Dengue hemorrhagic fever remains a major health concern in Thailand. Much effort has focused on the prevention and control of the disease. Detection of dengue virus infection rate in mosquitoes would evaluate dengue control programs and predict the epidemics of dengue hemorrhagic fever. To determine dengue virus infection rate in mosquitoes by Seminested RT-PCR. A total of 400 mosquitoes were collected from Rom Kao Community representing a crowded community
and another 9 non-crowded communities in Bangkok. Mosquitoes were then divided into 40 pools, each contained 10
mosquitoes. A total of 391 Aedes aegypti and 9 Aedes albopictus were screened for dengue virus. The mosquito infection rate in the Rom Klao community was 5% of the mosquito pool equal to that found in non-crowded communities. Both groups were found to have dengue virus serotype 3. The present study suggests a circulation of dengue virus serotype 3 in both crowded and non-crowed communities, the infection rates of which are indifferent during the dry season.

Keywords: Dengue virus, Aedes aegypti, Aedes albopictus, Mosquito infection rate