RESUMO
AIMS: In October 2023, the Tennessee Department of Health identified an outbreak of Shiga toxin-producing Escherichia coli (STEC) O157:H7 infections among elementary school students who attended school field trips to the same farm animal exhibit. Our aim was to determine STEC source and prevent additional illnesses by initiating epidemiologic, laboratory and environmental investigations. METHODS AND RESULTS: We identified cases using laboratory-based surveillance and by surveying caregivers of children who attended the exhibit. Probable cases were defined as illness with abdominal cramps or diarrhoea after attendance; confirmed cases were laboratory-confirmed STEC infection in an attendee or household contact. A site visit was conducted, and event organizers were interviewed. Human stool, animal faeces and environmental samples were tested for STEC O157:H7 by real-time polymerase chain reaction (PCR), culture and whole-genome sequencing (WGS). Approximately 2300 elementary school students attended the animal exhibit during 2 days. Field trip activities included contact with different farm animal species, drinking pasteurized milk outside animal enclosures and eating lunch in a separate building onsite. We received survey responses from 399 caregivers for 443 (19%) animal exhibit attendees. We identified 9 confirmed and 55 probable cases with illness onset dates during 26 September to 12 October. Seven children aged 1-7 years were hospitalized. Four children aged 1-6 years experienced haemolytic uraemic syndrome; none died. Laboratory testing identified STEC O157:H7 by culture from eight human stool samples with 0-1 allele difference by WGS. Three environmental samples had Shiga toxin (stx 2) genes detected by PCR, but no STEC isolates were recovered by culture. CONCLUSIONS: This is the largest reported STEC O157:H7 outbreak associated with an animal exhibit in Tennessee. We identified opportunities for educating school staff, event organizers and families about zoonotic disease risks associated with animal contact and published prevention measures.
RESUMO
BACKGROUND: The Southern US is confronting bourgeoning HIV and hepatitis C virus (HCV) epidemics among people who inject drugs (PWID), yet little is known about shared and unique risk factors across the region. We applied an intersectional risk environment framework to understand infectious disease outcomes for sub-groups of PWID that experience multiple axes of social marginalization related to racial and ethnic identity and social and economic vulnerability. METHODS: HIV and HCV prevalence was estimated from the first iteration of the CDC's National HIV Behavioral Surveillance respondent driven sample of PWID in Shelby County, Tennessee in 2018. We ran adjusted multinomial models to test main and interaction effects of race/ethnicity and structural factors on the prevalence of a three-level outcome: HIV-only, HCV-only, and no infection. RESULTS: A total of 564 PWID participated, 558 (99%) completed HIV testing, and 540 (96%) HCV testing. Thirty (5%) were HIV-positive, 224 (40%) HCV-positive, and less than 1% were co-infected. Descriptive differences by race/ethnicity and levels of structural vulnerability for HIV and HCV subpopulations were present; however, there was no evidence for statistical interaction. In the final main effects model, HIV status was positively associated with non-Hispanic Black identity (aRR 4.95, 95% CI 1.19, 20.6), whereas HCV status was associated with non-white identity (aRR 0.11 95% CI 0.07, 0.18). Factors associated with HCV infection were higher scores of structural vulnerability (aRR 2.19 95% CI 1.10, 4.35), and criminal legal involvement (aOR 1.99 95% CI 1.18, 3.37). CONCLUSION: This is the first study to implement local population-based survey data to evaluate distinctive intersections of ethnic/racial and social factors associated with HIV and HCV status among PWID in the Memphis region. Findings come at an opportune time as harm reduction programs are in development in the South and shed light to the need for socially equitable race conscious resource investment.