My girlfriend's sister died this week suddenly and unexpectedly at the age of 27.

From complaining about, and receiving medication for, a stomach infection her condition worsened and she died a few days later.

The only explaination I have heard is "fee nai samong".

Can anyone throw more light on this.

It seems to be pretty much what you put in the title - brain abscess.

ฝีในสมอง - fee^Rcan be abscess or pus ( inflammation like skin boil, acne, pox or even TB etc.) and sa^L maawng^R is brain, nai^M being in

I believe it could also be encephalitis (nflammation/infection of the brain tissue) which is more common.

Often a viral cause. One of which -- Japanese B -- can be preevented by vaccine. The virus is spread by a daytime biting mosquito, has its resevoir in pigs and is found throughout the countryside in areas where pigs are raised.

Years ago when I worked in the refugee camps on the Thai-Cambodian border a young farang woman in her 20's contacted it.

Onset is sudden, fatality rates high, and even if one survives there can be permanent brain damage. I've had the vaccine and strongly recommend that others do the same, especially if living or tarvekling in rural areas.

Recent studies in Cambodia have shown it to be a sufficiently common cause of death in children to persuade the Cambodian Ministry of Health (and its donors) to pay for its inclusion in the routine schedule of childhood immunuizations. However have not heard of this being done yet in Thailand.

According to the other half (a vet) - brain abcess, as paethon correctly said - but folk with a brain abcess normally complain of a roaring headache in the early stages - but no mention here of a headache (?)