Epidemiological and clinical characteristics of dengue during epidemic and nonepidemic periods in southern Sri Lanka- lessons learned from 2007 and 2012-2013

Abstract

We evaluated epidemiological, clinical characteristics of dengue, comparing two similar studies performed at Teaching Hospital Karapitiya (THK) Galle during outbreak (2012-2013) and without outbreak (2007). Two cross-sectional studies have been conducted at THK from March - October 2007 and June 2012 - February 2013. Adults and children with acute fever (tympanic > 100.4°F, documented > 102°F), with no obvious bacterial focus, have been enrolled within 48 hours of admission. Data and blood have been collected at enrollment and 2-4 weeks later. Acute dengue was confirmed by paired IgG and IgMIn 2007 total of 1079 patients (61.2% male, median age 30.7 years) and in 2012/2013 total 409 patients (64.3% male, median age 25.2 years) have been enrolled. Acute dengue was confirmed in 54 (6.3%) in2007and 188 (46.0%) in 2012-2013. Acute dengue had leukopenia (WBC <4.0x103/pl, p<0.01) and thrombocytopenia (platelets <100xl03/pl, p<0.01) than non-dengue in both studies. Total 3 (2007) and 7 (20012-2013) patients met criteria for dengue hemorrhagic fever. In 2007, clinical diagnosis sensitivity, specificity and positive predictive value were 14.0%; (95% Cl 11.6 -16.4), 97.8% (95% Cl 96.8 - 98.9) and 30.4% (95% Cl 27.2 - 33.6) respectively. In 2012/2013 the corresponding values were 64.4%; 95% Cl 57.1 - 71.2), 71.5%; 95% Cl 65.1 - 77.4) and 65.8% (95% Cl 58.4 - 72.6). Serotypes DEN 2-4 isolated in 2007, changed to DEN-1 (94.6%), DEN-4 (5.4%) in 2012/2013. Sero- prevalence increased from 50.9% (2007) to 83.7% 2 (2012/2013). ELISA, PCR or viral isolation.