On June 7, 1989, the Riyadh Region Health Department informed the Ministry of Health, Saudi Arabia, that five construction workers from a single construction camp had been hospitalized with right-sided high-output heart failure and peripheral neuropathy. Onset of symptoms happened slowly during April and May 1989. One patient died. The possibility of an unidentified toxic exposure or infectious agent raised concern. A total of 206 persons worked at the camp. Of these, 26 did not eat food prepared in the camp and did not complain of cardiac or neurological symptoms. Of the remaining 180 workers, 26 (14.4%) had cardiac or neurological symptoms and 17 (9.4%) of these had either tibial edema or a motor or sensory defect of the lower legs. We interviewed 156 of these 180 workers and reviewed the camp diet. All interviewed workers depended exclusively on the camp diet. This diet used polished rice as the principal energy source and contained 0.16 mg of thiamine per 1000 Kcal. Illness was more common in workers with heavy work or exercise than in those with only light work, but the difference was not statistically significant. Since beriberi develops in people on diets with less than 0.25 mg of thiamine per 1000 Kcal, we acted on the suspicion that this was an outbreak of beriberi. Thiamine was administered to all workers on the camp diet and a new diet with adequate amounts of all vitamins was instituted. Since then no more workers have been affected.
Conclusion: