Epidemiology and Host- and Variety-Dependent Characteristics of Infection Due to Cryptococcus neoformans in Australia and New Zealand

Abstract

A prospective population-based study was conducted in Australia and New Zealand during 1994-1997 to elucidate the epidemiology of cryptococcosis due to Cryptococcus neoformans var. neoformans (CNVN) and C. neoformans var. gattii (CNVG) and to relate clinical manifestations to host immune status and cryptococcal variety. The mean annual incidence per 10(6) population was 6.6 in Australia and 2.2 in New Zealand. Of 312 episodes, CNVN caused 265 (85%; 98% of the episodes in immunocompromised hosts) and CNVG caused 47 (15%; 44% of the episodes in immunocompetent hosts). The incidence of AIDS-associated cases in Australia declined annually (P<.001). Aborigines in rural or semirural locations (P<.001) and immunocompetent males (P<.001) were at increased risk of CNVG infection. Cryptococcomas in lung or brain were more common in immunocompetent hosts (P< or =.03) in whom there was an association only between lung cryptococcomas and CNVG. An AIDS-associated genetic profile of CNVN serotype A was confirmed by random amplification of polymorphic DNA analysis. Resistance to antifungal drugs was uncommon. The epidemiology of CNVN infection has changed substantially. Clinical manifestations of disease are influenced more strongly by host immune status than by cryptococcal variety.

In vitro antifungal susceptibility profiles and genotypes of 308 clinical and environmental isolates of Cryptococcus neoformans var. grubii and Cryptococcus gattii serotype B from north-western India

“…grubii, which agrees with several previous reports (Fernandes et al, 2003;Trilles et al, 2004;Khan et al, 2007Khan et al, , 2009Gomez-Lopez et al, 2008). However, there is divergence of results concerning the antifungal susceptibility patterns of the two species in some other studies, which reported no such difference (Chen et al, 2000;Calvo et al, 2001;Morgan et al, 2006;Tay et al, 2006;Thompson et al, 2009). This divergence in results may be due to a possible lack of uniformity in the methodologies of testing adopted by different investigators.…”

Phenotypic Switching of Cryptococcus neoformans and Cryptococcus gattii

“…The need for recognition of the two species within C. neoformans is warranted not only because of their biologic and ecological differences, but also because they tend to infect different hosts. C. gattii infections have been documented more commonly in immunocompetent individuals, whereas a majority of the patients infected with C. neoformans are immunocompromised, often due to HIV infection [10,11]. Furthermore, some reports have suggested that infections due to C. gattii carry a worse prognosis [12].…”

A rare genotype of Cryptococcus gattii caused the cryptococcosis outbreak on Vancouver Island (British Columbia, Canada)

“…This incidence is significantly greater than that of C. gattii infection typically observed in Australia (0.94 cases per million residents per year), where C. gattii is endemic (3,6). A public advisory was issued by the British Columbia Centre for Disease Control on June 6, 2002 (www.bccdc.org) advising the public, medical practitioners, and veterinarians of the potential health risk and telling them to be alert for symptoms and to seek early diagnosis.…”