Seroprevalence of Orthoflaviviruses in horses in 3 different Algerian climatic zones between 2021 and 2023
摘要
Orthoflaviviruses are etiological agents of neurological diseases in equines. Horses are susceptible to equine Tick-borne encephalitis virus (TBEV), Usutu virus (USUV), and West Nile virus (WNV), although mostly WNV has been associated with clinical disease. The aim of the present study was to estimate the prevalence of TBEV, USUV and WNV in 289 healthy horses from nine provinces of Algeria. This study was conducted between March 2021 and December 2023. Sera that tested positive, doubtful, or negative close to the doubtful threshold in the Orthoflavivirus-ELISA were further tested by the virus neutralization test (VNT), using TBEV, USUV, and WNV strains. The prevalence of Orthoflaviviruses antibodies by ELISA was 23.18% (67/289) compared with 16.95% (49/289) and 0.69% (2/289) detected by WNV and USUV VNT, respectively. TBEV antibodies were not detected in any samples. WNV seroprevalence varied with age, breed, climatic zones and altitude of the horses’ locations. This is the first screening of horse sera for TBEV in Algeria. This study indicates that WNV and USUV have circulated/are circulating in the horse population in three Algerian climatic zones, unlike TBEV, which does not seem to be present.