Review of a newly recognized disease of elephants caused by endotheliotropic herpesviruses

There are two newly recognized herpesviruses that cause a fatal disease syn drome in elephants. They are known as the elephant endotheliotropic herpesv iruses, of which one is fatal for Asian elephants (Elephas maximus) and the other for African elephants (Loxodonta africana) [Richman et al., Science 283:1171-1176, 1999a]. The disease syndrome affects predominantly young ele phants and has been described in North America [Richman et al., J Wildl Dis 36:1-12, 2000], Europe [Richman et al., Verhandlangsbericht des 39 Interna tional Symposium uben Erkrankungen der Zoo und Wildtiere, Wien, 39:17-21, 1 999b; Ossent et al., Vet Pathol 27:131-133, 1990], and Israel [Richman et a l., Verhandlangsbericht des 39 International Symposium uben Erkrankungen de r Zoo und Wildtiere, Wien, 39:17-21, 1999b]. The predominant clinical signs for both species include lethargy, edematous swellings of the head, neck, and thoracic limbs, oral ulceration, cyanosis of the tongue, and death of m ost elephants in 1-7 days [Richman et al., J Wildl Dis 36:1-12, 2000]. Thre e affected young Asian elephants recovered after a 3-4-week course of thera py with the anti-herpesvirus drug famciclovir [Richman et al., J Wildl Dis 36:1-12, 2000; Schmitt and Hardy, J Elephant Managers Assoc 9:103-4, 1998]. Additional reported herpesvirus-associated lesions in otherwise healthy el ephants include localized skin papillomas in African elephants [Richman et al., Science 283:1171-1176, 1999a; Jacobson et al., J Am Vet Med Assoc 189: 1075-8, 1986], proliferative vulval lymphoid patches in African elephants [ Richman et al., Science 283:1171-1176, 1999a; Munson et al., J Zoo Wildl Me d 26:353-8, 1995], and pulmonary nodules in African elephants [Richman et a l., J Wildl Dis 36:1-12, 2000; McCulley et al., Onderstepoort J Vet Res 38: 225-236, 1971]. Recent findings suggest that these localized herpesvirus-as sociated lesions in healthy African elephants may be one source of the herp esvirus that causes disseminated disease and death in the Asian species [Ri chman et al., Science 283:1171-1176, 1999a] and the African species [Richma n et al., J Wildl Dis 36:1-12, 2000]. These findings have implications for management practices in facilities keeping both African and Asian elephants and in protecting natural elephant habitats from virulent forms of the vir us. Zoo Biol 19:383-392, 2000. (C) 2000 Wiley-Liss, Inc.