Saidu's Death

I though it was interesting about the death of Saidu, one of Beah's friends from his second group. There is many possibilities of how he could have died, but it just came so randomly. He fainted in one chapter, but suddenly died in the next. My first thought would be severe exhaustion, or maybe malnutrition. It could be that he was just running on adrenaline some time due to the events that occurred, and his fainting could have do to lack of it. I would think though that he would show signs of weakening before fainting or his death, but no significant signs were shown. With Beah's detailed descriptions, it seems like it would most definitely be mentioned.
Another possibility could have been some kind of life form(including viruses) that could have been infecting his body, or using him a a host in a parasitic relationship. Then again, no signs of pain, or weakening were mentioned. I'm sure that in Africa there may be something that could kill without anyone knowing, but his death just doesn't seem to follow the path of an outside source.
A chapter before Saidu's fainting, he mentions that every time they get captured or caught, part of him dies on the inside. Eventually, he would just be there, but not mentally alive as he was. Beah even mentioned this possibility to the reader briefly showing how he though he went. I would agree. When those mystical men crossed the bridge, he was on the edge of breaking. As they got closer, he lost hope figuring they'd be caught triggering the mental shut down producing a faint. After he was revived, he acted normally. It would be reasonable to think that later on when Beah learns of his parents whereabouts that Saidu's may increase as well. Perhaps not though. My thought is that he gained a feeling in inner depression after realizing Beah would soon have his family, but he still wouldn't have his. This lack of will would probably kill his mental activity as he said. Once asleep, there was no will to wake up.