Rapid detection of virus genome from imported dengue fever and dengue hemorrhagic fever patients by direct polymerase chain reaction.

Serum specimens from patients with imported dengue fever and dengue hemorrhagic fever were directly subjected to reverse transcription and polymerase chain reaction (RT-PCR) without any RNA purification. The amplified virus genome was detected within 3 hours. The results of PCR corresponded closely to the results of virus isolation using cultured mosquito cells, suggesting that direct RT-PCR procedure greatly facilitates rapid diagnosis of dengue infection.