Evidence of coinfection of African swine fever virus genotype X and Porcine parvovirus type 3 at pig farms in the North Kivu province, Eastern Democratic Republic of Congo

Abstract

Background African swine fever virus (ASFV) and Porcine parvovirus (PPV) are highly contagious viral pathogens that can cause devastating diseases in the pig industry. The absence of studies on the coinfection of ASFV and PPV in North Kivu raises concerns, especially given the uncontrolled movement of pigs and pig products between North and South Kivu in neighbouring countries where both diseases have been reported in domestic and wild pigs. A multifaceted approach was carried out to identify putative pathogens and risk factors associated with the transmission and spread of African Swine Fever (ASF) and PPV coinfections at pig farms in North Kivu province. Materials and methods A structured questionnaire was administered to collect risk factors associated with ASFV and PPV transmission dynamics, alongside 117 blood samples collected from domestic pigs and tested for the presence of ASFV and PPV using Polymerase Chain Reaction (PCR). The resulting PCR amplification products were sequenced using the standard Sanger sequencing method. Results and Discussion The results of Multivariable logistic regression analysis indicated that free-ranging system of pigs (OR = 3.64 95% CI: 1.076–12.92) is a major risk factor positively associated with ASFV and PPV3 infections (OR = 4.82, 95% CI: 1.06–20.86) at pig farms in North Kivu Province, eastern DRC. Free-ranging systems, where pigs roam outdoors, may increase the risk of exposure to infected vectors, wildlife reservoirs, or contaminated environments, thereby facilitating the spread of ASFV and PPV3. From thirteen PCR-positive pigs for ASFV (23.5%), four were co-infected with PPV. Phylogenetic analysis of ASFV p72 and p54 protein genes revealed that ASFV field isolates belong to genotype X whilst PPV clustered with porcine reproductive virus (PPV type 3). Owing to the transboundary nature of ASFV and PPV3 infections, viruses can easily spread across borders. This highlights the need for enhanced surveillance, early detection, and rapid response mechanisms to prevent and control the spread of these diseases regionally and internationally.