Seroepidemiological Survey of West Nile Virus Infections in Horses from Berlin/Brandenburg and North Rhine-Westphalia, Germany.

Felicitas Bergmann,Joke Bernis Sierra,Martin H Groschup,Dagmar S Trachsel,Sabita D Stoeckle,Stephan Lübke,Heidrun Gehlen,Ute Ziegler

doi:10.3390/v14020243

Felicitas Bergmann, Joke Bernis Sierra + Show 6 more

Open Access

https://doi.org/10.3390/v14020243

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Journal: Viruses	Publication Date: Jan 25, 2022
Citations: 15	License type: CC BY 4.0

Affiliation: Friedrich-Loeffler-Institut, Freie Universität Berlin

Abstract

Following the introduction of the West Nile virus (WNV) into eastern Germany in 2018, increasing infections have been diagnosed in birds, equines, and humans over time, while the spread of WNV into western Germany remained unclear. We screened 437 equine sera from 2018 to 2020, excluding vaccinated horses, collected from convenience sampled patients in the eastern and western parts of Germany, for WNV-specific antibodies (ELISAs followed by virus/specific neutralization tests) and genomes (RT-qPCRs). Clinical presentations, final diagnoses, and demographic data were also recorded. In the eastern part, a total of eight horses were found WNV seropositive in 2019 (seroprevalence of 8.16%) and 27 in 2020 (13.77%). There were also two clinically unsuspected horses with WNV-specific antibodies in the western part from 2020 (2.63%), albeit travel history-related infections could not be excluded. None of the horse sera contained WNV-specific genomes. Eight horses in eastern Germany carried WNV-IgM antibodies, but only four of these showed typical clinical signs. These results underline the difficulty of detecting a WNV infection in a horse solely based on clinical signs. Thus, WNV circulation is established in the horse population in eastern Germany, but not yet in the western part.

Highlights

IntroductionWe screened 437 equine sera from 2018 to 2020, excluding vaccinated horses, collected from convenience sampled patients in the eastern and western parts of Germany, for West Nile virus (WNV)-specific antibodies (ELISAs followed by virus/specific neutralization tests) and genomes (RT-qPCRs)
Cavalleri, Lutz Steffen Goehring and Friedrich-Loeffler Institut, Federal Research Institute for Animal Health, Institute of Novel and Emerging
West Nile virus (WNV) did not arrive in eastern Germany until the end of August 2018, the serum samples from North Rhine–Westphalia (NRW) 2018 were not tested by molecular methods

Summary

Introduction

We screened 437 equine sera from 2018 to 2020, excluding vaccinated horses, collected from convenience sampled patients in the eastern and western parts of Germany, for WNV-specific antibodies (ELISAs followed by virus/specific neutralization tests) and genomes (RT-qPCRs). There were two clinically unsuspected horses with WNV-specific antibodies in the western part from 2020 (2.63%), albeit travel history-related infections could not be excluded. Eight horses in eastern Germany carried WNV-IgM antibodies, but only four of these showed typical clinical signs. The virus circulates in an enzootic cycle between ornithophilic mosquitoes as vectors and various avian species [4,5] It has been found in over 150 bird species [6], passerines serve as the primary reservoir hosts, and corvids and birds of prey are often affected by severe clinical disease [7,8]. A variety of mammalian and reptilian species are susceptible to WNV infection under natural conditions

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