Assessment of vertical dengue virus transmission in Aedes aegypti and serotype prevalence in Bantul, Indonesia
To determine the reality of dengue virus (DENV) serotype circulation in Bantul and the potential impact of a vertical transmission in the maintenance of dengue. Mosquitoes were captured using ovitraps in the vicinity of households of patients diagnosed with severe forms of dengue. DENV was detected in mosquitoes by immunochemistry and typed by reverse transcription-polymerase chain reaction. Aedes aegypti mosquitoes infected with DENV were found in 14 out of 17 districts in the Bantul Regency. Vertical transmission was demonstrated and serotype prevalence was coherent with the current clinical situation and the previous reports. DENV-3 was the most common serotype (12 districts), followed by DENV-2 (3 districts) and DENV-4 (1 district). No DENV-1 was found. Unlike continental countries such as Cambodia or Thailand, where the replacement of serotypes is the rule, maintenance of DENV-3 is a major feature in Java. Vertical transmission is likely to play a major role along with the archipelago structure of Indonesia, which might help maintaining local mosquito populations. Regular survey of circulating DENV and prevalence will help predicting and controlling outbreaks.