Cleaning crews sanitized the elementary school with strong disinfectants used to kill staph infections after school Wednesday and Thursday, said Bob Mosier, Anne Arundel schools spokesman. "They cleaned every desk, every chair, every surface," he said, adding that the buses were sanitized after dropping off students at the school in the morning.
Students said that their teachers encouraged them to clean their hands throughout the day. "Our teacher had a row of soaps and hand sanitizers," said fourth-grader Coleman Bray. "We put a lot of hand sanitizer on."
About 45 percent of Folger McKinsey students did not attend school Thursday, but they would not be penalized and would be able to make up their work, Mosier said.
At Milford Mill Academy in southwest Baltimore County, where another student has probable swine flu, attendance on Thursday was about 68 percent, down from the usual 85 percent, said Charles A. Herndon, a school system spokesman.
Principal Nathaniel Gibson fielded a number of calls throughout the day from parents wondering whether they should keep their kids home, Herndon said.
"This is a very fluid situation, and we're in constant contact with the state and the county health department, and continue to take our lead from them and take counsel from them as well," Herndon said.
School systems sent out letters to parents this week giving them common-sense tips for avoiding contagious diseases, such as washing hands frequently, but there didn't appear to be any panic on the part of parents or students.
At Severna Park High School, Principal Patrick Bathras said he had received a few e-mails and phone calls from parents checking to make sure there were no cases at their school. Otherwise, he said, "Today's school day was business as usual."
Quiana Ojo, the nurse at Baltimore's Barclay Elementary School, said she did get a call from a parent who was going to keep her children home until the nurse explained what precautions - such as extra hand washing - would be taken to keep her children safe.
She is advising teachers to wipe down desks, particularly of the youngest children, during the day while they are at lunch and at the end of the day.
Baltimore Sun reporters Arin Gencer, Liz Bowie and Paul West contributed to this article.