ISOLATION AND DETECTION OF DENGUE VIRUS IN BANGLADESH

Dengue outbreak has occurred frequently in Bangladesh since the year 2000. To know the status of the circulating serotypes of DENV from each outbreak in this country, it is required to perform the detailed molecular epidemiological study. A total of 85 blood samples of clinically diagnosed dengue patients was collected from five different hospitals of Dhaka city during the outbreak year 2008 in Bangladesh. Isolation of dengue viruses was performed in mosquito (C6/36) cell line and their detection was done by multiplex reverse transcriptase-polymerase chain reaction (MRT-PCR). The occurrence of dengue virus infection was significantly (p<0.01) higher in the age group of 21-30 years, followed by the age group 11-20 years than any other age groups. With regards to sex-wise occurrence, significantly (p<0.01) higher cases of dengue fever were observed in male patients than female patients. Of the 85 serum samples, 7 (8.24%) were found positive for virus isolation using mosquito (C6/36) cell line. Dengue virus was isolated from patients who had a significantly (p<0.01) higher mean body temperature (102.6 ± 1.27 ^○F). The highest rate (42.9%) of virus isolation was found on fever day 3. Serotypes of the isolated dengue viruses were confirmed by MRT-PCR assay, which revealed that among the 7 isolates, 5 were DENV-3, and the rest 2 were DENV-1 and -2. This indicates the predominance of DENV-3 and co-occurrence of multiple serotypes of dengue viruses (e.g., DENV-1, -2 and -3) in Bangladesh.