Vietnam: Elevated dengue fever activity reported in Hanoi in early September /update 1

Event

Health officials have reported elevated dengue fever activity in Hanoi, with an additional 3,513 cases reported Aug. 15-31, bringing the total case count to 6,693 cases since Jan. 1. This is compared to the 3,023 cases reported in the municipality over a similar period in 2022. The Thach That district (715 cases) is the most affected, reporting the highest disease activity. Other districts reporting high disease activity include Hoang Mai (535 cases), Thanh Tri (509 cases), Bac Tu Liem (406 cases), Ha Dong (367 cases), Phu Xuyen (362 cases), Cau Giay (353 cases), Dong Da (335 cases), and Nam Tu Liem (328 cases). Local health officials have implemented various campaigns aimed at boosting environmental sanitation and destroying mosquito breeding sites, and have urged the public to implement prevention measures around their homes. This report represents the most complete information available as of Sept. 5.

Context

Dengue fever is a nationwide, year-round threat in Vietnam; however, risk is typically highest during and immediately following the rainy season, which occurs May-October in the northern part of the country, and September-December in central coastal areas. Vietnam reported roughly 367,729 cases of dengue fever in 2022, 71,000 cases in 2021 and over 133,000 cases in 2020.

A dengue fever vaccine is available in some countries. It is only recommended for individuals with a history of dengue infection and those in a country with a high dengue fever burden. Symptoms of dengue fever include a sudden onset of fever and at least one of the following: a severe headache, severe pain behind the eyes, muscle and/or joint pain, rash, easy bruising, and/or nose or gum bleeding. Symptoms typically appear 5-7 days after being bitten but can develop up to 10 days after exposure. Dengue fever can progress to a more severe form known as dengue hemorrhagic fever (DHF). DHF can be fatal if it is not recognized and treated promptly.

Advice

If you have previously been infected with dengue fever, consult with your physician regarding vaccination. Avoid mosquito bites and remove standing water to reduce the number of biting mosquitoes. Seek medical attention if symptoms develop within two weeks of being in affected areas. Do not use aspirin or ibuprofen products if dengue fever is suspected, as these could exacerbate bleeding tendencies associated with the disease.