ABSTRACT
We investigated an outbreak of non-O157 Shiga toxin-producing Escherichia coli at a high school in Minnesota, USA, in November 2010. Consuming undercooked venison and not washing hands after handling raw venison were associated with illness. E. coli O103:H2 and non-Shiga toxin-producing E. coli O145:NM were isolated from ill students and venison.
Subject(s)
Disease Outbreaks , Escherichia coli Infections/epidemiology , Foodborne Diseases/epidemiology , Meat/poisoning , Shiga-Toxigenic Escherichia coli/classification , Adolescent , Animals , Case-Control Studies , Deer , Diarrhea/microbiology , Escherichia coli Infections/microbiology , Female , Foodborne Diseases/microbiology , Humans , Male , Meat/microbiology , Minnesota/epidemiology , Serotyping , Shiga Toxin/genetics , Shiga-Toxigenic Escherichia coli/geneticsABSTRACT
We evaluated the positive predictive value (PPV) of rapid assays used by clinical laboratories in Minnesota to diagnose cryptosporidiosis. The overall PPV was 56% for rapid assays versus 97% for nonrapid assays; clinicians and laboratorians need to be aware of the low PPV of rapid assays when diagnosing cryptosporidiosis.
Subject(s)
Clinical Laboratory Techniques/methods , Cryptosporidiosis/diagnosis , Humans , Minnesota , Predictive Value of TestsABSTRACT
BACKGROUND: Escherichia coli O157:H7 (O157) is the Shiga toxin-producing E. coli (STEC) serotype most frequently isolated and most often associated with hemolytic uremic syndrome (HUS) in the United States. Non-O157 STEC serotypes can also cause serious illness, but their impact as pathogens remains undefined. We compared characteristics of non-O157 and O157 STEC infections identified through sentinel surveillance. METHODS: Sentinel sites included a metropolitan health maintenance organization laboratory and a hospital laboratory serving a small city and rural area. We received sorbitol-MacConkey agar plates from every stool culture performed at both sites during 2000-2006. Colony sweeps were screened for stx1 and stx2 by polymerase chain reaction. E. coli identity, serotype, and presence of stx1 and/or stx2 were confirmed on individual isolates. RESULTS: Two hundred six STEC isolates were identified: 108 (52%) were non-O157 serotypes, and 98 (48%) were O157. Of non-O157 cases, 54% involved bloody diarrhea, and 8% involved hospitalization. Non-O157 isolates with at least stx2 were not more likely to cause severe illness (bloody diarrhea, hospitalization, or HUS) than were non-O157 isolates with only stx1. O157 cases were more likely than non-O157 cases to involve bloody diarrhea (78% vs 54%; P < .001), hospitalization (34% vs 8%; P < .001 and HUS (7% vs 0%; P = .005). When including only isolates with at least stx2, O157 cases were still more likely to involve bloody diarrhea (78% vs 56%; P = .02) and hospitalization (33% vs 12%; P = .01) than non-O157 cases. CONCLUSIONS: Differences in severity among STEC infections could not be explained by stx2, suggesting that additional factors are important in STEC virulence.
Subject(s)
Escherichia coli Infections/microbiology , Escherichia coli Infections/pathology , Shiga-Toxigenic Escherichia coli/isolation & purification , Shiga-Toxigenic Escherichia coli/pathogenicity , Adolescent , Adult , Aged , Aged, 80 and over , Animals , Child , Child, Preschool , Escherichia coli Infections/epidemiology , Escherichia coli O157/isolation & purification , Escherichia coli O157/pathogenicity , Escherichia coli Proteins/genetics , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Minnesota/epidemiology , Serotyping , Shiga Toxin 1/genetics , Shiga Toxin 2/genetics , Shiga-Toxigenic Escherichia coli/classification , Young AdultABSTRACT
BACKGROUND: Transmission of enteric pathogens at venues where the public contacts farm animals is a growing problem, particularly among children. In 2000 and again in 2001, enteric illness outbreaks caused by multiple pathogens occurred at a farm day camp for children in Minnesota. METHODS: Camp attendees were interviewed about illness history and potential exposures each year. Stool samples from children and calves at the camp were tested for enteric pathogens. RESULTS: Eighty-four illnesses were documented among camp attendees in the 2 outbreaks; laboratory-confirmed infections included Cryptosporidium parvum (17 cases), Escherichia coli O157:H7 (4), non-O157 Shiga toxin-producing E. coli (STEC) (7) and Salmonella enterica serotype Typhimurium and Campylobacter jejuni (1 each). Kindergarten-fourth grade children provided 1-on-1 care for a bottle-fed calf. Sixty of 83 calves tested carried at least 1 pathogen, including Giardia spp. (26 calves), C. parvum (25), non-O157 STEC (17), Campylobacter spp. (11), 3 serotypes of Salmonella enterica (10) and E. coli O157:H7 (2). Risk factors among children included caring for an ill calf and getting visible manure on their hands. Always washing hands with soap after touching a calf and washing hands before going home were protective. Prevention measures implemented in 2000 failed to prevent the second outbreak. CONCLUSIONS: Calves were the reservoir of multiple enteric pathogens for children at a farm day camp. Health care providers should consider numerous zoonotic pathogens in patients presenting with gastroenteritis after contact with cattle. Public health officials should help venue operators prospectively implement published guidelines to prevent zoonotic disease transmission.
