A study of patients flown into a hospital by helicopter, done by Allegheny General Hospital emergency personnel, recently found that the antibiotic-resistant staph infection known as MRSA was detected in equal proportion among patients coming from another health care facility and those coming from non-health care sites.
The study's lead author, Peter S. Martin, AGH emergency medicine physician, said the finding contradicts the common assumption that patients coming from the community would be less likely to carry MRSA, or methicillin-resistant Staphylococcus aureus.
"It's the first study in a pre-hospital setting," Dr. Martin said. "There have been lots of studies done in a hospital setting and many studies done in communities themselves."
Published in the July edition of Air Medical Journal, the study took nasal swab samples from 827 patients out of a total 1,074 patients flown by LifeFlight to AGH in an eight-month period in 2007. Of the tested patients, 51 were positive for MRSA. Of that number, 34 were from the group of 576 interfacility transports. The remaining 17 with the bacteria were patients on 251 trips from other sites in the community (accident scenes, for example).
"There's no statistically significant difference at all," Dr. Martin said.
Patient consent was not taken, because all admissions to the intensive care unit require MRSA testing. "We're considered a critical care unit on our helicopter," Dr. Martin said.
Patients were more likely to be tested if they were being transported between facilities, where MRSA often has been detected, Dr. Martin said. After a swab was collected by a flight nurse, it was submitted to the AGH microbiology lab for testing.
"One would assume MRSA is higher in interhospital transport," he said.
Concerns about the resistant bacteria first arose among patients in hospitals and nursing homes, who are vulnerable with weakened immune systems as they recover from other medical conditions. The Centers for Disease Control and Prevention reports that in 1974, MRSA accounted for 2 percent of total staph infections. By 2004 it had grown to 63 percent.
MRSA normally causes skin infections, but it can also cause other infections, including pneumonia. It can be fatal. Hospitals have launched new procedures, including the frequent hand-washing, to prevent the spread of infection.
A second type of MRSA, primarily found in otherwise healthy people outside of hospitals and spread in other settings such as among athletes, has been reported in growing numbers in recent years.
Dr. Martin said he would like to determine where the LifeFlight patients contracted the MRSA infection.
"It would be nice to repeat the study and look at the genetic characteristics [of the bacteria samples], to see if the MRSA is hospital- or community-acquired."
MRSA acquired in the community has been considered more sensitive to antibiotics than the hospital-related infections, but Dr. Martin said if it is becoming more widespread, that may change.
"It's out there," Dr. Martin said. Eventually, the community-acquired version will become more resistant, he said.
"The best thing the general public can do is practice good hygience, good wound care; especially in places of high incidence, gymnasiums, schools, health clubs. If you're going to those places and you have an open wound, keep it covered. Don't let it become exposed to the environment."
The CDC advises that people with symptoms of a MRSA skin infection should bandage the area and see a health professional. As with other staph skin infections, it looks like a bump or infected area on the skin that may be red, swollen, painful, warm to the touch and full of pus or other drainage and may be accompanied by a fever.
Dr. Martin said his own 14-year-old son successfully received antibiotic treatment for a presumed case of MRSA through broken skin affected by his son's eczema.
The hospital's precautions don't stop at testing. Returning patients with a record of MRSA as well as newly tested-positive patients are put into isolation.
"We use our gloves," Dr. Martin said. "We're more careful about not making contact between patients."
The elderly still account for more of the hospital-acquired infections, he explained, and antibiotics aren't keeping pace with the increase in cases.
"It's out there. There's really nothing we can do about it. The drug companies aren't making antibiotics like they're making other medications. In all honesty, it doesn't pay well. It's rare for us to get a brand new antibiotic. Unfortunately when there is a new antibiotic, people go out there and use it and resistance starts. It's like chasing your tail."
Jill Daly: email@example.com or 412-263-1596.