An outbreak of Cryptosporidium hominis infection at an Illinois recreational waterpark

Division of Parasitic Diseases, National Center of Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA.
Epidemiology and Infection (Impact Factor: 2.54). 03/2006; 134(1):147-56. DOI: 10.1017/S0950268805004619
Source: PubMed


Cryptosporidium has become increasingly recognized as a pathogen responsible for outbreaks of diarrhoeal illness in both immunocompetent and immunocompromised persons. In August 2001, an Illinois hospital reported a cryptosporidiosis cluster potentially linked to a local waterpark. There were 358 case-patients identified. We conducted community-based and waterpark-based case-control studies to examine potential sources of the outbreak. We collected stool specimens from ill persons and pool water samples for microscopy and molecular analysis. Laboratory-confirmed case-patients (n=77) were more likely to have attended the waterpark [odds ratio (OR) 16.0, 95% confidence interval (CI) 3.8-66.8], had pool water in the mouth (OR 6.0, 95% CI 1.3-26.8), and swallowed pool water (OR 4.5, 95% CI 1.5-13.3) than age-matched controls. Cryptosporidium was found in stool specimens and pool water samples. The chlorine resistance of oocysts, frequent swimming exposures, high bather densities, heavy usage by diaper-aged children, and increased recognition and reporting of outbreaks are likely to have contributed to the increasing trend in number of swimming pool-associated outbreaks of cryptosporidiosis. Recommendations for disease prevention include alteration of pool design to separate toddler pool filtration systems from other pools. Implementation of education programmes could reduce the risk of faecal contamination and disease transmission.

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    • "Cryptosporidium has been recognized as the most frequent cause of recreational water-associated outbreaks of gastroenteritis, including treated and disinfected venues (CDC, 2007). Causer et al. (2006) reported an outbreak of Cryptosporidium infection at an Illinois recreational waterpark in 2001. From 13 August to 30 September a total of 358 cases were identified (281 clinical cases and 77 laboratory-confirmed), 77.9% of them were children (those less than 18 years old). "
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    • "C. hominis would be more prevalent in urban settings , a result of wastewater effluents, leaking sewage pipes or sanitary sewer overflows, or direct human fecal contamination of recreational waters (Peng et al. 1997; Carey et al. 2004; Gennaccaro et al. 2003). This pathogen has been implicated in many outbreaks of swimming-related outbreaks of cryptosporidiosis (Causer et al. 2006; Centers for Disease Control and Prevention 2007). Because not all infections with Cryptosporidium lead to apparent illness or symptoms, it is possible for infected persons to transmit these pathogens to others, namely household members and other recreationists via contact (Peng et al. 1997; Frost et al. 2004). "
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