Provinces and cities with many industrial parks are at a higher risk of a dengue fever outbreak, the head of Ho Chi Minh City's Pasteur Institute has said.

At a workshop on preventive methods against dengue fever held in mid-April, Phan Trong Lan said the number of dengue fever cases in the last 10 years in HCM City and the southern provinces of Binh Duong, Dong Nai, Ba Ria-Vung Tau and Long An were higher than in other areas in the country.

The Preventive Health Department said the number of cases in these areas has increased by 35.2 percent this year compared to the first three months of 2014, while the numbers have decreased in the rest of the country.

Lan attributed the increase to health officials' poor supervision of the control vector for mosquitoes and an increase in use of containers to store water.

Population density has also risen in many of these areas, making it easier to transmit the disease.

Lan said most dengue fever patients in the four provinces and HCM City were over the age of 15, but in the other areas in the southern region, the cases involved mostly children.

Tran Dac Phu, head of the Preventive Health Department, warned that dengue fever this year could be more widespread because of weather changes.

He said many provinces and cities have not taken measures to prevent dengue fever, which has no cure. There is still no vaccine against dengue fever, either.

Mosquitoes that have become resistant to certain chemicals also pose challenges to the prevention of the disease.

Luong Ngoc Khue, head of Medical Examination and Treatment Department, said that many hospitals have not made sufficient investments in their infectious diseases wards.-VNA