An outbreak of a food-related illness resembling boric acid poisoning

An outbreak of an illness suggestive of boric acid poisoning occurred among 51 persons who had eaten lunch at the cafeteria of the United States Agency for International Development in Islamabad, Pakistan, on February 11, 1990. Affected patients had headache and severe myalgias 2 to 4 hours after eating lunch. Fever, nausea and vomiting, red eyes, and photophobia were also reported. Among 25 patients (49%), a sunburn-like inflammation of the skin of the face developed, which subsequently desquamated. One patient required hospitalization for 1 day because of dehydration. Among all patients, the only symptoms remaining 72 hours after the meal were mild headache, fatigue, and peeling skin. Those persons who became ill were more likely to have eaten one particular food item (minestrone soup) for lunch than were those who did not become ill. A similar illness has been described following ingestion of boric acid. However, the results of an analysis of serum samples collected 3 days after the lunch from 24 patients did not show boron above normal background levels. Because of boron's short half-life, however, these data do not rule out the possibility that patients may have had higher boron levels at the onset of the illness.