<TABLE cellSpacing=0 cellPadding=0 width="100%" border=0><TBODY><TR>Rare dengue type on the rise in Singapore
</TR><!-- headline one : end --><TR>Alert for Den-3 virus, which can cause a major outbreak if not contained </TR><!-- Author --><TR><TD class="padlrt8 georgia11 darkgrey bold" colSpan=2>By Jessica Jaganathan
</TD></TR><!-- show image if available --></TBODY></TABLE>
<!-- START OF : div id="storytext"--><!-- more than 4 paragraphs -->DENGUE numbers are down but public health officers are on high alert.
The reason: An unfamiliar dengue virus has emerged which has the potential to spark a major outbreak.
<TABLE width=200 align=left valign="top"><TBODY><TR><TD class=padr8><!-- Vodcast --><!-- Background Story -->RELATED LINKS
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Dengue
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</TD></TR></TBODY></TABLE>Though officials said on Tuesday that they have managed to contain the Dengue-3 virus for now, they are still keeping a close watch on it, as it has not been seen here commonly for some 10 years.
With low immunity to Den-3 in the population, people are more vulnerable to infection.
Officials are concerned because cases increased more than three times last November and December, and were found mainly in two areas, sparking fears that transmissions were high and could spread.
There are four types of the dengue virus, and people who have been infected by any one type are immune to it for life. But that still means that an individual can get dengue fever up to four times.
In Singapore, two main types of the dengue virus have circulated in the past 10 years: Dengue-1 and Dengue-2, with the latter now predominant.
Past data shows that outbreaks in 2005 and 2007 were preceded by a switch in the predominant type of dengue virus.
In the past few months, researchers from the National Environment Agency (NEA) found that the third type, Den-3, had emerged in greater numbers in Little India and Geylang.
On average, Den-3 makes up about 5 per cent of all dengue cases here. But in November and December last year, it increased to more than 17 per cent.
Although the numbers dropped back to 5 per cent last month, after NEA officers went to war against mosquitoes in the hot spots, the authorities are still watchful. Because of the rarity of Den-3 here, Singaporeans' immunity to it is very low, said Dr Ng Lee Ching, head of the NEA's Environmental Health Institute.
Alarm bells went off as well, when infections clustered in two areas, Little India and Geylang, for two consecutive months.
'We straightaway launched our resources in these areas as we didn't want Den-3 to have a launching pad to spring out to the rest of Singapore,' said Mr Tai Ji Choong, head of operations at the NEA's environmental health department.
If it did spread, NEA officials feared a worse outbreak than in 2005, which infected more than 14,000 Singaporeans and caused 25 fatalities, he said.
They went to work on the main lines of defence that have been successful in reducing numbers in the past: eliminate breeding spots and rely on the research team's laboratory work to pinpoint where the dengue type was dominant.
Officers are now posted permanently in the two areas to wipe out breeding areas and two additional pest control teams have been deployed to check tricky spots like roof gutters for breeding, he said.
They are also keeping watch on neighbourhoods in the south-west, like Bukit Batok and Jurong as well as Woodlands and Joo Chiat, where there has been a sharp increase of 10 per cent to 20 per cent in Dengue-1 cases over this year.
The numbers fell last month, said Mr Tai, but the possibility of a new outbreak remains.
With warmer weather expected, NEA officers, together with other agencies, are stepping up efforts to reduce and remove possible mosquito breeding sites.
The World Health Organisation (WHO) warned last week that 1.8 billion people in the Asia-Pacific region are at risk of being infected with dengue, which has been gaining in South-east Asia. [email protected]
</TR><!-- headline one : end --><TR>Alert for Den-3 virus, which can cause a major outbreak if not contained </TR><!-- Author --><TR><TD class="padlrt8 georgia11 darkgrey bold" colSpan=2>By Jessica Jaganathan
</TD></TR><!-- show image if available --></TBODY></TABLE>
<!-- START OF : div id="storytext"--><!-- more than 4 paragraphs -->DENGUE numbers are down but public health officers are on high alert.
The reason: An unfamiliar dengue virus has emerged which has the potential to spark a major outbreak.
<TABLE width=200 align=left valign="top"><TBODY><TR><TD class=padr8><!-- Vodcast --><!-- Background Story -->RELATED LINKS
<!-- Audio --><!-- Video --><!-- PDF -->
<!-- Photo Gallery -->
</TD></TR></TBODY></TABLE>Though officials said on Tuesday that they have managed to contain the Dengue-3 virus for now, they are still keeping a close watch on it, as it has not been seen here commonly for some 10 years.
With low immunity to Den-3 in the population, people are more vulnerable to infection.
Officials are concerned because cases increased more than three times last November and December, and were found mainly in two areas, sparking fears that transmissions were high and could spread.
There are four types of the dengue virus, and people who have been infected by any one type are immune to it for life. But that still means that an individual can get dengue fever up to four times.
In Singapore, two main types of the dengue virus have circulated in the past 10 years: Dengue-1 and Dengue-2, with the latter now predominant.
Past data shows that outbreaks in 2005 and 2007 were preceded by a switch in the predominant type of dengue virus.
In the past few months, researchers from the National Environment Agency (NEA) found that the third type, Den-3, had emerged in greater numbers in Little India and Geylang.
On average, Den-3 makes up about 5 per cent of all dengue cases here. But in November and December last year, it increased to more than 17 per cent.
Although the numbers dropped back to 5 per cent last month, after NEA officers went to war against mosquitoes in the hot spots, the authorities are still watchful. Because of the rarity of Den-3 here, Singaporeans' immunity to it is very low, said Dr Ng Lee Ching, head of the NEA's Environmental Health Institute.
Alarm bells went off as well, when infections clustered in two areas, Little India and Geylang, for two consecutive months.
'We straightaway launched our resources in these areas as we didn't want Den-3 to have a launching pad to spring out to the rest of Singapore,' said Mr Tai Ji Choong, head of operations at the NEA's environmental health department.
If it did spread, NEA officials feared a worse outbreak than in 2005, which infected more than 14,000 Singaporeans and caused 25 fatalities, he said.
They went to work on the main lines of defence that have been successful in reducing numbers in the past: eliminate breeding spots and rely on the research team's laboratory work to pinpoint where the dengue type was dominant.
Officers are now posted permanently in the two areas to wipe out breeding areas and two additional pest control teams have been deployed to check tricky spots like roof gutters for breeding, he said.
They are also keeping watch on neighbourhoods in the south-west, like Bukit Batok and Jurong as well as Woodlands and Joo Chiat, where there has been a sharp increase of 10 per cent to 20 per cent in Dengue-1 cases over this year.
The numbers fell last month, said Mr Tai, but the possibility of a new outbreak remains.
With warmer weather expected, NEA officers, together with other agencies, are stepping up efforts to reduce and remove possible mosquito breeding sites.
The World Health Organisation (WHO) warned last week that 1.8 billion people in the Asia-Pacific region are at risk of being infected with dengue, which has been gaining in South-east Asia. [email protected]
