HANOI - Vietnam's capital city of Hanoi has a bad case of dengue fever with some 5,300 cases reported so far this year, of which 1,100 cases were recorded last week alone, Vietnam media reported, citing the city's health department.

The National Hospital for Tropical Diseases in Hanoi has been admitting 200 dengue patients per day over the past two weeks, four times higher than the same period last year, VnExpress reported on Wednesday (July 19).

Hospital director Nguyen Van Kinh told VnExpress that doctors are concerned about the unusually high number of deaths caused by brain hemorrhages. Five patients have already died from the condition so far this year, compared to only one or two in previous years.

Patients can suffer bleeding on the brain just three days after contracting the mosquito-borne virus, even when they appear healthy, Kinh said.

He said that anyone with a fever should seek medical treatment as soon as possible.

Across the country, more than 45,000 people caught dengue fever in the first half of the year, up 0.3 per cent on-year, data from the health ministry showed. Fifteen deaths have been reported, up by two from a year ago.

There is currently no vaccine or treatment for dengue.