Cryptosporidiosis among patients infected with human immunodeficiency virus. Factors related to symptomatic infection and survival.
The authors reviewed the medical records of 194 human immunodeficiency virus (HIV)-positive patients newly diagnosed with cryptosporidiosis and all 3,564 patients with newly diagnosed acquired immunodeficiency syndrome (AIDS) at San Francisco General Hospital for the period 1986-1992. The study was designed to address three questions: 1) How do AIDS patients who present with cryptosporidiosis differ from other patients with AIDS? 2) What factors are associated with survival among AIDS patients with newly diagnosed cryptosporidiosis? 3) Does a diagnosis of cryptosporidiosis impact survival after AIDS diagnosis? A total of 194 cases of cryptosporidiosis among HIV-infected patients were identified during the study period. Of the 194 patients, 109 (56%) had no prior diagnosis of AIDS. These 109 patients represented 3.1% of the 3,564 newly diagnosed cases of AIDS in the same period. Among the 134 patients with CD4 T-lymphocyte counts performed within 3 months of Cryptosporidium diagnosis, 34 (25%) had CD4 counts greater than 209 cells/ml. In a multivariate conditional logistic regression model, the incidence of Cryptosporidium was related to ethnicity (for blacks vs. whites, matched odds ratio (OR) = 0.15, 95% confidence interval (CI) 0.03-0.73), CD4 count (for a CD4 count of < or = 53 cells/ml vs. > 53 cells/ml, matched OR = 12.60, 95% CI 4.01-39.61), and age (for a 10-year increase, matched OR = 0.51, 95% CI 0.27-0.98). Two factors measured at the time of Cryptosporidium diagnosis were identified as being independently associated with survival (p < 0.001) in the proportional hazards model: CD4 count < or = 53 cells/ml versus > 53 cells/ml (relative hazard = 6.18, 95% CI 2.99-12.76) and hematocrit < or 37% versus > 37% (relative hazard = 2.27, 95% CI 1.22-4.22). The median durations of survival in the four subgroups of Cryptosporidium-infected patients defined by these two variables differed significantly from each other (range, 204-1,119 days). Cryptosporidiosis as an initial AIDS-defining diagnosis was associated with an elevated relative hazard of death in comparison with other AIDS-defining diagnoses (relative hazard = 2.01, 95% CI 1.38-2.93). These data identify the groups of HIV-infected individuals at risk for presentation with symptomatic Cryptosporidium infection; the distinct survival patterns among subgroups of those patients already infected with this parasite; and the survival of AIDS patients with newly diagnosed cryptosporidiosis relative to patients with other AIDS-defining conditions. Such information is necessary for the design of prospective studies, the development of prophylactic strategies, the evaluation of candidate therapies, and the provision of prognostic information to patients.
Division of Public Health Biology and Epidemiology, School of Public Health, University of California, Berkeley, USA.
J M
JM
Colford
I B
IB
Tager
A M
AM
Hirozawa
G F
GF
Lemp
T
T
Aragon
C
C
Petersen
D017088:AIDS-Related Opportunistic Infections / Q000453:epidemiology / Q000401:mortality*; D000163:Acquired Immunodeficiency Syndrome / Q000175:diagnosis / Q000401:mortality*; D000328:Adult; D018791:CD4 Lymphocyte Count; D016022:Case-Control Studies; D003457:Cryptosporidiosis / Q000453:epidemiology / Q000209:etiology / Q000401:mortality*; D005260:Female; D015658:HIV Infections / Q000150:complications / Q000401:mortality; D006801:Humans; D015994:Incidence; D008297:Male; D012307:Risk Factors; D012495:San Francisco / Q000453:epidemiology; D016019:Survival Analysis