Four gammaherpesviruses have been described in otariids, three of which have been primarily found in California sea lions (CSL; Zalophus californianus).1-4 Otarine herpesvirus-1 (OtHV-1) is closely associated with a high incidence of urogenital carcinoma in CSL.1-4 A single Peruvian fur seal (Arctocephalus australis) with urogenital carcinoma has been observed, with OtHV-1 likely contracted in managed care, but little is known about the herpesviruses present in free-ranging populations of South American otariids.3 While herpesviruses tend to be relatively host specific, host jumping has been reported in closely related species.3 OtHV-1 in CSL and otarine herpesvirus-4 in Northern fur seals (Callorhinus ursinus) appear to be very closely related.2 This study tested 67 genital swabs from a longitudinal study on South American pinnipeds from 2011, 2014, and 2015 using a consensus PCR. There was an overall prevalence of 21% (n=14). Sequencing revealed 99% homology to OtHV-1. Positive samples were observed mostly in Peruvian fur seals (n=13; 29% species prevalence), with a single sample from a South American sea lion (Otaria byronia; 5% species prevalence). Prevalence was not significantly different between 2011 (24%), 2014 (17%), and 2015 (18%). No animals showed any clinical signs of disease during their examinations. This study demonstrates, for the first time, the presence of herpesvirus in apparently healthy, free-ranging Peruvian fur seals and South American sea lions.
The authors would like to thank Jeremy Rayl for his extensive assistance in the laboratory. The authors also thank Dr. Gwen Jankowski, Dr. Jenny Meegan, and all staff of the Chicago Zoological Society that assisted in field sample collection.
1. Buckles EL, Lowenstine LJ, Funke C, Vittore RK, Wong HN, St Leger JA, Greig DJ, Duerr RS, Gulland FM, and Stott JL. Otarine herpesvirus-1, not papillomavirus, is associated with endemic tumours in California sea lions (Zalophus californianus). J Comp Pathol. 2006;135:183–189.
2. Cortes-Hinojosa G, Gulland FM, DeLong R, Gelatt T, Archer L, Wellehan JFX Jr. A novel gammaherpesvirus in Northern fur seals (Callorhinus ursinus) is closely related to the California sea lion (Zalophus californianus) carcinoma-associated otarine herpesvirus-1. J Wildl Dis. 2015;52:88–95.
3. Dagleish MP, Barrows M, Maley M, Killick R, Finlayson J, Goodchild R, Valentine A, Saunders R, Willoughby K, Smith KC, Stidworthy MF. The first report of otarine herpesvirus-1-associated urogenital carcinoma in a South American fur seal (Arctocephalus australis). J Comp Pathol. 2012;149:119–125.
4. King DP, Hure MC, Goldstein T, Aldridge BM, Gulland FM, Saliki JT, Buckles EL, Lowenstine LJ, Stott JL. Otarine herpesvirus-1: a novel gammaherpesvirus associated with urogenital carcinoma in California sea lions (Zalophus californianus). Vet Microbiol. 2002;86:131–137.