False positive results using PCR detection method for African swinefever virus in wild boars from northern Romanian hunting zones

Abstract

African swine fever virus (ASFV) is an acute virus with a tropism for the pig macrophage and the ability to persist. In the absence of a vaccine, a good understanding of the ecology and epidemiology of the disease is fundamental to implement effective control measures. The recent occurrence and spread of ASFV in East Europe is perceived as a serious risk for the pig industry in the European Union. The aim of this study was to evaluate the classic detection method using polymerase chain reaction (PCR). A total number of 107 wild boar blood, tissues, and organs samples were collected from hunting areas of Romania's northern counties, from which 24 samples were positive by conventional PCR using the OIE manual for ASFV diagnostics. The positive samples were analyzed by sequencing techniques and the results were negative. Furthermore, we obtained only sequences that corresponded with a predicted uncharacterized mRNA from the Sus scrofa genome, leading to false positive results. Due to these results, an improvement in the detection method should be made, diagnostics should be based on multiple molecular tests, and a continuous monitoring plan for Romania should be applied to avoid the appearance of outbreaks.