Emergence and Global Spread of a Dengue Serotype 3, Subtype III Virus

摘要

Over the past two decades, dengue virus serotype 3(DENV-3) has caused unexpected epidemics of denguehemorrhagic fever (DHF) in Sri Lanka, East Africa, andLatin America. We used a phylogenetic approach to evalu-ate the roles of virus evolution and transport in the emer-gence of these outbreaks. Isolates from these geographi-cally distant epidemics are closely related and belong toDENV-3, subtype III, which originated in the Indian subcon-tinent. The emergence of DHF in Sri Lanka in 1989 corre-lated with the appearance there of a new DENV-3, subtypeIII variant. This variant likely spread from the Indian sub-continent into Africa in the 1980s and from Africa into LatinAmerica in the mid-1990s. DENV-3, subtype III isolatesfrom mild and severe disease outbreaks formed genetical-ly distinct groups, which suggests a role for viral genetics inDHF