FOCAL DENGUE VIRUS TRANSMISSION IN KAMPHAENG PHET, THAILAND AND IMPLICATIONS FOR MANAGEMENT

Dengue is the most globally prevalent vector-borne viral disease. However, our understanding of dengue virus (DENV) transmission is incomplete. Prospective longitudinal cohort and cluster studies in Kamphaeng Phet, Thailand have contributed much to our understanding of DENV transmission. These studies have demonstrated the spatiotemporal heterogeneity of DENV transmission with highly focal transmission at small scales in a rural setting. Geographic cluster studies have suggested the presence of small "hotspots" of transmission at the house level that may have a disproportionately high impact on local spread. These hotspots should be considered when planning overall vector control interventions. The combined cohort and cluster design have shown that clinically inapparent DENV infections from prospective longitudinal cohorts likely consist of a clinical spectrum of infections from asymptomatic to mildly symptomatic with and without fever. The proportion of all DENV infections that are completely asymptomatic may be substantially lower than those considered to be inapparent in cohort studies. In addition, some of these inapparent infections from cohort studies have viable DENV and may potentially contribute to virus transmission. These findings require further validation in other settings and in adults and children. A more comprehensive understanding of DENV transmission will be critical to inform prevention, prognostication and management strategies.