大分県有酒店集體食物中毒

Recently the Asahi News reported the following:

大分県は１１日、同県九重町の筋湯観光ホテルで食事をした長崎県佐世保市の県立高校の生徒と職員計２０６人が、発熱や下痢などの症状を訴えたと発表した。患者の便や料理からサルモネラ菌が検出されたことから、保健所は集団食中毒と判断し、１２日まで２日間、ホテルでの調理業務を停止する処分を出した。
　大分県によると、ホテルには、職員を含めた１年生グループ２２８人が７月２８日～８月１日、３年生グループ２２３人が８月１日～７日に学習合宿で宿泊した。症状を訴えた２０６人のうち５７人が医師の診察を受けたが、全員快方に向かっているという。

On the 11th, Oita Prefecture announced that the Nagasaki Prefecture Sasebo City public high school students and staff in total 206 people that had eaten at the Sujiyu Sightseeing Hotel in Kujuuchou of Oita prefecture complained about having fever and symptom such as diarrhea. The public health center detected salmonella in patent's stool and in the food and judged it as a mass food poisoning, gave out a penalty of stopping the cooking business of the hotel for two days until the 12th.

According to Oita Prefecture, from July 28 to August 1 a group of 1st grader and staff totalling 228 people, and from August 1 to 7th, a group of third grader of 223 people all had stayed for the study camp. It was said that among the 206 people who had complained about the symptoms, 57 people had received evaluation by doctors, and all were recovering.

I am wondering how could a big hotel be so careless in providing unclean food to the customers.