In Niterói, state of Rio de Janeiro, dengue virus type 4 (DENV-4) was isolated for the first time in March 2011. We analysed the laboratory findings of the first cases and evaluated the use of molecular techniques for the detection of DENV-4 in Aedes aegypti
that were field-caught. Conventional reverse transcriptase-polymerase chain reaction (RT-PCR) and SimplexaTM
Dengue real-time RT-PCR confirmed DENV-4 infection in all cases. Additionally, DENV- 4 was confirmed in a female Ae. aegypti
with 1.08 x 103
copies/mL of virus, as determined by quantitative real-time RT-PCR. This is the first time the SimplexaTM
Dengue real-time assay has been used for the classification of cases of infection and for entomological investigations. The use of these molecular techniques was shown to be important for the surveillance of dengue in humans and vectors.