PURPOSE: Cryptosporidium oocysts are commonly detected in surface-derived drinking water, however, the public health significance of these findings is unclear. This study compared the evidence of prior Cryptosporidium infection for people drinking water derived from surface versus ground water sources. METHODS: This study measured serological responses to two Cryptosporidium antigen groups for blood donors from two midwestern United States cities with different drinking water sources: filtered and chlorinated river water receiving agricultural and domestic sewage upstream versus chlorinated water from an underground aquifer. Initial and nine-month paired serological responses to two Cryptosporidium antigen groups were compared. RESULTS: Initially, donors from the surface water city had a higher relative prevalence (RP) of a serological response (54% vs. 38%, RP = 1.39 (1.21,1.60)). Donors with a detectable baseline response who resided in the surface water city had a higher relative risk (RR) of an increased intensity of response on the follow-up blood draw (15/17-kDa, 40/100 vs. 11/100, RR = 3.78 (1.89,7.58)), (27-kDa 38/100 vs. 18/100, RR = 2.07 (1.31,3.25)). Donors with no baseline response to the 15/17-kDa marker who resided in the surface water city also had a higher risk of serconversion (38/100 vs. 14/100, RR = 2.63 (1.78,3.91)). CONCLUSIONS: These rates of both background and drinking water related Cryptosporidium infections are substantially higher than previously estimated, however, the risk of illness from infection may be lower.
PURPOSE: Cryptosporidium oocysts are commonly detected in surface-derived drinking water, however, the public health significance of these findings is unclear. This study compared the evidence of prior Cryptosporidium infection for peopledrinking water derived from surface versus ground water sources. METHODS: This study measured serological responses to two Cryptosporidium antigen groups for blood donors from two midwestern United States cities with different drinking water sources: filtered and chlorinated river water receiving agricultural and domestic sewage upstream versus chlorinated water from an underground aquifer. Initial and nine-month paired serological responses to two Cryptosporidium antigen groups were compared. RESULTS: Initially, donors from the surface water city had a higher relative prevalence (RP) of a serological response (54% vs. 38%, RP = 1.39 (1.21,1.60)). Donors with a detectable baseline response who resided in the surface water city had a higher relative risk (RR) of an increased intensity of response on the follow-up blood draw (15/17-kDa, 40/100 vs. 11/100, RR = 3.78 (1.89,7.58)), (27-kDa 38/100 vs. 18/100, RR = 2.07 (1.31,3.25)). Donors with no baseline response to the 15/17-kDa marker who resided in the surface water city also had a higher risk of serconversion (38/100 vs. 14/100, RR = 2.63 (1.78,3.91)). CONCLUSIONS: These rates of both background and drinking water related Cryptosporidium infections are substantially higher than previously estimated, however, the risk of illness from infection may be lower.
Authors: Jane W Wanyiri; Henry Kanyi; Samuel Maina; David E Wang; Aaron Steen; Paul Ngugi; Timothy Kamau; Tabitha Waithera; Roberta O'Connor; Kimani Gachuhi; Claire N Wamae; Mkaya Mwamburi; Honorine D Ward Journal: Am J Trop Med Hyg Date: 2014-05-27 Impact factor: 2.345
Authors: Cynthia C McOliver; Hanna B Lemerman; Ellen K Silbergeld; Richard D Moore; Thaddeus K Graczyk Journal: Am J Public Health Date: 2009-04-16 Impact factor: 9.308
Authors: Stella Goh; Mark Reacher; David P Casemore; Neville Q Verlander; Rachel Chalmers; Margaret Knowles; Joy Williams; Keith Osborn; Sarah Richards Journal: Emerg Infect Dis Date: 2004-06 Impact factor: 6.883