CD40LG and dengue disease: A school-based cohort study in Long Xuyen, Viet Nam, reported an acute dengue incidence ranging from 16.9 per 1,000 persons in 2005 to 40.4 per 1,000 persons in 2007.21 Based on active surveillance data from Cambodia during 2006–2008, the estimated annual incidence of clinical DF/DHF with IgM positivity was 13.7 per 1,000 population during an inter-epidemic year and 57.8 per 1,000 population during an epidemic year.27