Prevention and Treatment

Rodent control, by trapping, poisoning, and/or cats, on a village-wide basis is applicable where the reservoir host is a commensal animal, as in lymphocytic choriomeningitis (Mus musculus), Lassa fever (Mastomys natalensis), or Bolivian hemorrhagic fever {Calomys callosus). However, it is difficult in rural settings such as those characteristic of Argentine hemorrhagic fever. A live attenuated Junin virus vaccine is undergoing phase 2 clinical trials in Argentina, and a vaccinia recombinant carrying the Lassa virus glycoprotein gene has been shown to protect monkeys against challenge.

Isolation and barrier nursing are required to prevent nosocomial spread of arenaviruses to other patients and nursing staff. Fluid, electrolyte, and osmotic imbalances need correction. The main challenge is timely anticipation and management of the profound hypotension and shock, sometimes associated with acute pulmonary edema which may suddenly develop during the second week of the illness.

Ribavirin, administered intravenously in high dosage during the first 6 days of Lassa fever, has been shown to reduce viremia and mortality significantly. Oral ribavirin also has some effect and has been recommended for prophylaxis in close contacts of known cases.

The course of Argentine hemorrhagic fever has been modified by administration of high-titer convalescent-phase plasma within the first week of the illness, although late, generally reversible, neurologic sequelae occurred in about 10% of the treated patients. This unusual approach to treatment of acute infection (rather than prophylaxis) is being explored for other arenaviruses, but the high incidence of HIV infection in Africa would discourage its use on that continent at least.

Further Reading

Bishop, D. H L (1990) Arenaviridae and their replication In "Fields Virology" (B. N Fields, D M. Kriipc, R. M Chanock, M S. Hirsch, ] L Melmck, T P Monath, and B Roizman, eds ), 2nd Ed , p. 1231 Raven, New York Lopez, C , ed (1988) "Immunology and Pathogenesis of Persistent Virus Infections/' Chapters

6-12, pp 79-170. American Society for Microbiology, Washington, D C. McCormick, J B (1990) Arenaviruses.'/« "Fields Virology" (B. N Fields, D. M Knipe, R M. Chanock, M. S Hirsch, J L. Melnick, T P Monath, and B. Roizman, eds ), 2nd Ed., p 1245. Raven, New York.

McCormick, ) B , and Fisher-Hoch, S. P (1990) Viral hemorrhagic fevers hi "Tropical and Geographic Medicine" (K. S Warren and A. A F. Mahmoud, eds.), p 700 McGraw-Hill, New York.

Oldstone, M B A , ed (1987) Arenaviruses Curr Top Microbiol Immunol. 133, 134. Peters, C. J. (1991) Arenaviruses In "Textbook of Human Virology" (R. B Belshe, ed ), 2nd Ed., p 541. Mosby, St. Louis, Missouri Salvato, M S., ed (1993) "The Arenaviridae " Plenum, New York

Chapter 33 BS

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