Cryptococcosis in a North Island brown kiwi (Apteryx australis mantelli) in New Zealand

Abstract

A case of disseminated cryptococcosis in a North Island kiwi (Apteryx australis mantelli) caused by Cryptococcus neoformans var. gattii (serotype B) is reported. This is the first case of cryptococcosis to be reported in a kiwi and is also the first isolation of C. neoformans var. gattii from a veterinary source in New Zealand. The kiwi is an example of a ratite bird and as such has a lower body temperature approximating that of a mammal. As a consequence, the kiwi and other ratitis (e.g. emus) would be expected to show an increased susceptibility to cryptococcosis compared with other birds. There has been only one other isolate of this variety of C. neoformans in New Zealand and this was isolated from the sputum of a human male with leukaemia who was from the Gisborne area of the North Island, a region adjacent to Hawkes Bay where the case of kiwi cryptococcosis occurred. Some months prior to the development of the infection in the bird, a mulch of Eucalyptus leaves/twigs had been spread throughout the kiwi enclosure and this is considered to have been the probable source of the yeast. Neither Eucalyptus camaldulensis nor Eucalyptus tereticornis were among the species from which the mulch material originated and it is suggested another species may be the environmental host(s) of C. neoformans var. gattii in New Zealand.