Accordingly, functional agencies are asked to increase the monitoring of patients, mosquito density and mosquito larvae rate to promptly detect outbreaks and spray chemicals in high-risk areas.

The agencies also work to encourage households to cooperate with health workers to maintain the environment’s hygiene.

According to the Health Department of Hanoi, the city recorded 438 cases of dengue fever in 24 local districts and 153 wards in the first quarter of 2017, a rise of 44% year-on-year, with no fatalities. Ha Dong district has the highest number of the infected with 33 cases.