According to a report by the OIE, the outbreak started in February with minimal fatality, but then, the number of mortalities increased drastically in May/June. The affected pig population is in a large pig farm operation that feeds several other pig markets within and outside the country.
African swine fever is already confirmed in the states of Lagos and Abia with very high morbidity and mortality. Three other states awaiting laboratory confirmation are also reporting similar mortality patterns.
June 16, 2020/ OIE.
https://www.oie.int/