Dengue is the most widely distributed mosquito-borne virus affecting humans, with an estimated 100 million people infected worldwide each year. 40% (2.5 billion) of the world’s population is estimated to be at risk of infection. Dengue is caused by infection with one of four different dengue viruses (Dengue 1, 2, 3 and 4) that are spread by Aedes mosquitoes.

Many areas in Viet Nam have experienced increases in dengue incidence over the last 10 years. This is due to several factors including increased travel and movement of people, and thereby more frequent introduction of dengue viruses, and also the introduction of new Aedes breeding sites in the form of water storage containers such as jars and tanks, as well as refuse, such as discarded tyres, metal parts, plastic containers, tins and bottles.

Since 1998, we have been involved in implementing community-based dengue control projects in Viet Nam that target Aedes larvae, using naturally occurring Mesocyclops, tiny (1 mm) crustaceans that attack and kill the mosquito larvae. We have had success in communes in the northern and central areas of Viet Nam, and currently our project is active in three provinces in the Mekong delta, in southern Viet Nam.

By eliminating the Aedes mosquitoes that transmit dengue viruses, we are improving the health of people in these communes. Through our extension activities into the water supply industry, we are helping to improve design so that water does not bring with it an increased burden of dengue.