Barzon Luisa, Pacenti Monia, Montarsi Fabrizio, Fornasiero Diletta, Gobbo Federica, Quaranta Erika, Monne Isabella, Fusaro Alice, Volpe Andrea, Sinigaglia Alessandro, Riccetti Silvia, Molin Emanuela Dal, Satto Sorsha, Lisi Vittoria, Gobbi Federico, Galante Silvia, Feltrin Giuseppe, Valeriano Valerio, Favero Laura, Russo Francesca, Mazzucato Matteo, Bortolami Alessio, Mulatti Paolo, Terregino Calogero, Capelli Gioia
Department of Molecular Medicine, University of Padova, via A Gabelli 63, 35121 Padova, Italy.
Microbiology and Virology Unit, Padova University Hospital, via Giustiniani 2, 35128 Padova, Italy.
J Travel Med. 2022 Nov 4;31(8). doi: 10.1093/jtm/taac125.
A new strain of WNV lineage 1 (WNV - 1) emerged in the Veneto Region, northern Italy, in 2021, eight years after the last outbreak of WNV - 1 in Italy. The virus, which co-circulates with WNV-2, has become endemic in the Region, where, in 2022, most human cases of neuroinvasive disease (WNND) reported in Europe have occurred.
Comparative analysis of the epidemiology and clinical presentation of WNV-1 and WNV-2 infection in humans, as well as the temporal and geographic distribution of WNV-1 and WNV-2 among wild birds and Culex pipiens mosquitoes in Veneto, from May 16th to August 21st, 2022, to determine if the high number of WNND cases was associated with WNV-1.
As of August 21st, 2022, 222 human cases of WNV infection were confirmed by molecular testing, including 103 with fever (WNF) and 119 with WNND. WNV lineage was determined in 201 (90.5%) cases, comprising 138 WNV-1 and 63 WNV-2 infections. During the same period, 35 blood donors tested positive, including 30 in whom WNV lineage was determined (13 WNV-1 and 17 WNV-2). Comparative analysis of the distribution of WNV-1 and WNV-2 infections among WNND cases, WNF cases and WNV-positive blood donors showed that patients with WNND were more likely to have WNV-1 infection than blood donors (odds ratio 3.44; 95% CI 95% 1.54 to 8.24; p = 0.0043). As observed in humans, in wild birds WNV-1 had higher infectious rate (IR) and showed a more rapid expansion than WNV-2. At variance, the distribution of the two lineages was more even in mosquitoes, but with a trend of rapid increase of WNV-1 IR over WNV-2.
Comparative analysis of WNV-1 vs WNV-2 infection in humans, wild birds, and mosquitos showed a rapid expansion of WNV-1 and suggested that WNV-1 infected patients might have an increased risk to develop severe disease.
2021年，意大利北部威尼托地区出现了一种新型西尼罗河病毒1型（WNV-1）毒株，距意大利上一次WNV-1疫情爆发已有八年。该病毒与WNV-2共同传播，已在该地区流行，2022年欧洲报告的大多数人类神经侵袭性疾病（WNND）病例都发生在该地区。
对2022年5月16日至8月21日期间威尼托地区人类WNV-1和WNV-2感染的流行病学和临床表现，以及WNV-1和WNV-2在野生鸟类和致倦库蚊中的时间和地理分布进行比较分析，以确定WNND病例数高是否与WNV-1有关。
截至2022年8月21日，通过分子检测确诊222例人类WNV感染病例，其中103例为发热（WNF）病例，119例为WNND病例。在201例（90.5%）病例中确定了WNV谱系，包括138例WNV-1感染和63例WNV-2感染。同期，35名献血者检测呈阳性，其中30名确定了WNV谱系（13例WNV-1和17例WNV-2）。对WNND病例、WNF病例和WNV阳性献血者中WNV-1和WNV-2感染分布的比较分析表明，WNND患者比献血者更有可能感染WNV-1（比值比3.44；95%置信区间1.54至8.24；p = 0.0043）。正如在人类中观察到的那样，在野生鸟类中WNV-1的感染率（IR）更高，并且比WNV-2显示出更快的传播速度。不同的是，两种谱系在蚊子中的分布更为均匀，但WNV-1的IR有超过WNV-2快速增加的趋势。
对人类、野生鸟类和蚊子中WNV-1与WNV-2感染的比较分析表明WNV-1迅速传播，并提示WNV-1感染患者发生严重疾病的风险可能增加。
