CHICAGO (CBS) — An outbreak of norovirus, which raced through a suburban school last week, appears to be subsiding.

As WBBM Newsradio’s Regine Schlesinger reports, last Thursday, 129 children were out sick at the Westfield Community Elementary School in Algonquin. By Friday, that number soared to 289.

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Norovirus, commonly known as the stomach flu, is a highly contagious infection that can produce severe gastrointestinal symptoms. The most common symptoms are diarrhea, vomiting, and stomach pain.

Kane County Health Department spokesman Tom Schlueter said Monday that 76 children were out, still well above normal, but greatly improved from last week.

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“We really encouraged these children to stay home for 24 hours after their symptoms have gone away and to practice good hygiene – wash your hands, wash your hands, wash your hands,” he said.

So far, Schlueter said, no other school in the area has reported any unusual numbers of absences, so he’s hopeful the outbreak has been contained.

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LISTEN: WBBM Newsradio’s Regine Schlesinger reports