Barbic Ljubo, Vilibic-Cavlek Tatjana, Listes Eddy, Stevanovic Vladimir, Gjenero-Margan Ira, Ljubin-Sternak Suncanica, Pem-Novosel Iva, Listes Irena, Mlinaric-Galinovic Gordana, Di Gennaro Annapia, Savini Giovanni
1 Department of Microbiology and Infectious Diseases with Clinic, Faculty of Veterinary Medicine, University of Zagreb , Zagreb, Croatia .
Vector Borne Zoonotic Dis. 2013 Oct;13(10):772-4. doi: 10.1089/vbz.2012.1236. Epub 2013 Jun 29.
We report the first serological evidence of Usutu virus (USUV) infection in horses in Croatia. During 2011, 1380 horse serum samples from healthy animals were collected from six northern Croatian counties. All samples were first screened for West Nile virus (WNV) immunoglobulin G (IgG) antibodies using an enzyme-linked immunosorbent assay (ELISA). Sixty-nine WNV ELISA-reactive samples were further tested for WNV antibodies by a virus neutralization assay (VN assay) and plaque reduction neutralization test (PRNT), and USUV by a VN assay and tick-borne encephalitis virus (TBEV) antibodies by PRNT. During the same period, 306 human serum samples from patients coming for routine testing with no symptoms of acute febrile disease were tested for USUV IgG using ELISA. Reactive samples were tested for both USUV and WNV using a VN assay. USUV-specific neutralizing antibodies were detected in two of 69 WNV ELISA-reactive horse serum samples. Seropositive animals were found in two different regions of Croatia. One additional sample showed specific WNV-neutralizing antibodies that cross-neutralized USUV. Only one human sample (0.3%) was reactive to USUV antibodies in an ELISA test. In a confirmatory test, WNV-neutralizing antibodies were detected, indicating cross-reactive antibodies with USUV in ELISA. The exposure to USUV was documented in two WNV ELISA-reactive horses at distant locations. These results indicate the presence of USUV in northern Croatia.
我们报告了克罗地亚马匹感染乌苏图病毒（USUV）的首个血清学证据。2011年期间，从克罗地亚北部六个县的健康动物身上采集了1380份马血清样本。所有样本首先使用酶联免疫吸附测定（ELISA）筛查西尼罗河病毒（WNV）免疫球蛋白G（IgG）抗体。对69份ELISA反应性WNV样本进一步通过病毒中和试验（VN试验）和蚀斑减少中和试验（PRNT）检测WNV抗体，并通过VN试验检测USUV，通过PRNT检测蜱传脑炎病毒（TBEV）抗体。同期，对306份来自前来进行常规检测且无急性发热疾病症状患者的人血清样本，使用ELISA检测USUV IgG。对反应性样本使用VN试验检测USUV和WNV。在69份ELISA反应性马血清样本中有两份检测到USUV特异性中和抗体。在克罗地亚的两个不同地区发现了血清阳性动物。另外一份样本显示出特异性WNV中和抗体，该抗体可交叉中和USUV。在ELISA检测中，只有一份人样本（0.3%）对USUV抗体呈反应性。在确证试验中，检测到WNV中和抗体，表明ELISA中存在与USUV交叉反应的抗体。在相距遥远的两个ELISA反应性WNV马匹中记录到了USUV暴露情况。这些结果表明克罗地亚北部存在USUV。
