Preventing the multiplication of mosquito larvae is key to controlling the spread of dengue fever, the city's Department of Health reiterated at a workshop on Oct. 6.

Department officials expressed concern that the incidence of the fever had risen over the last several months and several localities were not taking preventive measures in a timely and effective manner.

Le Truong Giang, deputy head of the department, said that the preventive health centres in city districts had to guide grassroots administrations in spraying chemicals to kill mosquitoes and prevent their larvae from multiplying.

Companies, schools, offices, public spaces and residential areas were still to focus adequately on these tasks, he said.

The city would spray chemicals three times this month, he said, adding local authorities should encourage residents to implement preventive measures at least once a week.

The city's Preventive Medicine Centre has said that the number of patients with fever dengue has steadily increased over the last three months.

From 633 patients in July, the number increased to 1,133 in August and 1,624 in September.

As many as 166 out of 322 communes and wards, or almost 50 percent, have recorded increasing number dengue fever patients, accounting for 80 percent of the city's total.

In September alone, the number of dengue patients rose by more than 400 each week.

Nguyen Dac Tho, deputy head of the city's Preventive Medicine Centre, said the number would continue to increase as timely steps were not taken.

Tho also announced at the workshop a plan on vaccinating children for measles.

Under the plan, nearly 600,000 children between one and six years old will be vaccinated next month.

The department will co-operate with the Department of Education and Training to vaccinate children at schools from November 1-25.

There are an estimated 400,000 school-age children in the city. Children not of school-going age will get their measles shots at health clinics in their communes and wards.

Tho asked preventive medicine centres at districts as well as at communes and wards to ensure residents are aware of the measles vaccination programme so that it is implemented effectively./.