MIDDLETOWN, Conn. -- Students across the state head back to class after concerns over H1N1 shut down several schools.

Last week, schools in Middletown, Harwinton, Burlington and East Haven were closed.

Kegwin Middle School was one of the schools that gave students an unexpected four days off last week after 135 students, or 40 percent of the student body, displayed symptoms similar to H1N1. On Monday, the school reported only about 25 students were absent from school.

Janitors at the school spent four days disinfecting door handles, light switches and computer keyboards. The staff now hopes that the droopy-eyed, feverish students they saw last week return bright, refreshed and healthy.

If there are any snow days this year, there is a chance that Middletown may have to extend the school year into June because of the days missed last week.

State law requires that Connecticut schools run at least 180 days, so superintendents across the state are doing the math to figure out how to get to that number if they have to subtract days because of H1N1.

Guilford told Eyewitness News they’ll add four days to its calendar before cutting into April vacation.

New London said it will tack on as many extra days before cutting into school vacation. Region 7 in the northwest corner said it will first add three days in June, and if that’s not enough, will cancel professional days.

It’s a mathematical equation more schools in the state will likely have to compute this week. While Kegwin reopens, school officials will be monitoring other schools to determine if they should close.

In Avon, Farmington, Glastonbury, Berlin, Branford and Madison, students have showed up with H1N1 symptoms as well, according to officials.