Introduction
Trading livestock through live animal markets is an important part of the economy of many developing countries (Fèvre et al., 2006; Leslie et al., 2015; Perry et al., 2005). Demand for live pigs is high in pig-producing areas of Nigeria, because these animals play a vital role in the culture and tradition of the people as they are used for celebrations and festivities (Fasina et al., 2010). Pig marketing in Nigeria consists largely of live animal sales which are acquired from multiple sources either directly from farmers at farm gates or fellow traders at live pig markets (LPMs) (Ajala & Adesehinwa, 2008; Weka et al., 2021). Hence, LPMs are hubs for the congregation of animals from a wide range of locations some of which are reporting outbreak diseases. In addition, poor biosecurity practices, limited government regulation, and poor infrastructure enhance the ease of disease spread at these markets. Likewise, the trading and movement of sick pigs have been identified as a crucial pathway to the spread of transboundary diseases like African swine fever (ASF) in endemic countries such as Nigeria (Costard et al., 2013; Olugasa & Ijagbone, 2007). Pig husbandry system in Nigeria is differentiated into mostly free-roaming/extensive, semi-intensive and intensive pig production systems in pig producing areas in Northern Nigeria and intensive commercial/ communal pig estates in Southern Nigeria (Bourn et al., 1994, Ajala et al., 2006; Saka et al., 2010; Nwanta et al., 2011). In Nigeria, farmers restock their farms from LPMs and there have been reports of ASF outbreaks in pig farms following introduction of pigs from these markets. Also, due to high demand and need for better prices by farmers and traders, pigs reared in the northern parts of Nigeria are transported to southern parts of the country, the majority of such transactions is via LPMs. ASF is a lethal transboundary disease of pigs caused by the ASF virus (ASFV) which is the only member of the genus Asfivirus and familyAsfarviridae (Dixon et al., 2020). The disease is endemic and restricted to countries in sub-Saharan Africa, but due to the highly transboundary nature of ASFV, the disease has spread to domestic and wild pigs in Europe, Asia, and Oceania (Penrith, 2020; Sauter‐Louis et al., 2020). Genetic typing of the virus is based on characterization of the p72 capsid protein of B646L , the full length of the p54 ofE183L, and further differentiation using the central variable region of B602L (Bastos et al., 2003; Gallardo et al., 2009). Based on the p72 p rotein capsid, 24 genotypes of ASFV have been identified, most of which are restricted to East and Southern Africa (Bastos et al., 2003; Quembo et al., 2018). Genotyping methods are important tools for tracing the origin of ASFVs and quickly differentiate or related virus strains during ASF outbreaks (Malogolovkin et al., 2015a). The serogrouping-identification method can be used to further discriminate ASFV strains. Based on this method, 8 ASFV serogroups have been identified based on the EP402R gene encoding the CD2V protein (Malogolovkin et al., 2015a). ASF was first introduced into Nigeria in 1997 via the trading of pigs by communities along the international border with the Benin Republic (Odemuyiwa et al., 2000). Thereafter, the disease spread to other pig-producing areas of the country through livestock trading routes (Fasina et al., 2010; Luka et al., 2016; Owolodun, et al., 2010a). ASFV genotype I was the only circulating genotype in Nigeria, until recently when genotype II was introduced into the country (Adedeji et al., 2021). Despite the importance of live pig markets (LPM) in the pig value chain in Nigeria, there are no extensive studies on the role of these markets in the epidemiology of ASF in Nigeria (Fasina et al., 2010; Luka et al., 2016; Owolodun, Bastos, et al., 2010). Though, previous studies have detected ASFV and swine influenza virus in a live pig market in Nigeria (Dennis et al., 2019; Luka et al., 2016; Meseko et al., 2014). However, these studies involved only one pig market with limited information on activities and pig movements in and out of the market. Studies in Nigeria have revealed that live bird markets play an important role in the ecology and epidemiology of Avian influenza in Nigeria (Coker et al., 2014; Fusaro et al., 2009; Sulaiman et al., 2021). Similarly, it has been reported that livestock farmers in Nigeria sell their animals through live animal markets to mitigate economic losses during disease outbreaks (Bolajoko et al., 2019). This further emphasizes the importance of live animal markets in the epidemiology of transboundary livestock diseases in Nigeria. This study assessed the role of LPMs as hotspots for transmission and continuous spread of ASFV in Nigeria