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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    ABSTRACT: Recreational outbreaks associated with sprayparks are well recognized, and may be partly due to the engineering designs used for their water reclamation systems are problematic to control. This work is based on an outbreak of cryptosporidiosis linked to a spraypark in New York State, where it was determined, specifically that the spraypad (the main attraction) was the primary exposure point. We first determined the likely dose the spraypad users were exposed to, then modeled the efficacy of the treatment system and used this to inform a Monte Carlo method to estimate the probability of infection and illness for the users of the spraypad. The current treatment system which consists of; two holding tanks, a dual media filter and chlorine injection as well as two design change recommendations were modeled using three independent Markov chain models. Within the current treatment system design the receiving tank for the treatment train is also connected with a second pipe to the spraypad used to deliver the return (treated) water, this return pipe is acting potentially as a bypass for the treatment train. Based on the risk assessments performed it is recommended that the bypass pipe be removed from the treatment system since in doing so the probability of infection and illness were reduced appreciably. Secondarily including an ozone contactor was shown to slightly reduce the risk further and provide a multiple barrier.
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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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    ABSTRACT: Angling and other recreational water activities are integral activities for millions of Americans. Each year over 80 million Americans aged 16 years or older enjoy some recreational activity related to fish and wildlife. Urban waters used for such recreational activities and as sources of food supplementation and subsistence are often contaminated by pathogenic organisms such as Cryptosporidium species, yet few studies have specifically explored microbial risks to recreationists (swim-mers, boaters, anglers, and crabbers) from recreational water contact, despite occur-rences of waterborne illnesses and outbreaks. Our first study of risks from recreation-al water contact in Baltimore, Maryland demonstrated that (1) fishing can be a vector of exposure to Cryptosporidium for Baltimore anglers, and (2) there are high levels of recreational water contact, and consumption of fish and crab within this popula-tion. Based on these results, a second study was carried out to assess the prevalence of recreational water activities in Baltimore waters in a sub-population of HIV/AIDS patients, for whom cryptosporidiosis is a major opportunistic illness. Patients were surveyed at the Johns Hopkins Moore AIDS Clinic in Baltimore, Maryland. Oral interviews were conducted based on a convenience sample of 102 HIV/AIDS pa-tients, from August–September 2006. Almost 50% of patients reported taking part in recreational water activities, of which 65% reported participating in at least one recreational activity, including fish or crab consumption. These were surprising find-ings, and in addition to our first study, indicate that recreationists, specifically per-sons with HIV/AIDS, are engaging in recreational water activities that may lead to contact with pathogen-contaminated waters in urban settings. These findings raise concerns regarding the role of urban fisheries, outdoor recreational water programs, and regulatory agencies in addressing microbial risks posed to anglers and other recreationists in urban settings.
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    ABSTRACT: Objectives. We assessed the prevalence of recreational activities in the waterways of Baltimore, MD, among persons with HIV/AIDS and their risk of exposure to Cryptosporidium. Methods. We studied patients at the Johns Hopkins Moore Outpatient AIDS Clinic. We conducted oral interviews in 2007 with a convenience sample of 157 HIV/AIDS patients to ascertain the sites used for recreational water contact within Baltimore waters and assess risk behaviors. Results. Approximately 48% of respondents reported participating in recrea- tional water activities (fishing, crabbing, boating, and swimming). Men and women were almost equally likely to engage in recreational water activities (53.3% versus 51.3%). A majority (61%, or 46 of 75) of respondents who reported recreational water contact reported consumption of their own catch, and approx- imately 67% (105 of 157) ate their own catch or that of friends or family members. Conclusions. Baltimoreans with HIV/AIDS are engaging in recreational water activities in urban waters that may expose them to waterborne pathogens and recreational water illnesses. Susceptible persons, such as patients with HIV/AIDS, should be cautioned regarding potential microbial risks from recrea- tional water contact with surface waters. (Am J Public Health. 2009;99:XXX-XXX.
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