Introduction of Dengue Virus 4 (DENV-4) Genotype I into Brazil from Asia?

摘要

Dengue fever is the most important viral neglected tropical disease [1], and during 2008 more than 865,000 cases of dengue infection were reported in the American continent. Brazil is experiencing severe yearly outbreaks of dengue virus (DENV) serotypes 1 to 3 [2]. Since its brief incursion into the eastern Brazilian Amazon in 1982 [3], DENV-4 has not been detected or known to have caused outbreaks in Brazil; as a result, its inclusion in routine epidemiological surveillance protocols was deemed unnecessary by Brazilian health authorities. In 2008, however, DENV-4 was reported in three patients without any history of traveling outside Manaus (Brazil) by academic researchers who did not have any DENV-4 strains in their laboratories [4]. The Brazilian health authorities dismissed the work, not only by not being able to reproduce the findings in their own laboratories, but also by arguing that ultimately there is no apparent DENV-4 outbreak in Brazil.