The effect of urbanization on Neospora caninum seroprevalence in white-tailed deer (Odocoileus virginianus)

Authors: BALLASH, GREGORY - The Ohio State University; Jenkins, Mark; Kwok, Oliver; Dubey, Jitender; SHOBEN, ABIGAIL - The Ohio State University; ROBISON, TERRY - Cleveland Metroparks; KRAFT, TOM - Cleveland Metroparks; SHAFFER, ERIK - Cleveland Metroparks; DENNIS, PATRICIA - The Ohio State University

Submitted to: EcoHealth
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/12/2018
Publication Date: 1/9/2019
Citation: Ballash, G.A., Jenkins, M.C., Kwok, O.C., Dubey, J.P., Shoben, A.B., Robison, T.L., Kraft, T., Shaffer, E.E., Dennis, P.M. 2019. The effect of urbanization on Neospora caninum seroprevalence in white-tailed deer (Odocoileus virginianus) . EcoHealth. 16:109. https://doi.org/10.1007/s10393-018-1390-x
DOI: https://doi.org/10.1007/s10393-018-1390-x

Interpretive Summary: Toxoplasmosis, caused by the single celled parasite, Toxoplasma gondii, continues to be a public health probem. In addition to causing severe disease in humans, toxoplasmosis also causes abortions in livestock and mortality in many other hosts. Neosporosis, caused by a parasite Neospora caninum, is relatively a newly recognized entity. Until 1988, N. caninum was misdiagnosed as T. gondii. In 1988, J.P. Dubey (an ARS researcher) in collaboration with others, cultivated and named the parasite N. caninum. Neosporosis is now considered the most important cause of abortion in cattle worldwide. In The USA, white-tailed deer are considered the main reservoir of Neospora infection for cattle. Here, the authors surveyed 2 populations of deer from urban and suburban populations of deer in Ohio. Significant risk factors for seropositivity were age class and urbanization. Deer from urbanized environments were 2.74 times more likely to be seropositive than those from suburban habitats. The authors speculate the main route of exposure in white-tailed deer is ingestion of N. caninum oocysts from contaminated environments and urbanized habitats facilitate this exposure. This paper will be of interest to parasitologists, biologists and veterinarians.

Technical Abstract: The protozoan Neospora caninum is transmitted between domestic and wildlife species. Urbanized environments and deer density may facilitate this transmission and play a critical role in the spillover of N. caninum from domestic animals to wildlife. White-tailed deer (Odocoileus virginianus; WTD) are an important intermediate host for maintaining the sylvatic cycle of N. caninum in the USA. Here, we assayed serum samples from 444 WTD from a nature reservation across a suburban to urban gradient in Ohio, USA. Antibodies to N. caninum were found by using a recombinant NcGRA ELISA in 23.6% (105/444); 27.6% (89/323) from urban reservations and 13.2% (16/121) from suburban reservations. Significant risk factors for seropositivity were age class (p=0.002) and urbanization (p=0.031). Deer from urbanized environments were 2.74 times more likely to be seropositive than those from suburban habitats. We speculate the main route of exposure in white-tailed deer is ingestion of N. caninum oocysts from contaminated environments and urbanized habitats facilitate this exposure.