某部发生一起菜豆中毒。调查结果如下。 1 流行病学调查 1.1 中毒发生经过 1990年8月23日上午,某部战士灶从自由市场购回50斤菜豆,中午用25斤菜豆炒肉食用。烹调方法是:清洗干净后切段急火快炒。当天中午127人就餐,50名战士食菜豆炒肉后有47人出现中毒症状,发病率为94.0％,其中有3人食用后无自觉症状。77 A bean poisoning occurred in a department. The survey results are as follows. 1 Epidemiological Survey 1.1 Poisoning After the morning of August 23, 1990, a warrior stove purchased 50 pounds of beans from the free market, with no more than 25 pounds of roasted beans. Cooking method is: cut clean emergency fire fast fried. 127 people dined at noon on the same day, 50 soldiers fried beans after eating beans, 47 people showed symptoms of poisoning, the incidence was 94.0%, of which 3 people without symptoms after eating. 77