Doctors in India, Nepal and Singapore are battling growing outbreaks of potentially deadly mosquito-borne diseases. Hundreds of people have contracted Japanese encephalitis and dengue fever in recent months.

Some Singapore hospitals have been forced to postpone non-critical surgeries to free up beds for patients with dengue fever. Nearly 9,000 people have been infected with the mosquito-borne disease this year, nearly double last year's number. At least eight have died.

Mosquitoes also are wreaking havoc in northern India, where an outbreak of Japanese encephalitis has killed more than 500 people and infected more than 2,000 - mostly children - since July. In neighboring Nepal, Japanese encephalitis has reportedly killed more than 200 people in the past two months.

Outbreaks of both diseases occur often in Asia, but this year the caseload is surging. Dr. Kevin Palmer, a dengue specialist at the World Health Organization office in Manila, says people become complacent about controlling mosquitoes, which breed in stagnant water.

"It's like a three to five-year cycle. Between the cycle people forget," explained Dr. Palmer. "They start collecting containers in their houses, on their balconies or something, and all you need is a year with a good combination of the right temperatures and right amount of rainfall and bang - you've got an outbreak."

Dengue causes high fever and intense joint pain, and severe cases can lead to death. There is no vaccine. Unlike dengue, there is a vaccine for Japanese encephalitis, which attacks the membranes around the brain. But the vaccine may be too costly for the poor. The fatality rate reaches 60 percent, while a third of survivors may suffer nervous system damage.

In India's impoverished Uttar Pradesh state, hospitals have been struggling to cope with Japanese encephalitis. Authorities say a lack of vaccines, medicines and respirators hampers their efforts.

But Dr. Mahendra Bandari of the King George University Hospital in Lucknow said the situation in his hospital is improving. "There are enough ... medicines," he said. "We are looking after these patients, and the situation is under control."

Public health experts say mosquito-borne diseases fall low on the priority list of poor governments in Asia, although they are easily prevented with mosquito nets and sprays and by controlling breeding.

Experts are also urging changes at Asian farms where pigs and humans live close to each other, increasing the risk of Japanese encephalitis. Pigs carry the disease, and mosquitoes transmit it from the animals to humans.

The WHO says Japanese encephalitis kills some 15,000 people each year in Asia.