RÉSUMÉ
A descriptive observational study was conducted to identify the epidemiology, clinical features, laboratory investigations and markers for early diagnosis of acute dengue virus infection in adults. We enrolled 404 patients over a period of two years, beginning from 2001, at the Teaching Hospital Peradeniya, Sri Lanka. Based on serology, 239 patients were grouped as: IgM 43 (18%), IgG and IgM 140 (58%), and IgG 28 (12%). The clinically diagnosed group without serology numbered 165 patients. Most of the parameters between groups showed a similar pattern: mean age of 30 years, mean duration of fever 7 days (range 1-19 days). Mean total white blood cell and platelet counts started to fall from the second day of fever, with the lowest counts on the 5th to 7th days. Packed cell volume (PCV) showed minimum fluctuation. One hundred and sixty (88%) patients showed elevated liver enzymes (ALT and AST), with 122 of them having a two-fold increase. Three patients died, and complications such as myocarditis, large effusions, encephalopathy, acute renal failure, acute liver failure and diarrhea were observed. These results suggest that a combination of clinical picture, thrombocytopenia, leukopenia and elevated liver enzymes could be used as markers for early diagnosis of dengue infection. Furthermore, evidence-based guidelines should be developed for managing dengue infection in adults.