Clinical and virological features of dengue in 2010

Abstract

INTRODUCTION: Dengue is an important viral infection in Sri Lanka. All 4 serotypes co-circulate in Sri Lanka. OBJECTIVE: To study the clinical and virological features of dengue in 2010. DESIGN, SETTING AND METHODS: A hospital-based study was carried out at North Colombo Teaching Hospital, Ragama in 2010. Patients clinically suspected of having dengue, with fever less than 5 days were recruited. Acute and convalescent blood samples were collected within 7 days after obtaining informed written consent. Demographic, clinical information and laboratory results were obtained. Acute serum samples were tested using molecular (RT-PCR and Semi-Nested PCR) and serological (ELlSAs and HAI) assays. Convalescent samples were tested by serological assays. RESULTS: Of 209 patients enrolled, 93 % (195/209) were laboratory confirmed as recent positive cases of dengue viral infection; of these, 5% (9/195) were classified as dengue fever; 85%(1G5/195) dengue haemorrhagic fever (DHF) and 0.5% (1/195) dengue shock syndrome. Mean platelet value and packed cell volume (PCV) in laboratory confirmed dengue patients were 56,107/mm3 (range 10,000-306,000) and 42%(range 34-61 %) respectively. Patients infected with DHF showed both primary (n=45) and secondary (n=102) infections. Interestingly, secondary infection was not significantly correlated with DHF (x2-0.3:p=0.6). DEN-1 was responsible for the majority of cases, with a minority due to other three serotypes; all serotypes contributed to severe disease. CONCLUSION: DEN-1 was responsible for the majority of cases in 2010 but it circulated at a low level during previous epidemics. Majority of patients had severe clinical symptoms. In this epidemic, the clinical presentation of dengue differed according to the geographic region and viral serotype. ACKNOWLEDGMENTS: Financial assistance and technical co-operation by International Center for Genetic Engineering and Biotechnology (ICGEB CRP SRL 08/02), National Science Foundation (NSF/RG/2009/BT/01) and International Atomic Energy Authority (lAEA/SRL/5/042) is acknowledged.