Dengue Cases in Hanoi, Vietnam: Unseasonal Surge Foreshadows Increased Incidence That Demands Organized Preventive Action

Abstract

Dengue is now a major public health risk to the people of southeast Asia, as forewarned in an editorial published by a regional biomedical journal a decade ago.⁽¹⁾ In the intervening years, this threat has escalated due to dramatic changes in climatic factors that have facilitated the extended distribution and increased numbers of the vector mosquito Aedes spp., Like its neighboring countries, Vietnam has not been spared the public health impact of this arboviral infection. Together with other mosquito-transmitted diseases, dengue is regarded almost exclusively as a problem confined to the southern part of the nation, especially Ho Chi Minh City, which experiences a year-round tropical climate. This (mis) perception has dictated national policy on vector surveillance, control, and prevention. Guidelines on dengue for central and north Vietnam now need to be urgently revised. This is exemplified by the situation in Hanoi, the capital city, located in the north of the country, in which there was a surge in dengue cases in the first quarter of 2024, a time when dengue transmission is historically not at its peak.