Evaluation of Captive Gibbons for an Epizoonotic Agent: The Gibbon Ape Leukemia Virus (GALV)
The gibbon ape leukemia virus (GALV) is an infectious Gammaretrovirus associated with neoplasias in gibbons. Highly related retroviruses have been isolated from other animals (woolly monkey, koalas).1-4 The virus is shed in urine, feces, and saliva, and can be transmitted in utero and via postnatal contact. Since its initial characterization in the 1970s and 80s, the incidence of GALV has not been assessed in gibbons. Investigating the disease status of captive animals as well as factors affecting their health is a critical first step in determining if captive gibbons are infected, and if an etiologic linkage between infection and neoplastic diseases exists. Three diagnostic assays (ELISA, western blot, and PCR) were used to identify the presence or absence of GALV antibodies, viral proteins, and infection status in five captive gibbons using samples obtained during routine and diagnostic examinations. Studies revealed possible exposure to GALV, but lack of integration or expression of the virus. Future studies on samples from other gibbon-holding institutions are planned in coordination with the gibbon SSP. This will aid in the determination, frequency, and time course of GALV seroconversion among captive animals, and further characterize any etiologic link between infection and disease.
The authors would like to thank the members of the primate team, Department of Animal Programs at the National Zoo for their care of these animals, and the medical technologists in the Department of Pathology for their assistance.
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