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Category: Clinical Microbiology
Emerging Food- and Waterborne Protozoan Diseases, Page 1 of 2
< Previous page | Next page > /docserver/preview/fulltext/10.1128/9781555815585/9781555813772_Chap15-1.gif /docserver/preview/fulltext/10.1128/9781555815585/9781555813772_Chap15-2.gifAbstract:
This chapter describes the most relevant features of protozoan agents of foodborne diseases and waterborne diseases, specifically, Cryptosporidium and Cyclospora, which cause diarrheal illness in humans, and Toxoplasma, which is associated with encephalitis, chorioretinitis, and abortion. In developing countries, human cryptosporidiosis and cyclosporiasis occur most frequently in children. While Cryptosporidium is common worldwide, endemic Cyclospora may be restricted to those communities that lack adequate water treatment (e.g., filtration) and sanitation (sewage treatment). Children can have multiple episodes of cryptosporidiosis and cyclosporiasis, implying that the acquired anti-Cryptosporidium or anti-Cyclospora immunity in children is short-lived or incomplete. Toxoplasmosis is one of the most common causes of primary chorioretinitis in children. In industrialized nations, the most effective treatment and prophylaxis for cryptosporidiosis in AIDS patients is the use of highly active antiretroviral therapy (HAART). Reports of food-related infections by Cryptosporidium are few, difficult to document, and probably greatly underreported, with individual cases and small-group outbreaks unlikely to be recognized. A small number of food-borne outbreaks of cryptosporidiosis have been reported. Genetic characterization of 25 T. gondii isolates from market pigs identified three distinct strains based on RFLP assays at the SAG2 locus with no evidence of recombinants, implying that three distinct exposure events occurred during the lifespans of the pigs. Whether the risks are associated with improper water or sewage treatment, improper or inadequate food preparation or agricultural practices, or simply hygiene failures leading to person-to-person transmission, the efforts to control these opportunistic parasites will continue to be a challenge.
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Cryptosporidiosis: drinking-water outbreaks
Cryptosporidiosis: recreational-water outbreaks
Cryptosporidiosis: food-borne outbreaks
Cyclosporiasis: food-borne and waterborne outbreaks