Prevalence of Otarine Herpesvirus-1 in Wild Populations of Peruvian Pinnipeds: Effects of Species, Sex, Age Class, and Sampling Site
Otarine herpesvirus-1 (OtHV-1) is associated with urogenital carcinoma in free-ranging California sea lions (Zalophus californianus, CSL), and has recently been documented in urogenital swabs from wild populations of South American sea lions (Otaria byronia, SASL) and Peruvian fur seals (Arctocephalus australis unnamed subspecies, PFS) in Peru.1-4 The objective of this study was to determine if prevalence of OtHV-1 infection varies by species, age class, sex, or sample site in these species. Urogenital swabs collected from 132 live pinnipeds at Punta San Juan, Peru over six years (2011, 2014–2018) were analyzed via qPCR for OtHV-1. Prevalence of OtHV-1 infection in SASL and PFS on urogenital swabs was 39.5% (32/81) and 37.3% (19/51), respectively. Adults were significantly more likely to be positive than pups (chi-square, p<0.01), but there was no significant difference between species, sexes, or years. Only 5.6% (4/71) and 1.1% (1/90) of concurrent conjunctival and oropharyngeal swabs were positive, respectively. Agreement in OtHV-1 detection between sampling sites was poor (Cohen’s kappa=0.027–0.386). Detection of OtHV-1 was highest in urogenital swabs; two animals were positive at one of the other sites but negative on a urogenital swab. The much higher prevalence in adults compared with pups, as well as the higher prevalence in urogenital swabs, suggests a sexual transmission, which is similar to CSL.1,5 These data provide insight into dynamics of the potentially oncogenic OtHV-1 in a different ecosystem, emphasizing the importance for continued monitoring of disease that may improve conservation efforts at Punta San Juan.
The authors thank Marco Cardeña and the biologist teams at the Punta San Juan Program, as well as Dr. Gwen Jankowski, Dr. Jenny Meegan, and all those who assisted with animal immobilization and sample collection. We thank Jeremy Rayl and Emilie Ospina for their extensive assistance in the laboratory, as well as Dr. Alissa Deming and Dr. Jim Wellehan for their expertise. Funding for this project was provided in part by the generous support of the Chicago Board of Trade Endangered Species Fund, the Paul M. Angell Family Foundation, and the Feay Family. We acknowledge the Peruvian government agencies SERNANP for access inside the RNSIIPG-Punta San Juan reserve and AGRORURAL for use of field facilities. Research and samples were collected under permits RJ No. 23-2011, 024-2014, and 019-2016-SERNANP-RNSIIPG.
1. Buckles EL, Lowenstine LJ, DeLong RL, Melin SR, Vittore RK, Wong HN, Ross GL, St Leger JA, Greig DJ, Duerr RS, Gulland FMD, Stott JL. 2007. Age-prevalence of otarine herpesvirus-1, a tumor-associated virus, and possibility of its sexual transmission in California sea lions. Vet Microbiol 120:1–8.
2. Buckles EL, Lowenstine LJ, Funke C, Vittore RK, Wong HN, St Leger JA, Greig DJ, Duerr RS, Gulland FM, and Stott JL. 2006. Otarine herpesvirus-1, not papillomavirus, is associated with endemic tumours in California sea lions (Zalophus californianus). J Comp Pathol 135:183–189.
3. King DP, Hure MC, Goldstein T, Aldridge BM, Gulland FM, Saliki JT, Buckles EL, Lowenstine LJ, Stott JL. 2002. Otarine herpesvirus-1: a novel gammaherpesvirus associated with urogenital carcinoma in California sea lions (Zalophus californianus). Vet Microbiol 86:131–137.
4. Tang K, Adkesson MJ, Adamovicz L, Cortes-Hinojosa G, Cardenas-Alayza S, Allender MC. 2017. Detection of herpesvirus in wild populations of South American sea lions (Otaria bryoniai) and Peruvian fur seals (Arctocephalus australis) in Peru. American Association of Zoo Veterinarians Annual Conference Proceedings, Dallas, TX; Pp. 62–63.
5. Barragan-Vargas C, Montano-Frias J, Avila Rosales G, Godinez-Reyes CR, Acevedo-Whitehouse K. 2016. Transformation of the genital epithelial tract occurs early in California sea lion development. R Soc Open Sci 3:150419. http://dx.doi.org/10.1098/rsos.150419.