Nosocomial infections with methicillin and tobramycin resistant Staphylococcus aureus--implication of physiotherapy in hospital-wide dissemination

Analysis of the Microbiota of the Physiotherapist's Environment

OBJECTIVES

To analyze the microbiota of the physiotherapist's work environment to understand the existing potential risks and to adopt appropriate preventive measures.

DESIGN

Cross-sectional descriptive observational study.

SETTING

Physiotherapist's working environment.

PARTICIPANTS

Physiotherapy and rehabilitation centers (N=19).

INTERVENTIONS

A microbiological sampling was carried out in the physiotherapy centers. The samples were studied using the usual culture and analysis methodology for characterization and isolation of a range of bacteria.

MAIN OUTCOME MEASURES

Absolute and relative frequency of microorganism isolation.

RESULTS

In the analysis, pathogens normally responsible for nosocomial infections were detected, especially on instruments and equipment used by the physiotherapist such as sponge electrodes, and were significantly more contaminated than the rest of the places studied (P<.01).

CONCLUSION

This situation confirms the absence of measures and protocols for the prevention and control of such infections in the physiotherapist's environment, which is why they must be considered to protect both physiotherapy professionals and patients.

Effectiveness of Simple Measures to Control an Outbreak of Nosocomial Methicillin-Resistant Staphylococcus aureus Infections in an Intensive Care Unit

Between June 1985 and March 1986, 14 cases of severe nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infection, including septicemia, were observed in the intensive care unit (ICU) of a 400-bed cancer reference center. Simple control measures including contact isolation of colonized patients and reinforcement of handwashing practices among personnel were followed by a sharp decrease in the rate of infection and colonization. An epidemiological investigation showed that a single serophage variant MRSA strain was involved; peak incidence of infection was 17 per 100 ICU patient discharges; the index case was identified as a patient admitted from another hospital and the epidemic strain was then transmitted from patient-to-patient in the ICU; risk factors for acquiring infection were length of prior hospitalization, invasive procedures and number of antibiotic treatments; dissemination of the strain to other wards was only anecdotal. These results stress the effectiveness of simple measures to control outbreaks of MRSA nosocomial infections even in immunocompromised cancer patients.

Should We Vigorously Try to Contain and Control Methicillin-Resistant Staphylococcus aureus?

Objective:

To review practices currently used to control transmission of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals, determine the frequency of their use, and discuss the indications for implementing such measures.

Design:

A questionnaire survey to determine how commonly selected control practices are used, and a literature review of the efficacy of control practices.

Participants:

Two hundred fifty-six of 360 hospital-based members fo the Society for Hospital Epidemiology of America, Inc. (SHEA) completed the survey questionnaire.

Result:

Many different combinations of surveillance and control measures are used by hospitals with MRSA. Nine percent of hospitals stated that no special measures were used to control MRSA. The efficacy of commonly used control measures has not been established by controlled trials.

Conclusions:

Implementing control measures is warranted when MRSA causes a high incidence of serious nosocomial infections, and is desirable when MRSA has been newly introduced into a hospital or into an intensive care unit, or when MRSA accounts for more than 10% of nosocomial staphylococcal isolates. While the value of some practices is well established, measures such as routinely attempting to eradicate carriage of MRSA by colonized patients and personnel require further evaluation.

Methicillin-Resistant Staphylococcus aureus Outbreak at a Veterans' Affairs Medical Center: Importance of Carriage of the Organism by Hospital Personnel

The reported prevalence of nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) by hospital personnel averages 2.5%. From August 1985 to September 1987, 155 patients at our Veterans' Affairs Medical Center (VAMC) were colonized or infected with MRSA. In December 1986, only two (2.1%) of 94 healthcare workers were identified as nasal carriers. Prompted by a sharp increase in the number of patients with MRSA in early 1987, contact tracing identified 450 employees, of whom 36 (8%) were nasal carriers. Thirty-five percent of surgical residents (7 of 20) were nasal carriers. Prior to being identified as a nasal carrier, one surgical resident was associated with the inter-hospital spread of the VAMC MRSA strain to the burn unit of the affiliated university hospital. Three family members of two employee carriers were also found to harbor the epidemic strain. All 36 carriers were decolonized with various antimicrobial combinations. Vigorous infection control measures were effective in controlling the epidemic. The frequency of MRSA carriage by hospital personnel at our medical center during the epidemic proved higher than previously appreciated. Thus, healthcare workers may comprise a sizable MRSA reservoir. During an MRSA epidemic, infection control should attempt to identify and decolonize this hospital reservoir, as these individuals can disseminate MRSA both within the hospital as well as into the community.

The role of healthcare personnel in the maintenance and spread of methicillin-resistant Staphylococcus aureus

Healthcare workers may acquire methicillin-resistant Staphylococcus aureus (MRSA) from patients, both hospital and home environments, other healthcare workers, family and public acquaintances, and pets. There is a consensus of case reports and series which now strongly support the role for MRSA-carrying healthcare personnel to serve as a reservoir and as a vehicle of spread within healthcare settings. Carriage may occur at a number of body sites and for short, intermediate, and long terms. A number of approaches have been taken to interrupt the linkage of staff-patient spread, but most emphasis has been placed on handwashing and the treatment of staff MRSA carriers. The importance of healthcare workers in transmission has been viewed with varying degrees of interest, and several logistical problems have arisen when healthcare worker screening is brought to the forefront. There is now considerable support for the screening and treatment of healthcare workers, but it is suggested that the intensity of any such approach must consider available resources, the nature of the outbreak, and the strength of epidemiological associations. The task of assessing healthcare personnel carriage in any context should be shaped with due regard to national and international guidelines, should be honed and practiced according to local needs and experience, and must be patient-oriented.

MRSA and the environment: implications for comprehensive control measures

Environmental contamination with methicillin-resistant Staphylococcus aureus (MRSA) is established soon after colonized or infected patients become resident. There are many studies that detail the mechanisms of spread and environmental survival of methicillin-susceptible Staphylococcus aureus (MSSA); this knowledge translates directly into the same findings for MRSA. The potential ubiquity of MRSA in a health-care setting poses challenges for decontamination. Whereas patients and medical staff are important sources for MRSA spread, the environmental burden may contribute significantly in various contexts. Effective control measures must therefore include consideration for MRSA in the environment.

SHEA guideline for preventing nosocomial transmission of multidrug-resistant strains of Staphylococcus aureus and enterococcus

BACKGROUND

Infection control programs were created three decades ago to control antibiotic-resistant healthcare-associated infections, but there has been little evidence of control in most facilities. After long, steady increases of MRSA and VRE infections in NNIS System hospitals, the Society for Healthcare Epidemiology of America (SHEA) Board of Directors made reducing antibiotic-resistant infections a strategic SHEA goal in January 2000. After 2 more years without improvement, a SHEA task force was appointed to draft this evidence-based guideline on preventing nosocomial transmission of such pathogens, focusing on the two considered most out of control: MRSA and VRE.

METHODS

Medline searches were conducted spanning 1966 to 2002. Pertinent abstracts of unpublished studies providing sufficient data were included.

RESULTS

Frequent antibiotic therapy in healthcare settings provides a selective advantage for resistant flora, but patients with MRSA or VRE usually acquire it via spread. The CDC has long-recommended contact precautions for patients colonized or infected with such pathogens. Most facilities have required this as policy, but have not actively identified colonized patients with surveillance cultures, leaving most colonized patients undetected and unisolated. Many studies have shown control of endemic and/or epidemic MRSA and VRE infections using surveillance cultures and contact precautions, demonstrating consistency of evidence, high strength of association, reversibility, a dose gradient, and specificity for control with this approach. Adjunctive control measures are also discussed.

CONCLUSION

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.

Clinical and epidemiologic investigations of nosocomial pulmonary infections caused by methicillin-resistant Staphylococcus aureus

We evaluated the clinical features of 32 patients with pulmonary infections caused by methicillin-resistant Staphylococcus aureus (MRSA). Most of the patients were elderly, postoperative, and had severe underlying diseases. Chest radiograph typically showed bilateral and multilobar involvement. Empyema was not common and no abscess was identified. Mortality rate was 38 percent. We also performed an epidemiologic study of MRSA infections by chromosomal DNA analysis using pulsed-field gel electrophoresis. Thirty-two strains were classified into 20 different types by chromosomal DNA pattern, and 5 epidemic strains were observed. These strains were considered to be transmitted among patients by hospital personnel.

The incidence of isolation of methicillin-resistant Staphylococcus aureus (MRSA) strains from skin infections during the past three years (1989-1991)

We did a statistical study of 294 strains of Staphylococcus aureus (S. aureus) isolated from skin infections during the period from January of 1989 to December of 1991 in the Department of Dermatology, Kansai Medical University Hospital. We especially examined methicillin-resistant S. aureus (MRSA) from the point of view of incidence, variety of skin infections with MRSA, coagulase type, phase type, and resistance against antimicrobial agents. The frequency of isolation of MRSA has been increasing. In 1991, the proportion of MRSA isolates among all S. aureus strains isolated from skin infections was 41.5%. MRSA was isolated most often from infectious decubitus. Coagulase type II and phage group NT (not typable) MRSA were most frequently isolated. The resistance of MRSA to OFLX and IMP/CS had remarkably increased. Notably, the resistance to MINO was low before 1991.

Should we vigorously try to contain and control methicillin-resistant Staphylococcus aureus?

OBJECTIVE

To review practices currently used to control transmission of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals, determine the frequency of their use, and discuss the indications for implementing such measures.

DESIGN

A questionnaire survey to determine how commonly selected control practices are used, and a literature review of the efficacy of control practices.

PARTICIPANTS

Two hundred fifty-six of 360 hospital-based members fo the Society for Hospital Epidemiology of America, Inc. (SHEA) completed the survey questionnaire.

RESULTS

Many different combinations of surveillance and control measures are used by hospitals with MRSA. Nine percent of hospitals stated that no special measures were used to control MRSA. The efficacy of commonly used control measures has not been established by controlled trials.

CONCLUSIONS

Implementing control measures is warranted when MRSA causes a high incidence of serious nosocomial infections, and is desirable when MRSA has been newly introduced into a hospital or into an intensive care unit, or when MRSA accounts for more than 10% of nosocomial staphylococcal isolates. While the value of some practices is well established, measures such as routinely attempting to eradicate carriage of MRSA by colonized patients and personnel require further evaluation.

Methicillin-resistant Staphylococcus aureus outbreak at a Veterans' Affairs Medical Center: importance of carriage of the organism by hospital personnel

The reported prevalence of nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) by hospital personnel averages 2.5%. From August 1985 to September 1987, 155 patients at our Veterans' Affairs Medical Center (VAMC) were colonized or infected with MRSA. In December 1986, only two (2.1%) of 94 healthcare workers were identified as nasal carriers. Prompted by a sharp increase in the number of patients with MRSA in early 1987, contact tracing identified 450 employees, of whom 36 (8%) were nasal carriers. Thirty-five percent of surgical residents (7 of 20) were nasal carriers. Prior to being identified as a nasal carrier, one surgical resident was associated with the inter-hospital spread of the VAMC MRSA strain to the burn unit of the affiliated university hospital. Three family members of two employee carriers were also found to harbor the epidemic strain. All 36 carriers were decolonized with various antimicrobial combinations. Vigorous infection control measures were effective in controlling the epidemic. The frequency of MRSA carriage by hospital personnel at our medical center during the epidemic proved higher than previously appreciated. Thus, healthcare workers may comprise a sizable MRSA reservoir. During an MRSA epidemic, infection control should attempt to identify and decolonize this hospital reservoir, as these individuals can disseminate MRSA both within the hospital as well as into the community.

Effectiveness of simple measures to control an outbreak of nosocomial methicillin-resistant Staphylococcus aureus infections in an intensive care unit

Between June 1985 and March 1986, 14 cases of severe nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infection, including septicemia, were observed in the intensive care unit (ICU) of a 400-bed cancer reference center. Simple control measures including contact isolation of colonized patients and reinforcement of handwashing practices among personnel were followed by a sharp decrease in the rate of infection and colonization. An epidemiological investigation showed that a single serophage variant MRSA strain was involved; peak incidence of infection was 17 per 100 ICU patient discharges; the index case was identified as a patient admitted from another hospital and the epidemic strain was then transmitted from patient-to-patient in the ICU; risk factors for acquiring infection were length of prior hospitalization, invasive procedures and number of antibiotic treatments; dissemination of the strain to other wards was only anecdotal. These results stress the effectiveness of simple measures to control outbreaks of MRSA nosocomial infections even in immunocompromised cancer patients.

World-wide antibiotic resistance in methicillin-resistant Staphylococcus aureus

Antibiotic resistance patterns were determined for 106 strains of methicillin-resistant Staphylococcus aureus (MRSA) from 21 countries. Resistance to gentamicin, tobramycin, netilmicin, amikacin, streptomycin, or erthromycin was recorded in more than 90% of strains. Resistance to the other compounds tested was as follows: tetracycline 86%, minocycline 76%, trimethoprim 69%, clindamycin 66%, neomycin 59%, chloramphenicol 39%, rifampicin 26%, fosfomycin 22%, ciprofloxacin 17%, fusidic acid 12%, bacitracin 2%, and novobiocin 1%. All the stains were sensitive to mupirocin, pristinamycin, ramoplanin, teicoplanin, and vancomycin. There were geographical patterns of resistance: MRSA from the UK and Australia were predominantly resistant to trimethoprim, whereas many strains from centres in Europe and the USA were sensitive. MRSA that were resistant to ciprofloxacin were of French and German origin. 15 strains, 12 of which came from France, Turkey, or Brazil, were resistant either to thirteen or to fourteen agents.

Methicillin-resistant Staphylococcus aureus in Veterans Administration Medical Centers

To determine the frequency of isolation of methicillin-resistant Staphylococcus aureus (MRSA) at Veterans Administration Medical Centers, 163 hospitals were surveyed; 137 responded. Between 1975 and 1984, the number of Veterans Administration Medical Centers with known MRSA increased from 3 to 111. This increase was geographically widespread and occurred in hospitals of all sizes. In Veterans Administration Medical Centers, isolation policies for MRSA-infected patients were (% of hospitals using): strict (19%), contact (52%), site-related (28%), no isolation (1%). For patients colonized with MRSA policies were: strict (15%), contact (44%), site-related (35%), and no isolation (6%). Only 41% of Veterans Administration Medical Centers reported discharging known MRSA-colonized patients to nursing homes. Most attempts to eradicate MRSA carriage used trimethoprim-sulfamethoxazole plus rifampin with or without bacitracin ointment; success rates were low. MRSA incidence is increasing at Veterans Administration Medical Centers across the United States. Improved regimens to eliminate MRSA carriage are needed.

Plasmid analysis of simultaneous nosocomial outbreaks of methicillin-resistant Staphylococcus aureus

A large outbreak of infections caused by methicillin and aminoglycoside resistant Staphylococcus aureus provided the opportunity to evaluate mechanisms of resistance and compare the usefulness of typing systems. Between January 1979 and December 1980, 63 patients developed infections with S aureus resistant to multiple antibiotics, including methicillin and tobramycin. All isolates had an identical antibiogram and were phage type 47/54/75/77/83A. Beginning in January 1981, a superimposed outbreak caused by S aureus of the same phage type but with a resistance pattern now including gentamicin occurred. The two strains contained different aminoglycoside inactivating enzymes. The initial strain contained a single plasmid of 21.5 mDa molecular weight, whereas the subsequent strain which had acquired gentamicin resistance contained this plasmid plus a heavier one of 33 mDa. Plasmid analysis complements the analysis of antibiograms and phage types and aids in defining epidemiologic patterns of transmission.

Gastrointestinal carriage of methicillin-resistant Staphylococcus aureus

Nasal and rectal cultures were taken from all patients with methicillin-resistant Staphylococcus aureus identified on routine cultures obtained because of clinical indications. Of 117 patients studied over a 3-year period, 70 (60%) had rectal colonization and 62 (53%) had nasal colonization. Rectal colonization, probably reflecting gastrointestinal carriage, may be a source of transmission of methicillin-resistant S. aureus in hospitalized patients and may be difficult to eradicate.

Development of antibiotic resistance by staphylococcus aureus in a single patient. Confirmation by phage typing, antibiograms, and plasmid analysis

A patient is described who had colonization and infection with strains of Staphylococcus aureus increasingly resistant to multiple antibiotics while receiving several courses of broad-spectrum antibiotics. S. aureus strains with different phage types, antibiograms, and plasmid profiles were isolated from different sites at the same time. After the patient was transferred to an intermediate-care service where he received only supportive care and no further antibiotics, culture samples from areas previously colonized or infected (sputum, anterior nares, perineal region, rectum) showed no S. aureus. This patient graphically demonstrates that antibiotics may create an environment allowing the overgrowth of resistant organisms and that withdrawal of this selection pressure may allow more sensitive organisms to recolonize.