BANGKOK, 5 June 2008 (IRIN) - Rising temperatures, longer rainy seasons and increased urbanisation are leading to an explosion of dengue fever cases in Thailand in what health officials are calling a near-crisis situation.

"At least 14,000 people have been diagnosed with dengue in 2008 alone - most since April when the rains started early," said Wichai Satimai, director of the Department of Disease Control.

The 2008 outbreak marks a 72 percent increase in proven cases since last year, according to the department.

Neglected disease

"[Dengue] is the most important neglected communicable disease in Thailand … it is all over the country," said Chawalit Tantinimitkul, a spokesman for the World Health Organization (WHO), in Bangkok.

At the BNH Hospital in Bangkok, one doctor said dozens of cases had been admitted in May alone. "It is impossible to cure dengue," the doctor, who wished to remain anonymous, told IRIN. "We just monitor their blood platelet levels and make sure they are properly hydrated and fed."

Dengue is a tropical, mosquito-borne virus found mostly in urban areas. The disease is more common than malaria in Thailand. "Malaria is mostly confined to the border areas [of Thailand],'' according to Chawalit, while dengue is more common in urban areas. With dengue, the patient usually develops a high fever, joint pain and a rash that can last up to six weeks.

Health authorities are also reporting increases in the more dangerous form of the disease, Dengue Haemorrhagic Fever (DHF) and Dengue Shock Syndrome (DSS), which are more likely to kill. In a written response to IRIN, the WHO called the spread "a major public health problem of international concern".

According to the WHO, the disease was first detected in Thailand in 1949 when about 2,100 cases were reported. Since then there have been two major epidemics – in 1987 and 1998. The most recent outbreak has been more severe because of increased population and warmer and wetter conditions, said government officials.

Dengue is transmitted by the aedes aegypti mosquito. Unlike malarial mosquitoes, which live in rural or forested areas and breed in muddy water, the aedes aegypti mosquitoes breed in stagnant, clean water. Often called Tiger Mosquitoes because of their stripy tails, they are active during the day, unlike malarial mosquitoes.

Awareness campaign

Wichai said local authorities were being urged to take extra measures to prevent the virus from spreading further.

"We have enlisted the help of more than 800,000 volunteers nationwide to help to get the word out about this dangerous virus," he said. They are helping authorities hold awareness workshops and conduct patrols to spot areas of standing water that are potential mosquito breeding grounds.

"The government has also launched a major television campaign aimed at educating the public about how to prevent the virus," he said. "We are telling people to make sure that there are no containers where mosquitoes can breed and to be careful of everything from flower pots to old tyres," Wichai said. "The rainy season has been coming earlier than normal, and there are a lot of containers where mosquitoes can breed."

A WHO report, ''Dengue/DHF Situation of Dengue/Dengue Haemorrhagic Fever in the South-East Asia Region'' (http://www.searo.who.int/EN/Section10/Section332_1103.htm) stated that the higher dengue infection rates were a result of "demographic explosion" and "rapid growth of urban centres with a strain on public services, such as potable water".

Bangkok's growing slums are especially susceptible to dengue outbreaks, according to the WHO. Residents have poor access to drinking water and often use ceramic jugs to collect rainwater. The jugs are ideal breeding grounds for dengue mosquitoes.

According to Wichai, undernourished poor people are most vulnerable to serious symptoms or death.

"Their immune systems are weaker, and their symptoms are worse … especially for children under nine," he said. The problem is only expected to get worse when Thailand's wet season peaks in June and July, Wichai told IRIN. "It is not yet a national crisis, but we are trying very hard to get things under control to prevent a crisis situation."

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