Nosocomial pneumonia in Medicare patients. Hospital costs and reimbursement patterns under the prospective payment system.

To determine the extent to which hospitals are reimbursed for Medicare patients who develop nosocomial pneumonia, we analyzed hospital accounting costs, reimbursements received, and the net income from 33 Medicare patients who developed nosocomial pneumonia. In 31 of the 33 cases, hospital costs for the entire admission exceeded reimbursements, with a median net loss of $5800 per case. Eleven randomly selected pneumonia cases were compared with control patients matched by diagnosis related group, age, sex, and service. Cases had significantly longer hospital stays, had greater total hospital costs, and caused greater net losses than did matched controls. We conclude that hospitals are seldom reimbursed adequately for Medicare patients who develop nosocomial pneumonia. With the advent of the prospective payment system, hospitals now have substantial financial incentives for implementing cost-effective measures for preventing nosocomial pneumonias.

Hospital reimbursement patterns among patients with surgical wound infections following open heart surgery.

Of the more than 200,000 patients who undergo open heart surgery annually in the United States, 2% to 10% will develop a post-operative infection related to their surgery. The economic impact of such infections on hospitals under the prospective payment system is unclear. To study the effect of such infections on hospital costs and reimbursement patterns, we compared case patients with controls of similar age, sex, urgency of surgery and type of surgery. The postoperative stay for cases was significantly longer than for matched controls (26.8 days and 8.3 days, respectively; p = .0002). The mean hospital cost for case admissions ($25,957) was twice as high as for control admissions ($12,795) (p = .0002). Cases resulted in an average net loss to the hospital of $2,344 per patient, while controls yielded an average net gain of $3,196 per patient (p = .02). We conclude that hospitals have substantial financial incentives to minimize the incidence of postoperative wound infections associated with open heart surgery.

Environmental contamination due to methicillin-resistant Staphylococcus aureus: possible infection control implications.

OBJECTIVE: To study the possible role of contaminated environmental surfaces as a reservoir of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals. DESIGN: A prospective culture survey of inanimate objects in the rooms of patients with MRSA. SETTING: A 200-bed university-affiliated teaching hospital. PATIENTS: Thirty-eight consecutive patients colonized or infected with MRSA. Patients represented endemic MRSA cases. RESULTS: Ninety-six (27%) of 350 surfaces sampled in the rooms of affected patients were contaminated with MRSA. When patients had MRSA in a wound or urine, 36% of surfaces were contaminated. In contrast, when MRSA was isolated from other body sites, only 6% of surfaces were contaminated (odds ratio, 8.8; 95% confidence interval, 3.7-25.5; P < .0001). Environmental contamination occurred in the rooms of 73% of infected patients and 69% of colonized patients. Frequently contaminated objects included the floor, bed linens, the patient's gown, overbed tables, and blood pressure cuffs. Sixty-five percent of nurses who had performed morning patient-care activities on patients with MRSA in a wound or urine contaminated their nursing uniforms or gowns with MRSA. Forty-two percent of personnel who had no direct contact with such patients, but had touched contaminated surfaces, contaminated their gloves with MRSA. CONCLUSIONS: We concluded that inanimate surfaces near affected patients commonly become contaminated with MRSA and that the frequency of contamination is affected by the body site at which patients are colonized or infected. That personnel may contaminate their gloves (or possibly their hands) by touching such surfaces suggests that contaminated environmental surfaces may serve as a reservoir of MRSA in hospitals.

Controlling vancomycin-resistant enterococci.

After controlling an epidemic of vanB-type vancomycin-resistant Enterococcus faecium (VRE), we contained a subsequent vanA E faecium outbreak by using prospective laboratory-based surveillance, placing patients with VRE in private rooms, requiring the use of both gowns and gloves by all personnel entering the patients' rooms, and conducting prevalence surveys of patients on affected wards.

A common-source outbreak of Staphylococcus epidermidis infections among patients undergoing cardiac surgery.

A single strain of Staphylococcus epidermidis caused an outbreak of postoperative wound infections and endocarditis during a 6-month period. Infections caused by the epidemic strain developed more frequently in valve surgery patients than in those undergoing coronary artery bypass graft surgery (P = .03) and occurred only in patients operated on by surgeon A. None of 17 members of the cardiac surgery team carried the epidemic strain in their anterior nares, axillae, or inguinal folds. Hand cultures were performed on 8 surgical personnel, and only surgeon A carried the epidemic strain on his hands. Isolates from cardiac surgery patients, bypass pump blood cultures, and the hands of the implicated surgeon all had identical antimicrobial susceptibility patterns, plasmid profiles, and EcoRI restriction endonuclease digest patterns. In the 24 months after control measures were implemented, no infections caused by the epidemic strain occurred among open heart surgery patients. The findings suggest that the common-source outbreak of infections among cardiac surgery patients was due to carriage of a strain S. epidermidis on the hands of a cardiac surgeon.

Spread of methicillin-resistant Staphylococcus aureus in a hospital after exposure to a health care worker with chronic sinusitis.

A dramatic increase in the incidence of methicillin-resistant Staphylococcus aureus at a teaching hospital was documented to be due to three factors: a hospital-wide outbreak of 32 cases caused by an epidemic strain, an increase in the number of nosocomial cases caused by several other strains, and an increase in the number of patients admitted carrying strains acquired at other institutions. Case patients with the epidemic strain were significantly more likely than control patients to have had previous exposure to a respiratory therapist (P = .005) who had chronic sinusitis due to the epidemic strain. The plasmid DNA of isolates from the implicated respiratory therapist and affected patients yielded the same patterns on restriction endonuclease digestion. Implementation of general control measures and eradication of the respiratory therapist's sinusitis and nasal carriage terminated the epidemic. Establishing the importance of the infected health care worker by epidemiological methods led to control of the outbreak without the institution of wide-scale culture of specimens from personnel and the environment or other expensive and labor-intensive measures.

Emergence and nosocomial transmission of ampicillin-resistant enterococci.

Between 1986 and 1988, the incidence of ampicillin-resistant enterococci increased sevenfold at a university-affiliated hospital. Forty-three patients acquired nosocomial infections with ampicillin-resistant enterococci, most of which were also resistant to mezlocillin, piperacillin, and imipenem. An analysis of plasmid and chromosomal DNAs of isolates revealed that the increase was due to an epidemic of 19 nosocomial infections that yielded closely related strains of Enterococcus faecium and to a significant increase in the incidence of nonepidemic, largely unrelated strains of ampicillin-resistant enterococci. The nonepidemic strains were identified as E. faecium, E. raffinosus, E. durans, and E. gallinarum. A logistic regression analysis revealed that patients with nonepidemic resistant strains were 16 times more likely than controls to have received preceding therapy with imipenem. In our institution, the increase in the incidence of ampicillin-resistant enterococci appears to be due to the selection of various strains of resistant enterococci by the use of imipenem and to the nosocomial transmission of E. faecium and E. raffinosus.

Outbreak of multidrug-resistant Enterococcus faecium with transferable vanB class vancomycin resistance.

Enterococcus faecium strains resistant to ampicillin, high levels of gentamicin, and vancomycin but susceptible to teicoplanin (vanB class vancomycin resistance) were recovered from 37 patients during an outbreak involving a 250-bed university-affiliated hospital. Three isolates with vancomycin MICs ranging from 8 to 256 micrograms/ml all hybridized with a vanB probe. Restriction endonuclease analysis of chromosomal and plasmid DNA suggested that all isolates tested were derived from a single clone. Vancomycin resistance was shown to be transferable. Risk factors for acquiring the epidemic strain included proximity to another case patient (P, 0.0005) and exposure to a nurse who cared for another case patient (P, 0.007). Contamination of the environment by the epidemic strain occurred significantly more often when case patients had diarrhea (P, 0.001). Placing patients in private rooms and requiring the use of gowns as well as gloves by personnel controlled the outbreak. These findings suggest that multidrug-resistant E. faecium strains with transferable vanB class vancomycin resistance will emerge as important nosocomial pathogens. Because extensive environmental contamination may occur when affected patients develop diarrhea, barrier precautions, including the use of both gowns and gloves, should be implemented as soon as these pathogens are encountered.