Tuesday, 30 April 2013

NEA gets tough in fighting dengue

It will take faster action against uncooperative residents in hot spots
By Salma Khalik, The Straits Times, 29 Apr 2013

THE National Environment Agency (NEA) will break into homes in dengue hot spots after waiting just a week, instead of two, for residents to allow them in.

"This is about life and death," said Environment and Water Resources Minister Vivian Balakrishnan, asking for understanding as Singapore grapples with what is expected to be its worst dengue epidemic.

So far this year, the NEA has forcibly entered three homes - two of which were vacant - with the aid of a locksmith in the Tampines area where the epidemic is raging. Mosquitoes were found breeding in them. There is one cluster in Tampines with 126 victims, with 34 in just one block of flats.

"We are facing a full-blown epidemic and it's going to grow," said Dr Balakrishnan, whose ministry is in charge of preventing the breeding of mosquitoes.

"We fear it's going to be Singapore's worst epidemic...possibly with more than 1,000 infections a week at its peak."

He warned it is only a matter of time before the epidemic, currently centred in the east, moves across the island. NEA has found more Aedes mosquitoes in the west compared to previous years.

Yesterday, Prime Minister Lee Hsien Loong led ministers, MPs and 30,000 grassroots leaders in a door-to-door campaign across the nation to raise awareness of the dangers of dengue and to get everyone to cooperate in eradicating mosquito breeding.

They will advise people to check pails and vases regularly, use insect repellent and wear long-sleeved tops and pants to avoid being bitten.

In the first 15 weeks of the year, NEA has found 5,347 breeding spots, mostly in homes. In launching the national Mozzie Wipeout campaign in Ang Mo Kio, Mr Lee said: "We're trying to do it nationwide, all the estates, all the towns, all the homes, over this weekend and the next few weekends, to try to break the chains of mosquitoes breeding.

"If we can cut down the mosquitoes, then I think we can cut down the dengue fever cases this year."

The idea is to get the whole nation mobilised because without the mosquito as an intermediary, dengue cannot spread.

Singapore is facing a huge epidemic, with more than 5,200 people infected so far this year, compared to 4,632 cases for the whole of last year.

Meanwhile, Health Minister Gan Kim Yong told reporters after the launch at Chua Chu Kang GRC that hospitals are gearing up for a greater influx of dengue patients.

Currently, people down with severe dengue are taking up 1 per cent of hospital beds, he said. Should their numbers grow, hospitals have contingency plans that include temporary beds, postponing non-urgent surgery and sending the less ill to community hospitals.

Dr Balakrishnan hopes that the concerted efforts by everyone - including the opposition MPs who are fully behind the national campaign - will break the chain of transmission.

He said one advantage over the epidemic of 2005, when 14,000 people were infected and 25 died, is that more people are aware of the problem and seek medical help early. So NEA gets the information and acts on it faster, before a dengue cluster gets too big.

To beat dengue, know thy enemy
By Leo Yee Sin, Published The Straits Times, 18 Nov 2013

IN 2005, Singapore reported 14,000 dengue cases, the highest number in its history.

This year, however, has been worse. By October, the number of reported cases had passed 18,000, with six deaths.

Not surprisingly, a common question is being asked: "Are we making good progress in the management of dengue?"

Despite the fact that dengue has existed in Singapore for decades, the disease still holds many mysteries. Prevention is important, of course, but that is not the only problem.

As an infectious disease specialist who has witnessed several large dengue outbreaks, I am challenged all the time to understand the disease better so as to develop more effective ways to diagnose and treat dengue patients.

Fortunately, progress is being made, but much more research is also needed.

Singapore's experience has shed more light on two issues. The first is the vulnerability of older adults, while the second has to do with hospitalisation rates.

Older patients more vulnerable

ALL four sero-types or variations of dengue are in circulation in Singapore and in most parts of the world. However, while most places experience dengue as a childhood disease, in Singapore most victims are adults, and in recent years, older adults.

Research carried out by Stop Dengue in Singapore shows that older adults stricken by dengue tend to have fewer and less common symptoms. This makes diagnosis very challenging.

Older individuals also have a higher risk of complications. This is evident in Singapore's statistics. Fatalities are disproportionately higher in older individuals, particularly those with pre-existing medical ailments.

More research is needed to further understand how the immune system responds to dengue and how this might vary with the age of the patient.

Fluid replacement is a common approach to plasma and fluid leaks in the young. However, it does not work very well in the treatment of older adults, who are likely to have hypertension, diabetes and chronic heart disease that make their care more complex.

If struck by dengue, older people are more likely to bleed internally and suffer damage to other vital organs such as the kidney, the liver, and the brain.

In addition, any alteration of their immune system due to ageing might predispose them to a higher risk of an accompanying bacterial infection that can trigger a string of side effects leading to unfortunate outcomes.

In recent years, more countries are reporting a seeming shift of dengue towards adults and senior citizens. In fact, there is keen international interest in Singapore's research and management of the disease.

Hospitalisation not always best option

IN 2005, about 70 to 80 per cent of 14,000 dengue patients were hospitalised.

Of the 14,000 cases notified to the Ministry of Health in 2005, about 70 to 80 per cent were hospitalised. Doctors are required to report the cases back to MOH.

This meant that at the height of the epidemic, approximately 10 per cent of hospital beds were occupied by dengue sufferers. The situation crippled the health-care delivery system. Emergency departments were overcrowded, and non-urgent surgeries had to be deferred. Other patients with chronic conditions were not given full attention either.

During this year's outbreak, the proportion of dengue patients who have been hospitalised has declined by more than half to approximately 30 per cent.

Beds occupied by dengue cases in public hospitals are now barely exceeding 1 per cent of the total available, compared to 10 per cent in 2005.

This helps to ensure that hospitals can continue to admit other non-dengue patients who require hospitalisation.

The lower hospitalisation rate can be attributed to several factors.

First, research findings identifying the risks associated with the progression of the disease have helped to focus attention on those who need inpatient care. Doctors are now better able to identify and properly care for dengue patients who need hospital care.

Second, sharing of knowledge and experience across all health-care levels has given doctors the confidence to treat patients in clinics. Doctors in Singapore are now better able to manage the care of dengue patients in the community.

Last but not least, the community is more aware of the fact that not all dengue patients require hospitalisation. Dengue patients need lots of rest to enable the body to fight against the infection. Under the care of their family physicians, a patient's home provides the most comfort for rest and recovery.

Some might ask if the lower bed occupancy rate by dengue patients implies a compromised level of care. The statistics, however, suggest otherwise. In the 2005 outbreak there were 27 fatal cases. So far there have been six fatal cases this year. And this is despite the larger number of cases and the lower hospitalisation rate.

Research has and will continue to play a significant role in helping us understand and treat the disease. As Sun Tzu says, "Know thy self. Know thy enemy. A thousand battles, a thousand victories."

The writer is director of the Institute of Infectious Diseases and Epidemiology at Tan Tock Seng Hospital.

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