Zoonoses and haemorrhagic fever.

Virus zoonoses causing haemorrhagic fever have been recognized in three major families: Arenaviridae, Bunyaviridae and Filoviridae. All are negative-stranded RNA viruses, with genomes in two segments, three segments, or non-segmented, respectively. Acquisition of haemorrhagic fever in man generally requires close contact with a vertebrate vector species, usually rodents, for the arenaviruses and bunyaviruses. In the case of filoviruses, the vector is currently unknown, but these viruses may infect monkeys, and may contaminate cell cultures prepared from them. Both bunyavirus and arenavirus haemorrhagic fevers have arisen in humans following exposure to rodents, and in the case of Hantaan, a virus causing haemorrhagic fever with renal syndrome (HFRS), there have been numerous laboratory-acquired infections among animal care workers. As the technology to differentiate virus species has improved, it has become clear that there are numerous potentially hazardous viruses capable of causing HFRS or hantavirus pulmonary syndrome (HPS) within the feral rodent population. In many cases it would be desirable to introduce screening methods for such viruses before preparing cell cultures from these rodent or simian species that will be used to prepare biological products for human use.