Outbreak of Food Poisoning from Bleaching Agents in Pickled Bamboo Shoot in a School in Amphoe Song, Changwat Phrae - การระบาดของโรคอาหารเป็นพิษจากสารฟอกขาวในหน่อไม้ดอง ในโรงเรียนแห่งหนึ่ง อำเภอสอง จังหวัดแพร่ กรกฎาคม ๒๕๔๘

Abstract

            Bleaching agents, especially sodium hydrosulfite, is a chemical used to inhibit color change in foods. Ingestion may cause abdominal pain, headache, dizziness, nausea and hypotension or even death at excessives dose. This retrospective cohort study examined the outbreak of food poisoning from bleaching agents in a school in Amphoe Song, Changwat Phrae in July 2005.

             There were 43 cases (24.3%) from a total of 177 students, teachers and cooks. Most presented with abdominal pain (79.1 %) and nausea/ vomiting (76.7%). The patients presented with symptoms at noon, indicating an incubation time of 30 minutes. The majority of patients (88.4%) became symptomatic in the period 12.00-13.00 a.m. The suspected cause was pickled bamboo shoot curry with pork, one of the main dishes for lunch provided by this school. The relative risk, was 60.79 (95% CI = 8.56-431.58). From the examination of the feces of all the patients and cooks, drinking water as well as the curry indicated no pathogenic enteric organisms. However a screening test for sodium hydrosulfite were positive in the pickled bamboo shoot, while titration method 15.79 mg/kg sulfur dioxide.

              The outbreak of food poisoning in this school could be caused by sodium hydrosulfite, which is a chemical prohibited by the Ministry of Public Heath as a preservative. Therefore, school cooks and consumers should be further educated.