Patricia A. Webb

Lassa fever: Effective therapy with ribavirin

Abstract In a study of Lassa fever in Sierra Leone, West Africa, we identified two variables associated with a high risk of death, and we evaluated the efficacy of ribavirin and Lassa virus-convalescent plasma for the treatment of Lassa fever. A serum aspartate aminotransferase level greater than or equal to 150 IU per liter at the time of hospital admission was associated with a case-fatality rate of 55 percent (33 of 60). Patients with the same risk factor who were treated for 10 days with intravenous ribavirin, begun within the first 6 days after the onset of fever, had a case-fatality rate of 5 percent (1 of 20) (P = 0.0002 by Fishers exact test). Patients whose treatment began seven or more days after the onset of fever had a case-fatality rate of 26 percent (11 of 43) (P = 0.01). Viremia with levels greater than or equal to 10(3.6) TCID50 per milliliter on admission was associated with a case-fatality rate of 76 percent (35 of 46). Patients with this risk factor who were treated with intravenous ribavirin within the first six days after onset of fever had a case-fatality rate of 9 percent (1 of 11) (P = 0.006), whereas those treated after seven days or more of illness had a fatality rate of 47 percent (9 of 19) (P = 0.035). Oral ribavirin was also effective in patients at high risk of death. Lassa-convalescent plasma did not significantly reduce mortality in any of the high-risk groups. We conclude that ribavirin is effective in the treatment of Lassa fever and that it should be used at any point in the illness, as well as for postexposure prophylaxis.

Filoviridae: a taxonomic home for Marburg and Ebola viruses?

Filoviridae: a Taxonomic Home for Marburg and Ebola Viruses ? M.P. Kiley E.T.W. Bowen G.A. Eddy M. Isaäcson K.M. Johnson J.B. McCormick F.A. Murphy S.R. Pattyn D. Peters O.W. Prozesky R.L. Regnery D.I.H. Simpson W. Slenczka P. Sureau G. van der Groen P.A. Webb H. Wulff Center for Infectious Diseases, Centers for Disease Control, Atlanta, Ga., USA; PHLS Centre for Applied Microbiology and Research, Porton Down, Salisbury, Wiltshire, UK; US Army Medical Research Institute for Infectious Diseases, Ft. Detrick, Frederick, Md., USA; The South African Institute for Medical Research, Johannesburg, South Africa; Colorado State University, College of Veterinary Medicine and Biomedical Sciences, Ft. Collins, Col., USA;Prins Leopold Instituut voor Tropische Geneeskunde, Antwerpen, Belgium; Bernard-Nocht-Institut für Schiffsund Tropenkrankheiten, Abteilung für Virologie, Hamburg, FRG; National Institute for Virology, Sandringham, Transvaal, South Africa;Hygiene-Institut der Universität, Marburg, FRG; Institut Pasteur, Paris, France

A Search for Ebola Virus in Animals in the Democratic Republic of the Congo and Cameroon: Ecologic, Virologic, and Serologic Surveys, 1979–1980

More than 30 years after the first outbreak of Marburg virus disease in Germany and Yugoslavia and 20 years after Ebola hemorrhagic fever first occurred in central Africa, the natural history of filoviruses remains unknown. In 1979 and 1980, animals in the Democratic Republic of the Congo and Cameroon were collected during the dry season near the site of the 1976 Ebola hemorrhagic fever epidemic. The study objectives were to identify local animals and search for evidence of Ebola virus in their tissues. A total of 1664 animals representing 117 species was collected, including >400 bats and 500 rodents. Vero and CV-1 cells and IFA and RIA were used for virus and antibody detection, respectively. No evidence of Ebola virus infection was found. This study was limited in time and animal collections and excluded insects and plants. Long-term, prospective, multidisciplinary comparative studies will yield more information than will repeat short forays on the ecology of filoviruses.

Interrelationships Among Arenaviruses Measured by Indirect Immunofluorescence

An evaluation of reciprocal indirect immunofluorescent antibody titers for at least one representative of each known arenavirus serotype leads to the conclusion that the Old World aranaviruses are more closely related to each other than to other members of the group. These relationships are particularly evident in evaluations of human convalescent sera. New World arenaviruses cross-react strongly with each other in most instances but only weakly with with Old World arenaviruses.

No evidence for increased risk of Lassa fever infection in hospital staff.

A prospective serological study was undertaken in hospital personnel who care for Lassa fever (LF) patients in an endemic region of Sierra Leone, West Africa. Among personnel from three hospitals where barrier nursing is practised, antibody prevalence and seroconversion by age and sex were consistently equal to or lower than those of persons in nearby village populations. No group among hospital personnel evaluated by age, sex, contact, or occupational exposure was at higher risk than another. Hospital staff in Sierra Leone who care for LF patients using simple barrier nursing methods have no higher risk of infection than the local population. These findings support the proposal that patients with LF in non-endemic countries need not be confined to isolators.