Living in close quarters, college students are the classic at-risk population for any number of contagious diseases. And as news spreads about cases of antibiotic-resistant staph infections, campuses are taking notice.

More than 90,000 cases of methicillin-resistant Staphylococcus aureus, known as MRSA, were reported in 2005, according to a recent study from the Centers for Disease Control and Prevention. Nearly 19,000 people died from staph infections that year, and most of the invasive cases involved people inside health care facilities.

But students, especially those who play sports or share bathroom facilities, are also affected by the infections, which often appear as pimples, boils or rashes and in certain cases can lead to serious illnesses. The bacterial infections don't respond to penicillin-related antibiotics but can sometimes be treated with other drugs. They are commonly transmitted through open wounds or breaks in the skin, and by sharing items such as towels and sports equipment.

Recent outbreaks have caused high schools across the Eastern part of the country to cancel classes or sports practices. A high school football player in Virginia died from the bacteria last week. Colleges have also seen cases appear, prompting officials to monitor some students and remind others not to share personal items.

At Monmouth College, in Illinois, 19 members of the football team have been treated for staph infections, with the drug-resistant strand being mentioned in at least one case. The outbreak started in September, and the affected students were barred from practice while recovering.

Barry McNamara, a Monmouth spokesman, said the cases aren't considered serious, and most of the players have healed by using antibiotics. The college hasn't had to cancel any football games, and no infections have been found outside the team.

"The fact that this has been going on since September, it's been amazing how contained it has been," McNamara said. "These players have girlfriends and roommates, so this could have been much worse."

At least nine athletes at Iona College have been confirmed to have antibiotic-resistant staph infections. Cecelia Donohoe, a college spokeswoman, said the cases have been mild -- "along the lines of a pimple and a boil; not life threatening."

When Iona learned of the first case in late September, the college sent to students a text message and e-mail alert with a staph infection fact sheet. All cases have been confined to one team, and Donohoe said that officials in Westchester County, the area north of New York City where Iona is located, has found there is no health risk to the general public.

Like other colleges confronted with the infections, Iona disinfected the locker room and temporarily closed athletics facilities where athletes might be exposed.

Among the other institutions affected: University of Maryland at College Park; Clarion University, in Pennsylvania; Albertus Magnus College, in Connecticut, and the Community College of Allegheny County.

Patricia Ketcham, who serves on the American College Health Association's board of directors, said colleges are trying to impress upon students the importance of hand washing and maintaining clean environments.

Colleges are used to reminding students about diseases such as meningitis and mononucleosis, and while drug-resistant staph infections aren't as commonly mentioned, Ketcham said they should be on the list.

"For any type of communal living, it's always a concern," said Ketcham, associate director of health promotion at Oregon State University.

Even though many of the cases are isolated to one sports team or residence hall suite, Norb Dunkel, president-elect of the Association of College and University Housing Officers International, said colleges need to respond quickly to outbreaks to squelch any inklings of student (or parent) panic.

One method that colleges have found useful: setting aside a room for a student who needs to be monitored, and immediately bringing in cleaning crews to decontaminate common areas.

Dunkel, who is also director of housing and residence education at the University of Florida, said his housing staff does room inspections a few weeks into the school year to check for unhygienic setups.

While more and more residence halls have decreased the student-to-shower ratio, which can lower the chance of spreading infections, Dunkel said cleaning and sanitizing is necessary.