ABSTRACT
Viral hemorrhagic fever (VHF) is an acute systemic illness classically involving fever, a constellation of initially nonspecic signs and symptoms, and a propensity for bleeding and shock. The syndrome may be caused by more than 25 different viruses from four taxonomic families. One of the most important hemorrhagic fever viruses is Lassa virus (LASV), the cause of Lassa fever (LF), a rodent-borne disease that is endemic in West Africa (Figure 15.1) (Enria et al., 2011). LF was rst recognized in Nigeria in 1969 and named after the village Lassa in
15.9.3 Pathogenesis .............................................................................................................. 281 15.9.4 Basic Science Investigation....................................................................................... 281 15.9.5 Field Studies on Epidemiology and Control ............................................................. 282
Acknowledgments .......................................................................................................................... 282 References ...................................................................................................................................... 282
FIGURE 15.1 Geographic distribution of Old World arenaviruses. The virus name and date of discovery of each virus are shown, with the known or suspected rodent reservoir listed in parentheses. Countries where LF (virus discovered 1969, reservoir Mastomys natalensis) has been denitively shown are depicted in dark gray. Indirect evidence, such as anecdotal reports or seroprevalence data, exists for the other named countries in West Africa. The distribution of rodents of the genus Mastomys is shown in light gray. With the exception of Lassa and lymphocytic choriomeningitis viruses, most Old World arenaviruses have been isolated on single or very few occasions, and the precise distribution of the virus beyond the place of rst isolation is unknown. Not shown on the map: Lymphocytic choriomeningitis viruses (discovered 1933, reservoir Mus musculus), which has a worldwide distribution, and Dandenong virus (discovered 2009, unknown reservoir), which is thought to be found in Eastern Europe. Only Lassa, Lujo, Dandenong, and lymphocytic choriomeningitis viruses are known to be human pathogens.
