Tsai Wen-Yang, Tseng Alanna C, Chen Guan-Hua, Hsieh Szu-Chia, Balmaseda Angel, Nerurkar Vivek R, Harris Eva, Wang Wei-Kung
Department of Tropical Medicine, Medical Microbiology and Pharmacology, University of Hawaii at Manoa, Honolulu, Hawaii, USA.
Pacific Center for Emerging Infectious Diseases, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, Hawaii, USA.
Microbiol Spectr. 2025 Jul;13(7):e0004725. doi: 10.1128/spectrum.00047-25. Epub 2025 May 22.
Since its introduction to the Western Hemisphere in 1999 in New York City, West Nile virus (WNV) has spread throughout the continental USA and moved into Canada, Mexico, Caribbean, and Central and South Americas. While WNV has caused ~7 million human infections and >59,000 cases in the USA and >6,000 cases in Canada, only few human cases have been reported in Latin America. Due to the cross-reactivity of anti-envelope antibodies, the detection of WNV infection by serology to explore its epidemiology in Latin America, where multiple flaviviruses co-circulate, remains a challenge. Previously, we reported that anti-premembrane (prM) antibodies can distinguish between four flavivirus (WNV, dengue, Zika, and yellow fever viruses) infections. In this study, we examined 73 samples from 40 Zika cases from a pediatric cohort in Nicaragua using Western blot analysis and detected anti-prM antibodies to WNV in three participants in samples collected between 2016 and 2017, suggesting previous WNV infection prior to ZIKV infection. Analysis of available archived samples revealed anti-WNV prM antibodies in the earliest samples (2007-2009), which were further confirmed by plaque reduction neutralization test, suggesting that they were infected by WNV prior to 2007-2009. Our report of WNV infection in three Nicaraguan children, corresponding to a seropositive rate of 7.5%, highlights the transmission of WNV in humans in Central America prior to 2007. Future studies with improved serological tests for WNV surveillance in Latin America are needed to enhance our understanding of the epidemiology and transmission of WNV in the Western Hemisphere.
Since its arrival to North America in 1999, West Nile virus (WNV) has caused multiple outbreaks in birds and humans, with thousands of human cases in the USA and Canada, whereas in Latin America, WNV has mainly been detected in birds and horses with few human cases. Due to cross-reactivity of anti-envelope antibodies among different flaviviruses, detection of WNV infection by serology to explore its epidemiology in Latin America remains a challenge. Previously, we reported that anti-premembrane antibodies can discriminate four flavivirus infections using Western blot analysis. Based on anti-WNV premembrane antibodies and confirmation by neutralization test, we report three Nicaraguan children with WNV infection, corresponding to a seropositive rate of 7.5%. Our findings underscore the transmission of WNV in humans in Central America and the application of improved seroepidemiological tools to address the knowledge gaps on the prevalence and distribution of WNV in Latin America and the Western Hemisphere.
自1999年在纽约市传入西半球以来，西尼罗河病毒（WNV）已在美国大陆传播，并蔓延至加拿大、墨西哥、加勒比地区以及中美洲和南美洲。在美国，WNV已导致约700万人感染，超过59000例病例，在加拿大超过6000例病例，但拉丁美洲仅报告了少数人类病例。由于抗包膜抗体的交叉反应性，在多种黄病毒共同传播的拉丁美洲，通过血清学检测WNV感染以探索其流行病学仍然是一项挑战。此前，我们报道抗前膜（prM）抗体可以区分四种黄病毒（WNV、登革热、寨卡和黄热病病毒）感染。在本研究中，我们使用蛋白质印迹分析检查了来自尼加拉瓜一个儿科队列的40例寨卡病例的73份样本，并在2016年至2017年期间采集的样本中检测到3名参与者体内存在针对WNV的抗prM抗体，这表明在寨卡病毒感染之前曾有过WNV感染。对现有存档样本的分析显示，最早的样本（2007 - 2009年）中存在抗WNV prM抗体，这通过蚀斑减少中和试验得到进一步证实，表明他们在2007 - 2009年之前就感染了WNV。我们报告了3名尼加拉瓜儿童感染WNV，血清阳性率为7.5%，这突出了2007年之前中美洲地区WNV在人类中的传播情况。未来需要开展改进的血清学检测以对拉丁美洲的WNV进行监测，从而增进我们对西半球WNV流行病学和传播情况的了解。
自1999年抵达北美以来，西尼罗河病毒（WNV）已在鸟类和人类中引发多次疫情，在美国和加拿大导致数千例人类病例，而在拉丁美洲，WNV主要在鸟类和马匹中被检测到，人类病例较少。由于不同黄病毒之间抗包膜抗体的交叉反应性，通过血清学检测WNV感染以探索其在拉丁美洲的流行病学仍然是一项挑战。此前，我们报道抗前膜抗体可通过蛋白质印迹分析区分四种黄病毒感染。基于抗WNV前膜抗体并经中和试验确认，我们报告了3名感染WNV的尼加拉瓜儿童，血清阳性率为7.5%。我们的研究结果强调了中美洲地区WNV在人类中的传播情况，以及应用改进的血清流行病学工具来填补拉丁美洲和西半球WNV流行率和分布方面的知识空白。
