Evaluation of a West Nile virus surveillance and early warning system in Greece, based on domestic pigeons

Abstract

a b s t r a c tIn the summer of 2010 an epidemic of West Nile virus (WNV) occurred in Central Macedonia, Greece, with 197 human neuroinvasive disease (WNND) cases. In the following years the virus spread to new areas, with a total of 76 WNND cases in 2011, and 109 WNND cases in 2012 (14 and 12 WNND cases, respectively, in Central Macedonia). We established a surveillance system based on serological testing of domestic pigeons, using cELISA confirmed by serum neutralization test. In Central Macedonia, pigeon seroprevalence was 54% (95% CI: 49-59%) and 31% (95% CI: 24-37%) at the end of the 2010 and 2011 epidemic seasons, respectively. One serum was positive for neutralizing antibodies directed against Usutu virus. Pigeon WNV seroprevalence and incidence rates of human WNND after the 2010 epidemic were positively correlated ( = 0.94, at the regional unit level), while in 2011 the correlation ( = 0.56) was not statistically significant, possibly due to small number of human WNND cases recorded. To evaluate the efficacy of the system at alerting upon WNV enzootic circulation before the onset of human cases, we tested 270 pigeons in 2011 and 240 pigeons in 2012. In Central Macedonia, the first seroconversions in pigeons were recorded 44 and 47 days, respectively, before the first human WNND cases. Pigeon surveillance was used successfully for identification of areas with WNV enzootic transmission and for early warning. Timely diffusion of information to health authorities facilitated the implementation of preparedness plans to protect public health.

Spatio-temporal trends and risk factors affecting West Nile virus and related flavivirus exposure in Spanish wild ruminants

“…Additionally, given the possibility of cross-reaction with antigenically-related flaviviruses not included within the Japanese encephalitis serocomplex such as Meaban virus (MBV), bELISA-positive and doubtful samples were also tested by VNT against this flavivirus (MBV; Brest ART707 strain). VNTs were performed as previously described [3, 33]. Samples that showed neutralization and absence of cytopathic effect at dilutions ≥ 10 for WNV and USUV and ≥ 20 for MBV were considered positive.…”

First detection ofWest Nile virusin domestic pigeon in Korea

“…Accordingly, South Korea should consider adopting an Early-Warning system, such as the WNV surveillance program that is currently in place in Greece, to prevent WNV infection [1]. Overall, this is the first study to investigate WNV in South Korea, and the results highlight the risk of WNV that is occurring in South Korea and the significance of further studies.…”

Evaluation of a Multivariate Syndromic Surveillance System for West Nile Virus

“…Only two attempts to assess the sensitivity and specificity of surveillance have been made (Leblond et al 2007a, Andersson et al 2014, but the parameters of interest were only evaluated based on a limited number of outbreaks, which did not allow any conclusions to be drawn regarding the overall system performance. Timeliness has occasionally been evaluated, but only based on a limited number of real WNV outbreaks, and has not been associated with a further evaluation of system performance (Eidson et al 2001, Mostashari et al 2003, Johnson et al 2006, Veksler et al 2009, Chaintoutis et al 2014. In our study, we have refrained from assessing timeliness as there is currently little or no data to support assumptions on the temporal course on WNV outbreak in Europe, especially, in wild birds.…”