Battle of the bitten

PUBLISHED : Wednesday, 03 October, 2007, 12:00am
UPDATED : Wednesday, 03 October, 2007, 12:00am

Jakarta's foremost dengue fever expert, H. Nazir, said he once had dengue haemorrhagic fever - and it was bad. He was fighting for his life after his blood platelet count - needed for clotting - dropped to critically low levels.

But he lived to tell the tale, said the doctor at the Jakarta Government Hospital. He then pointed to his colleague, the hospital's medical director, Sutirto Basuki, whose 17-year-old daughter survived two attacks of dengue haemorrhagic fever.

As the regional referral centre for dengue fever, the 212-bed hospital in Central Jakarta is where patients suffering from the severe form of the disease - dengue haemorrhagic fever (DHF) - are treated. At its peak in April, the hospital admitted more than 100 cases every day, said Dr Sutirto.

He said that, during the outbreak, sufferers with mild symptoms of dengue fever stayed at home or were treated by their private doctors. Others thought they had flu.

So when Indonesia tallies its number of dengue fever cases, the figure refers only to the severe DHF cases requiring hospital treatment. Health experts say there is no database indicating the prevalence of the symptomless dengue fever.

That reality underscores the difficulty in fighting dengue fever, a disease that is a growing threat in Indonesia and the rest of Asia.

WHO Southeast Asia regional director Samlee Plianbangchang said about 75 per cent of the Asia-Pacific population was at risk of dengue fever.

And whereas many mosquito-borne diseases around the world are confined to developing countries, the city state of Singapore has had to deal with more than 6,000 cases since the beginning of this year, with eight deaths. Hong Kong has so far reported 45 imported cases this year.

Singapore now has more than 10 ongoing clusters of cases, and a special team has been set up to look out for 'unconventional breeding sites' at the Bukit Batok cluster, the city state's worst-hit area. By September 28, there had been 112 cases in that cluster.

Dengue fever is spread by infected female anopheles mosquitoes, which breed in containers holding stagnang water, such as old tyres, flowerpots or cans, and are active in the morning. There are four serotypes of the dengue virus, called types 1 to 4, and while there is global funding to control malaria, dengue has remained an Asian disease.

WHO's Western Pacific regional director, Shigeru Omi, said at a regional meeting last month in South Korea that dengue fever and dengue haemorrhagic fever remained 'major public health problems' in Asia. Dr Omi highlighted a massive outbreak in Cambodia this year, with more than 30,000 infections and 327 deaths. Malaysia, the Philippines, Singapore and Vietnam also reported increased cases.

With the cooler weather of October and the start of the rainy season, everyone is hoping the region's dengue outbreak is nearing its end.

October did not come soon enough for a young Indonesian mother, whose five-month-old daughter, Cindi, was admitted to the Jakarta hospital on August 31 and diagnosed with DHF. She had a dangerously low thrombocyte - blood platelet - count of 15,000. With a drip attached to her right arm, the baby now has her thrombocyte count back up to 100,000 after treatment. The normal level is 150,000 to 400,000.

The 20-year-old receptionist had no idea how her baby was exposed to the mosquitoes. 'Our house is clean. I do not know where the mosquitoes came from. I know about dengue and that it is passed by mosquito bites.'

Dr Nazir said Jakarta was looking to emulate Cuba's success in eradicating dengue. Singapore has already signed an agreement with Cuba on technical expertise and to see whether any of its seven anti-dengue vaccines are effective.

In Jakarta, more adults than children have dengue, a trend that puzzles experts such as Dr Nazir. 'Maybe it's because the adults have a second dengue fever infection,' he said.

In Vietnam, the disease is more likely to infect children, according to Vu Sinh Nam, deputy director general of Vietnam Administration of Preventive Medicine at the health ministry.

At the country's premier Children's Hospital No1 in Ho Chi Minh City, the whole third floor of one building is occupied by children with severe cases of dengue.

Sixty per cent to 70 per cent of the dengue sufferers in the southern Vietnamese provinces were children under 15, said Nguyen Thanh Hung, head of the department of dengue haemorrhagic fever. 'The mosquitoes are in the environment and in southern Vietnam the viral transmission is year-round. Children do not have enough antibodies so they are infected easily,' he said.

Ho Chi Minh City's government-funded hospital serves as the regional hospital for receiving children who have dengue, bird flu or other infectious diseases. It also trains doctors from around the country in f how to treat dengue.

Dr Hung said improved care management for severe cases - dengue fever/haemorrhagic fever (DHF) and dengue shock syndrome (DSS) - was developed at the hospital and had led to a drastic reduction in mortality rates, from 12.5 per cent in 1975 to less than 1 per cent.

Mothers in Vietnam are being educated to recognise early symptoms of dengue, and a hotline links district-level hospitals with the Children's Hospital No1 to ensure early treatment of severe cases.

Vietnam, which spends up to US$2 million on dengue control each year, is one of three countries recognised by the WHO for having sound control programmes. The others are Singapore and Cuba.

The awareness campaign extends to the city's historic Hotel Majestic, located on the Saigon River. Guests receive a rolled scroll each morning bearing a Vietnamese myth or a proverb for the day. A note on the scroll also advises guests to be careful of mosquitoes, in an effort to stop tourists transmitting the disease further afield.

In rural Vietnam, at least 50 communes, home to half a million people, had implemented a system of biological control using predatory microscopic crustaceans in ponds to eradicate mosquito larvae, said Dr Nam.

The first outbreak was reported in the north of Vietnam in 1958 and in the south in 1960. There have been three major epidemics, in 1987, 1999, and last year.

Dr Nam said about 85 to 90 per cent of the dengue cases had occurred in the southern region around the Mekong River Delta.

The ongoing outbreak pales in comparison with the 1987 epidemic, when there were more than 354,000 cases and 1,500 deaths. In 1988, there were 232,000 infections and 377 deaths.

Vietnam launched a mosquito control programme in 1999, reducing the number of cases. 'But in recent years, especially since last year, the number of dengue cases has increased,' said Dr Nam.

So far this year, Hong Kong's 45 cases are below the 49 cases for the whole of 2003, which remains an annual record.

In the city's first local outbreak in 2002, 20 people were infected. That outbreak was preceded by an increased number of dengue cases in Guangdong and Macau.

In Indonesia, I Nyoman Kandun, director general of disease control and environmental health for the Indonesian health ministry, said dengue was once called the 'urban disease', but it was now spreading through rural areas and increasingly affecting adults.

He said the mortality rate was between 1 per cent and 1.3 per cent, drastically down from a decade ago, due to early diagnosis, prompt treatment and better hospital standards.

Experts in Indonesia said deaths from DHF or DSS now occurred because of delayed treatment.

As the rainy season began last month, and with cases of dengue fever expected to peak early next year, the government launched a '3M' campaign. Named for the Bahasa Indonesian words manguras, menutup, menoubur, the scheme asks people to eliminate breeding places, to clean water containers and to interrupt the life cycle of the larvae.

Erna Tresnaningsih, director of vector-borne diseases control at the ministry, said: 'Prevention of dengue is key to effective control.'

For the next two years, Indonesian authorities say they will focus on high-endemic areas, strengthen outbreak response teams and provide funds and sectoral support for provinces and districts. They are also planning cross-border co-ordination and collaboration, as well as a surveillance network - but questions remain as to whether the government has the resolve - or the funding - to carry out the plan.