Record dengue season predicted in Thailand

With more than 40 deaths and almost 40,000 cases of dengue fever reported in Thailand so far this year, health experts are warning this could be the largest-ever epidemic.

“About 25 years ago we had a dengue outbreak of around 170,000 cases,” Pornthep Siriwanarangsun, the director of Thailand’s Department of Disease Control, told IRIN. “This year, we expect 150,000 to 200,000 cases.”

Up to 200 people could die in a worst-case scenario, he said. Even if dengue cases surpass the 1987 record, the death toll that year of more than 1,000 is unlikely to be exceeded owing to improved health care and preventive measures.

There is still no vaccine for dengue, a mosquito-borne disease.

Health officials claim that unseasonably wet and warm weather has made the situation worse, allowing mosquitoes to reproduce at a rapid rate. In May, the country reported 16,500 dengue cases, almost three times as many as in the previous month. In June there could be up to 30,000 cases, they say.

“Our country is now on high alert because we had way too many cases last month,” Siriwanarangsun said. “It’s normal to have only 50,000 to 70,000 cases each year.”

Carrot and stick

Government officials are calling for local communities to take more responsibility in combating the disease, especially during the annual monsoon season from May to October when mosquito activity flourishes.

Siriwanarangsun advises villages to use monetary penalties and public shame to urge vigilance against Aedes mosquitoes, the carriers of dengue that often use man-made containers as breeding grounds where eggs can survive up to one year. Households that do not rid or clean mosquito safe havens - old tyres, flower pots or rainwater collection jugs - could face a small fine (less than US$2) or a red flag could be put in front of their home. Villagers who do their bit can be rewarded with chicken eggs, he said.

Dengue fever in Thailand
Year Cases Deaths Case Fatality Rate (CFR)
2009 30,480 9 0.03%
2010 60,770 35 0.06%
2011 38,639 16 0.04%
2012 78,542 82 0.10%
2013 39,029* 44 0.11%
*Figures from 1 January to 31 May 2013. Higher numbers expected in summer monsoon season.

The worst-recorded epidemic occurred in 1987 which saw more than 174,000 cases and 1,007 deaths, with a CFR of 0.6 percent. Thai officials caution that 2013 may see 150,000 to 200,000 cases with up to 200 dead.

Sources: WHO, Thailand Ministry of Public Health

Also under way is a five-pronged response which integrates health promotion, prevention measures, protection, outbreak control, and efforts to improve care and treatment of patients.

“This process is already in place, but in some areas it is not effective,” Pasakorn Akarasewi, director of the national bureau of epidemiology, told IRIN, adding that he is worried that some villages are being more reactive than proactive.

Rising dilemma

As a long-time researcher of dengue, Suchitra Nimmannitya has witnessed the disease’s ascent. In the 1950s, she studied the emergence of a more lethal form of dengue, called severe dengue or dengue hemorrhagic fever (DHF). Later, she was able to classify the disease’s severity into four grades, which are still used in diagnosing patients.

Nimmannitya blames urbanization, population growth and globalization as contributing factors to the worldwide spread of dengue. The World Health Organization (WHO) reports that roughly half the world’s population is at risk from dengue, with 50-100 million people infected each year.

Most people infected are asymptomatic while others can show flu-like symptoms: high fever, nausea, body pain or even rash. Severe dengue can be deadly due to plasma leakage, among other serious ailments. In rare cases, patients can also develop Dengue Shock Syndrome, which has a 50 percent fatal rate without urgent medical care, according to the WHO.

If symptoms appear, fever-reducing medication, such as aspirin or ibuprofen, should be avoided as they can increase bleeding complications, said Nimmannitya, who recommends paracetamol.

She also rejected the idea that the disease only affects impoverished people living in squalid conditions. “It’s not the disease of the poor,” she told IRIN. “Anybody can get it.”

The nation’s most prosperous city, Bangkok, has seen almost 4,000 dengue cases this year. One hospital in central Bangkok, the Queen Sirikit National Institute of Child Health, treats roughly 1,200 cases annually. From October 2012 to April 2013, the hospital had 815 dengue patients, two of whom died, with many more cases expected. “We just entered the peak for dengue - the rainy season,” said Mookda Wangverawong, a dengue specialist at the hospital. “We will do everything we can to prevent death in these cases.”

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