Spatial–temporal patterns of dengue in areas at risk of dengue hemorrhagic fever in Kaohsiung, Taiwan, 2002

Summary Objective This study aimed to examine whether spatial–temporal patterns of dengue can be used to identify areas at risk of dengue hemorrhagic fever (DHF). Methods Three indices – probability of case-occurrence, mean duration per wave, and transmission intensity – were used to differentiate eight local spatial–temporal patterns of dengue during the 2002 epidemic in Kaohsiung, Taiwan. DHF densities (DHF cases/km 2 per 100 dengue cases) in each spatial–temporal typed area were compared. Results Areas with three high indices correlated with the highest DHF density: (1) high transmission intensity only; (2) long duration of wave only, and (3) high transmission intensity plus long duration of wave. However, cumulative incidences of dengue cases were not correlated with DHF densities. Conclusion Three spatial–temporal indices of dengue could provide useful information to identify areas at high risk of DHF.