinea, Gabon, Niger, Nigeria, Democratic Republic of the Congo, São Tomé and Principe; Southern Africa = Angola, Botswana, Lesotho, Madagascar, Malawi, Mauritius, Mozambique, Namibia, South Africa, Zambia, Zimbabwe; North America = Canada, United States; Central America = Belize, Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama; Caribbean = Antigua and Barbuda, Bahamas, Barbados, Bermuda, Cayman Islands, Cuba, Dominica, Dominican Republic, Grenada,The Grenadines, Guadeloupe, Jamaica, Haiti, Martinique, Netherlands Antilles, Puerto Rico, Saint Kitts-Nevis, Saint Lucia, Saint Vincent,Trinidad and Tobago,Virgin Islands; South America = Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Honduras, Paraguay, Peru, Suriname, Uruguay, Venezuela. ‡ Includes 77 outbreak cases from Turkey during the second half of 1999. References
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