26% increase in Singapore's dengue cases in first 9 weeks of 2009

Chew Wui Lynn, Channel NewsAsia 10 Mar 09;

"The principal drivers of the re-emergence or emergence of epidemic dengue and dengue hemorrhagic fever are a combination of uncontrolled urbanisation and movement of viruses and vectors not necessarily in this region, but around the world by people in airplanes."

SINGAPORE: Singapore had seen a 26 per cent jump in dengue cases in the first nine weeks of this year, compared to the same period in 2008.

And authorities are taking a more concerted approach in the fight against the mosquito-borne disease, which can be fatal in its severest form.

According to the National Environment Agency (NEA), there were 1205 cases of dengue in Singapore since the beginning of the year, an increase of 253 cases on-year.

This is a 26 per cent increase, compared to the 952 cases registered in the same period last year.

The rising trend of dengue was also being seen across the Asia Pacific region.

The World Health Organization (WHO) said the Aedes mosquito, which transmits dengue fever, was spreading to areas that were once unaffected.

Coordinator, Communicable Diseases Control, WHO Southeast Asia Region, Chusak Prasittisuk, said: "The latest one (to be affected with dengue) was Nepal. Few years ago, Bhutan was also not reported (to be affected). Timor Leste, (although) not many cases were reported, but (there is an) increase now. I could say in general, the disease had spread to the new areas within the countries and also to new countries."

Recognising that dengue poses a serious public health threat, Singapore's NEA and the Foreign Affairs Ministry worked together to co-host the first Asia Pacific dengue workshop with the WHO.

Chief executive officer, NEA, Andrew Tan, said: "The long-term goal through a workshop like this and through future workshops is to develop a regional surveillance network that will allow us to share information, to share also the different genotypes of dengue and best practices not only from the laboratory, but also what's taking place in the field."

Sharing his expertise at the eight-day workshop on Tuesday was Professor Duane Gubler, who had spent 20 years carrying out field research on tropical diseases in Asia, the Pacific and the Caribbean.

Speaking on the global dengue situation, Dr Gubler said many challenges remain, especially with globalisation.

Director, Programme on Emerging Infectious Diseases, Duke-NUS Graduate Medical School, Dr Gubler, said: "The principal drivers of the re-emergence or emergence of epidemic dengue and dengue hemorrhagic fever are a combination of uncontrolled urbanisation and movement of viruses and vectors not necessarily in this region, but around the world by people in airplanes."

The workshop attracted 42 participants from the Western Pacific and Southeast Asia.
- CNA/yt

Dengue threat growing in Asia-Pacific
It caused more than 3,000 deaths in S-E Asia last year
Jessica Jaganathan, Straits Times 11 Mar 09;

DENGUE fever, an old enemy to the region, is gathering strength, with almost three times as many people in South-east Asia dying of the haemorrhagic form last year, compared with five years ago.

Far from defeated, it is fast spreading to newer areas in the Asia-Pacific region, and with more frequent outbreaks. Altogether, 1.8 billion people in the region are at risk of being infected.

The disease has also become more severe. According to latest statistics from the World Health Organisation (WHO), cases of dengue haemorrhagic fever - in which uncontrollable bleeding occurs - have increased by more than 70 per cent since 2003.

Last year, 3,255 people died of it in South-east Asian countries, compared with 1,202 in 2003.

The deaths are a concern, as they reflect the medical community's inability to manage the cases, said WHO South-east Asia Region's Communicable Diseases Control coordinator Chusak Prasittisuk.

'The medical community may need more training because the younger generation of practitioners may not be aware of early detection and proper case management. This is our big concern.'

In Singapore, dengue cases were up in the first nine weeks of the year, with 1,205 people infected, compared with 951 during the same period last year. The authorities are studying if the increase is part of the normal cycle.

Last year, Singapore recorded 7,032 cases, a 20 per cent dip over the 8,826 in 2007. It bucked the trend, as the rest of the region saw an upswing in cases.

Dr Prasittisuk said dengue fever was spreading to countries that were unaffected before, such as Nepal, Bhutan and Timor Leste. Within countries, it is moving from urban to rural areas, where malaria is usually the main scourge.

A regional and international approach is essential to tackle the disease, which is spread by the Aedes aegypti mosquito, he said.

Dr Prasittisuk was speaking at the opening yesterday of the first Asia-Pacific dengue workshop in Singapore, organised by the WHO, Ministry of Foreign Affairs and National Environment Agency (NEA). Forty-two participants from 29 countries are taking part in the workshop, which runs till next Thursday.

It is part of the Asia-Pacific Dengue Strategic Plan, by the WHO and its member states, to eradicate the disease in the region. This trip to Singapore will comprise site visits and field experience to study Singapore's dengue programme.

NEA chief executive officer Andrew Tan said Singapore took a proactive and pre-emptive approach to reduce mosquito breeding and 'deal with the problem before it hits us'.

'The long-term goal through a workshop like this and through future workshops is to develop a regional surveillance network that will allow us to share information, such as the different genotypes of dengue and best practices not only from the laboratory, but also in the field,' he said.

The head of Duke-NUS Graduate Medical School's emerging infectious diseases research programme, Professor Duane Gubler, said dengue's resurgence in the region could be due to the lack of effective mosquito controls in most countries, the movement of virus vectors around the world by air travel, and a continuous importation of new viruses to which people are not immune in the cities.

Dengue cases usually follow a six- to seven-year cyclical trend, with each year surpassing the one before. Singapore is now in the third year of a cycle that began in 2007. Mr Tan said Singapore should remain prepared for the year ahead. He said the NEA would work with the community to ensure simple measures to eradicate mosquito breeding in homes and offices are followed.

Expert warns against re-emerging diseases
Straits Times 11 Mar 09;

TWO mosquito-borne diseases re-emerging in the Americas and Australia might be a concern if they spread, warned an expert in infectious diseases.

Professor Duane Gubler, head of the Duke-NUS Graduate Medical School's emerging infectious diseases research programme, said that yellow fever - which has a 20 per cent fatality rate and an urban transmission cycle identical to dengue's - could become a problem if not controlled quickly. Most recently, two monkeys died of it in Trinidad.

According to the World Health Organisation, an estimated 200,000 cases of yellow fever, with 30,000 deaths, are reported every year, mainly in Africa. Infection causes a wide range of symptoms, and they can lead to severe illness and death.

While yellow fever has never been reported in Asia, the region is at risk because the appropriate primates and mosquitoes are present.

'If we see it in the Americas now, with globalisation, it will quickly move to Asian cities and if that happens, it will create a global public health emergency that will make Sars pale in comparison,' said Prof Gubler. He said health officials should be ready with the same control measures used to tackle dengue, namely eradicating mosquito breeding and checking for transmissions.

Another mosquito-borne disease from Australia, called the Ross River virus, has a similar transmission cycle to chikungunya and dengue. It has re-emerged there due to recent heavy rains and high humidity creating more mosquito-breeding sites.

Symptoms include joint swelling and stiffness and rashes, along with feelings of tiredness and weakness. The majority of people recover fully within a few weeks.