Pathogenicity and Pathophysiology of Dengue Virus type 2 Strains in Mice

Abstract

This study compared the pathogenesis of dengue virus type 2 (DV-2), a mouse-adapted strain and two wild type strains, following intracerebral c. ) or intraperitoneal (i. p.) inoculation in ICR and C3H/He suckling mice. There were no significant differences in the mortality rates and viral growth of a mouse-adapted strain between ICR and C3H/He suckling mice by either i. c. or i. p. inoculation. Suckling mice infected by i. p. inoculation with a mouse-adapted strain resulted in fatal infection, while those infected with wild type strains did not. Wild type strains replicated moderately in the brains of suckling mice by i. c. inoculation. Various passage lines of wild type strains showed different mortality rates and viral growth as compared to those of parent strains. The wild type strains in suckling mouse brain passage showed more striking lesions in the infected brain than those of parent strains. Specific DV-2 antigen was revealed by the immunofluorescent stains in cells of the infected brains.