Epidemiology and Infection

Research Article

Paired city Cryptosporidium serosurvey in the southwest USA

F. J.  FROST  a1 c1, T.  MULLER  a1, G. F.  CRAUN  a2, R. L.  CALDERON  a3 and P. A.  ROEFER  a4
a1 The Lovelace Clinic Foundation, 2425 Ridgecrest Drive S.E. Albuquerque, 87108 USA
a2 101 West Frederick Street, The Professional Building, Staunton, VA, 24401
a3 National Health and Environmental Effects Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27111
a4 Southern Nevada Water Authority, 243 Lakeshore Road, Boulder City, NV 89005


In 1996, serological responses to two Cryptosporidium antigens were determined for 200 Las Vegas (LV), Nevada, and 200 Albuquerque, New Mexico, blood donors to evaluate associations between endemic infections, water exposures, and other risk factors. LV uses chlorinated filtered drinking water from Lake Mead while Albuquerque uses chlorinated ground water. The intensity of serological response to both markers was higher for older donors (P < 0·05), donors who washed food with bottled water (P < 0·05) and donors from LV (P < 0·05). A decreased serological response was not associated with bottled water consumption, nor was an increased response associated with self-reported cryptosporidiosis-like illness or residence in LV at the time of a cryptosporidiosis outbreak 2 years earlier. Although these findings suggest the serological response may be associated with type of tap water and certain foods, additional research is needed to clarify the role of both food and drinking water in endemic Cryptosporidium infection.

(Accepted October 24 2000)

c1 Author for correspondence.