HOUSTON, Feb. 6 (Xinhua) -- Dozens of students at three elementary schools in the U.S. city of Houston were sickened by lunch food Thursday, local media reported.
About 50 students at Wolman, Morton Ranch and Kilpatrick elementary schools in west Houston had an allergic reaction after lunch Thursday, daily newspaper the Houston Chronicle quoted a statement published by the school district as saying.
Symptoms included a skin rash and shortness of breath.
None of the students required outside medical attention, the statement said, but district officials continued to monitor their condition and were investigating the source of the allergic reaction.
In a message sent to parents and school staff, the district said the allergic reaction was believed to be caused by "a product within the rice that was served with the meal."
District officials "are collecting additional information and are continuing to investigate to determine if any product modifications were made by the company that manufactures the rice."
The incident happened a week after a gastrointestinal illness sent home hundreds of students at a high school in northern Texas. Lab results later pointed to norovirus being the culprit.
Norovirus is highly contagious and can be passed on by an infected person, contaminated food or water or by coming into contact with a contaminated surface. It causes stomachaches, nausea, diarrhea and vomiting.