African swine fever virus, illustration. This is the structure of the intracellular form of the virus. It consists of a protein capsid (blue) that encloses an inner lipid envelope, a protein core shell and a core of double-stranded DNA (deoxyribonucleic acid) genetic material. The capsid has protruding surface proteins that allow the virus to attach to its target cells. African swine fever virus causes African swine fever, a haemorrhagic fever in pigs that has a high mortality rate.