Retrovirus-related disease in zoo-based koalas (Phascolarctos cinereus) in North America
Abstract
Koala retrovirus (KoRV)-related disease is a major suspected cause of death in koalas (Phascolarctos cinereus) in zoos in North America. There are currently eleven zoos exhibiting koalas in North America. A mortality survey of these institutions indicated that mortalities directly related to KoRV (e.g., lymphoma, leukemia, anemia, bone marrow hypoplasia, osteochondromatosis) and mortalities suspected to be KoRV-related (e.g., immunosuppression, unusual opportunistic infections [e.g., Coccidioidomycosis], potentially other neoplasia) account for 41% of deaths. Testing of the living North American koala population for a recently reported, exogenous koala retrovirus variant (KoRV-B) identified four KoRV-B-positive individuals in a population of 54 koalas (7.4%).
