[Show abstract][Hide abstract] ABSTRACT: SUMMARY US cholera surveillance offers insight into global and domestic trends. Between 2001 and 2011, 111 cases were reported to the Centers for Disease Control and Prevention. Cholera was associated with international travel in 90 (81%) patients and was domestically acquired in 20 (18%) patients; for one patient, information was not available. From January 2001 to October 2010, the 42 (47%) travel-associated cases were associated with travel to Asia. In October 2010, a cholera epidemic started in Haiti, soon spreading to the Dominican Republic (Hispaniola). From then to December 2011, 40 (83%) of the 48 travel-associated cases were associated with travel to Hispaniola. Of 20 patients who acquired cholera domestically, 17 (85%) reported seafood consumption; 10 (59%) ate seafood from the US Gulf Coast. In summary, an increase in travel-associated US cholera cases was associated with epidemic cholera in Hispaniola in 2010-2011. Travel to Asia and consumption of Gulf Coast seafood remained important sources of US cholera cases.
Epidemiology and Infection 05/2014; 143(04):1-9. DOI:10.1017/S0950268814001186 · 2.54 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In July–August 2009, eight patients with bloody diarrhea complicated by hemolytic uremic syndrome (HUS) were admitted to hospitals in Tbilisi, Georgia. We started active surveillance in two regions for bloody diarrhea and post-diarrheal HUS. Of 25 case-patients who developed HUS, including the initial 8 cases, half were ⩾15 years old, 67% were female and seven (28%) died. No common exposures were identified. Among 20 HUS case-patients tested, Shiga toxin was detected in the stools of 2 patients (one with elevated serum IgG titers to several Escherichia coli serogroups, including O111 and O104). Among 56 persons with only bloody diarrhea, we isolated Shiga toxin-producing E. coli (STEC) O104:H4 from 2 and Shigella from 10; 2 had serologic evidence of E. coli O26 infection. These cases may indicate a previously unrecognized burden of HUS in Georgia. We recommend national reporting of HUS and improving STEC detection capacity.
Journal of Epidemiology and Global Health 04/2014; 4(4). DOI:10.1016/j.jegh.2014.03.004
[Show abstract][Hide abstract] ABSTRACT: To assess the spectrum of illness from toxigenic Vibrio cholerae O1 and risk factors for severe cholera in Haiti, we conducted a cross-sectional survey in a rural commune with more than 21,000 residents. During March 22-April 6, 2011, we interviewed 2,622 residents ≥ 2 years of age and tested serum specimens from 2,527 (96%) participants for vibriocidal and antibodies against cholera toxin; 18% of participants reported a cholera diagnosis, 39% had vibriocidal titers ≥ 320, and 64% had vibriocidal titers ≥ 80, suggesting widespread infection. Among seropositive participants (vibriocidal titers ≥ 320), 74.5% reported no diarrhea and 9.0% had severe cholera (reported receiving intravenous fluids and overnight hospitalization). This high burden of severe cholera is likely explained by the lack of pre-existing immunity in this population, although the virulence of the atypical El Tor strain causing the epidemic and other factors might also play a role.
The American journal of tropical medicine and hygiene 10/2013; 89(4):654-664. DOI:10.4269/ajtmh.13-0208 · 2.70 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: An outbreak of cholera began in Haiti in October of 2010. To understand the progression of epidemic cholera in Haiti, in April of 2012, we initiated laboratory-enhanced surveillance for diarrheal disease in four Haitian hospitals in three departments. At each site, we sampled up to 10 hospitalized patients each week with acute watery diarrhea. We tested 1,616 specimens collected from April 2, 2012 to March 28, 2013; 1,030 (63.7%) specimens yielded Vibrio cholerae, 13 (0.8%) specimens yielded Shigella, 6 (0.4%) specimens yielded Salmonella, and 63 (3.9%) specimens tested positive for rotavirus. Additionally, 13.5% of children < 5 years old tested positive for rotavirus. Of 1,030 V. cholerae isolates, 1,020 (99.0%) isolates were serotype Ogawa, 9 (0.9%) isolates were serotype Inaba, and 1 isolate was non-toxigenic V. cholerae O139. During 1 year of surveillance, toxigenic cholera continued to be the main cause of acute diarrhea in hospitalized patients, and rotavirus was an important cause of diarrhea-related hospitalizations in children.
The American journal of tropical medicine and hygiene 10/2013; 89(4):641-646. DOI:10.4269/ajtmh.13-0307 · 2.70 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: SUMMARY In June 2011, a cluster of suspected cases of Guillain-Barré syndrome (GBS), which can follow Campylobacter jejuni infection, was identified in San Luis Río Colorado (SLRC), Sonora, Mexico and Yuma County, Arizona, USA. An outbreak investigation identified 26 patients (18 from Sonora, eight from Arizona) with onset of GBS 4 May-21 July 2011, exceeding the expected number of cases (n = 1-2). Twenty-one (81%) patients reported antecedent diarrhoea, and 61% of 18 patients tested were seropositive for C. jejuni IgM antibodies. In a case-control study matched on age group, sex, ethnicity, and neighbourhood of residence, all Arizona GBS patients travelled to SLRC during the exposure period vs. 45% of matched controls (matched odds ratio 8·1, 95% confidence interval 1·5-∞). Exposure information and an environmental assessment suggested that GBS cases resulted from a large outbreak of C. jejuni infection from inadequately disinfected tap water in SLRC. Binational collaboration was essential in investigating this cross-border GBS outbreak, the first in mainland North America since 1976.
Epidemiology and Infection 08/2013; 142(5):1-11. DOI:10.1017/S0950268813001908 · 2.54 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The bacterium Salmonella enterica serovar Typhi causes typhoid fever, which is typically associated with fever and abdominal pain. An outbreak of typhoid fever in Malawi-Mozambique in 2009 was notable for a high proportion of neurologic illness.
Describe neurologic features complicating typhoid fever during an outbreak in Malawi-Mozambique
Persons meeting a clinical case definition were identified through surveillance, with laboratory confirmation of typhoid by antibody testing or blood/stool culture. We gathered demographic and clinical information, examined patients, and evaluated a subset of patients 11 months after onset. A sample of persons with and without neurologic signs was tested for vitamin B6 and B12 levels and urinary thiocyanate.
Between March - November 2009, 303 cases of typhoid fever were identified. Forty (13%) persons had objective neurologic findings, including 14 confirmed by culture/serology; 27 (68%) were hospitalized, and 5 (13%) died. Seventeen (43%) had a constellation of upper motor neuron findings, including hyperreflexia, spasticity, or sustained ankle clonus. Other neurologic features included ataxia (22, 55%), parkinsonism (8, 20%), and tremors (4, 10%). Brain MRI of 3 (ages 5, 7, and 18 years) demonstrated cerebral atrophy but no other abnormalities. Of 13 patients re-evaluated 11 months later, 11 recovered completely, and 2 had persistent hyperreflexia and ataxia. Vitamin B6 levels were markedly low in typhoid fever patients both with and without neurologic signs.
Neurologic signs may complicate typhoid fever, and the diagnosis should be considered in persons with acute febrile neurologic illness in endemic areas.
PLoS ONE 12/2012; 7(12):e46099. DOI:10.1371/journal.pone.0046099 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: An international multilaboratory collaborative study was conducted to develop standard media and consensus methods for the performance and quality control of antimicrobial susceptibility testing of Mycoplasma pneumoniae, Mycoplasma hominis, and Ureaplasma urealyticum using broth microdilution and agar dilution techniques. A reference strain from the American Type Culture Collection was designated for each species, which was to be used for quality control purposes. Repeat testing of replicate samples of each reference strain by participating laboratories utilizing both methods and different lots of media enabled a 3- to 4-dilution MIC range to be established for drugs in several different classes, including tetracyclines, macrolides, ketolides, lincosamides, and fluoroquinolones. This represents the first multilaboratory collaboration to standardize susceptibility testing methods and to designate quality control parameters to ensure accurate and reliable assay results for mycoplasmas and ureaplasmas that infect humans.
[Show abstract][Hide abstract] ABSTRACT: OBJECTIVE To describe pathogens identified through routine clinical practice and factors associated with identifying Shiga toxin-producing Escherichia coli (STEC) infection in patients with postdiarrheal hemolytic uremic syndrome (D+HUS). DESIGN Population-based active surveillance. SETTING Hospitals in the FoodNet surveillance areas from 2000 through 2010. PARTICIPANTS Children younger than 18 years with D+HUS. MAIN EXPOSURES Testing for STEC and demographic and clinical characteristics. MAIN OUTCOME MEASURES Percentage of patients with evidence of infection with likely HUS-causing agents and associations between exposures and evidence of STEC infection. RESULTS Of 617 patients, 436 (70.7%) had evidence of infection with likely HUS-causing agents: STEC O157 (401 patients), non-O157 STEC (21 patients), O157 and non-O157 STEC (1 patient), Streptococcus pneumoniae (11 patients), and other pathogens (2 patients). Among patients without microbiological evidence of STEC, 76.9% of those tested had serologic evidence of STEC infection. Children more likely to have evidence of STEC infections included those patients tested for STEC less than 4 days after diarrhea onset, 12 months or older (71.6% vs 27.8% if <12 months of age), with infections as part of an outbreak (94.3% vs 67.3%), with bloody diarrhea (77.2% vs 40.4%), with onset during June through September (76.9% vs 60.1%), with a leukocyte count greater than 18 000/μL (to convert to ×109/L, multiply by 0.001) (75.7% vs 65.3%), or with only moderate anemia (hemoglobin >7.0 g/dL [to convert to grams per liter, multiply by 10] or hematocrit greater than 20% [to convert to a proportion of 1, multiply by 0.01]) (75.1% vs 66.3%). However, many of these associations were weaker among children with thorough STEC testing. CONCLUSIONS Early stool collection for E coli O157 culture and Shiga toxin testing of all children with possible bacterial enteric infection will increase detection of STEC strains causing HUS. In the absence of microbiological evidence of STEC, serologic testing should be performed.
[Show abstract][Hide abstract] ABSTRACT: We investigated an outbreak initially attributed to norovirus; however, Clostridium perfringens toxicoinfection was subsequently confirmed. C. perfringens is an underrecognized but frequently observed cause of food-borne disease outbreaks. This investigation illustrates the importance of considering epidemiologic and laboratory data together when evaluating potential etiologic agents that might require unique control measures.
[Show abstract][Hide abstract] ABSTRACT: We report a cluster of severe diarrheal disease caused by Vibrio mimicus infection among four persons who had consumed leftover crayfish the day after a private crayfish boil. Gastrointestinal illness caused by Vibrio mimicus has not been reported previously in Washington State. Three cases were laboratory confirmed by stool culture; using PCR, isolates were found to have ctx genes that encode cholera toxin (CT). Two of the cases were hospitalized under intensive care with a cholera-like illness. The illnesses were most likely caused by cross-contamination of cooked crayfish with uncooked crayfish; however, V. mimicus was not isolated nor were CT genes detected by PCR in leftover samples of frozen crayfish. Clinicians should be aware that V. mimicus can produce CT and that V. mimicus infection can cause severe illness.
[Show abstract][Hide abstract] ABSTRACT: Salmonella enterica serovar Typhi (Salmonella Typhi) causes an estimated 22 million typhoid fever cases and 216 000 deaths annually worldwide. In Africa, the lack of laboratory diagnostic capacity limits the ability to recognize endemic typhoid fever and to detect outbreaks. We report a large laboratory-confirmed outbreak of typhoid fever in Uganda with a high proportion of intestinal perforations (IPs).
A suspected case of typhoid fever was defined as fever and abdominal pain in a person with either vomiting, diarrhea, constipation, headache, weakness, arthralgia, poor response to antimalarial medications, or IP. From March 4, 2009 to April 17, 2009, specimens for blood and stool cultures and serology were collected from suspected cases. Antimicrobial susceptibility testing and pulsed-field gel electrophoresis (PFGE) were performed on Salmonella Typhi isolates. Surgical specimens from patients with IP were examined. A community survey was conducted to characterize the extent of the outbreak.
From December 27, 2007 to July 30, 2009, 577 cases, 289 hospitalizations, 249 IPs, and 47 deaths from typhoid fever occurred; Salmonella Typhi was isolated from 27 (33%) of 81 patients. Isolates demonstrated multiple PFGE patterns and uniform susceptibility to ciprofloxacin. Surgical specimens from 30 patients were consistent with typhoid fever. Estimated typhoid fever incidence in the community survey was 8092 cases per 100 000 persons.
This typhoid fever outbreak was detected because of an elevated number of IPs. Underreporting of milder illnesses and delayed and inadequate antimicrobial treatment contributed to the high perforation rate. Enhancing laboratory capacity for detection is critical to improving typhoid fever control.
[Show abstract][Hide abstract] ABSTRACT: Salmonella enterica serovar Typhi causes an estimated 22 million cases of typhoid fever and 216 000 deaths annually worldwide. We investigated an outbreak of unexplained febrile illnesses with neurologic findings, determined to be typhoid fever, along the Malawi-Mozambique border.
The investigation included active surveillance, interviews, examinations of ill and convalescent persons, medical chart reviews, and laboratory testing. Classification as a suspected case required fever and ≥1 other finding (eg, headache or abdominal pain); a probable case required fever and a positive rapid immunoglobulin M antibody test for typhoid (TUBEX TF); a confirmed case required isolation of Salmonella Typhi from blood or stool. Isolates underwent antimicrobial susceptibility testing and subtyping by pulsed-field gel electrophoresis (PFGE).
We identified 303 cases from 18 villages with onset during March-November 2009; 214 were suspected, 43 were probable, and 46 were confirmed cases. Forty patients presented with focal neurologic abnormalities, including a constellation of upper motor neuron signs (n = 19), ataxia (n = 22), and parkinsonism (n = 8). Eleven patients died. All 42 isolates tested were resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole; 4 were also resistant to nalidixic acid. Thirty-five of 42 isolates were indistinguishable by PFGE.
The unusual neurologic manifestations posed a diagnostic challenge that was resolved through rapid typhoid antibody testing in the field and subsequent blood culture confirmation in the Malawi national reference laboratory. Extending laboratory diagnostic capacity, including blood culture, to populations at risk for typhoid fever in Africa will improve outbreak detection, response, and clinical treatment.
[Show abstract][Hide abstract] ABSTRACT: In October 2010, the US Centers for Disease Control and Prevention received reports of cases of severe watery diarrhea in Haiti. The cause was confirmed to be toxigenic Vibrio cholerae, serogroup O1, serotype Ogawa, biotype El Tor. We characterized 122 isolates from Haiti and compared them with isolates from other countries. Antimicrobial drug susceptibility was tested by disk diffusion and broth microdilution. Analyses included identification of rstR and VC2346 genes, sequencing of ctxAB and tcpA genes, and pulsed-field gel electrophoresis with SfiI and NotI enzymes. All isolates were susceptible to doxycycline and azithromycin. One pulsed-field gel electrophoresis pattern predominated, and ctxB sequence of all isolates matched the B-7 allele. We identified the tcpETCIRS allele, which is also present in Bangladesh strain CIRS 101. These data show that the isolates from Haiti are clonally and genetically similar to isolates originating in Africa and southern Asia and that ctxB-7 and tcpET(CIRS) alleles are undergoing global dissemination.
[Show abstract][Hide abstract] ABSTRACT: Cholera was absent from the island of Hispaniola at least a century before an outbreak that began in Haiti in the fall of 2010. Pulsed-field gel electrophoresis (PFGE) analysis of clinical isolates from the Haiti outbreak and recent global travelers returning to the United States showed indistinguishable PFGE fingerprints. To better explore the genetic ancestry of the Haiti outbreak strain, we acquired 23 whole-genome Vibrio
cholerae sequences: 9 isolates obtained in Haiti or the Dominican Republic, 12 PFGE pattern-matched isolates linked to Asia or Africa, and 2 nonmatched outliers from the Western Hemisphere. Phylogenies for whole-genome sequences and core genome single-nucleotide polymorphisms showed that the Haiti outbreak strain is genetically related to strains originating in India and Cameroon. However, because no identical genetic match was found among sequenced contemporary isolates, a definitive genetic origin for the outbreak in Haiti remains speculative.
[Show abstract][Hide abstract] ABSTRACT: Cholera is rare in the United States (annual average 6 cases). Since epidemic cholera began in Hispaniola in 2010, a total of 23 cholera cases caused by toxigenic Vibrio cholerae O1 have been confirmed in the United States. Twenty-two case-patients reported travel to Hispaniola and 1 reported consumption of seafood from Haiti.
[Show abstract][Hide abstract] ABSTRACT: Although pneumonia is a leading cause of death from infectious disease worldwide, comprehensive information about its causes and incidence in low- and middle-income countries is lacking. Active surveillance of hospitalized patients with pneumonia is ongoing in Thailand. Consenting patients are tested for seven bacterial and 14 viral respiratory pathogens by PCR and viral culture on nasopharyngeal swab specimens, serology on acute/convalescent sera, sputum smears and antigen detection tests on urine. Between September 2003 and December 2005, there were 1730 episodes of radiographically confirmed pneumonia (34·6% in children aged <5 years); 66 patients (3·8%) died. A recognized pathogen was identified in 42·5% of episodes. Respiratory syncytial virus (RSV) infection was associated with 16·7% of all pneumonias, 41·2% in children. The viral pathogen with the highest incidence in children aged <5 years was RSV (417·1/100,000 per year) and in persons aged ≥50 years, influenza virus A (38·8/100,000 per year). These data can help guide health policy towards effective prevention strategies.
Epidemiology and Infection 03/2010; 138(12):1811-22. DOI:10.1017/S0950268810000646 · 2.54 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Mycoplasmas are a class of fascinating wall-less bacteria that cause disease in humans, animals, and plants. They include
species recognized as among the smallest known free-living cells. These microbes have very small genomes and unique genetic
features. Their temporary classification as viruses and fastidious growth requirements set the stage early for the use of
diagnostic techniques better suited to viral detection and for the well-known difficulties of diagnosing infections in the
clinical laboratory. Systemic infections are well known in both immunocompetent and immunocompromised patients, but the host
and bacterial factors that allow invasion from epithelial colonization sites are poorly understood. The focus of this chapter
will be respiratory and extrapulmonary infections caused by Mycoplasma pneumoniae and genitourinary tract infections caused by M. hominis, M. genitalium, and Ureaplasma species. Some less common mycoplasma infections will also be addressed.
[Show abstract][Hide abstract] ABSTRACT: Background: Hemolytic uremic syndrome (HUS) is a leading cause of acute renal failure in children, with a mortality rate of 5%. Most HUS cases follow diarrheal illness caused by Shiga toxin-producing Escherichia coli (STEC), primarily STEC O157. HUS is often diagnosed when STEC may no longer be detectable in stool. We evaluated the contribution of serologic testing in HUS cases. Methods: FoodNet conducts population-based active surveillance for STEC infections and HUS. Sites are encouraged to submit sera from HUS patients to test for STEC O157 antibodies. Results:
During 2000-2005, 315 pediatric HUS cases were reported. The median age was 3.6 years; 56% were girls. STEC O157 was isolated from the stool of 177 (56%) children. Of 133 culture-negative children, only 44 (33%) had sera tested but 24 (55%) had antibodies to STEC O157. Children with only positive serology (n=24) were older (4.6 versus 3.5 years), reported bloody diarrhea less frequently (67% versus 95%), and had more days between diarrhea onset and stool culture (7.5 versus 3), than those with only positive culture (n=172). Additionally, a larger proportion of seropositive children received antibiotics for diarrhea (42% versus 27%). Conclusions:
Serologic testing increased the proportion of HUS cases attributable to STEC by 8% (24 cases). Children with STEC infection identified by serology alone were slightly older, less likely to report bloody diarrhea, were cultured later, and more frequently received antibiotics. Culture-negative children without serologic testing represent a lost opportunity for diagnosis.
Infectious Diseases Society of America 2008 Annual Meeting; 10/2008
[Show abstract][Hide abstract] ABSTRACT: The ResPlex I assay (Qiagen) was designed to amplify and detect DNA of six bacterial respiratory pathogens. This assay was
compared with real-time PCR assays based upon the same target sequences for the ability detect the target bacteria by use
of both stock strains and specimens from respiratory disease patients. The ResPlex I assay is somewhat less sensitive than
real-time PCR assays but offers the advantage of multiple assays in a single reaction.