BACKGROUND: More than 11 million children and adults attend over 12,000 camps in the United States annually. Factors such as primitive infrastructure, close quarters, and minimal health education can facilitate acute gastroenteritis (AGE) outbreaks. We analyzed data on AGE outbreaks at youth camps to evaluate the frequency, etiologies, and outcomes of these outbreaks.
METHODS: We obtained data on youth camp AGE outbreaks resulting from foodborne, waterborne, animal contact, person-to-person, environmental, or unknown modes of transmission, that occurred during January 2009-December 2013 and were reported to CDC through the National Outbreak Reporting System (NORS). To further understand the sources of these outbreaks and control measures, we conducted a systematic literature search for publications through June 2015 that reported AGE outbreaks at United States youth camps. Two independent reviewers abstracted data on outbreak characteristics. NORS and literature review data were compiled for descriptive analysis.
RESULTS: A total of 103 camp-associated outbreaks were reported to NORS by 29 states for 2009–2013, with 24 outbreaks (23%) involving campers from multiple states. Almost half of the outbreaks (50, 49%) were reported as resulting from person-to-person transmission; 23 outbreaks (22%) from foodborne transmission, 13 (13%) from waterborne transmission, 13 (13%) from an unknown transmission mode, and 4 (4%) from animal contact. Seventy-eight (76%) outbreaks had at least one suspected or confirmed etiology, among which norovirus (43 outbreaks, 55%), Cryptosporidium spp. (16, 21%), and Escherichia coli (11, 14%) were most frequently implicated. These outbreaks occurred over a median of 6 (range: 1–89) days, with a median of 21 (range: 2–350) cases. Among those for whom data were reported, 258 case-patients sought healthcare (12.0 visits/100 case-patients), 93 visited an emergency department (4.5 visits/100 case-patients), and 37 were hospitalized (1.4 hospitalizations/100 case-patients). Our literature search yielded 20 publications detailing 24 additional camp-associated outbreaks from 15 states, occurring during 1938–2009. Most of these outbreaks (20, 83%) implicated a suspected source; however, only half (12) detailed specific measures implemented during the outbreak to control further transmission. These measures included thoroughly disinfecting surfaces, installing handwashing stations, educating campers on proper handwashing, cohorting of ill individuals, and educating counselors about food handling.
CONCLUSIONS: AGE outbreaks occur at youth camps throughout the United States and are caused by a wide variety of infectious agents and toxins. Preventive education, particularly focusing on appropriate hygiene and proper cooking and handling of food, could help decrease the frequency and spread of such outbreaks.