2010年5月13日19:20,北京市某医院报告当天下午有10例头晕、呕吐、腹痛等胃肠道症状的患者。本文以对该事件的调查为背景,运用描述和分析流行病学方法,并结合现场卫生学调查和实验室检测结果,分析推断本次事件的致病因子、可 At 13:20 on May 13, 2010, a hospital in Beijing reported 10 patients with gastrointestinal symptoms such as dizziness, vomiting and abdominal pain in the afternoon of that day. In this paper, the background of the investigation of the incident, the use of description and analysis of epidemiological methods, combined with on-site hygiene surveys and laboratory testing results to infer the causative factor of this incident may be