RESUMO
Serosurvillance of 650 children of clinically suspected dengue infection based on simple laboratory tests were evaluated to find out the early indicator for diagnosis of dengue infection. The study was conducted among the patients attending the Sir Salimullah Medical College (SSMC) and Mitford Hospital and Popular Diagnostic Center, Dhaka, during July 2002 to September 2002. Of these 650 suspected dengue cases, 294 were in the age group 1-5 years, 206 were in age group 6-10 years and 150 cases in age group 11-15 years, of which Seropositivity was found in 78 (26.53%), 60 (24.12%) and 65 (43.33%) cases respectively. Primary dengue IgM was positive in 123 (60.59%) cases and secondary dengue (IgG & IgM combined or IgG alone) was positive in 80 (39.41%) cases. Leucopenia was found in 90 (75%) cases and Thrombocytopenia was found in 95 (79.16%) cases in primary dengue cases. Similarly in secondary dengue cases TWBC and PLT was decreased in 60 (72.29%) and 65 (78.15%) cases respectively. Haemoconcentration was found in 40 (36.67%) cases of primary dengue and 13 (18%) cases in secondary dengue. Month wise distribution of dengue seropositivity shows that 10 (8.53%) cases was found in July, 175 (50.10%) cases in August and 78 (10.00%) cases in September. This study reveals that seropositivity is highest (43.33%), in the age group 11-15 years and incidence of dengue increased in the month of August. Leucopenia (WBC <or= 5000) and Thrombocytopenia (Patelet count <or= 100000) were two findings that help in the early diagnosis of dengue infection.