One female cheerleader was sickened with the antibiotic-resistant infection MRSA and 12 others tested positive for staph and were treated with antibiotics at Belen High School in New Mexico.
The sometimes lethal bacteria was probably spread on mats in the wrestling and weight room, which is also used for the cheerleaders.
"All the kids will make a complete recovery," said the school's athletic coordinator Rodney Wright.
He said the school had closed the rooms and disinfected the mats, light switches and door knobs up to 40 times since the case was reported last week.
"According to the doctors, they have seen an increase in this particular bacteria, not just at Belen, but across the country," said Wright.
Methicillin-resistant staphylococcus aureus, or MRSA, is a type of staph bacteria that is resistant to antibiotics such as methicillin and its pharmaceutical relatives, oxacillin, penicillin and amoxicillin. In the community-acquired virus, the infections appear on the skin, but can be life-threatening if not treated properly, according to the Centers for Disease Control and Prevention.
An estimated 3 to 6 percent of the population carries the community form of MRSA, according to Dr. Silvania Ng, an infectious disease specialist and medical director of infection control at Bethesda Hospital in Cincinnati.
"It is very aggressive in the skin and go to the lungs, especially in kids and can cause necrotizing pneumonia," Ng said. "If there is not drainage quickly, it can spread through the body."
Typically, MRSA is seen mostly in adults, but it spreads more quickly in children, who can quickly go from experiencing a skin abscess to being on a lung respirator, she said. Several died when the disease was first recognized in the late-1990s.
The bacterium is carried in the mucosa of the nose, armpits or groin and spreads with close contact. Wright said the school sent home letters to parents of every winter athlete, reporting they had at least a staph infection (but not necessarily MRSA).
Not every parent received a notification at first from Belen High School.
"Probably, in hindsight, I will tell you that's probably something we could have done district-wide," Wright told ABC's affiliate KOAT.
Officials first took action last week when the cheerleader was diagnosed with the infection after developing an abscess. "She had it lanced and is going to be fine," said Wright.
"The remainder [of the students] basically had scabby-type rashes that were superficial on the surface of the skin," he said. "They had not gone deep."
"But the original case did go to a more serous level," said Wright. "The remaining 12 showed symptoms last week and a big percentage were placed on antibiotics."
MRSA infections can occur in any geographic location and anywhere on a person's body, according to the CDC. It was first reported in 1997 when most cases were hospital-borne infections among patients with weakened immune systems.
MRSA in hospital settings has declined by 28 percent between 2005 and 2008, according to a 2010 CDC report that was published in the Journal of the American Medical Association.
Now, they are more common in the community. The biggest risk factors are open or broken skin, such as a wound or surgical site. But MRSA can also occur on areas of the skin where there are no obvious breaks in the skin.
MRSA Can Strike Anywhere, Say Doctors
"It's everywhere," Ng said, especially in school sports and health club settings where athletes have abrasions. About 90 percent of all these community MRSA cases begin as skin infections
"The bacteria needs an entry point in the body," she said. "In wrestling, one can be a carrier and the other can be infected ... with little abrasions and close skin contact."
"Most schools use a detergent disinfectant that is effective against MRSA," she said. "But it's something that can happen, even in a sterile environment."
Wright said that the school had been routinely "diligent" about disinfecting mats four times a day, despite the apparent outbreak. Those cleanings have been increased.
The school has encouraged students to take their clothes home each day and make sure they are clean before returning to school. They have also kept athletes out of competitions to minimize spreading.
"We feel we have probably tried to do everything we can to stop it in its tracks," said Wright.