Isolation and serotyping of dengue viruses by mosquito inoculation technique from clinically suspected cases of dengue fever.

Dengue virus was isolated from 44 clinically suspected cases of dengue fever by mosquito inoculation technique using Aedes aegypti mosquito in the department of virology, BSMMU in the year 2000. Identification of dengue virus was done by direct fluorescent antibody technique using FITC conjugated anti-dengue monoclonal antibody and serotyping was carried out by indirect fluorescent antibody technique using serotype specific monoclonal anti-dengue antibody. The dengue virus isolation rate was 41.9%. The result of serotyping revealed circulation of all four serotypes of dengue viruses in Dhaka, Bangladesh and DEN-3 was the predominant (70.5%) serotype during the outbreak in 2000. The rate of isolation was higher in patient's serum at an early stage of fever (p<0.01) and with higher body temperature (p<0.01). The rate of isolation was 77.77% in patient's serum collected on the 1st day of fever, and then the rate gradually declined and lowest (16.6%) on the 5th day of fever. The mosquito inoculation technique is an easy, economical and sensitive method for dengue virus isolation and is recommended for routine virological surveillance in laboratories of Bangladesh where sophisticated facilities are limited.