Patients with resistant staph infections are putting health care workers at risk

Rise in MRSA renews pressure for precautions

In the battle against nosocomial spread of methicillin-resistant Staphylococ-cus aureus (MRSA), health care workers are more than just potential carriers. They may be at risk for occupationally acquired infection.

Employee health professionals increasingly are at the center of efforts to combat MRSA, educating health care workers about the importance of precautions such as hand hygiene to protect patients — and themselves.

"The paradigm may be changing a little bit," says Trish Perl, MD, MSc, hospital epidemiologist at Johns Hopkins Hospital in Baltimore and past president of the Society of Healthcare Epidemiology of America. "There is an additional risk [beyond patient safety] we need to consider in all of this."

MRSA also has caught the attention of unions that represent health care workers. "Nurses and other health care workers could become colonized and not be aware of it," says Evie Bain, RN, MEd, COHN-S, coordinator of the division of health and safety at the Massachusetts Nurses Association in Canton. "If they had an adverse health event, like a surgical procedure themselves, they could then develop an infection."

Although health care workers may view MRSA as solely a patient safety issue, concerns about MRSA have grown as its prevalence increases. About 60% of S. aureus cultures isolated from patients in intensive care units were methicillin-resistant in 2003, according to the Centers for Disease Control and Prevention in Atlanta.1

A review of 45 million hospital discharge records indicated that the prevalence S. aureus in general infections rose at a rate of 7.1% a year from 1998 to 2003 (and 9.3% in orthopedic surgery), which indicates that current rates of infection may be significantly higher.2

In addition, an increasing proportion of MRSA is community-acquired, which presents an exposure risk for health care workers. At Johns Hopkins Hospital, for example, two health care workers developed soft-tissue infections that were due to hospital contamination with community-acquired strains.3 Community-acquired MRSA (CA-MRSA) is not isolated to high-risk subgroups. One study in an Atlanta hospital found that 72% of community-onset skin and soft-tissue infections due to S. aureus were methicillin-resistant.4

"The health care institutions in this country have to come up with some kind of program to protect everybody — patients and health care workers," says Darryl Alexander, MS, occupational and environmental health coordinator at the American Federation of Teachers (AFT) in Washington, DC. The union also is an advocacy group for nurses.

Health care workers had expressed concern about the possible risk of MRSA when Johns Hopkins began an investigation in an outpatient HIV and infectious disease clinic. Through surveys and cultures, the hospital discovered two health care workers who had developed skin and soft-tissue infections due to MRSA. One had cared for patients with CA-MRSA; the other had no direct patient contact.

Further investigation revealed substantial environmental contamination with MRSA, including a patient examination table, a computer keyboard, and patient chairs in the triage area, waiting room and examination room. "It was extraordinary for us to see so much environmental contamination," Perl says.

As a result, after a thorough decontamination of the clinic, Johns Hopkins placed disinfectant wipes in examination rooms and added additional dispensers of alcohol-based hand gels.

Topple the silo

Hospitals also need to include employees in their surveillance of S. aureus infections, Perl notes. "Employee health needs to work very closely with infection control. That's probably the most important message," she says. "We can't work in silos anymore."

Johns Hopkins also has instituted active surveillance among high-risk patient populations, such as adult and pediatric intensive care units. Patients who have spent time in a long-term care facility in the past six months also will be screened for MRSA and other high-risk bacteria.

Some hospitals have begun to conduct active surveillance of patients on admission to determine if they are colonized with MRSA, but the CDC has not recommended the practice for all facilities. A CDC advisory panel noted that a hospital's interventions should vary based on the nature of the MRSA problem at the facility. "More research is needed to determine the circumstances under which ASC are most beneficial, but their use should be considered in some settings, especially if other control measures have been ineffective," the Healthcare Infection Control Practices Advisory Committee (HICPAC) concluded.

Yet SHEA issued guidelines in 2003 recommending active surveillance of patients at high risk for MRSA, such as those with a history of dialysis, a stay in long-term care, or previous MRSA infection. "Active surveillance cultures are essential to identify the reservoir for spread of MRSA and VRE infections and make control possible using the CDC's long-recommended contact precautions," the SHEA guidelines state.5 Neither the CDC nor SHEA recommend the routine testing of health care workers for nasal colonization of S. aureus.

Hospital targets surgical patients

New England Baptist Hospital in Boston has focused MRSA screening efforts on its 6,000 inpatient orthopedic surgeries a year. The hospital purchased a rapid polymerase chain reaction (PCR) test by Cepheid of Sunnyvale, CA, which provides results on MRSA within two hours.

A preliminary screening of 133 patients revealed that 29% had methicillin-susceptible S. aureus and 4% had MRSA. The hospital now screens all of its surgical inpatients.

The hospital spent about $400,000 on new equipment to set up the active surveillance program and hired a microbiologist. Of 200 patients identified with MRSA, only one has developed a post-surgical infection, says Maureen Spencer, RN, MEd, CIC, infection control manager. The hospital's surgical-site infection rate has steadily dropped since 2004, to about 0.4%. Only 28% of the infections are caused by S. aureus, compared with 60% before the surveillance program, she says.

Those identified with MRSA receive vancomycin before surgery. They also undergo a five-day full-body wash with chlorhexidine as a preparation for surgery. Another culture is taken before surgery; the hospital found it eradicated MRSA in 82% of the cases.

Additional precautions are taken with those who remain MRSA-positive. The identification also ensures that they receive effective antibiotics, says Spencer. "It's better for the patient and hospital to know so you can get them on precautions right away," she says.

Do HCWs need masks in MRSA rooms?

Meanwhile, it's vital for health care workers to use proper hand hygiene with all patients and to use contact precautions with patients who have been identified with MRSA. Again, CDC and SHEA differ in their recommendations.

CDC recommends the use of gloves and gown, but says that masks are not recommended except with "splash-generating" procedures such as wound irrigation or intubation, patients who have open tracheostomies, or "where there is evidence of transmission from heavily colonized sources."

SHEA advises that "[m]asks should be worn as part of isolation precautions when entering the room of a patient colonized or infected with MRSA … to decrease nasal acquisition by health care workers."

The AFT's Alexander advocates the more stringent SHEA guidelines. A comprehensive program designed to protect patients also will benefit health care workers, she says.

"We want to make sure that workers have the right kind of training," she says. "Health care workers should be encouraged to wear masks and gowns. Studies show that can reduce the risk of [them] becoming carriers."

References

1. Siegel JD, Rhinehart E, Jackson M, et al. Centers for Disease Control and Prevention. Healthcare Infection Control Practices Advisory Committee. Management of multidrug-resistant organisms in healthcare settings, 2006. www.cdc.gov/ncidod/dhqp/pdf/ar/mdroGuideline2006.pdf. [Accessed on April 23, 2007.]

2. Noskin G, Rubin R, Schentag J, et al. Trends in the prevalence rate of S. aureus infection in U.S. hospitals, 1998-2003. Abstract 132. Presented at the Society for Healthcare Epidemiology of America. Baltimore; April 14-17, 2007.

3. Johnston CP, Cooper L, Ruby W, et al. Epidemiology of community-acquired methicillin-resistant Staphylococcus aureus skin infections among healthcare workers in an outpatient clinic. Infect Control Hosp Epidemiol 2006; 27:1,133-1,136.

4. King MD, Humphrey BJ, Wang YF, et al. Emergence of community-acquired methicillin-resistant Staphylococcus aureus USA 300 clone as the predominant cause of skin and soft-tissue infections. Ann Intern Med 2006; 144:309-317.

5. Muto CA, Jernigan JA, Ostrowsky BE, et al. SHEA guideline for preventing nosocomial transmission of multidrug-resistant strains of Staphylococcus aureus and Enterococcus. Infect Control Hosp Epidemiol 2003; 24:362-386.