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Cryptosporidium surveillance and risk factors in the United States

Division of Parasitic Diseases, Centers for Disease Control and Prevention, Department of Health and Human Services, Atlanta, GA, USA.
Experimental Parasitology (Impact Factor: 1.86). 09/2009; 124(1):31-9. DOI: 10.1016/j.exppara.2009.09.020
Source: PubMed

ABSTRACT Surveillance for Cryptosporidium in the United States indicates that the reported incidence of infection has increased dramatically since 2004. The reasons for this increase are unclear but might be caused by an actual increase in incidence, improved surveillance, improved awareness about cryptosporidiosis, and/or increases in testing practices resulting from the licensing of the first-ever treatment for cryptosporidiosis. While regional differences remain, the incidence of cryptosporidiosis appears to be increasing across the United States. Onset of illness is most common during the summer, particularly among younger children. Cryptosporidiosis case reporting also influences outbreak detection and reporting; the recent rise in cases coincides with an increase in the number of reported cryptosporidiosis outbreaks, particularly in treated recreational water venues. Risk factors include ingesting contaminated recreational or drinking water, exposure to infected animals, having close contacts with cryptosporidiosis, travel to disease-endemic areas, and ingestion of contaminated food. Advances in molecular characterization of clinical specimens have improved our understanding of the changing epidemiology and risk factors. Prevention and control of cryptosporidiosis requires continued efforts to interrupt the transmission of Cryptosporidium through water, food, and contact with infected persons or animals. Of particular importance is continued improvement and monitoring of drinking water treatment and advances in the design, operation, and management of recreational water venues coupled with behavioral changes among the swimming public.

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    • "The highest prevalence rate of cryptosporidiosis was found among children aged between 0 and 10 years age (63.2%) as compared to 20.8% among children 11 to 15 years of age. This is consistent with reports of higher prevalence in younger children from other parts of the world (Iqbal et al., 1999; Abu-alrub et al., 2008; Yoder and Beach, 2010). This significant difference could be attributed to the poor living conditions of these children, lack of selfawareness , personal hygiene and cleanliness at this critical age. "
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    • "During hot weather, over 300 people have been observed to swim in the reservoir. These observations are similar to previous studies of recreational waters and catchments that had an increase in the number of visitors to the catchment during summer (Craun et al., 2005; Lake et al., 2008; McCarthy et al., 2008; Yoder and Beach, 2010). In the non-recreational sites, the prevalence ranged from 8.3% to 33.3% with the highest prevalence in site 5. Positives were detected during the winter months and only C. parvum was detected in the non-recreational sites. "
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    • "Cryptosporidium is an important cause of gastrointestinal illnesses in many countries (WHO, 2009b). In the United States of America alone, at least 143 water-associated outbreaks of cryptosporidiosis have been reported (Yoder and Beach, 2010). For immunocompetent people, the symptom of watery diarrhea may be self-limiting and persists for up to 2 weeks (Dietz "
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