Highly divergent herpesviruses in threatened river dolphins

Authors

Exposto Novoselecki, H.

Additional Authors

J.L. Catão-Dias, A.C. Ewbank, P.E. Navas-Suárez, A. Duarte-Benvenuto, H. Christino Lial, S. Costa Silva, A.M. Sánchez-Sarmiento, W. Gravena, V.M. Ferreira da Silva, V.L. Carvalho, M. Marmontel, C.P. Bertozzi, V. Lanes Ribeiro, R. del Rio do Valle, J. Marigo, C.G. das Neves, F. Esperón & C. Sacristán

Year

2021

Volume & Issue

Volume 11, Article number: 24528 (2021)

Country / Region

Bolivia, South America, Brazil

Document Type

Peer-reviewed journal article

Species

Amazon river dolphin, Boto

Science Keywords

Animal Health

Conservation Measure

Species knowledge and understanding

Abstract

River dolphins are a highly threatened polyphyletic group comprised of four odontocete families: Iniidae, Pontoporiidae, Lipotidae, and Platanistidae, the first two endemic to South America. To address the knowledge gap regarding infectious agents in this cetacean group, we surveyed the presence of herpesviruses by PCR in skin and/or blood samples of live-captured Amazon (Inia geoffrensis, n = 25) and Bolivian (Inia boliviensis, n = 22) river dolphins of the Amazon basin and in selected tissue samples of franciscanas (Pontoporia blainvillei, n = 27) stranded or bycaught in southeastern Brazil. Additionally, available franciscana tissue samples were examined by histopathology. Herpesvirus DNA was amplified in 13 Bolivian river dolphins (59.1%, 95% CI 38.5–79.6%) and 14 franciscanas (51.9%, 95% CI 33.0–70.7%). All Amazon river dolphins were herpesvirus-negative. Two different herpesviruses were found in Bolivian river dolphins: a previously known gammaherpesvirus detected in blood and/or skin samples of all positive individuals and a novel alphaherpesvirus in the skin of one animal. A new gammaherpesvirus was found in several franciscana samples—the first herpesvirus recorded in Pontoporiidae. Intranuclear inclusion bodies consistent with herpesvirus were observed in the lymph node of one franciscana. The high divergence among the obtained herpesviruses and those previously described can be explained by viral-host coevolution, and by the fact that these populations are fairly isolated.