INCIDENCE AND FACTORS ASSOCIATED WITH EXTRAPULMONARY CRYPTOCOCCOSIS AMONG PERSONS WITH HIV-INFECTION IN LOS-ANGELES-COUNTY

Objective: To determine the incidence and factors associated with extr apulmonary cryptococcosis among a cohort of persons with HIV in Los An geles County. Design: Records-based cohort study. Methods: Data were a nalysed from a cohort of 3836 persons aged greater than or equal to 13 years with HIV infection enrolled from four outpatient facilities in Los Angeles from 1990 to 1995. The potential association between crypt ococcosis and demographic risk behavior and clinical factors was asses sed. Possible seasonal clustering was evaluated and an estimate of sur vival following cryptococcosis was calculated. Multivariate analysis w as performed using a Cox proportional hazards approach. Results: Crypt ococcosis was identified in 112 patients (2.9%) representing a crude i ncidence rate of 1.7 cases per 100 person-years experience. The rate o f cryptococcosis was higher among men than women (1.9 and 0.6, respect ively; P < 0.01) and in Hispanics than in whites (2.3 and 1.2, respect ively; P < 0.01). A significant trend of decreasing cryptococcosis was observed with increasing age (P < 0.01). Cryptococcosis increased wit h declining CD4+ lymphocyte count, with risk being greatest at CD4+ ce ll counts below 100 x 10(6)/l (P < 0.001). In bivariate analysis perso ns with a history of antifungal medication had a marginally lower rate of cryptococcosis, but this difference was not statistically signific ant. The rate of cryptococcosis was significantly higher in fall and w inter months [rate ratio (RR), 1.45; 95% confidence interval (CI), 1.0 -2.3; P = 0.05]. After controlling for other variables, cryptococcosis was more common in men than women (adjusted RR, 3.2; 95% CI, 1.0-10.4 ) and in Hispanics than whites (adjusted RR, 1.6; 95% CI, 0.9-2.7). Bo th CD4+ count and age continued to be strongly associated with the occ urrence of cryptococcosis. After controlling for other factors a subst antial protective effect was observed for antifungal therapy (adjusted RR, 0.48; 95% CI, 0.29-0.79). Conclusion: Our data suggest that HIV-i nfected men, Hispanics, persons aged under 45 years and those with CD4 + counts under 100 x 10(6)/l have an increased risk of extrapulmonary cryptococcosis. A fall-winter seasonality in the occurrence of cryptoc occosis may exist. Significant primary protection against cryptococcal disease is afforded by antifungal therapy. These results may provide insight into possible routes of transmission and sources of cryptococc al infection and help guide both primary prophylaxis and early recogni tion and diagnosis in persons likely to be at increased risk.