Recent Trends in Dengue Virus Infection; An Analysis of Virological, Clinical and Laboratory Profiles of Patients with Dengue Virus Infection in the Center for Clinical Management of Dengue Fever and Dengue Hemorrhagic Fever, Sri-Lanka

Background: Dengue is hyper-endemic with outbreaks around the country. Clinical presentation is influenced by presence of previous exposures to infection and circulating serotype. Changes in circulating serotype, frequently lead to outbreaks as well. Early identification of changes in circulating serotypes and clinical pattern is invaluable for outbreak prediction, control and efficient patient management. Objectives: Study aimed to describe demographic, clinical and laboratory parameters of dengue patients during the interepidemic period in Sri-Lanka, and to identify circulating serotypes and their association with clinical/laboratory parameters to understand future occurrence of dengue. Study design: Laboratory based cross-sectional study was conducted at National Arbovirus Diagnostic Laboratory, including 129 plasma samples tested positive by Dengue serotyping real-time PCR. All samples were also tested for secondary dengue. Results: Mean age was 20.8years and 41.8% belonged to 6-15years. Primary infection was noted in 56.9%.Majority had platelet <50,000/ uL, leucopenia, ALT and AST above the upper limit of the normal (38.7%, 58.1%, 55, 8% and 71.3% respectively). DENV2 was 45.7% and DENV3 was 27.1%. Severe dengue was seen in 48.1% in DENV3 cases. Majority with DENV2 had platelets < 50,000/uL (68.8%). Leucopenia (82.6%) was higher in DENV3. Primary and secondary infection for DENV2 was 43.9%&54.8%. For DENV3 primary infections (22%) were higher than secondary infections (19.4%). Conclusion: Primary non-severe dengue cases of were predominant. Principal circulating serotype was DENV2 with cocirculation of DENV3 and1.DENV2 was more frequently associated with secondary-infection, thrombocytopenia and elevated AST while DENV3 was mostly associated with primary-infection, severe dengue, leucopenia and elevated ALT.