SCREENING FOR MRSA: ONLY TIME WILL TELL

Volume 29, Issue 511 March 17, 2008

Christina Kent

To mandate screening or not. In the case of Methicillin-resistant Staphylococcus aureus (MRSA), that is a difficult question for lawmakers—and it won’t be answered any time soon.

MRSA is an antibiotic-resistant staph infection that is often transmitted in hospitals or other health-care institutions. In 2005, MRSA caused 94,000 life-threatening infections and 18,650 deaths, according to the Centers for Disease Control and Prevention (CDC). That estimate is more than double the prevalence reported by the CDC five years earlier.

Some people carry inactive MRSA germs in their noses or on their skin without knowing it. Once admitted to the hospital, these MRSA-positive patients shed the germs on bedrails, blood pressure cuffs and other surfaces, where the germs can live for many hours and be carried to other patients on the hands of caregivers or equipment. If the germs get inside the body—via a catheter, a ventilator, or an incision or other open wound—they can turn into an active infection.

All hospitals have established infection control programs, such as repeated hand-washing and the use of alcohol-based hand scrubs. But some lawmakers are concerned that voluntary measures are not enough.

Last year, four states—Illinois (SB 233), New Jersey (S2580), Pennsylvania (S 968) and Tennessee (S 268)— enacted laws that require hospitals to screen patients for MRSA. The laws vary in their specifics, but they generally require hospitals to establish a screening program for “at-risk” patients (such as those intensive care units or people who are readmitted, some of whom have been infected with the bacteria while they were hospitalized). Those who are infected must be isolated and treated, and MRSA infection rates reported to the state and/or the CDC.

“We may not be able to totally eliminate such infections, but we are past the point where they must be considered an inevitable byproduct of health care,” said Pennsylvania Senator Ted Erickson.

Of the four measures, the New Jersey law is probably the toughest, as it also requires that all patients be cultured for MRSA upon discharge or transfer to another ward, as well as the “flagging” of patients who are readmitted to the hospital.

Virtually all published analyses have found that screening patients upon admission is cost-effective, a summary of the New Jersey law states. For example, a pilot program undertaken by the Department of Veterans Affairs (VA) Pittsburgh Healthcare System tested new patients for MRSA, using a nose swab. Those who had the germ were isolated, and MRSA infections in the hospital’s surgical care unit fell by 70 percent. The pilot was so successful that the VA is putting a $28 million testing system in place for all its 155 hospitals.

But a report in the March 12 Journal of the American Medical Association found that screening patients did not reduce the number of MRSA infections and was not cost-effective. Swiss researchers screened slightly more than 10,000 surgery patients who were admitted to the University of Geneva Hospitals. A control group of 10,000 others were admitted without screening.

Those who tested positive were isolated, scrubbed with disinfectants and given antibiotics. But the rates of hospital-acquired MRSA did not differ significantly between the two groups. “A universal, rapid MRSA admission screening strategy did not reduce nosocomial MRSA infection in a surgical department,” the researchers reported.

In its infection-control guidance, the CDC lists MRSA screening as an option because, the agency says, it is not clear if screening works better than other measures, such as judicious use of antibiotics, hand washing, use of alcohol-based hand rubs, and wearing gloves, gowns and other protective gear.

What to Do?

About half the states require that hospitals report health-care-acquired infection rates to the state and/or the CDC. Extending the Cure, a non-partisan organization funded by the Robert Wood Johnson Foundation, examined the evidence and concluded that it’s too soon to know how effectively state infection reporting and control laws will limit hospital-acquired infections. The group suggests that if screening is required, it should focus on high-risk patients, and facilities should be given the flexibility to address local needs.