abnormally, and sometimes coughing. If forced to stand, they appear unsteady on their legs; this is called congenital tremor type A-I in newborn piglets. Within a few days of infection, they enter a comatose state and then die. In pregnant sows, spontaneous abortions may occur. In milder infections, affected pigs lose weight, become thin, and develop signs of pneumonia, skin ulcers, and swollen joints. Diagnosis The clinical symptoms of ASFV infection are very similar to classical swine fever, and the two diseases normally have to be distinguished by laboratory diagnosis. This diagnosis is usually performed by an ELISA, real time PCR or isolation of the virus from either the blood, lymph nodes, spleen, or serum of an infected pig. Spread The virus can be spread by ticks, but also by swine eating pork products that contain the virus. Biosecurity measures are essential for prevention and control of African swine fever. Disinfection procedures are an important asset of the mitigation phase. Laboratory tests have been conducted to assess the efficacy of chemical products and commercial disinfectants against African swine fever. The National Pig Association, a UK industry body, states that the virus can also be transmitted by direct or indirect contact with infected pigs, faeces or body fluids. As the virus may survive 11 days in pig faeces, and months or years in pork products, the association advises strict biosecurity measures for pig farms including a three-day quarantine on entering the UK, and avoiding both pigs and areas where wild boar are found. Vaccine research Vietnam successfully produced the first vaccine against African swine fever on June 1, 2022. An experimental vaccine is in development against the 2007 Georgia isolate currently circulating, which is attenuated by deletion of the viral I177L gene. History The first outbreak was retrospectively recognized as having occurred in 1907 after ASF was first described in 1921 in Kenya. The disease remained restricted to Africa until 1957, when it was reported in Lisbon, Portugal. A further outbreak occurred in Portugal in 1960. Subsequent to these initial introductions, the disease became established in the Iberian peninsula, and sporadic outbreaks occurred in France, Belgium, and other European countries during the 1980s. Both Spain and Portugal had managed to eradicate the disease by the mid-1990s through a slaughter policy. ASFV crossed the Atlantic Ocean, and outbreaks were reported in some Caribbean islands, including Hispaniola (Dominican Republic and Haiti). Resultantly US