We report the findings of a longitudinal observational study on HIV-infected patients grouped by presumed transmission group, who had diarrhoea. The purpose of this study was to assess the prevalence of and factors associated with
Cryptosporidium infection on these patients. Modifiied
formol-
ether concentration followed by modified Ziehl-Neelsen and
phenol-
auramine/
carbol-fuchsin staining techniques were used to identify Cryptosporidium from 465 patients.
Cryptosporidiosis was reported in 36/465 (8% and 95% confidence interval 6, 10) patients. Of the positive patients 30 (83%) were men and 6 (17%) women. Prevalence of
infection was higher among HIV-seropositive patients whose exposure category was through sexual contact (69%) than among patients in other HIV exposure categories (9%, Standard Z test, P < 0.001). Median CD4+ cell count/mm3 was 120 (range 3-600). Besides diarrhoea, the main clinical manifestations were
fever and
weight loss in 14 (39%) and 26 (72%) patients, respectively.
Cryptosporidium infection was considered to be the
first AIDS defining disease in 31% of the patients followed by
tuberculosis in 19%,
Pneumocystis carinii pneumonia in 14%, Salmonella
sepsis in 6%,
isosporiasis in 3%, toxoplasmic
encephalitis in 3%,
leishmaniasis in 3% and
Kaposi's sarcoma in 3% of the patients. There was no significant difference (P = 0.82) in survival times for those given
folate antagonists to treat other
opportunistic infections. The decrease in prevalence of
cryptosporidiosis observed from 1994 until May 1997 is not statistically significant (P = 0.11). Most cases of cryptosporidial
infection in
AIDS patients in Lisbon occurred in those whose
HIV infection was assumed to have been acquired by the sexual route (hetero-, homo- and bisexual), with few cases occurring in drug-abusers.