According to government reports, dengue fever has killed 321 people in Vietnam so far. The figure has risen by more than 50 per cent since 1997. Tran Hung, an official in the ministry of health, said 159,449 people had contracted the disease, and southern province accounts for 80 per cent of the cases and 95 per cent of the deaths.

The 12 Mekong Delta provinces were most severely hit. Swamps and water tanks prepared by farmers for use during the five-month dry season became an ideal environment for the mosquitoes to breed. Dengue infects an estimated 15 million people each year in the geographic band around the equator. it causes joint pains, fever and serious cases of brain hemorrhage. There is still no vaccine to prevent the disease.