First Record of West Nile Virus Specific Seroconversion in Dogs From Eastern Romania

Abstract

West Nile virus (WNV) infection causes diseases that vary in intensity from asymptomatic to fatal encephalitis in humans and animals. The etiological agent is a Flavivirus belonging to Japanesse Encephalitis complex. This zoonotic virus is maintained in nature in an enzootic cycle between mosquitoes and birds as amplifying hosts. Except birds, a wide variety of animals develop seroconversion caused by infection, and previous studies indicated that dogs may be considered as sentinel for WNV. The importance of studying this virus is caused by its zoonotic character, limited possibilities of active surveillance and real-time alertness of the infection’s presence in the human and animal populations. The aim of the study was to demonstrate and estimate the seroconversion in dogs within an area with confirmed cases in humans and animals. A total number of 76 serum samples were evaluated for the presence of specific anti WNV antibodies using a commercial competitive ELISA kit, for the detection of anti-pr-E antibodies (ID Screen® West Nile Competition Multi-species). The results indicated specific antibodies in 32 (42.1%) out of 76 samples tested. Positive results were recorded in all four counties from which samples were collected. Our preliminary results proved the circulation of WNV in dogs in areas where the infection was previously reported in animals and humans.