Infection patterns in mice of an avirulent and virulent strain of Semliki Forest virus.

Google Scholar
  • 1 December 1971
    • journal article
    • Vol. 52  (6) , 669-77
Abstract
Young mice injected i.p. with a virulent (V 13) or an avirulent (A 7) strain of Semliki Forest virus suffered a severe generalized infection over the first 2 days with prolific virus replication in the peritoneal wall and other muscle. This replication and the level of the resulting viraemia were as high for A 7 as V 13 and possibly higher. Despite this similarity in the extent of systemic infection significant replication of V 13 was detectable in the brain, the probable site of fatal damage, at 36-40 hr, 12 hr before that of A 7: and subsequently V 13 increased until death of the mice whereas A 7 declined. After intracerebral inoculation early virus replication in the brain was similar for both strains and a generalized infection ensued similar in extent to that seen after intraperitoneal injection. Within 24 hr a primary injection of the avirulent strain by either route protected mice against a subsequent injection of the virulent strain. The different patterns of brain infection occurring after intraperitoneal injection are probably due to differential interactions of the 2 virus strains with host defence mechanisms.