Lassa Fever Immune Plasma

122 Units of plasma were obtained in Liberia from convalescents from Lassa fever. 98 units were forwarded to the USAMRIID for its use, of these, 59 were found to have Log Neutralization titers of 00.3 or higher, indicating a protective value against Lassa fever (LF) adequate for the use of USAMRIID. Surveys of patient sera in a number of hospitals indicated that as many as 15% of adults admitted for fever had LF. Surveys of hospital staffs throughout Liberia indicated that LF is endemic in all parts of the country. Surveys of village populations revealed prevalences of Lassa virus (LV) antibodies at a titer of 1:8 or more by the indirect fluorescent antibody technique. Prevalences were higher in roadside villages than in villages in the bush. LV was isolated 38 times from 31 patients in specimens forwarded to USAMRIID. At least one virus type was found differing from that previously discovered in nearby Sierra Leone.