DALLAS (February 4, 2014) The highly contagious norovirus believed to be what sickened hundreds of students and staffers at Richardson High School.
The school’s principal, Charles Bruner, sent a letter to parents Tuesday in which he said the number of students who fell ill peaked Friday at more than 600.
The number fell to about 240 Monday.
The school has 2,550 students.
Workers began wiping down all surfaces on Thursday, a practice that's been repeated each subsequent night.
An anti-bacterial solution also is being applied through the day in high-traffic areas, such as bathrooms, hallways and elsewhere.
The norovirus can cause stomach pain, nausea, vomiting and other complications.
The gastrointestinal illness is believed to have sickened hundreds of passengers aboard two separate cruise ships in the last week.