According to a report on BruneiDirect.com, one of the victims, a teacher, described his experience.
"About two hours after eating it [the nasi ayam]," he said, "I started feeling dizzy and had a stomach ache. I started vomiting a lot and so my wife brought me to the emergency ward. It was here I met some other patients with food poisoning who also attended the seminar."The teacher added that the other victims he met at the emergency ward had also eaten nasi ayam, "which tasted quite good actually."
The symptoms that this food poisoning victim described are very suggestive of either Staphylococcus aureus or Bacillus cereus. The very short incubation period is consistent with B. cereus, which has often been associated with food poisoning in rice-based dishes.
Both S. aureus and B. cereus produce heat-stable toxins, and do not cause any change to the appearance or taste of a food in which they have multiplied. The only protection against these microbes is careful attention to hand-washing when preparing food (especially for S. aureus, which is carried by a large fraction of the general population), and proper temperature control – something that we often found lacking in our travels through Southeast Asia.