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About 10% of CNS cryptococcosis in India is caused by Cryptococcus gattii with 80% mortality

September 13 2017

About 10% of CNS cryptococcosis in India is caused by Cryptococcus gattii in a prospective 3 year study conducted by Shayanki Mukhopadhyay and colleagues at the National Institute of Mental Health and Neuro Sciences, Bangalore, India. A total of 199 cases of CNS cryptococcosis were diagnosed between January 2012 and December 2015, 20 (10%) of which were due to C. gattii. Most 75% (n=15) of the C. gattii-infected patients presented with meningitis and 25% (n=5) with a cryptococoma. Mortality was 80% in both cryptococcoma (4/5) and meningitis (12/15) cases.

There was a male predominance among these patients (13/20), 50% of whom were immunocompromised either by HIV (n=9) or leukaemia (n=1).

The predominant clinical features were headache (100%), neck rigidity (73.3%-80%), vomiting (60%-80%) and impairment of vision (40%-60%) for both patients with meningitis and cryptococcoma. Fever (93.3%) and behavioural abnormalities (66.7%) were exclusively observed in meningitis cases.

All the 20 isolates were fully sensitive to amphotericin B, flucytosine and voriconazole. However, only 10 (50%) of the isolates were susceptible to fluconazole, five (25%) were resistant and the rest five (25%) had intermediate sensitivity. The non-susceptible isolates were all from meningitis cases.

Concerning the molecular epidemiology of C. gattii in this population, 75% of the isolates were identified as C. tetragattii, 20% as C. gattii sensu stricto and 5% were C. bacillisporus and all had α type mating.

Cryptococcus gattii is a well-known pathogen of both the immunocompetent and immunocompromised hosts mainly in the tropics and sub-tropical regions of the world, linked to eucalyptus trees.   It is important to understand the emergence and the geographic distribution of this important fungus as the geographic variation in the distribution of this fungus is striking.