Isolation of haemorrhagic fever with renal syndrome virus from leukocytes of rats and virus replication in cultures of rat and human macrophages.

Newborn rats were inoculated intraperitoneally with haemorrhagic fever with renal syndrome (HFRS)-related virus (B-1 strain), and virus isolation from their various organs was attempted between 1 and 25 weeks after inoculation. Virus could be isolated repeatedly from lung, brain, spleen and kidney and also from peripheral blood. When virus isolation was carried out on fractionated peripheral blood cells, virus was associated mainly with the macrophage fraction and to a lesser extent with granulocytes. Virus replicated well in peritoneal exudate cells of normal rats and it grew in the adherent mononuclear cells from normal human peripheral blood. These data suggest that macrophages, permissive for HFRS-related virus replication, might contribute to the spread of viral infection in vivo.