The presence of an aggressive antibiotic-resistant staph infection continues in the Helena area, with a second high school student's confirmed diagnosis and worries about the disease prompting a four-hour closing of Carroll College's fitness center on Thursday.

The college briefly shuttered its fitness center after concerns that a staff member with the methicillin resistant Staphylococcus aureus -- or MRSA -- used some of the exercise equipment.

But the case wasn't confirmed as MRSA, a hard-to-treat type of staph infection that is killing more Americans than AIDS, and after a deep cleaning, the college re-opened the fitness center.

"We thoroughly scoured the whole room, even though we don't know if the staff member even had MRSA," said Ashley Oliverio, Carroll spokesperson. "The call went out at 10 a.m. that no one could use it, and that was recalled around 2 (p.m.).

"We wanted to be proactive just in case, but we have not had any confirmed cases of MRSA on campus."

The staff member was cleared by her doctor to return to work, although she's on antibiotics as a preventive measure.

Staph infections, including the serious MRSA strain, have become more common in hospitals in recent years and have spread through schools nationwide in the past few months.

Concerns took center stage this fall, after a Bedford, Va., student died from a MRSA infection. Bedford shut down 21 schools for cleaning to keep the illness from spreading.

Bruce Messinger, superintendent of Helena schools, said a second Helena High School student was diagnosed a few weeks ago with MRSA, about two months after the district had its first confirmed case.

In both incidents, the school analyzed who the students may have been in contact with and sent letters to those families to be watchful.

The district also gave a thorough cleaning to the areas commonly used by the students.

About one-third of the general population carries Staphylococcus aureus on their skin, and no one knows what causes it to turn into the MRSA strain that doesn't respond to penicillin or other general antibiotics.

One reason for its prevalence at places like schools, gyms, nursing homes or even jails is that MRSA can be spread by close, personal contact often associated with those types of facilities or in contact sports like football or wrestling.

The initial case at Helena High involved a football player, and the more recent one occurred in a female active in theater, Messinger said.

He doesn't believe the two incidents are related, since there wasn't much overlap, if any, with the two students' school activities.

"Basically, like the first case, this was brought to our attention by the family and the student's doctor," Messinger said. "We worked both with the same protocol -- looking at their peers and settings, then did direct communication with the families.

"We don't know why she may have contracted it; it may not even have had anything to do with the school setting."

Even though MRSA can be passed between people, it's not required to be reported to health officials unless there's some kind of "cluster," noted Mike Henderson, a communicable disease prevention specialist with the Lewis and Clark County Health Department.

He defined a cluster as two or more cases that can be linked to commonalities between people, whether it's a location or social connection, and said they haven't had any clusters locally.

"We haven't had any reports of outbreaks in places like nursing homes, but it's not a reportable disease," Henderson said. "I know it is an ongoing concern in places where there are athletes or in places where people's health is compromised, like a nursing home."

Bonnie Barnard, state communicable disease surveillance coordinator, said she's fielding about a call a day from concerned citizens seeking more information about MRSA.

She generally directs them to the Center for Disease Control Web site -- http://cdc.gov/features/mrsainschools/#q6 -- that can supply answers to basic questions.

"We're getting questions about anything from how to clean to whether they can get more posters for schools," Barnard said. "They're calling either because they've had cases and don't really know how to handle it, or because there's been so much national press."

The state also has participated in some recent presentations in conjunction with local groups.

Messinger said the district is trying to balance parents' concerns about MRSA and being sensitive to the individuals and their families, while increasing the general awareness about how to limit exposure to MRSA.

Generally, the best tactic is to practice basic good hygiene by washing hands often and avoiding sharing personal items.

Oliverio said they're also increasing awareness of MRSA on the college campus, which is what partially prompted the fitness center's closure.

"We're taking prophylactic measures to ensure the students' health and well-being," Oliverio said. "This is the type of thing the college responds to immediately."

Reporter Eve Byron: 447-4076 or eve.byron@helenair.com.