Inpatients With MRSA Much More Common Than Suspected

SAN FRANCISCO, June 28 -- The rate of methicillin-resistant Staphylococcus aureus in U.S. hospital patients is now nearly 5% -- dramatically higher than previously thought, according to a nationwide survey of healthcare facilities.

In a one-day snapshot of infection rates conducted late last year, 46 of every 1,000 patients harbored MRSA, according to the Association for Professionals in Infection and Epidemiology (APIC). This is eight to 11 times higher than earlier estimates.

Of those MRSA patients, the survey found, 34 of every 1,000 were infected while 12 of every 1,000 were simply colonized and -- while they did not yet have active disease -- could potentially have transmitted the organism.

The survey "presents a grim picture," according to principal investigator William Jarvis, M.D., of Jason and Jarvis Associates, a private consulting firm in healthcare epidemiology.

"The findings argue for immediate, aggressive efforts to detect and prevent transmission of MRSA," Dr. Jarvis said.

The survey results, released here at APIC's annual meeting, includes data from 1,237 healthcare facilities in 50 states, each of which was asked to provide a "snapshot" of all MRSA cases in the hospital during a single day.

The survey included almost all types of healthcare facilities, including acute, cancer, cardiac, pediatric, rehabilitation, and long-term care. County, public, and private facilities were included and sizes ranged from fewer than 100 beds to more than 300.

The snapshots found 8,654 MRSA cases, including both community-acquired MRSA and healthcare-associated MRSA, in a total of 187,058 inpatients.

The survey also found:

• 54% of MRSA cases were in men.
• 67% were on the medical service of their respective hospitals.
• 81% of cases were detected by clinical cultures and the remainder by active surveillance cultures.
• 77% were detected less than 48 hours after admission.
• 37% only had skin and soft tissue infections, which are most commonly seen with community-acquired MRSA, and the rest had infections of the lungs, bloodstream, and urinary tract.
• Fewer than 30% of isolates were susceptible to clindamycin (Cleocin) and fewer than 20% were susceptible to levofloxacin (Levaquin).

Because 81% of cases were detected only after clinical manifestations of disease, the association said, it is likely that a "significant number" of patients have the potential to transmit MRSA to healthcare workers or other patients.

"This survey is a wake up-call for healthcare facilities," APIC president Denise Murphy, R.N., said, "because the transmission of MRSA is preventable."

"The scope of this public health threat demands commitment and participation from every hospital, at all levels of the facility," said Murphy, who is a senior safety officer at Barnes-Jewish Hospital in St. Louis.

According to the CDC, MRSA infections accounted for 2% of the total number of staph infections in 1974, but by 1995 it was 22% and in 2004 it was 63%.

The agency last year issued new recommendations for managing MRSA and other drug-pathogens in hospitals that urged "judicious use" of antibiotics, frequent hand washing, and active surveillance.