Seroepizootiological-epidemiological investigation and mapping of West Nile infection in the Republic of Serbia

Abstract

The disease caused by the West Nile virus (WNV) has been known since 1937 when it was described for the first time in Uganda. After spreading to Europe and the Middle East, the disease has changed its primary location. Today WN infection is a significant health problem in the world. As a result of the current epizootiological and epidemiological situation in Europe studies on the occurrence of WND were introduced in Serbia, also. The investigation on the presence of WNV antibodies was intensified in the period from 2008 to 2012. In this period a total of 3618 serum samples were tested from 18 localities (2736 animal sera from 8 different species and 882 human sera samples). The method applied was gel immunodiffusion and the representative samples were confirmed by the plaque reduction test (PRNT-90). Out of the total number of samples WNV antibodies were present in 3.97% horses, 0.93% dogs, 0.31% poultry and 1.36% man. In one horse serum sample there was a positive reaction with a positive control serum, thus indicating the presence of WNV antigen. The results have confirmed that WNV antibodies are present in 9 out of 18 tested locations in the Republic of Serbia. The percentage of seropositive samples varies from 0.42% in Pozarevac (horses and humans) up to 6.45% in Novi Pazar (dogs). Out of the investigated species the highest seropositivity was recorded in horses (3.97%), and lowest in poultry (0.31%). WNV is present and widespread in the Republic of Serbia, thus enabling distribution mapping.

Bolest koju izaziva virus Zapadnog Nila (WNV) je poznata još od 1937. kada je po prvi put opisana u Ugandi. Posle širenja virusa u Evropu i na Bliski istok, bolest je promenila prvobitnu lokaciju. Danas je WN infekcija značajan zdravstveni problem u svetu. Kao rezultat trenutne epizootiološko-epidemiološke situacije u Evropi, uvedena su istraživanja prisustva WNV i u Srbiji. Istraživanja prisustva antitela za WNV intenzivirana su u periodu od 2008. do 2012. godine. U ovom periodu ukupno je ispitano 3618 seruma sa 18 lokaliteta (2736 seruma životinja, od 8 različitih vrsta i 882 seruma ljudi). Korišćen je metod imunodifuzije u gelu a reprezentativni uzorak potvrđen je testom neutralizacije plaka (PRNT- 90). Od ukupnog broja uzoraka na prisustvo antitela za WNV bilo je pozitivno 3,97% konja, 0,93% pasa, 0,31% domaće živine i 1,36% ljudi. U serumu jednog konja pojavila se pozitivna reakcija sa pozitivnim kontrolnim serumom, ukazujući na prisustvo antigena WNV. Dobijeni rezultati su potvrdili da su antitela za WNV prisutna u 9 od 18 ispitivanih lokacija u Republici Srbiji. Procenat seropozitivnih varira od 0.42% u Požarevcu (konji i ljudi) do 6,45% u Novom Pazaru (psi). Od ispitivanih vrsta najveća seropozitivnost je registrovana kod konja (3,97%), a najniža kod živine (0,31%). Raspoloživi podaci ukazuju da je WNV prisutan i značajno raširen u Republici Srbiji, što je omogućilo i mapiranje njegovog širenja.