African swine fever virus

African Swine Fever Virus (ASFV) is a widespread disease which infects members of the pig family(Suidae). Anumberoftick species are believed to be the vector for the disease,as well as being transmitted by raw pork and pig excrement [1]. After firstly being identified in Kenya in 1921, ASFV became endemic in sub-Saharan Africa, with regular outbreaks being reported across Europe, Asia and South America throughout the century [2]. More recently the virus was introduced in Georgia and spread throughout the region, as well as mass outbreaks occurring in China in 2018 [3].
ASFVistheonlymemberoftheAsfaridaefamily.ItisalargeenvelopeddoublestrandedDNA virus of icosahedral morphology with an average diameter of 200nm and isolates contain genomes between 170-190Kbp encoding for up to 167 open reading frames [2]. The morphology of ASFV consist of several concentric domains. An inner core contains the nucleoid coated with a thick protein layered core shell, which is surrounded by an inner lipid envelope , all of which is encompassed by the capsid [2]. ASFV begins its replication cycle in the nucleus of infected cells before moving to the cytoplasm where the majority of the replication takes place [2]. Gene transcription is highly regulated, with distinct classes of mRNA identified to accumulate at early, intermediate and late transcripts of the virus [2]. The disease induces acute haemorrhagic disease within its hosts, causing high fevers and skin haemorrhages, with death often occurring within ten days of clinical symptoms appearing [4].

References: 1: The Centre for Food Security and Public Health (2015), African Swine Fever. 2: Galindo, I. and Alonso, C., 2017. African swine fever virus: a review. Viruses, 9(5), p.103. 3: Zhou, X., Li, N., Luo, Y., Liu, Y., Miao, F., Chen, T., Zhang, S., Cao, P., Li, X., Tian, K. and Qiu, H.J., 2018. Emergence of African swine fever in China, 2018. Transboundary and emerging diseases, 65(6), pp.1482-1484. 4: Gallardo, C., Ademun, A.R., Nieto, R., Nantima, N., Arias, M., Martín, E., Pelayo, V. and Bishop, R.P., 2011. Genotyping of African swine fever virus (ASFV) isolates associated with disease outbreaks in Uganda in 2007. African Journal of biotechnology, 10(17), pp.3488-3497.