Epidemiologic and Environmental Investigation of a Recreational Water Outbreak Caused by Two Genotypes of Cryptosporidium Parvum in Ohio in 2000

Abstract

In August 2000, the Ohio Department of Health requested assistance to investigate a cryptosporidiosis outbreak with more than 700 clinical case-patients. An epidemiologic and environmental investigation was conducted. Stool specimens, pool water, and sand filter samples were analyzed. A community-based case-control study showed that the main risk factor was swimming in pool A (odds ratio [OR] = 42, 95% confidence interval [CI] = 12.3-144.9). This was supported by results of polymerase chain reaction (PCR) analysis, which showed the presence of both the human and bovine genotypes of Cryptosporidium parvum in case-patients and samples from the filter of pool A. A pool-based case-control study indicated that the highest risk was related to exposure to pool water via the mouth (OR = 5.1, 95% CI = 2.1-12.5) or to pool sprinklers (OR = 2.5, 95% CI = 1.3-4.7). Fecal accidents at the pool were documented. Records indicated that the pool met local health regulations. The outbreak, caused by co-infection with two C. parvum genotypes (human and bovine), underscores the need for concerted action to improve public health policies for recreational water facilities and enhanced education regarding the potential for disease transmission through pools.

Towards a US national estimate of the risk of endemic waterborne disease – sero-epidemiologic studies

“…tions differs between C. parvum and C. hominis (Hunter et al 2004). A variety of species, genotypes and hostadapted strains may be present in water, some of which are of doubtful pathogenicity to humans but may stimulate an immune response (Chalmers et al 2002a, b;Ong et al 2002;Ward et al 2002;Mathieu et al 2004;Zhou et al 2004). …”

“…In some cases, the two species and others were likely present in the water and/or in infections in humans Tanriverdi et al 2003;Mathieu et al 2004;Priest et al 2006). It is unclear how important the anamnestic The infectivity of different isolates of C. parvum is known to vary Teunis et al 2002).…”

A population-based exposure assessment of risk factors associated with gastrointestinal pathogens: aCampylobacterstudy

“…3 billion [4] and England approximately £750 million per annum [5]. These pathogens cause a range of symptoms from diarrhoea, abdominal pain, fever and vomiting [6][7][8][9][10][11][12] to haemolytic-uraemic syndrome (e.g. E. coli O157) [13,14], Guillian-Barre´syndrome (e.g.…”

Cryptosporidium outbreaks associated with swimming pools

“…In Canada and the United States, the two most common species of Cryptosporidium associated with outbreaks in swimming pools are Cryptosporidium parvum and Cryptosporidium hominis (Hopkins et al 2013;Mathieu et al 2004;Health Canada 2004;Polgreen et al 2012;Boehmer et al 2009;Wheeler et al 2007;Causer et al 2006). Many studies report that pool-fouling was a risk factor for infection with Cryptosporidium (Hopkins et al 2013;Mathieu et al 2004;Health Canada 2004).…”

“…There is a 3%Á8% increased risk of AGI after swimming (Sanborn and Takaro 2013). The most common pathogen in waterborne infections is Cryptosporidium (Craun et al 2005); it is a protozoan that causes diarrheal illness and has been linked to recreational water illness in swimming pools (Craun et al 2005;Hopkins et al 2013;Mathieu et al 2004). Cryptosporidium oocytes are highly resistant to chemical disinfectants used to purify recreational water sources (Boehmer et al 2009).…”