Sunday, September 21, 2008

Dengue Second Time around can be fatal

If you are like me and had dengue once, you should really cover up. Don't listen to people who know nothing about the disease telling you you would be immune cos you got it once. Dengue is unusual that way--it gets more serious the second time around. The reason is that there are 4 strains of dengue and if you contract any one of the 3 strains different from the one you got the first time round, your body will use all its resources to fight what it thinks is the first strain, leaving it defenceless against the new virus. You may then get Dengue Hemorrhagic Fever - which effectively destroys the platelets that cause blood to clot, meaning you can bleed to death.

It's rainy season now and I got dengue in Oct 2006 in Phnom Penh. Now, Chhun Hy, the young Cambodian man who lives with us here in Siem Reap has it. Which means if a mozzie bites him and then me, I will get it. Alan contracted dengue in Singapore, and the chances that he'll get a new variant here in Cambodia is higher for him. Very worrying.

You can read more about dengue here:

Scientists crack dengue fever puzzle

Experts may have solved the mystery of why dengue fever, unlike other infections, is usually more severe the second time around. Dengue is a debilitating, sometimes fatal illness endemic to much of the tropics. Caused by a virus, it is characterized by high fever, bone and muscle pain and -- in the most serious cases -- hemorrhage and fatal shock.
Dengue is also unusual in that //symptoms are more severe during a second or third infection compared to first-time infection. Experts estimate that over 50 million people are affected by dengue each year, with about five percent of patients dying of the illness.

The findings may complicate the search for a vaccine against the deadly mosquito-borne illness, according to British and Thai scientists. Now scientists believe they have solved the dengue paradox. The key to the puzzle, say researchers is the fact that the dengue virus falls into four distinct subtypes. Initial infection with one subtype causes the immune system to direct its response to that specific variant. But if an individual later contracts any of the three other variants, he or she is left virtually defenseless against the virus.

The scientists evaluated the immune cell response of 73 Thai children hospitalized with dengue fever and found that all but two had been infected at least once before.

What's more, these children had relatively low levels of infection-fighting T cells specific for the new virus. Normally infection with viruses such as hepatitis C or Epstein-Barr result in high levels of such T cells. The researchers think a second infection triggers the immune system to frantically hunt for the wrong subtype of the virus, causing painful inflammatory symptoms such as aching and fever.

However, this second immune response generates immune cells that only react weakly to the new virus. And the duration of the disease is also much longer because the body fails to clear the infection quickly.

There is no vaccine for dengue, so you just have to use repellent and cover up.


Anonymous said...

try this

MumMe said...

it's my second time also...praying for the best...even i look healthy as usual,i can feel the inside of me not the same...


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