BILIARY CRYPTOSPORIDIOSIS IN HIV-INFECTED PEOPLE AFTER THE WATERBORNEOUTBREAK OF CRYPTOSPORIDIOSIS IN MILWAUKEE

Background. In March 1993, the municipal water supply in Milwaukee bec ame contaminated with cruptosporidium and a widespread outbreak of cry ptosporidiosis occurred. Methods. We retrospectively studied the relat ions among the clinical presentation, CD4 count, and survival in a gro up of 82 patients infected with the human immunodeficiency virus (HIV) in whom cryptosporidiosis developed during the outbreak. Infection wa s documented by the finding of cryptosporidium in stool. Results. Ther e was a sharp increase in the number of HIV-infected patients with cry ptosporidiosis after the period of water contamination. Four of 24 pat ients with biliary symptoms (17 percent) and 30 of 58 without biliary symptoms (52 percent) were alive one year after the outbreak (P = 0.00 3). Twenty-one of the patients with biliary symptoms had CD4 counts le ss than or equal to 50 per cubic millimeter, as compared with 36 of 57 patients without biliary symptoms (88 percent vs. 63 percent, P = 0.0 3). The CD4 count was not available for one patient in the latter grou p, Within one year, 41 of the patients with CD4 counts less than or eq ual to 50 per cubic millimeter had died, as compared with 6 of those w ith higher counts (72 percent vs. 25 percent, P < 0.001). After adjust ment for the CD4 count, independent predictors of death were older age and the presence of nausea and vomiting. Conclusions, When HIV-infect ed patients are exposed to cryptosporidium, those with CD4 counts less than or equal to 50 per cubic millimeter are at increased risk for bi liary symptoms and for death within one year after the infection. (C) 1996, Massachusetts Medical Society.