Rusenova Nikolina, Rusenov Anton
Department of Veterinary Microbiology, Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, Bulgaria.
Department of Internal Diseases, Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, Bulgaria.
Vet Sci. 2025 Apr 16;12(4):373. doi: 10.3390/vetsci12040373.
This study aimed to assess West Nile virus (WNV) and Usutu virus seroprevalence among the dog population in the Danube region, Bulgaria, to confirm the results of ELISA by the virus neutralisation test (VNT), as well as to analyse several risk factors of seropositivity in dogs. To implement this, a total of 201 blood samples were collected from dogs in four districts bordering the Danube River. All the samples were tested for anti-WNV protein E antibodies using competitive ELISA. Neutralising antibodies against WNV and Usutu virus were tested in all the ELISA-positive samples. The results show a WNV seroprevalence of 45.3% ( = 91, CI = 36.45-55.59) by ELISA, whereas the virus neutralisation test indicated a seroprevalence of 21.9% (n = 44, CI = 15.91-29.39). Neutralising antibodies against Usutu virus were detected for the first time in Bulgaria, with a prevalence of 6% (n = 12, CI = 3.09-10.43). Compared to VNT, ELISA demonstrated 100.0% sensitivity and 70.1% specificity. The region ( < 0.0187), the district ( = 0.0258) and the ages of the dogs ( = 0.0180) were identified as statistically significant risk factors associated with WNV seropositivity. This study provides indirect evidence of WNV and Usutu virus circulation among dogs in the Danube region of Bulgaria, highlighting a potential risk for susceptible hosts in the area.
本研究旨在评估保加利亚多瑙河地区犬类群体中的西尼罗河病毒（WNV）和乌苏图病毒血清阳性率，通过病毒中和试验（VNT）确认酶联免疫吸附测定（ELISA）的结果，并分析犬类血清阳性的若干风险因素。为实现这一目标，从多瑙河沿岸四个地区的犬类中总共采集了201份血液样本。所有样本均使用竞争ELISA检测抗WNV E蛋白抗体。对所有ELISA阳性样本检测针对WNV和乌苏图病毒的中和抗体。结果显示，ELISA检测的WNV血清阳性率为45.3%（n = 91，CI = 36.45 - 55.59），而病毒中和试验显示的血清阳性率为21.9%（n = 44，CI = 15.91 - 29.39）。保加利亚首次检测到针对乌苏图病毒的中和抗体，流行率为6%（n = 12，CI = 3.09 - 10.43）。与VNT相比，ELISA显示出100.0%的灵敏度和70.1%的特异性。地区（P < 0.0187）、行政区（P = 0.0258）和犬龄（P = 0.0180）被确定为与WNV血清阳性相关的统计学显著风险因素。本研究提供了WNV和乌苏图病毒在保加利亚多瑙河地区犬类中传播的间接证据，突出了该地区易感宿主面临的潜在风险。
