ARS | Publication request: Prevalence and species of Cryptosporidium in human populations worldwide

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: November 16, 2011
Publication Date: N/A

Technical Abstract: A high prevalence of cryptosporidiosis has been reported in children under 5 years of age in sub-Saharan Africa, especially, but not exclusively, the malnourished and those positive for HIV infection. Infection rates are highest during the rainy season. Cryptosporidium hominis, which is transmitted through a human- to- human cycle, is reported more frequently than other species in cases in this region. This is despite the fact that Cryptosporidium parvum, a species with many animal hosts, and thereby more potential sources, will dominate when a host is simultaneously exposed to both species. The reasons for this possible discrepancy in prevalence of C. hominis versus C. parvum infection are unknown but might be based on limited or selective sampling or an incomplete understanding of transmission in this region where sanitation is generally poor, HIV/AIDS rates are high, food and water supplies are limited, living conditions are crowded, and other diseases are prevalent. The foregoing conditions can likely add large numbers of Cryptosporidium oocysts to the environment while affecting the body’s ability to mount a positive immune response to cryptosporidiosis or other infections. Furthermore, vaccines for common childhood disease are limited or unavailable. Given the range and severity of these conditions, safe and effective methods to prevent and treat cryptosporidiosis in children are urgently needed. In addition to improvements in sanitation, clean water, and sufficient nutrition and housing, highly effective prophylactic and therapeutic drugs could be extremely beneficial. Development of an effective vaccine would require a greater and longer term effort but would ultimately be more beneficial.