During the summer of 2000, the Ohio Department of Health requested assistance from the Centers for Disease Control and Prevention (CDC) to investigate a recreational water outbreak of cryptosporidiosis. Investigators collected descriptive case information and stool specimens from patients and conducted two case-control studies: 1) a community-based study to examine potential sources of the outbreak and 2) a swim-club-based study to identify pool-related risk factors. Investigators inspected the implicated pool and analyzed water and sand filter samples. More than 700 patients (151 laboratory-confirmed), with mean age of 6 years, became ill with cryptosporidiosis. Symptoms included diarrhea (91%), loss of appetite (87%) and abdominal cramps (83%). The mean duration of illness was 7 days. Persons who swam in the implicated pool were 42 times more likely to become ill than other members of the community (odds ratio [OR]: 42.3, 95% confidence interval [CI] 12.3-144.9). Exposure to pool water via the mouth (OR 5.1; 95% CI 2.1-12.5) and standing under a pool sprinkler (OR 2.5; 95% CI 1.3-4.7) also increased the likelihood of becoming ill. Co-infection with two Cryptosporidium parvum genotypes (human and bovine) occurred, a finding not previously documented. Both fecal accidents and swimming in the pool by ill persons were documented during the outbreak period. This large recreational water outbreak of infection with the chlorine-resistant Cryptosporidium parasite underscores the need for concerted action to improve public health policies, operations, and practices for recreational water facilities, and to enhance education of pool patrons and staff regarding the potential for disease transmission.
Learning Objectives: The participant of this session will be able to : 1/Define the different steps in an outbreak investigation 2/Recognize the public health impact of a cryptosporidiosis outbreak
Keywords: Environmental Exposures, Outbreaks
Presenting author's disclosure statement:
Organization/institution whose products or services will be discussed: None
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.