Nipah virus. Coloured transmission electron micrograph (TEM) of a mature extracellular Nipah virus particle (virion, green), near the periphery of an infected cultured VERO cell (brown). Nipah virus is zoonotic (transmitted to humans from animals) and has been associated with encephalitis (inflammation of the brain). Nipah virus infection is characterised by fever and drowsiness and more serious central nervous system disease, such as coma, seizures and an inability to maintain breathing. It was first described in Malaysia and Singapore in pig farmers but is also found in the wild in bats.