Serotype distribution of Cryptococcus neoformans in patients in a tertiary care center in India

The prevalence of specific serotypes of Cryptococcus neoformans in a given area bears on regional epidemiological patterns, the expected spectrum of clinical disease, and predicted response to therapy. In this retrospective study we analyzed the serotypes of 45 C. neoformans isolates from 36 North Indian patients with varied clinical presentations. The majority of the isolates were serotype A (87%), and surprisingly, a significant number were serotype B (five isolates, 11%), which caused infection in patients both positive and negative for HIV. One unusual isolate was not typable with factor sera. Study of serotype distribution in patients showed serotypes A and B to be present, respectively, in 92% and 8% of 36 patients. In one apparently immunocompetent patient two serotypes, A and B, were isolated simultaneously from two different sites, lung and scalp abscess. This is the first reported case in which an individual was infected with two serotypes at the same time. In one HIV-infected child serotype A was isolated from blood. Our results suggest that the distribution of serotypes in Indian clinical isolates is different than that found in other regions.