A primary school campus in Putuo District, Shanghai was set to be closed on Thursday as officials investigate a virus outbreak there that left 52 pupils and two of their teachers sick.
The incident started on Tuesday when a first-grader at Wuning Road Primary School's First Wuning Village Campus — which is home to 535 first and second-graders — began vomiting in class.
The girl was taken home by her parents and kept off school the following day. By yesterday morning, however, 51 of her classmates and two of her teachers had also fallen ill, prompting the school to suspend all classes for first-graders yesterday, and later to call for the total closure of the campus.
"Information provided by the hospital where several children were treated suggests the incident was caused by an outbreak of norovirus," Sun Naxin, the school's headmaster, told Shanghai Daily yesterday.
"Also, after talking to the parents of the first girl who fell sick, we discovered that she had attended a wedding banquet on Sunday and that several other guests had experienced fever and vomiting," he said.
Officials from the Putuo District Food and Drug Administration said that an initial investigation had ruled out the possibility of the outbreak originating in the school canteen.
"Food samples were taken away, but none were infected," Sun said.
He added that after suspending classes for first-graders yesterday, cleaners at the school disinfected the entire campus as a precaution. In the interests of safety, however, he said he later decided to close the whole campus.
"All of the pupils who fell sick were first-graders, and 20 were classmates of the first girl," Sun said.
"More than 10 of the others were from the classroom next door, so it seems the chances of falling sick increased the closer the children were to the first girl," he said.
"There were no cases reported on floors other than the one occupied by the first-graders," he said.
Norovirus is highly contagious and has an incubation period of between 12 and 72 hours. A major cause of gastroenteritis, the symptoms of infection include fever, vomiting and diarrhea. Outbreaks are most common between October and March.
