Clinical insights and epidemiology of central nervous system infection due to Cryptococcus neoformans/gattii species complexes: A prospective study from South India

In the last two decades, central nervous system (CNS) cryptococcosis (CNSc) has emerged as a major opportunistic infection in the immunocompromised population of India. We have analyzed the clinical features of CNSc and epidemiology of Cryptococcus neoformans and Cryptococcus gattii. A total of 160 clinical isolates of C. neoformans/gattii recovered from CNSc patients were analyzed. The origin, clinical parameters, and imaging features of the patients were recorded, and clinical parameters were analyzed based on their human immunodeficiency virus (HIV) status and infecting species, namely, C. neoformans or C. gattii. Serotypes and mating types of the isolates were determined. Molecular typing was performed by polymerase chain reaction (PCR) fingerprinting using M13 microsatellite primer (GTG)5, and multilocus sequence typing (MLST). Majority of the patients were from Bangalore Urban, Karnataka. Among 160 cases 128 (80%) were HIV seropositive, and 32 (20%) were HIV negative. Middle-aged males (36-55 years) were highly affected. There were statistically significant differences in the clinical manifestations, imaging and CSF parameters of HIV coinfected and noninfected cases, whereas limited differences were observed in these parameters in the cases infected with C. neoformans and C. gattii. We identified 80% C. neoformans VNI, 8.75% VNII and 22.5% C. gattii (VGI), 8.75% C. tetragattii (VGIV) among clinical strains. This comprehensive study will contribute toward a better prognosis of CNS cryptococcosis patients during the hospital stay, treatment strategies for HIV coinfected and noninfected cases and will provide the molecular epidemiology of these two pathogenic fungal species in south India, which was unclear in this part of the country.