Cryptococcal antigen survey among racing pigeon workers and patients with cryptococcosis, pythiosis, histoplasmosis and penicilliosis.

The cryptococcal antigen latex agglutination system (CALAS) test is simple, sensitive and specific. A total of 129 serum samples, 29 cerebrospinal fluids (CSF) and one ascitic fluid from 143 subjects were tested in the study. Cryptococcal antigenaemia was present in all CSF specimens tested from patients with culture-proven cryptococcal meningitis and cryptococcaemia, and in 91% of tested serum from the same group of patients with cryptococcal meningitis and cryptococcaemia. The occurrence of false positive results among sera obtained from patients with phycomycosis (zygomycosis) due to Mucor spp., Conidiobolus coronata and Pythium spp., and from patients with Penicillium marneffei infections, was not observed. A random survey of 101 high risk subjects, who had fed pigeons for two months up to 40 years, for cryptococcal antigenaemia was also carried out and 4% were positive for cryptococcal antigenaemia. Of 14 Cryptococcus neoformans strains obtained from CSF cultures of patients with cryptococcal meningitis, and with cryptococcaemia, during 1977-1986, ten strains were serotype A and D, and four strains were serotype B and C.