1. INTRODUCTION
African Swine Fever (ASF) is a highly fatal viral infectious disease that manifests as a haemorrhagic fever in affected pigs (Penrith and Vosloo, 2009). ASF has been listed as a priority disease in World Organisation for Animal Health (OIE) owing to its socio-economic importance and transboundary potential (OIE, 2020a). The first report of ASF was detected in Kenya as a disease entity distinct from Classical Swine Fever (CSF) (Montgomery, 1921). Since its first inception, ASF has spread from its historic range of Africa, to several countries in Europe (France, Italy, Malta, Belgium and the Netherlands and Iberian Peninsula) (Penrith and Vosloo, 2009; Blome et al., 2013) and more recently to Asia (China, Mongolia, Vietnam, Cambodia, Korea, Lao, Myanmar, Philippines and Indonesia) threatening both domestic and wildlife conservation (FAO, 2020a). The disease ASF is caused byAfrican swine fever virus (ASFV) of genus Asfivirus and is currently the sole member of the family Asfarviridae (Alonso et al., 2018). ASFV infects domestic and wild swine (Sus scrofa ), warthogs (Phacochoerus africanus; Phacochoerus aethiopicus ) and bush pigs (Potamochoerus porcus ) (Alonso et al., 2018). ASFV can be transmitted directly during (i) contact between infected and susceptible pigs (ii) consumption of the meat from infected pigs (iii) bites of infected soft ticks (Ornithodoros species), and indirectly(iv) by contact with fomites contaminated by virus-containing matters such as blood, faeces, urine or saliva from infected pigs (Penrith and Vosloo, 2009).Clinical disease of ASF can manifest in multiple ways ranging from peracute (mortality ~100%) to an asymptomatic infection (Penrith and Vosloo, 2009).  Acute infections are typically characterized by a high fever, anorexia, lethargy, weakness, recumbency, diarrhoea and/or constipation, abdominal pain, hemorrhagic signs, respiratory distress, nasal and conjunctival discharge, and abortions in pregnant females followed by death within 6-13 days after the onset of clinical signs (Sanchez-Vizcaino, 2010). Subacute infections are often recorded with high mortality in young animals and include clinical signs such as abortion, fever, and transient haemorrhage with death or recovery within 3-4 weeks (Penrith and Vosloo, 2009; Schulz et al., 2017). Chronic infections are associated with low mortality and clinical signs such as intermittent or low fever, loss of appetite and depression which might develop over 2-15 months (Sanchez-Vizcaino, 2010).
India has reported the first outbreak of ASF in the domestic pig population of two of the North-Eastern states viz. Arunachal Pradesh and Assam to OIE on the 21st May, 2020 (OIE, 2020b). The North Eastern Region (NE) of India, owing to its unique geographical location while sharing international boundaries with China, Bhutan, Bangladesh and Myanmar bears a constant threat of transboundary emerging diseases though its porous borders (Barman et al., 2016). Apart from the first outbreak of ASF in NE India, this region has also reported several other emerging diseases of pigs such as Porcine reproductive and respiratory syndrome (Rajkhowa et al., 2015) and PorcineCircovirus -2 infections (Mukherjee et al., 2018).In this article, the authors will discuss the risk factors/indicators that might favour the spread of ASF infections in India, its possibilities of establishment of endemic infections and the control strategies to prevent future outbreaks.