Emergence of Dengue virus 4 genotypes II b and I in the city of Rio de Janeiro

摘要

Dengue virus (DENV) is an arthropod-borne virus (arbovirus) within the family Flaviviridae and consists of four serotypes (DENV-1.DENV-2, DENV-3 and DENV-4). Human infection with DENV result in a spectrum of manifestations ranging from asymptomatic and subclinical (70% of all DENV infections) to dengue fever (DF) or dengue hemorrhagic fever (DHF). There are an estimated 100 million infections occurring annually worldwide, of which ~500,000 are severe life-threatening infections. The principal risk factors for DHF include the strain of virus, prior infection with a heterologous serotype, age and genetic background of the individual. In Brazil, outbreaks of DF caused by DENV-1 occurred since the early 1980s of the last century and the number of DHF cases increased after 1994, as a result of the introduction of DENV-2 and DENV-3 and the spread of the main vector/ledes aegypti. DENV-4 was first detected in 1982 in the Amazon region of Brazil, co-circulating with DENV-1.