84-year-old woman dies from dengue in 5th fatal case this year

Channel NewsAsia 20 Jun 19;

SINGAPORE: An 84-year-old woman died from dengue last week, marking the fifth such death in Singapore this year, according to a joint statement by the National Environment Agency (NEA) and the Ministry of Health (MOH) on Thursday (Jun 20).

The woman, who died last Friday, lived within an active dengue cluster at Lorong 6 Geylang.

As of Monday, 108 dengue cases have been reported in the cluster at Geylang Road, said NEA and MOH.

Since it was notified of the cluster on Apr 26, NEA said it had detected and destroyed 64 mosquito breeding habitats.

Two-thirds of these were found in homes, while the rest were found at common areas and other types of premises.

The woman is the fifth person to die from dengue this year.

Last month, a 63-year-old man who lived at Hougang Avenue 1 died from the disease.

In March, a 71-year-old woman who lived in Ang Mo Kio Avenue 4 died from dengue.

Two people died from the disease in February. The first was a 74-year-old man who lived in Bedok Reservoir Road and the second a 77-year-old male resident at Hougang Avenue 3.

Singapore has seen a surge in dengue cases this year, with the number of weekly reported dengue cases more than quadrupling in the past three months.

Just last week, the number of reported dengue cases spiked to a three-year high, with 468 reported cases in the week ending Jun 15 - the highest weekly figure since March 2016.

READ: Weekly dengue cases in Singapore spike to highest in more than 3 years
As of Jun 15, there have been 5,184 dengue cases reported in total this year, more than the 3,285 cases reported in the whole of 2018 and 2,772 cases in 2017.

"While there are certain geographical clusters which accounted for the bulk of the increase in dengue cases, such as at Woodlands, Geylang, Jalan Lembah Thomson and Chai Chee, there has been a general uptrend in dengue cases across the island," said NEA and MOH.

"The dengue transmission is therefore not localised, and everyone has to be alert to the threat."

The two bodies added that as the year enters the warmer months of June to October, the number of dengue cases is expected to rise further.

MAJORITY OF BREEDING HABITATS FOUND IN HOMES

NEA and MOH also called for home owners and residents to step up their efforts, pointing out that the majority of mosquito breeding habitats have been found in residential premises.

"Between January and March this year, about 60 per cent of the breeding habitats detected across the island have been found in residential premises and the numbers of such breeding in homes remain high," said NEA and MOH.

"Despite various efforts to raise awareness and heightened alert, (the) majority of mosquito breeding is still detected in homes, highlighting the urgent need for residents and premises owners to step up to eradicate mosquito breeding habitats."

NEA also urged premises owners and residents to "cooperate fully" with the agency and allow officers to carry out inspections and spray insecticide to kill any mosquitoes.

Source: CNA/nc(hs)

Low immunity among people a likely cause of dengue surge
Aedes mosquitoes may also be thriving due to warmer weather this year, experts warn
Cara Wong Straits Times 23 Jun 19;

Low immunity among the population against the dengue virus may be contributing to a surge in infections this year, especially as mosquito numbers remain persistently high, said health and environment experts yesterday.

This comes as dengue cases spike in the region, indicating that the Aedes mosquito - the carrier of the disease - may be thriving with a warmer weather pattern this year.

At a media sharing session in commemoration of Asean Dengue Day 2019 a week ago, a panel of experts also raised concerns about patients over 65, who tend to suffer more, yet typically do not display the usual dengue symptoms.

These patients are likely to have contributed to the small uptick in the average hospitalisation rate for the disease in recent years.

Singapore is in the midst of a dengue outbreak, with five reported deaths from the disease so far this year. As of last Monday, there were 5,261 infections reported, a 60 per cent increase over the total for the whole of last year, and close to double of 2017's overall numbers.

Associate Professor Ng Lee Ching, director of National Environment Agency's (NEA) Environmental Health Institute, said Singapore has low herd immunity against the disease as good mosquito control over the years means that many people have never been infected.

An NEA study on the prevalence of the disease in healthy adults showed that only about 16 per cent of Singapore's youth aged between 16 and 20 years in 2009 had had dengue before, she said.

5,261
Number of dengue infections reported this year as of last Monday, a 60 per cent surge over that for the whole of last year.

The study, which is the latest one available on the topic, was published in 2015.

A recovered patient is immune to the particular strain of dengue he or she was infected with.

"When we say we have low herd immunity and that we are very sensitive to outbreaks, that means that we just need a few mosquitoes to have an outbreak," said Prof Ng.

Professor Leo Yee Sin, executive director of the National Centre for Infectious Diseases, said a particular group of concern was the elderly.

A study published last month that reviewed dengue hospitalisations showed a higher proportion of dengue patients hospitalised from 2003 to 2017 were the elderly. In 2017, 47.2 per cent of dengue patients admitted to hospitals were aged 65 and above.

This has probably contributed to the slight increase in the average hospitalisation rate for dengue, from 2014's low of 25.6 per cent, to 2017's 35.9 per cent, said Prof Leo.

The elderly tend to face more complications with the disease because they may have existing chronic conditions, and they are more susceptible to secondary infections, she said.

Another factor which compounds the problem is the difficulty of diagnosing dengue in the elderly, as they tend not to display the typical symptoms such as fever, body aches and rash, according to experts.

Dr Wong Wei Mon, a senior physician with the College of Family Physicians Singapore, said the elderly may have only fever or nausea when they visit the doctor, or may even have symptoms not listed as common dengue symptoms.

"Doctors, if they are not alert enough, may not trigger the definitive test to confirm the presence of dengue," said Dr Wong. By the time they are diagnosed, the disease may be severe, he added.

To combat this, the authorities have been urging doctors to keep a keen eye out for dengue among the elderly, said the experts.

The NEA, too, has been ramping up efforts to prevent mosquito breeding, such as introducing Aedes moquitoes infected with the Wolbachia bacteria into the wild to help reduce the mosquito population, said Dr Christina Liew, NEA's medical entomologist.