Disease risk and inter-institutional transfer of specimens in cooperative breeding programs: Herpes and the Elephant Species Survival Plans

Managers of cooperative breeding programs and re-introduction projects are increasingly concerned with the risk of disease transmission when specimens are transferred among facilities or between facilities and the natural env ironment. We used data maintained in North American studbooks to estimate t he potential risks of disease transmission by direct and indirect contact o f specimens in the American Zoo and Aquarium Association's Elephant Species Survival Plan. Histological evidence for a novel herpesvirus disease trans mitted between and within elephant species housed in North American facilit ies prompted an examination of the scope of possible transmission routes wi thin the captive population. We found that, compared with other species man aged through Species Survival Plans, elephants experience relatively few tr ansfers between toes. Nevertheless, the number of direct contacts with othe r elephants born during the study period of 1983-1996 (excluding stillbirth s) was much higher than we had anticipated (mu = 25 +/- 27; N = 59) and the number of potential indirect contacts was surprisingly large (mu = 143 +/- 92; N = 59). Although these high rates of potential contacts complicate ex act identification of infection pathways for herpesvirus, we were able to p ropose potential routes of transmission for the histologically identified c ases. Furthermore, the extraction of data from studbooks allowed us to read ily identify other specimens that did not succumb to the disease despite si milar exposure. Moreover, we were able to identify other possible cases to recommend for histological examination. Herein we reveal the possibilities of multiple disease transmission pathways and demonstrate how complex the p atterns of transmission can be, confounded by the unknown latency of this n ovel herpesvirus. This emphasizes the need for zoo veterinarians and cooper ative breeding programs to consider the full potential for disease transmis sion associated with each and every inter-zoo transfer of specimens. (C) 20 01 Wiley-Liss, Inc.