EPIDEMIOLOGY OF CRYPTOSPORIDIOSIS AMONG PERSONS WITH ACQUIRED-IMMUNODEFICIENCY-SYNDROME IN LOS-ANGELES-COUNTY

To determine the occurrence and factors associated with Cryptosporidiu m among persons with acquired immunodeficiency syndrome (AIDS) in Los Angeles County, data were analyzed from the AIDS surveillance registry for the 10-year period 1983-1992. Among 16,953 persons with AIDS, a t otal of 638 (3.8%) cryptosporidiosis cases were reported during the st udy period. The prevalence of cryptosporidiosis was higher in persons whose suspected human immunodeficiency virus (HIV) exposure category w as through sexual contact (3.9%) than among persons in other HIV expos ure categories (2.6%; P < 0.01) and in immigrants from Mexico (5.2%) t han in American born patients (3.8%; P < 0.01). Blacks (2.7%) were les s likely than whites (4.1%) and Latinos (4.2%) to be reported with cry ptosporidiosis (P < 0.001). A temporal trend was observed from 1983 to 1986 when the prevalence decreased from 6.7% to 3.6% (P < 0.001, by c hi-square test for trend). After controlling for confounding variables by stratified analysis, persons whose HIV exposure was sexual (adjust ed odds ratio [OR] = 1.7, 95% confidence interval [CI] 1.3, 2.4, P < 0 .01) and immigrants from Mexico (adjusted OR = 1.6, 95% CI 1.2, 2.1, P < 0.01) were more likely to have cryptosporidiosis. The negative asso ciation with black race remained significant (adjusted OR = 0.7, 95% C I 0.57, 0.96, P = 0.02). The prevalence of cryptosporidiosis decreased with age in gay and bisexual males (Mantel-Haenszel test for trend, P < 0.01) but not among female and heterosexual male cases. The tempora l trend of decreasing prevalence observed was a result of a decrease i n cryptosporidiosis prevalence among gay and bisexual men with AIDS fr om 1983 to 1986 (P < 0.01, by Mantel-Haenszel test for trend), which c orresponded to a time of modified sexual behavior in this group. These data suggest the existence of modes of Cryptosporidium infection in p ersons with AIDS, including sexual transmission among gay and bisexual men and the occurrence of travel-related infections. Such information may be of value in recommending strategies for preventing Cryptospori dium infection in HIV-infected persons.