Hands Of Personnel Research Articles

Nosocomial infection by gentamicin-resistant Streptococcus faecalis. An epidemiologic study.

Enterococci with high-level resistance to gentamicin account for 55% of clinical isolates of enterococci found in patients at the Ann Arbor Veterans Administration Medical Center. We prospectively studied cultures obtained from all 100 patients hospitalized from 1 December 1985 through 23 January 1986 on the surgical and thoracic intensive care units and a general medical floor. Ten patients' cultures grew colonies of gentamicin-resistant enterococci--six after admission to the intensive care units and four after hospitalization on the medical ward. The initial sites of colonization were the rectal and perineal areas in seven patients, sternal wound in one, urine in one, and the rectal and perineal areas as well as urine after Foley catheter insertion in one. Nine patients died and three of the deaths were associated with enterococcal infection. The acquisition of resistant strains was associated with previous and more frequent exposure to antimicrobial agents, and with geographic clustering of patients. Resistant enterococci were isolated from the hands of hospital personnel and were frequently isolated from environmental surfaces. Nosocomial acquisition and interhospital spread of gentamicin-resistant enterococci was shown to have occurred when plasmid content was used as an epidemiologic marker.

Gram-negative bacilli as nontransient flora on the hands of hospital personnel.

The possibility that gram-negative bacilli (GNB) are part of the nontransient flora on hands was examined by using a broth rinse technique to detect low titers of GNB after a hygienic hand wash with soap and water. A total of 100 nurses who had direct patient contact and 40 controls without patient contact had a similar rate of recovery of GNB (46 and 55%, respectively). GNB persisted on the hands of 10 nurses throughout five successive hand washes with soap and water. Hand cultures were obtained daily from 12 nurses before and after a work shift in a surgical intensive care unit. GNB were recovered from 57% of individuals before patient contact and from only 24% after the work shift. Nontransient GNB on the hands of hospital personnel are a potential reservoir for hospital strains, and patient contact is not an obvious source for the acquisition of nontransient GNB.

Hospital outbreak of multi-resistant Acinetobacter anitratus: an airborne mode of spread?

During a 10-month period, from October 1984 to July 1985, a multi-resistant strain of Acinetobacter anitratus was isolated from 36 patients in three neurosurgical wards, one medical ward and the intensive care unit of a district general hospital, and from two patients in the intensive care unit of a hospital in another district. Fourteen patients developed significant infection including pneumonia (10), meningitis (2), septicaemia (2) and wound infection (4). The majority of cases (28) involved the respiratory tract of ventilated patients, although respiratory equipment was not implicated as a source of the infection. The epidemic strain was recovered from the skin, nose, mouth and rectum of colonized patients and from the hands of personnel. However, extensive air and environmental contamination in the vicinity of colonized patients was also demonstrated. This is the first outbreak of infection with Acinetobacter, of which we are aware, where airborne spread has been observed.

Oxacillin-resistant coagulase-negative staphylococcal carriage rates in neonatal intensive care nurses and non-patient care hospital personnel

Coagulase-negative staphylococci (CNS) have emerged in recent years as a common cause of sepsis in critically ill newborn infants.‘-’ Infections are often caused by strains resistant to the semisynthetic penicillinase-resistant penicillins. Such is the case in our nursery, where surveillance culturing has indicated that colonization occurs in more than 80% of infants within 2 weeks of admission to the infant intensive care unit. Sepsis caused by CNS has been previously associated with the presence of a central venous catheter and with infusion of hyperalimentation fluid.4 Routine surveillance culturing of hyperalimentation fluids in our hospital has rarely yielded CNS. Other possible sources of oxacillin-resistant coagulase-negative staphylococci (R-CNS) that could explain the rapid colonization of infants are the hands and noses of patient care personnel. Maki et al .6 reported that R-CNS frequently colonized the hands of intensive care unit personnel. Our purpose was to compare R-CNS colonization rates of two groups of hospital employees: infant intensive care unit personnel (PCP) and non-patient care personnel (NPCP), to de-

Outbreak due to methicillin- and rifampin-resistant Staphylococcus aureus: epidemiology and eradication of the resistant strain from the hospital.

A methicillin- and rifampin-resistant strain of Staphylococcus aureus was introduced into a university hospital by interstate transfer of an infected surgical patient. An outbreak occurred, and 17 patients became infected or colonized with the epidemic strain. Reservoirs appeared to be patients who were infected or colonized with the resistant S aureus and possibly two nurses who were nasal carriers. The outbreak isolate was likely spread by contact with contaminated hands of personnel. A retrospective case-control study identified tracheostomy, débridement, and irrigation of wounds by power spray and prolonged nasogastric intubation as risk factors for acquisition of the epidemic strain. Analysis of factors by groups indicated that surgical procedures, wound care procedures and instrumentation of the respiratory tract were significantly associated with cases. The nasal carrier state was eradicated in two nurses by topical application of 5% vancomycin. The epidemic strain was eradicated from the hospital 8 months after it was introduced.

Efficacy of alcohol-based hand rinses under frequent-use conditions

Fifty volunteers randomly assigned to one of five hand washing agents (10 subjects per agent)--a nonantiseptic liquid soap (control), an antiseptic hand rinse containing 60% isopropyl alcohol (IPA) with emollients (Alc A), an antiseptic hand rinse containing 70% IPA and 0.5% chlorhexidine gluconate with emollients (Alc B), an antiseptic containing 4% chlorhexidine gluconate and 4% IPA (CHG), and 70% IPA--washed their hands 15 times per day for 5 days under supervision by using a standardized technique and measured amounts of test agent. Microbiologic samples of hand flora were obtained at base line and after hand washes 1 and 15 on test days 1 and 5. After the initial hand wash there were significant reductions over base line in aerobic and anaerobic log CFU among those using Alc A, CHG, and IPA. By the end of the first day of hand washing (15 washes), there were 2-log or greater reductions in aerobic counts among subjects using all antiseptics, but no significant reductions in controls. By the end of day 5, all agents produced significant reductions in aerobic (P = 0.0002) and anaerobic (P = 0.002) counts over control soap. Subject assessment of effects of hand washing on the skin and overall satisfaction varied significantly by product (P = 0.04 and 0.05, respectively). We conclude that alcohol-based hand rinses are highly efficacious, and such products are recommended as a health care personnel hand wash, particularly when sink and running water are inaccessible.

Streptococcus faecium outbreak in a neonatal intensive care unit.

An outbreak of bacteremia and meningitis in a neonatal intensive care unit is described. Seven cases occurred in premature infants with severe underlying diseases. An epidemiological investigation failed to document the reservoir of the epidemic strain but suggested that its transmission among the infants was via the hands of hospital personnel. All patients had nasogastric tubes and multiple intravascular devices, and the portal of entry may have been either the gastrointestinal tract or the sites of the intravascular devices. Conventional biotyping of isolates failed to differentiate between isolates from infected patients and isolates recovered from prevalence surveys and from the environment. However, rapid identification systems (API-20S [Analytab Products, Plainview, N.Y.] and the AutoMicrobic system [Vitek Systems, Inc., Hazelwood, Mo.]) were able to distinguish isolates recovered from infected patients and hands of hospital personnel from isolates recovered during prevalence and environmental surveys and 29 isolates from widespread geographical areas. This is the first known report of a nosocomial neonatal outbreak of bacteremia and meningitis due to Streptococcus faecium; it underscores the importance of identifying streptococci to species level.

Outbreak of Salmonella typhimurium gastroenteritis due to an imported strain resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole in a nursery.

An outbreak caused by a highly resistant strain of Salmonella typhimurium occurred in a nursery at a university medical center. The outbreak strain, which was resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole, was apparently imported from the Far East by a Cambodian refugee. The five patients involved had severe underlying diseases, and bacteremia and meningitis developed in one of these patients. The only reservoir identified was the gastrointestinal tracts of the infected patients, and infection was probably transmitted by the contaminated hands of hospital personnel. The outbreak was rapidly brought under control by isolating cases outside of the nursery and by instituting enteric precautions for infants who remained in the nursery. When compared by disk diffusion susceptibility tests with 353 strains of S. typhimurium tested at the Centers for Disease Control, the imported strain had a unique antibiogram. Bacteriophage typing of the strains revealed that all were untypable; this, in itself, was a good marker, because only 5 to 10% of S. typhimurium isolates in this country have this property. Agarose gel electrophoresis of isolates from the five patients revealed an identical plasmid banding pattern consisting of three large and three small plasmids. Highly resistant strains of S. typhimurium imported from the Far East may spread rapidly when introduced into a hospital nursery. Prompt institution of control measures may limit the outbreak and prevent systemic infections for which there are few effective therapeutic agents.

A nursery outbreak of multiple-aminoglycoside-resistant Escherichia coli.

In the neonatal intensive care unit (NICU) of one hospital, 16 infants became colonized or infected with multiply-resistant Escherichia coli (MR-E.coli) over an 8-month period. Isolates were obtained from blood, urine, and sputum of three patients and from rectal surveillance cultures of 13 patients. The one patient with the blood isolate died. A matched case-control study identified continuous feeding (nine of 16 cases vs. one of 16 controls, p less than or equal to 0.001) and receipt of aminoglycosides (p less than or equal to 0.03) as risk factors. For case-babies not exposed to continuous feeding, duration of bolus feeding was significantly greater than for their controls (cases, 22 days; controls, 7 days; p less than or equal to 0.02). All 16 isolates were the same serotype and were resistant to amikacin, tobramycin, kanamycin, and gentamicin. The epidemiologic investigation suggested that MR-E. coli may have spread from person-to-person on the hands of personnel and that MR-E. coli persisted in the NICU for 8 months until effective control measures were instituted.

Prevalence of gram-negative bacilli in nares and on hands of pharmacy personnel: lack of effect of occupational exposure to antibiotics.

Exposure to antibiotics alters host flora and facilitates colonization by gram-negative bacilli (GNB). This may be important among pharmacy personnel, who have frequent contact with antibiotics and who have sometimes been suspected of inadvertently introducing GNB into parenteral solutions during admixture. We evaluated the risk of colonization by GNB, especially by tribe Klebsielleae (TK) which can proliferate in intravenous fluids, by culturing the hands and nares of 98 pharmacy personnel and 56 control subjects. Four culture surveys of pharmacy personnel yielded mean isolation rates of 79 and 52% for GNB and TK, respectively, from hands and 12 and 6.7% for GNB and TK, respectively, from nares; these rates did not differ significantly from those for control subjects (P greater than 0.1). The frequency with which pharmacy personnel performed antibiotic admixture did not significantly affect the rate of isolation of GNB or TK (P greater than 0.2). No multiresistant strains were isolated, and susceptibility patterns were similar for GNB species from pharmacy personnel and controls. These data indicate that occupational exposure of pharmacy personnel to antibiotics is not of sufficient magnitude to increase rates of nasal colonization or hand contamination with GNB.

Postoperative infections following cardiac surgery: association with an environmental reservoir in a cardiothoracic intensive care unit.

During 1981, 39 nosocomial infections occurred in 27 of 223 patients undergoing cardiac surgery in the North Carolina Memorial Hospital. The peak attack rate (23.7%) occurred in August and September compared to 10.1% in January through July. A case-control study demonstrated that the only risk factor common to poor and stable health groups compared to controls was duration of stay in the cardiothoracic intensive care unit (CTICU). Microbiologic studies of the environment, personnel and patients showed that colonization or infection of patients occurred 1 to 6 days after admission to the CTICU and that nosocomial pathogens were found: 1) in and around the unit's soiled utility sink, 2) in pooled handwashing cultures of unit personnel, and 3) on contaminated clean hands and air near the soiled utility sink, plus nearby bedside air only while the water in the sink was running. Environmental and personnel hand contamination by soiled utility sink aerosols likely contributed to these infections. Infection control measures, including discontinued use of the soiled utility sink, resulted in a significantly lower infection rate (5.6%).

Extrinsic risk factors for pneumonia in the patient at high risk of infection

Most nosocomial pathogens cause pneumonia through the following sequence: transit to the patient on the hands of medical personnel or perhaps in food, proliferation in the nasopharynx, and subsequent pulmonary aspiration. There are three exceptional pathogens, each of particular concern as a cause of pneumonia in the immunocompromised patient, which follow atypical routes. Important recent advances in understanding these routes permit more rational preventive measures. This report examines the evidentiary basis for the following pathophysiolgic propositions about these three pathogens: Aspergillus, Pneumocystis carinii, and Legionella. Aspergillus spores are almost ubiquitous. Spore generation, except in very unusual circumstances, takes place outside the hospital. Most spores enter the hospital borne in air by infiltration or because of incomplete filtration. Air filtration systems of moderate efficiency remove Aspergillus spores. Nosocomial pulmonary and disseminated aspergillosis arises from inhalation of airborne spores. A nasopharygeal colonization intermediate step before pulmonary disease has not yet been solidly established. It is now firmly established that airborne Pneumocystic carinii transmission occurs between animals. Airborne acquisition probably occurs early in human life. However, in-hospital, person-to-person transmission has yet to be convincingly demonstrated. Most or all cases of pneumocystosis in adults are due to reactivation of endogenous pulmonary organisms. Intensive diagnostic efforts reveal that Legionella is a common cause of community-acquired and nosocomial pneumonia in hospitals where it had not previously been recognized. However, there are at least a few hospitals where it is an uncommon source of pneumonia. Several hospitals have demonstrated a temporal association between the presence of Legionella in hot water systems and nosocomial cases of Legionella pneumonia. The mechanism or mechanisms of transmission to the patient remain to be delineated. It is also not determined if all hospital hot water systems should be maintained Legionella free.

PATTERNS OF FUNGAL COLONIZATION IN VERY LOW BIRTH-WEIGHT (VLBW) INFANTS

We previously documented fungal sepsis in 4% of our VLBW (<1500g)infants, with a 79% mortality. To determine sources, timing and sites of acquisition in this high risk population, weekly oropharyngeal, rectal, groin and, if intubated, endotracheal(ET) Sabouraud cultures were obtained from 115 VLBW infants, plus equipment and staff. 4.3% of infants were colonized(col.)at birth, rising to 28% at lwk, peaking at 39% ⩾2wks. The sites at which col. were first detected varied with age at col: InitiallyGI/respiratory, later, skin. No fungi were cultured from 62 umbilical/central lines, 14 chest tubes, 157 breast milks, 20 personnel hands, 106 respiratory tubings or 183 isolettes. Candida albicans was the major fungus grown at birth and at lwk(66.7%), but no new col. occurred >2wks. Infants col. later grew C.parapsilosis(37.5%)or a yeast unable to be grown for identification (37.5%). C.albicans(60%)and C.parapsilosis(40%)grew from 7.9% of ET aspirates, with 60% of them present from birth. 2 infants, 6.5% of col. infants, developed systemic C.albicans infections (1 meningitis, endophthalmitis; 1 peritonitis). We conclude that col. by C.albicans, the major pathogen in this population, occurs in the first wk of life, with both GI and respiratory contamination. Attempts to prevent systemic disease must take these data into account.

Care of Severely Compromised Patients

Patients with certain diseases (for example, leukemia, cancer, and extensive skin conditions, such as severe burns or dermatitis) and patients who are receiving certain therapeutic regimens (for example, total body irradiation, steroid or antimetabolite therapy) are highly susceptible to infection. These compromised patients are often on special “protective” patient-care regimens intended to reduce the risk of infection. One such regimen, Protective Isolation (as outlined in the previous editions of Isolation Techniques for Use in Hospitals), does not appear to reduce this risk any more than strong emphasis on appropriate handwashing during patient care.Protective isolation, as previously outlined, may fail to reduce the risk of infection because compromised patients are often infected by their own (endogenous) microorganisms or are colonized and infected by microorganisms transmitted by the inadequately washed hands of personnel or by nonsterile items used in routine protective isolation. Such items may include patient-care equipment, food, water, and air. Some studies suggest that vigorous efforts to exclude all microorganisms by using patient-isolator units, eradicating endogenous flora, and sterilizing food, water, and fomites may prevent or delay onset of some infections; thus, these procedures have been recommended by some for use with very-high-risk patients who have a predictable temporary period of high susceptibility. However, these extraordinary and expensive precautions do not appear warranted for most compromised patients.

Epidemiology of nosocomial infections caused by methicillin-resistant Staphylococcus aureus.

Outbreaks of hospital-acquired infections caused by methicillin-resistant Staphylococcus aureus are being recognized with increasing frequency in the United States. Two thirds of outbreaks have been centered in critical care units. Infected and colonized inpatients appear to be the major institutional reservoir, and transient carriage on the hands of hospital personnel appears to be the most important mechanism of serial patient-to-patient transmission. In over 85% of hospitals into which they have been introduced, methicillin-resistant strains of S. aureus have become established as endemic nosocomial pathogens. A program designed to control a widespread outbreak in a university hospital used three surveillance methods to identify the major institutional reservoir of colonized and infected inpatients. Daily clinical laboratory surveillance, monthly prospective microbiology surveys of high-risk inpatients, and the recognition of previously infected 38%, 31%, and 31% of new cases, respectively. After control measures were instituted, the prevalence (p less than 0.001) and the number of acquisitions (p less than 0.002) of methicillin-resistant S. aureus declined over a 12-month period.

Possible mechanisms for vaginal infection with Staphylococcus aureus: inferences drawn from studies of nosocomial infection of newborn infants and surgical patients.

Previous epidemiologic studies of staphylococcal infections in newborn infants and surgical patients provide clues to the method of infection in toxic shock syndrome. In newborn infants, staphylococci were shown to be transmitted most often by the hands of nursery personnel to the umbilical stump, which afforded a warm, moist milieu for bacterial growth. Studies indicated that many surgical wound infections were due to the patients' own organisms, which were carried into the operating room on the patient's skin. It is hypothesized that in toxic shock syndrome the tampon becomes contaminated with a staphylococcal strain from the woman's own hands or skin during the process of insertion. With menstrual blood retained by the tampon in the warm vagina acting as a culture medium, the organism multiplies and elaborates toxin.

Persistent carriage of gram-negative bacteria on hands

The hand floras of 103 hospital personnel and 50 controls were studied over a mean of 35 days. One or more of 22 species of gram-negative bacteria (GNB) were found to be carried persistently on the hands of 22 (21%) hospital personnel and 40 (80%) controls (age-adjusted relative risk (RR) 3.2; p less than 0.001). Males were significantly more often carriers than females (age-adjusted RR 1.8; p less than 0.01), and persons who washed hands less than eight times per day were significantly more likely to persistently carry the same species of GNB on the hands than those who washed more than eight times per day (group-adjusted RR 2.4: p less than 0.001). Predominant organisms from both groups were species of Acinetobacter (45%) and Klebsiella-Enterobacter (39%). Twenty-one percent of 541 nosocomial infections over a 7-month period in the study institution were caused by species found on personnel hands. The same distribution of species types between hospital personnel and controls indicated that handwashing regimens used by hospital personnel were reducing numbers of organisms without shifting the ecologic balance of bacterial populations on the hands. It was concluded that such organisms are much more prevalent on normal skin than generally thought.

A remote device for de-encapsulating reactor-irradiated samples

A remotely operated motorized apparatus is described which facilitates the recovery of Ci levels of radioactive samples, such as 18F, 24Na, etc. without excessive personnel hand or whole-body dose, from sealed quartz ampoules which have been irradiated in a reactor in standard polythylene or aluminum containers. The device is operated in a small hot cell located in a walk-in hood and is used in the routine preparation of reactor-produced radioisotopes for nuclear medicine.

Hand-washing patterns in medical intensive-care units.

ORGANISMS that cause nosocomial infections can be transmitted by the hands of physicians, nurses, technicians, and other hospital personnel.1 2 3 4 Hand washing is considered the single most important procedure in preventing nosocomial infections, and it has been recommended after contact with every patient by both the Centers for Disease Control and the Americal Hospital Association.5 , 6 The risk of acquiring organisms, transmitting them to others, or causing a nosocomial infection may vary with the susceptibility of the patient and the type of patient contact.7 However, because patients in intensive-care units are highly susceptible to nosocomial infections,7 , 8 it has been suggested that personnel . . .

Meningococcal Pneumonia

• Pneumonia apparently resulting from aspiration became clinically apparent in an elderly man two days after admission to a private room on a general medical ward. Pneumonia developed in a patient in an adjacent room three days later. Both patients had group B<i>Neisseria meningitidis</i>isolated from a percutaneous transtracheal aspirate. A prevalence survey failed to identify meningococcal carriers among other ward patients. The index patient required frequent nasotracheal suctioning during the first two hospital days prior to penicillin G potassium therapy. The second patient was simultaneously receiving continuous oxygen therapy administered by nasal cannula. Events suggested that the organism may have been transmitted by direct contact, probably on the hands of hospital personnel. (<i>Arch Intern Med</i>1981;141:575-577)