DENV-3 in Ae. aegypti Mosquitoes, Brazil | CDC EID

EID Journal Home > Volume 16, Number 6–June 2010

Volume 16, Number 6–June 2010
Dispatch
Dengue Virus 3 Genotype I in Aedes aegypti Mosquitoes and Eggs, Brazil, 2005–2006
Ana P.P. Vilela, Leandra B. Figueiredo, João R. dos Santos, Álvaro E. Eiras, Cláudio A. Bonjardim, Paulo C.P. Ferreira, and Erna G. Kroon
Author affiliations: Universidade Federal de Minas Gerais, Belo Horizonte, Brazil

Suggested citation for this article

Abstract
Dengue virus type 3 genotype I was detected in Brazil during epidemics in 2002–2004. To confirm this finding, we identified this virus genotype in naturally infected field-caught Aedes aegypti mosquitoes and eggs. Results showed usefulness of virus investigations in vectors as a component of active epidemiologic surveillance.
Dengue virus (DENV) is a member of the family Flaviviridae and a positive-sense RNA virus. Epidemics caused by the 4 DENV serotypes have emerged as major public health problems in tropical and subtropical regions over the past 20 years (1). DENV is transmitted to humans by the bite of an infected mosquito. Female Aedes aegypti mosquitoes are the main vector involved in the urban transmission cycle of the virus. Ae. aegypti is a tropical mosquito that lays its eggs on the walls of containers commonly found in and around homes (1). Female mosquitoes remain infectious for their entire lives and have the potential to transmit virus during each human feeding.

Mosquitoes and larvae may be infected by vertical transmission and maintain the virus in nature (2). Spread of the mosquito vector and virus has led to a resurgence of dengue fever epidemics and the emergence of dengue hemorrhagic fever (DHF) (3). No dengue vaccine is currently available, and dengue control relies solely on vector control. For successful epidemiologic investigations, identification and typing of DENV from field-caught mosquitoes and eggs are needed.

The current epidemiology of dengue in Minas Gerais state, Brazil, is characterized by cocirculation of DENV-1, DENV-2 and DENV-3 serotypes (state and metropolitan health departments, unpub. data). DENV-3 serotype was detected in 2002 and during 2005–2006; this was the most common serotype detected in Minas Gerais in those periods (4,5). Previous work in our laboratory identified DENV-3 genotype I, which was associated with dengue fever and DHF in Minas Gerais (6).

In this study, we confirm circulation of DENV-3 genotype I in naturally infected field-caught Ae. aegypti mosquitoes and eggs. We show the useful role of virus investigations in mosquitoes and eggs for monitoring DENV circulation.

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