Lozano A, Filipe A R
Centro Nacional de Microbiología, Instituto de Salud Carlos III, Ministerio de Sanidad y Consumo.
Rev Esp Salud Publica. 1998 May-Jun;72(3):245-50.
The West Nile Virus (WNV) is a Flavivirus which is transmitted to man by means of different species of mosquitoes and causes outbreaks and sporadic cases of illness in different regions of the Old World, including the Mediterranean Basin. Europe's wetlands which comprise a stopping-off point for birds migrating from Africa are high-risk areas as regards this infection, as well as other arthropod-borne virus infections.
For the purpose of researching the prevalence of the WNV infection and other viruses transmitted similarly among the human population of the Ebro Delta, 1037 samples of serum taken in 10 towns in this area were analyzed to detect the presence of WNV antibodies and antibodies of another 12 arthropod-borne viruses (3 Alphaviruses, 8 Flaviviridae and 1 Bunyaviridae) by means of titration by inhibition of hemagglutination (HAI). In some cases, the presence of HAI-specific IgM was analyzed after breaking down the serum by centrifuging into sucrose gradients.
In all, a significant degree of reaction was found to some of the viruses tested in 130 cases (12.5%; 4.1% to Alphavirus; 8% to Flaviviridae and 0.4% to Bunyaviridae). The analysis of the antibody titers revealed significant percentages of samples showing high was titers to WNV and other types of antigens. The spread for the antibody prevalence was highly uneven, being focused mainly in 3 localities located in land on the Delta (Ampolla, San Jaime and Montells), where the prevalence of Flaviviridae antibodies totaled as high as 30%, with residual levels of WNV-related IgM having been found in some serum samples.
These results and those obtained previously in other parts of the Iberian Peninsula suggest that the WNV is moving throughout the human population in the areas where this risk is found to exist and periodically gives rise to epidemic outbreaks. Bearing in mind the high percentage of neurological complications found to exist in the most recent outbreaks of WNV infections recorded in the Mediterranean Basin (Bucharest, Algeria), it can be thought that the WNV plays some role in the factors contributing to viral meningitis and encephalitis which occur within the population of the areas at risk within Spain.
西尼罗河病毒（WNV）是一种黄病毒，通过不同种类的蚊子传播给人类，在包括地中海盆地在内的旧大陆不同地区引发疫情和散发病例。欧洲的湿地是从非洲迁徙鸟类的停歇点，就这种感染以及其他节肢动物传播的病毒感染而言，是高风险地区。
为了研究西尼罗河病毒感染以及其他以类似方式传播的病毒在埃布罗三角洲人群中的流行情况，对该地区10个城镇采集的1037份血清样本进行分析，通过血凝抑制滴定法（HAI）检测西尼罗河病毒抗体以及另外12种节肢动物传播病毒（3种甲病毒、8种黄病毒科病毒和1种布尼亚病毒科病毒）的抗体。在某些情况下，通过蔗糖梯度离心分解血清后分析血凝抑制特异性IgM的存在情况。
总共在130例（12.5%；甲病毒为4.1%；黄病毒科为8%；布尼亚病毒科为0.4%）中发现对某些测试病毒有显著程度的反应。抗体滴度分析显示，有相当比例的样本对西尼罗河病毒和其他类型抗原呈现高滴度。抗体流行率的分布极不均衡，主要集中在三角洲陆地上的3个地方（安波利亚、圣海梅和蒙特尔斯），那里黄病毒科抗体的流行率总计高达30%，在一些血清样本中还发现了与西尼罗河病毒相关的IgM残留水平。
这些结果以及先前在伊比利亚半岛其他地区获得的结果表明，西尼罗河病毒在发现存在这种风险的地区的人群中传播，并定期引发疫情爆发。鉴于在地中海盆地（布加勒斯特、阿尔及利亚）最近记录的西尼罗河病毒感染疫情中发现存在高比例的神经并发症，可以认为西尼罗河病毒在导致西班牙有风险地区人群中发生的病毒性脑膜炎和脑炎的因素中起到了一定作用。
