Pneumocystis carinii in wildlife.

Pneumocystis carinii is a eukaryotic organism capable of causing life-threatening pneumonia (PCP) in immunocompromised hosts. Despite intensive investigation in human and laboratory animal hosts, information on the occurrence and nature of infections in wild animals is scarce, although characterisation of infections in wild-animal populations may help to elucidate the life-cycle and transmission of this elusive organism. Due to the interspecific differences in prevalence and intensity of P. carinii infection, and to the antigenic and genetic diversity of P. carinii organisms originating from various host species, which may affect the infectivity and pathogenicity of these organisms, we should be cautious when making generalisations about the nature of P. carinii infection. This review summarises the present state of knowledge on the occurrence of P. carinii in wild mammals in their natural habitats, and briefly discusses various characteristics of P. carinii infection important for understanding the distribution and abundance of this organism. Some aspects of P. carinii infection in wild hosts of particular interest for future research in this field will also be discussed.