S'pore-MIT team finds way to predict severity of dengue

SINGAPORE - Most dengue patients have a mild but painful form of the mosquito-borne illness, but a fraction develop its more severe form, dengue haemorrhagic fever.

Now, researchers from Singapore and the Massachusetts Institute of Technology (MIT) have found a molecular signature that could predict which form the disease may take in a patient.

Their method can come up with an answer between 48 and 72 hours of a patient coming down with fever. It now takes four to seven days before doctors can tell if a patient has the more serious form.

This could help cut the number of hospitalisations, said research team member Lee Yie Hou of the Singapore-MIT Alliance for Research and Technology.

Between 0.5 and 1 per cent of dengue patients here turn out to have the more severe haemorrhagic fever. But more than 25 per cent are hospitalised.

If a patient finds out quickly that he has the mild form of dengue, "it means you can just go home, take lots of fluids and rest well", Dr Lee said.

Currently, there is no anti-viral treatment that specifically targets dengue, nor is there a vaccine.

The researchers studied 62 patients suffering from their first dengue infection - 44 had dengue fever and 18 had dengue haemorrhagic fever.

In the latter group, there were lower levels of proteins called cytokines in the early days of illness - a sign that these patients' immune systems might not be fighting off the disease as effectively, Dr Lee said.

The new method was developed after a study on patients with the Den-1 and Den-3 types of dengue. It must, however, be proven to work with a third strain of the disease - the Den-2 type - and be validated on a new set of patients before it can be used in clinical practice, he added.

The team, in collaboration with the Communicable Disease Centre and National University Hospital, will take about a year to do that. "We are trying to complement what is done clinically," he said, and not to replace current tests.

Dr Lim Poh Lian, deputy clinical director of the Communicable Disease Centre, who was not involved in the research, said it was a "holy grail" of dengue, and of infectious disease in general, to predict who will do better and who will get worse.

The number of dengue infections is particularly high this year, with more than 4,000 cases in Singapore so far, though there have been no fatalities. With the warmer season coming, the number of weekly infections - it was 492 last week - is expected to peak in about five weeks.

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