S'pore scientists develop rapid test kit for killer 'soil' disease
Shobana Kesava
Wed, Jan 02, 2008
The Straits Times
A LITTLE-UNDERSTOOD bacterium in the soil, which killed one in three infected patients in 2004, can now be identified in mere hours instead of days.
A research team at DSO National Laboratories has developed a rapid test kit that will diagnose the disease it causes - melioidosis - in about three hours. It currently takes up to five days to do a diagnosis in a hospital.
Research-clinician Dr Ooi Eng Eong, who heads the research team, told The Straits Times that this is the first such test kit to be commercialised.
He said the Ministry of Defence (Mindef) is interested in using the typewriter-size kit to diagnose soldiers in the field.
The bacterium Burkholderia pseudomallei, which can enter the body through a small cut, can cause death from pus infection within one week.
DSO has been at the forefront of melioidosis research because of its potential to affect Singapore Armed Forces (SAF) soldiers in training.
The bacterium is also considered a potential biological weapon.
This is why Dr Ooi's team is hoping to diagnose the disease quickly.
The test kit will be able to identify 70 per cent of cases on the very first day symptoms emerge.
'The problem is melioidosis is a great mimicker of different diseases, and can take on the forms of an abscess from anywhere on the skin to the liver, blood infections or pneumonia,' said Dr Ooi.
His team is also applying for a $5 million grant from Mindef to begin to understand the disease better.
Scientists are still not sure how infections happen in Singapore. In other parts of South-east Asia, the disease is linked to rural areas where farmers work in paddy fields, for example. Present in almost any kind of soil, the bacteria survive in water, too.
Research clinicians believe the unusually high rate of 24 deaths out of 79 cases reported in 2004 were linked to flash floods after heavy rains.
That year, 70 per cent of cases had pneumonia. Research clinicians widely believe this was a result of inhaling the bacteria present in water droplets in the air.
'For example, it could have been breathed in from the spray created by a passing car,' said Dr Ooi.
In an average year, nearly one in five cases of melioidosis - 12 out of 67 - ends in fatalities in Singapore.
Death is more likely when immunity is low. Some survivors suffer a relapse of the illness years later.
The death rate was three times higher 20 years ago.
Associate Professor Raymond Lin, head of the National University Hospital's (NUH) microbiology division at the laboratory medicine department, said new steps have been taken since the 1990s.
'Medical staff are more alert to melioidosis now. They start treatment even before diagnosis, just on suspicion of it.'
Bacteria from the patient's sample of blood or sputum are cultured over a few days, and tested for a conclusive diagnosis. A test costs up to $50 at public hospitals like NUH.
The rapid test that DSO has developed would cost at least twice this, but NUH's Prof Lin sees a potential for hospital use when it becomes cheaper and more sensitive.
'If it can be incorporated into a battery of tests, this will be very useful,' he added.
