[Show abstract][Hide abstract] ABSTRACT: Background:
Studies in the literature have indicated that the timing of seasonal influenza epidemic varies across latitude, suggesting the involvement of meteorological and environmental conditions in the transmission of influenza. In this study, we investigated the link between meteorological parameters and influenza activity in 9 sub-national areas with temperate and subtropical climates: Berlin (Germany), Ljubljana (Slovenia), Castile and León (Spain) and all 6 districts in Israel.
We estimated weekly influenza-associated influenza-like-illness (ILI) or Acute Respiratory Infection (ARI) incidence to represent influenza activity using data from each country's sentinel surveillance during 2000-2011 (Spain) and 2006-2011 (all others). Meteorological data was obtained from ground stations, satellite and assimilated data. Two generalized additive models (GAM) were developed, with one using specific humidity as a covariate and another using minimum temperature. Precipitation and solar radiation were included as additional covariates in both models. The models were adjusted for previous weeks' influenza activity, and were trained separately for each study location.
Influenza activity was inversely associated (p<0.05) with specific humidity in all locations. Minimum temperature was inversely associated with influenza in all 3 temperate locations, but not in all subtropical locations. Inverse associations between influenza and solar radiation were found in most locations. Associations with precipitation were location-dependent and inconclusive. We used the models to estimate influenza activity a week ahead for the 2010/2011 period which was not used in training the models. With exception of Ljubljana and Israel's Haifa District, the models could closely follow the observed data especially during the start and the end of epidemic period. In these locations, correlation coefficients between the observed and estimated ranged between 0.55 to 0.91and the model-estimated influenza peaks were within 3 weeks from the observations.
Our study demonstrated the significant link between specific humidity and influenza activity across temperate and subtropical climates, and that inclusion of meteorological parameters in the surveillance system may further our understanding of influenza transmission patterns.
PLoS ONE 08/2015; 10(8):e0134701. DOI:10.1371/journal.pone.0134701 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We used physician sentinel surveillance to identify 25 (7.7%) mild to severe infections with enterovirus D68 (EV-D68) in children and adults among 325 outpatients with acute respiratory infections in Germany during August-October 2014. Results suggested low-level circulation of enterovirus D68 in Germany. Viruses were characterized by sequencing viral protein (VP) 1 and VP4/VP2 genomic regions.
[Show abstract][Hide abstract] ABSTRACT: The influenza season 2014/15 started in Europe in week 50 2014 with influenza A(H3N2) viruses predominating. The majority of the A(H3N2) viruses characterised antigenically and/or genetically differ from the northern hemisphere vaccine component which may result in reduced vaccine effectiveness for the season. We therefore anticipate that this season may be more severe than the 2013/14 season. Treating influenza with antivirals in addition to prevention with vaccination will be important.
Eurosurveillance: bulletin europeen sur les maladies transmissibles = European communicable disease bulletin 01/2015; 20(4):1-5. · 5.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In March 2011, the German sentinel surveillance system for influenza (Arbeitsgemeinschaft Influenza (AGI)) was complemented by an Internet-based syndromic monitoring system (GrippeWeb) for acute respiratory infections (ARI) and influenza-like-illness (ILI). To assess representativeness of GrippeWeb participants, key demographic variables and lifetime prevalence of asthma and diabetes were compared with data from the general population of Germany. To 'validate' GrippeWeb, we compared weekly ARI and medically attended ARI (MAARI) rates, generated between weeks 35/2011 and 34/2012, with AGI MAARI rates and overlaid GrippeWeb ILI rates with the number of positive influenza samples obtained by the AGI. GrippeWeb had high weekly participation rates (62% of participants reported in ≥90% of possible weeks). Although it varied by age group, participants reported a mean of between 1.3 and 6.0 ARI episodes and between 0.1 and 2.4 ILI episodes during the study year. Estimated GrippeWeb MAARI incidence was very similar to the AGI MAARI incidence and influenza circulation was reflected well in the GrippeWeb ILI rates. GrippeWeb became a reliable monitoring system shortly after implementation, capturing the burden of ARI and ILI at general population level. The high degree of agreement between GrippeWeb's and AGI's MAARI data lends support to the validity of both systems.
Eurosurveillance: bulletin europeen sur les maladies transmissibles = European communicable disease bulletin 01/2014; 19(4). DOI:10.2807/1560-7917.ES2014.19.4.20684 · 5.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background:
In preparation of an influenza pandemic, public health authorities and professional organisations recommend physicians to change practice management for patients with acute respiratory infections (ARI), in order to reduce transmission and protect practice staff. This study evaluates the implementation of these recommendations during the influenza pandemic 2009/10.
In 2010, we sent a standardised paper-and-pencil questionnaire on information sources, practice management, occupational safety and vaccination to physicians participating in the national sentinel syndromic influenza surveillance in Germany. Taken measures were compared according to specialisation of physicians.
Out of 1,150 physicians, 760 replied (66%). The recommendations were considered reasonable by 64%. Physicians used hand disinfection (76%), gloves (62%) and facial masks (52%) more frequently than usual. Overall, 68% changed their practice management during the pandemic. Physicians separated ARI patients spatially (74%) and in time (38%) from others. In 72%, physicians were vaccinated against pandemic influenza. The physicians found time and effort spent on the sentinel appropriate (82%), even during the influenza pandemic. Paediatricians considered the recommendations less practicable than GPs or internists.
The majority of participating physicians considered the recommendations on occupational safety reasonable and changed their practice management accordingly. However, the recommendations might not reflect the special needs of paediatricians.
Das Gesundheitswesen 10/2013; 76(10). DOI:10.1055/s-0033-1355402 · 0.62 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The World Health Organization recommends early antiviral treatment for patients with severe influenza illness or those at increased risk for severe illness.
The aim of this study was to determine the proportion of cases with laboratory-confirmed A(H1N1)pdm09 infection that have been treated with antivirals in Germany during the pandemic (H1N1) 2009 and to investigate factors associated with the use of antivirals.
We analyzed cases with laboratory-confirmed A(H1N1)pdm09 infection notified to national health authorities in Germany between week 29/2009 and week 17/2010 using multivariable logistic regression. Severity of disease was defined by pneumonia or death.
Of 160 804 cases with laboratory-confirmed A(H1N1)pdm09 infection, 22% were treated with antivirals. Cases with severe disease were more likely to be treated with antivirals than cases without severe disease (odds ratio = 1·66; 95% confidence interval: 1·46-1·89). In the group with at least one underlying medical condition, only children aged between 1 and 4 years had significant lower odds for receiving antiviral treatment compared with cases in the age group 15 to 49 years (odds ratio = 0·75; 95% confidence interval: 0·6-0·94). In conclusion, the implementation of international recommendations on use of antivirals differed according to the age of patients in Germany during the pandemic (H1N1) 2009. This indicates that the potential of antivirals to prevent severe influenza might not have been fully exhausted. The reasons leading to the observed differences in patient management need to be investigated.
Influenza and Other Respiratory Viruses 08/2013; 7(6). DOI:10.1111/irv.12152 · 2.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: THE NUMBER OF PATIENTS SEEKING HEALTH CARE IS A CENTRAL INDICATOR THAT MAY SERVE SEVERAL DIFFERENT PURPOSES: (1) as a proxy for the impact on the burden of the primary care system; (2) as a starting point to estimate the number of persons ill with influenza; (3) as the denominator data for the calculation of case fatality rate and the proportion hospitalized (severity indicators); (4) for economic calculations. In addition, reliable estimates of burden of disease and on the health care system are essential to communicate the impact of influenza to health care professionals, public health professionals and to the public.
Using German syndromic surveillance data, we have developed a novel approach to describe the seasonal variation of medically attended acute respiratory infections (MAARI) and estimate the excess MAARI attributable to influenza. The weekly excess inside a period of influenza circulation is estimated as the difference between the actual MAARI and a MAARI-baseline, which is established using a cyclic regression model for counts. As a result, we estimated the highest ARI burden within the last 10 years for the influenza season 2004/05 with an excess of 7.5 million outpatient visits (CI95% 6.8-8.0). In contrast, the pandemic wave 2009 accounted for one third of this burden with an excess of 2.4 million (CI95% 1.9-2.8). Estimates can be produced for different age groups, different geographic regions in Germany and also in real time during the influenza waves.
PLoS ONE 07/2013; 8(7):e64593. DOI:10.1371/journal.pone.0064593 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: On 24 October 2012, a patient with acute respiratory distress syndrome of unknown origin and symptom onset on 5 October was transferred from Qatar to a specialist lung clinic in Germany. Late diagnosis on 20 November of an infection with the novel Coronavirus (NCoV) resulted in potential exposure of a considerable number of healthcare workers. Using a questionnaire we asked 123 identified contacts (120 hospital and three out-of-hospital contacts) about exposure to the patient. Eighty-five contacts provided blood for a serological test using a two-stage approach with an initial immunofluorescence assay as screening test, followed by recombinant immunofluorescence assays and a NCoV-specific serum neutralisation test. Of 123 identified contacts nine had performed aerosol-generating procedures within the third or fourth week of illness, using personal protective equipment rarely or never, and two of these developed acute respiratory illness. Serology was negative for all nine. Further 76 hospital contacts also tested negative, including two sera initially reactive in the screening test. The contact investigation ruled out transmission to contacts after illness day 20. Our two-stage approach for serological testing may be used as a template for similar situations.
Eurosurveillance: bulletin europeen sur les maladies transmissibles = European communicable disease bulletin 03/2013; 18(8). · 5.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Die Arbeitsgemeinschaft Influenza (AGI) ist seit vielen Jahren das wichtigste Instrument zur Influenzaüberwachung in Deutschland. Sie besteht aus einer syndromischen und einer virologischen Komponente. Die Überwachung einer repräsentativen Stichprobe der Bevölkerung ermöglicht es, den Beginn und Verlauf der Influenzawelle zu beobachten sowie die Krankheitslast in der Bevölkerung zu analysieren und zeitnah darüber zu berichten. Kleinere, Influenzavirus-bedingte Ausbrüche sind mit dem AGI-Sentinel jedoch nicht zu erfassen. Zum Erkennen und zur Untersuchung von Ausbrüchen dienen im Rahmen des Infektionsschutzgesetzes (IfSG) übermittelte Daten, die die zweite Säule der Influenzasurveillance darstellen. Wege zum Erkennen von Ausbrüchen basieren entweder auf einem gemeldeten Influenzavirusnachweis und nachfolgenden Ermittlungen des Gesundheitsamtes oder auf der Meldung einer Häufung an respiratorischen Erkrankungen oder nosokomialen Infektionen und nachfolgenden Laboruntersuchungen. Die virologische Diagnostik spielt dabei eine zentrale Rolle. Das galt nicht nur während der Frühphase der A(H1N1)-Pandemie 2009, denn generell ist eine frühzeitige Diagnostik essenziell für das Erkennen von Ausbrüchen. Es ist es wichtig, auch animale Influenzaviren, die wiederholt humane Infektionen verursacht haben, im Blick zu behalten. Dies betrifft vor allem die aviären Influenzaviren der Subtypen H5, H7 und H9 sowie porcine Influenzaviren, für die eine spezifische Diagnostik im Nationalen Referenzzentrum für Influenza (NRZ) etabliert ist. Das gehäufte Auftreten von respiratorischen Erkrankungen nicht nur während, sondern auch außerhalb der Saison, sollte immer Anlass für eine virologische Labordiagnostik sein. Auf Basis dieser Ergebnisse können umfangreiche Untersuchungen eingeleitet werden, um ein optimales Ausbruchsmanagement zu ermöglichen.
[Show abstract][Hide abstract] ABSTRACT: For many years, the Working Group on Influenza (AGI) has been the most important influenza surveillance system in Germany. An average sample of the population is covered by both syndromic and virological surveillance, which provides timely data regarding the onset and course of the influenza wave as well as its burden of disease. However, smaller influenza outbreaks cannot be detected by the AGI sentinel system. This is achieved by the information reported by the mandatory notification system (Protection Against Infection Act, IfSG), which serves as the second pillar of the national influenza surveillance. Approaches to recognize such outbreaks are based either on reported influenza virus detection and subsequent investigations by local health authorities or by notification of an accumulation of respiratory diseases or nosocomial infections and subsequent laboratory investigations. In this context, virological diagnostics plays an essential role. This has been true particularly for the early phase of the 2009 pandemic, but generally timely diagnostics is essential for the identification of outbreaks. Regarding potential future outbreaks, it is also important to keep an eye on animal influenza viruses that have repeatedly infected humans. This mainly concerns avian influenza viruses of the subtypes H5, H7, and H9 as well as porcine influenza viruses for which a specific PCR has been established at the National Influenza Reference Centre. An increased incidence of respiratory infections, both during and outside the season, should always encourage virological laboratory diagnostics to be performed as a prerequisite of further extensive investigations and an optimal outbreak management.
[Show abstract][Hide abstract] ABSTRACT: We conducted a nationwide hospital-based prospective study in Germany of influenza A(H1N1)pdm09 cases among children <15 years of age admitted to pediatric intensive care units and related deaths during the 2009-10 pandemic and the 2010-11 postpandemic influenza seasons. We identified 156 eligible patients: 112 in 2009-10 and 44 in 2010-11. Although a shift to younger patients occurred in 2010-11 (median age 3.2 vs. 5.3 years), infants <1 year of age remained the most affected. Underlying immunosuppression was a risk factor for hospital-acquired infections (p = 0.013), which accounted for 14% of cases. Myocarditis was predictive of death (p = 0.006). Of the 156 case-patients, 17% died; the difference between seasons was not significant (p = 0.473). Our findings stress the challenge of preventing severe postpandemic influenza infection in children and the need to prevent nosocomial transmission of influenza virus, especially in immunosuppressed children.
[Show abstract][Hide abstract] ABSTRACT: Surveillance of severe acute respiratory infections (SARI) in sentinel hospitals is recommended to estimate the burden of severe influenza-cases. Therefore, we monitored patients admitted with respiratory infections (RI) in 9 Berlin hospitals from 7.12.2009 to 12.12.2010 according to different case definitions (CD) and determined the proportion of cases with influenza A(H1N1)pdm09 (pH1N1). We compared the sensitivity and specificity of CD for capturing pandemic pH1N1 cases.
We established an RI-surveillance restricted to adults aged ≤ 65 years within the framework of a pH1N1 vaccine effectiveness study, which required active identification of RI-cases. The hospital information-system was screened daily for newly admitted RI-patients. Nasopharyngeal swabs from consenting patients were tested by PCR for influenza-virus subtypes. Four clinical CD were compared in terms of capturing pH1N1-positives among hospitalized RI-patients by applying sensitivity and specificity analyses. The broadest case definition (CD1) was used for inclusion of RI-cases; the narrowest case definition (CD4) was identical to the SARI case definition recommended by ECDC/WHO.
Over the study period, we identified 1,025 RI-cases, of which 283 (28%) met the ECDC/WHO SARI case definition. The percentage of SARI-cases among internal medicine admissions decreased from 3.2% (calendar-week 50-2009) to 0.2% (week 25-2010). Of 354 patients tested by PCR, 20 (6%) were pH1N1-positive. Two case definitions narrower than CD1 but -in contrast to SARI- not requiring shortness of breath yielded the largest areas under the Receiver-Operator-Curve. Heterogeneity of proportions of patients admitted with RI between hospitals was significant.
Comprehensive surveillance of RI cases was feasible in a network of community hospitals. In most settings, several hospitals should be included to ensure representativeness. Although misclassification resulting from failure to obtain symptoms in the hospital information-system cannot be ruled out, a high proportion of hospitalized PCR-positive pH1N1-patients (45%) did not fulfil the SARI case-definition that included shortness of breath or difficulty breathing. Thus, to assess influenza-related disease burden in hospitals, broader, alternative case definitions should be considered.
BMC Public Health 03/2012; 12(1):245. DOI:10.1186/1471-2458-12-245 · 2.26 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To establish strategic priorities for the German national public health institute (RKI) and guide the institute's mid-term strategic decisions, we prioritized infectious pathogens in accordance with their importance for national surveillance and epidemiological research.
We used the Delphi process with internal (RKI) and external experts and a metric-consensus approach to score pathogens according to ten three-tiered criteria. Additional experts were invited to weight each criterion, leading to the calculation of a median weight by which each score was multiplied. We ranked the pathogens according to the total weighted score and divided them into four priority groups.
127 pathogens were scored. Eighty-six experts participated in the weighting; "Case fatality rate" was rated as the most important criterion. Twenty-six pathogens were ranked in the highest priority group; among those were pathogens with internationally recognised importance (e.g., Human Immunodeficiency Virus, Mycobacterium tuberculosis, Influenza virus, Hepatitis C virus, Neisseria meningitides), pathogens frequently causing large outbreaks (e.g., Campylobacter spp.), and nosocomial pathogens associated with antimicrobial resistance. Other pathogens in the highest priority group included Helicobacter pylori, Respiratory Syncytial Virus, Varicella zoster virus and Hantavirus.
While several pathogens from the highest priority group already have a high profile in national and international health policy documents, high scores for other pathogens (e.g., Helicobacter pylori, Respiratory syncytial virus or Hantavirus) indicate a possible under-recognised importance within the current German public health framework. A process to strengthen respective surveillance systems and research has been started. The prioritization methodology has worked well; its modular structure makes it potentially useful for other settings.
PLoS ONE 10/2011; 6(10):e25691. DOI:10.1371/journal.pone.0025691 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The threat of avian influenza (AI) viruses to humans in Europe in 2005 prompted the Robert Koch Institute to establish a routine monitoring instrument condensing information on all human AI cases worldwide reported from the World Health Organization (WHO) and other sources into a line list for further analysis. The 235 confirmed AI cases captured from September 2006 to August 2010 had a case fatality rate of 56% (132/235), ranging from 28% (27/98) in Egypt to 87% (71/82) in Indonesia. In a multivariable analysis, odds of dying increased by 33% with each day that passed from symptom onset until hospitalisation (OR: 1.33, p=0.002). In relation to children of 0–9 years, odds of fatal outcome were more than six times higher in 10–19 year-olds and 20–29 year-olds (OR: 6.06, 95% CI: 1.89–19.48, p=0.002 and OR: 6.16, 95% CI: 2.05– 18.53, p=0.001, respectively), and nearly five times higher in patients of 30 years and older (OR: 4.71, 95% CI: 1.56–14.27, p=0.006) irrespective of the country, which had notified WHO of the cases. The situation in Egypt was special in that case number and incidence in children were more than twice as high as in any other age group or country. With this study, we show that data from the public domain yield important epidemiological information on the global AI situation. This approach to establish a line list is time-consuming but a line list is a prerequisite to such evaluations. We thus would like to encourage the placing of a publicly accessible line list of anonymised human AI cases, e.g. directly by WHO. This might enhance our understanding of AI in humans and permit the rapid detection of changes in its epidemiology with implications for human health.
Eurosurveillance: bulletin europeen sur les maladies transmissibles = European communicable disease bulletin 08/2011; 16(32). · 5.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: During the autumn wave of the pandemic influenza virus A/(H1N1) 2009 (pIV) the German population was offered an AS03-adjuvanted vaccine. The authors compared results of two methods calculating the effectiveness of the vaccine (VE). The test-negative case-control method used data from virologic surveillance including influenza-positive and negative patients. An innovative case-series methodology explored data from all nationally reported laboratory-confirmed influenza cases. The proportion of reported cases occurring in vaccinees during an assumed unprotected phase after vaccination was compared with that occurring in vaccinees during their assumed protected phase. The test-negative case-control method included 1,749 pIV cases and 2,087 influenza test-negative individuals of whom 6 (0.3%) and 36 (1.7%), respectively, were vaccinated. The case series method included data from 73,280 cases. VE in the two methods was 79% (95% confidence interval (CI) = 35-93%; P = 0.007) and 87% (95% CI = 78-92%; P<0.001) for individuals less than 14 years of age and 70% (95% CI = -45%-94%, P = 0.13) and 74% (95% CI = 64-82%; P<0.001) for individuals above the age of 14. Both methods yielded similar VE in both age groups; and VE for the younger age group seemed to be higher.
PLoS ONE 07/2011; 6(7):e19932. DOI:10.1371/journal.pone.0019932 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Since the start of the 2009 influenza A pandemic (H1N1pdm), the World Health Organization and its member states have gathered information to characterize the clinical severity of H1N1pdm infection and to assist policy makers to determine risk groups for targeted control measures.
Data were collected on approximately 70,000 laboratory-confirmed hospitalized H1N1pdm patients, 9,700 patients admitted to intensive care units (ICUs), and 2,500 deaths reported between 1 April 2009 and 1 January 2010 from 19 countries or administrative regions--Argentina, Australia, Canada, Chile, China, France, Germany, Hong Kong SAR, Japan, Madagascar, Mexico, The Netherlands, New Zealand, Singapore, South Africa, Spain, Thailand, the United States, and the United Kingdom--to characterize and compare the distribution of risk factors among H1N1pdm patients at three levels of severity: hospitalizations, ICU admissions, and deaths. The median age of patients increased with severity of disease. The highest per capita risk of hospitalization was among patients <5 y and 5-14 y (relative risk [RR] = 3.3 and 3.2, respectively, compared to the general population), whereas the highest risk of death per capita was in the age groups 50-64 y and ≥65 y (RR = 1.5 and 1.6, respectively, compared to the general population). Similarly, the ratio of H1N1pdm deaths to hospitalizations increased with age and was the highest in the ≥65-y-old age group, indicating that while infection rates have been observed to be very low in the oldest age group, risk of death in those over the age of 64 y who became infected was higher than in younger groups. The proportion of H1N1pdm patients with one or more reported chronic conditions increased with severity (median = 31.1%, 52.3%, and 61.8% of hospitalized, ICU-admitted, and fatal H1N1pdm cases, respectively). With the exception of the risk factors asthma, pregnancy, and obesity, the proportion of patients with each risk factor increased with severity level. For all levels of severity, pregnant women in their third trimester consistently accounted for the majority of the total of pregnant women. Our findings suggest that morbid obesity might be a risk factor for ICU admission and fatal outcome (RR = 36.3).
Our results demonstrate that risk factors for severe H1N1pdm infection are similar to those for seasonal influenza, with some notable differences, such as younger age groups and obesity, and reinforce the need to identify and protect groups at highest risk of severe outcomes. Please see later in the article for the Editors' Summary.
PLoS Medicine 07/2011; 8(7):e1001053. DOI:10.1371/journal.pmed.1001053 · 14.43 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In order to detect levels of pre-existing cross-reactive antibodies in different age groups and to measure age-specific infection rates of the influenza A (H1N1) 2009 pandemic in Germany, we conducted a seroprevalence study based on samples from an ongoing nationwide representative health survey.
We analysed 845 pre-pandemic samples collected between 25 Nov 2008 and 28 Apr 2009 and 757 post-pandemic samples collected between 12 Jan 2010 and 24 Apr 2010. Reactive antibodies against 2009 pandemic influenza A (H1N1) virus (pH1N1) were detected using a haemagglutination inhibition test (antigen A/California/7/2009). Proportions of samples with antibodies at titre ≥ 40 and geometric mean of the titres (GMT) were calculated and compared among 6 age groups (18-29, 30-39, 40-49, 50-59, 60-69, ≥ 70 years). The highest proportions of cross-reactive antibodies at titre ≥ 40 before the pandemic were observed among 18-29 year olds, 12.5% (95% CI 7.3-19.5%). The highest increase in seroprevalence between pre- and post-pandemic was also observed among 18-29 year olds, 29.9% (95% CI 16.7-43.2%). Effects of sampling period (pre- and post-pandemic), age, sex, and prior influenza immunization on titre were investigated with Tobit regression analysis using three birth cohorts (after 1976, between 1957 and 1976, and before 1957). The GMT increased between the pre- and post-pandemic period by a factor of 10.2 (95% CI 5.0-20.7) in the birth cohort born after 1976, 6.3 (95% CI 3.3-11.9) in those born between 1957 and 1976 and 2.4 (95% CI 1.3-4.3) in those born before 1957.
We demonstrate that infection rates differed among age groups and that the measured pre-pandemic level of cross-reactive antibodies towards pH1N1 did not add information in relation to protection and prediction of the most affected age groups among adults in the pandemic.
PLoS ONE 06/2011; 6(6):e21340. DOI:10.1371/journal.pone.0021340 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The mortality in Germany caused by the 2009 pandemic influenza A(H1N1) seems to have been one of the lowest in Europe. We provide a detailed analysis of all 252 fatal cases of confirmed infection with the pandemic virus notified between 29 April 2009 and 31 March 2010. The overall mortality was 3.1 (95% confidence interval (CI): 2.7 to 3.5) per one million inhabitants. We observed an increase in the case fatality rate of notified cases over time; notified cases aged 60 years or older had the highest case fatality rate (2.16%; 95% CI: 1.61 to 2.83; odds ratio: 5.4; p<0.001; reference group: 35–59 years). The median delay of four days (interquartile range (IQR): 2–7) between symptom onset and antiviral treatment was significantly longer in fatal cases than for non-fatal cases (median: two days (IQR: 1–3; p<0.001). Analysis of the underlying medical conditions of fatal cases, based on the observed frequency of the conditions in the general population, confirms the risk for fatal outcome, which is most notably due to immunosuppression, diabetes and respiratory diseases. Our results suggest that early treatment might have had an impact on overall mortality. Identification of risk groups for targeted intervention to prevent fatalities needs to take into account the distribution of underlying conditions in the population.
Eurosurveillance: bulletin europeen sur les maladies transmissibles = European communicable disease bulletin 12/2010; 15(49). · 5.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of the investigation is the descriptive analysis of case-based information from mandatory notifications in the first year of the influenza pandemic (H1N1) 2009 in order to identify and describe epidemiological characteristics and risk factors for severe outcome. Four distinct time periods were defined to describe the age distribution of hospitalized and fatal cases. In contrast, stratified (age, sex) analysis of risk factors was carried out for the whole time period of pandemic influenza activity (notification weeks 18/2009 to 17/2010). Characteristic differences in the age distribution of reported cases were observed according to the time period. Among the reported risk factors, immunosuppression exhibited the highest probability for hospitalization or a fatal outcome (OR=8.82; CI95% 7.3-10.6 and OR=37.4; CI95% 25.5-54.8, respectively). The stratified analysis showed that this was especially pronounced for patients in the age group 60 years and above. Single case-based notifications of pandemic influenza have proven to be an invaluable source of information for assessing the epidemiological characteristics of the influenza pandemic 2009 in Germany. In addition, it allows comparative analysis of certain risk groups for severe disease. The information, thus, provides an important contribution for further developing and improving of public health recommendations.