Toxic shock outbreaks include wound patients

The first nosocomial outbreak of a toxic shock-producing strain of methicillin-resistant Staphylococcus aureus (MRSA) was recently reported in St. Louis at the annual conference of the Society for Healthcare Epidemiology of America (SHEA). 

The outbreak involved 27 patients with nosocomial infections, six of which occurred in wounds, reported Karen Hoffman, RN, infection control professional at Moore Regional Hospital in Chapel Hill, NC. Of the 27 infected patients, four developed toxic shock symptoms and one of those died. Symptoms included fever, skin rash, hypotension, and multisystem involvement. 

A total of six hospital units were eventually involved, suggesting cross-transmission between patients. Major infection sites included seven in the blood, six wound infections, six in the respiratory tract, and three in the gastrointestinal tract. 

Most of the infected patients had undergone surgical procedures, and there was some evidence that the outbreak may have begun with one patient serving as a reservoir to infect others via hand carriage by health care workers, Hoffman said. The MRSA isolates among the 27 patients and three colonized nurses were identical, she added. 

"These were the primary workers on the units that took care of these patients, so they were definitely linked," she told SHEA attendees. 

The outbreak began in April 1996, when two patients in a cardiovascular intensive care unit were noted to have profuse diarrhea with stool cultures positive for MRSA. Within several days, two other MRSA infections were observed in patients who had undergone coronary artery bypass graft procedures. A second group of MRSA cases was found between October and December of last year. The number of cases was telling, as the hospital only had nine nosocomial MRSA cases in 1995 and six in 1994, Hoffman said. 

Control measures included increased surveillance for cases, hand washing education, contact isolation measures, disinfection of shared patient equipment, and use of waterless, antiseptic hand cleaning lotion, which was instituted because of poor sink access in the intensive care unit. In addition, all patients previously identified with MRSA are now isolated at the time of admission until they are culture-negative. All health care workers with positive MRSA nasal cultures have been removed from direct patient care activities until their cultures are negative. Colonized employees were treated under a protocol that included mupirocin and rifampin, and all were culture-negative within 10-14 days following therapy. 

"We believe this is the first report of an outbreak with MRSA associated with toxic shock syndrome in a community hospital," Hoffman said.