The virus has killed at least 163 people and infected 14,750 across the country so far this year, more than double the cases from all of last year, Dharma Wanninayake, an official from the health ministry, said Tuesday.

Dengue fever is a flu-like illness spread by the bite of an infected Aedes mosquito. The disease often spikes during the annual monsoons, when the rains leave puddles of stagnant water where the insects breed.

Wanninayake blamed the increase in infections on the people's carelessness in cleaning their properties and eliminating the mosquito breeding grounds.

In recent weeks, government inspectors have gone across Colombo and other cities, giving people accused of harboring mosquito breeding grounds two weeks to clean them up or face fines of up to 25,000 rupees (US$220) or a six month jail-term, Wanninayake said.

The government is also importing a bacteria from Cuba to kill mosquito larvae, he said.

Dengue fever usually starts suddenly with a high fever, rash, severe headache, pain behind the eyes, and in the muscles and joints. The severity of the joint pain has given dengue the name "breakbone fever." Nausea, vomiting and loss of appetite are common.