Long-term use of indwelling urinary catheters in nursing home (NH) patients is a potential cause of significant morbidity. We retrospectively studied 10 NH patients with chronic indwelling urinary catheters. Sixty-four percent of all 84 antibiotic courses prescribed were for bacteriuria alone without clinical infection. Seventy percent of 63 antibiotic courses were followed by bacteriuria with organisms resistant to the antibiotic administered. Bacteria isolated from NH patients often displayed greater resistance to specific antibiotics than those isolated from hospitalized patients. Four of the 20 urinary tract infections were associated with bacteremia. Three episodes of bacteremia were with highly-resistant organisms and one was fatal. Use of urinary catheters and inappropriate use of antibiotics in NH patients results in urinary tract colonization and infection with resistant bacteria and is an important cause of morbidity and mortality.

Sixty-three cases of nosocomial sepsis occurring from April through October 1981, in a 500-bed pediatric hospital, were traced to bacterial contamination of intravenous fluid produced by a single manufacturer. Two species of uncommon blood stream pathogens, Enterobacter cloacae and Enterobacter agglomerans contaminated the fluid. Infections with these organisms might have contributed to the death of four patients; two who were immunosuppressed, one who was asplenic and one premature infant. Epidemiologic and laboratory investigations identified the site of contamination to be within the screw-caps of the bottles containing the intravenous fluid. Contamination occurred during insertion of the intravenous fluid administration set into the bottle. The “epidemic” terminated when the hospital discontinued the use of infusion fluids from that manufacturer. We conclude that intravenous fluids should be examined during outbreaks of nosocomial bacteremia due to unusual pathogens.

A well-characterized unusual Pseudomonas species contaminated the piped disinfectant system of a newly-opened laminar air flow intensive care facility. This organism was frequently isolated (104-106 cfu/ml) from phenolic diluted 1:256 in the system, and could also be recovered (0.01-0.2 cfu/ml) from undiluted phenolic. During the 20-month period when this unusual Pseudomonas was present, none of the severely compromised, granulocytopenic oncology patients treated in the intensive care facility were either colonized or infected with this Pseudomonas sp. Eradication of the organism from the system proved difficult and was accomplished by removing a contaminated reservoir of diluted phenolic disinfectant followed by transient cleansing of the system with very high concentrations (84,000 ppm) of chlorine. This experience demonstrates that phenolics should be added to the list of disinfectants which can harbor Pseudomonas spp. in the clinical setting.

The purpose of hygienic hand disinfection is to render hands safe after contact with pathogens. Comparing effects of disinfection procedures on infection ratios is too difficult for routine purposes but the degerming efficacy may be determined in laboratory tests with volunteers. In the Vienna test model the efficacy of a specific procedure being tested is compared to that of a standard disinfection (rubbing into hands 3 ml of iso-propanol 60% v/v, 30 seconds, twice) tested in parallel with the same volunteers. This ensures standardization, thus comparability of results between laboratories, and provides the investigator with a yardstick for efficacy. The model includes artificial contamination, assessment of the release of test bacteria (E. Coli ATCC 11229) before and after disinfection by the finger tip method, and addition of neutralizers to sampling fluids. Alcohols in appropriate concentrations are highly effective (log reductions: >4.0) whereas procedures employing disinfectant detergents act like soap (log reductions: ≤ 3.2) and may cause dissemination of pathogens.

Postoperative wound infections following open heart cardiac surgery increased markedly after hospital relocation (7 of 77 v; 4 of 320; p = .0007). Of the multiple identified risk factors, significant patient and procedural association included prolonged operative time of infected patients (384 minutes ± 115 SD v 318 ± 67, p = .025) and operation in a room used within the previous 48 hours for a contaminated case (4/7 infected v 10/67 not infected; p = .023). Several defects were discovered in the air handling system. After appropriate changes, the infection rate decreased in the next 12 months (1 of 109; p < .02). Other concurrent surgical wound infection rates remained unchanged suggesting that defective air handling may have impacted only on the open heart cardiac surgery patients. Preceding contaminated surgery and prolonged operative time were associated with postoperative wound infections in cardiac surgery.

Serratia marcescens is recognized as an important and potentially hazardous nosocomial pathogen. The organism has been implicated here as the first reported case of S. marcescens meningitis associated with skin disinfection. A quaternary ammonium compound (QAC—Benzalkonium Chloride), was used to sterilize the skin prior to injection in a physician's office. Epidemiological studies were initiated. Six spray bottles containing disinfectant, the opened stock bottle of QAC, and an unopened bottle of disinfectant were all cultured. S. marcescens was noted growing in the spray bottles as well as in the opened stock bottle. Anti-biograms of the patient and epidemiological isolates are essentially the same. It is our contention as well as that of the Centers for Disease Control that an appropriate skin disinfectant such as Tincture of Chlorhexidine, Iodophors, or Tincture of Iodine should be used, and that physicians performing surgical techniques in the office be aware of the potential hazard of contamination. The consequences of nosocomial infection with resistant organisms warrant every precaution by health care professionals.

A prevalence survey of infections among 572 acute and long-term care patients in the Albany Veterans Administration Medical Center was conducted in September 1979. Presence of infection was determined by patient examination and chart review. Urine specimens from 94% of patients were cultured. The total number of clinically significant infections was 178; 117 were nosocomial (20.5 per 100 patients). The prevalence rate of nosocomial infections was highest on the Intermediate Service (long-term medical care) followed by the Surgical and Medical Services. Sites with the highest nosocomial infection rates were urinary tract (10.7), skin and subcutaneous tissues (5.1), and surgical wounds (3.0) per 100 patients. Nosocomial infections increased with age and length of hospital stay which partially explained the higher rate on the Intermediate Service. Patients using condom drainage and Foley catheters showed similarly high rates of bacteriuria. Antimicrobial drug use was 17% for acute care patients and 4% for long-term and psychiatry patients. Excepting Providencia stuartii urinary tract infection confined to the Intermediate Service, the bacterial isolates and their antibiotic susceptibilities were similar for the acute and long-term care services.

We analyzed 14 cases of nosocomial infective endocarditis which occurred over a seven-year period at the Beth Israel Hospital in Boston, and compared them with 90 cases of community-acquired endocarditis. Patients with nosocomial endocarditis were older, more often female, and had a greater incidence of underlying valvular heart disease and bacteremia precipitating invasive procedures (93% v 50%, P < .05). Forty-three percent of patients had infection at the site of prosthetic valves or intracardiac prosthetic material. The disease carried a significantly higher mortality than community-acquired endocarditis (43% v 11%, P < .01). The clinical presentation was acute and the infecting organisms reflected the site of origin of bacteremia, with staphylococci from skin and enterococci from urinary sources. Half of the cases in this series may have been prevented by the application of currently recommended preventive and therapeutic practices. Nosocomial endocarditis occurs in a definable sub-population of hospitalized patients and is potentially preventable.

In an acute-care general hospital, 114 telephones, intercoms, dictaphones, and bedpan flusher handles were sampled in patient-care areas for type of bacterial contamination. Nine of these (7%) demonstrated potentially pathogenic bacteria including Klebsiella, Enterobacter, Pseudomonas and Aeromonas. Inanimate, environmental, staff hand-contact objects were only lightly contaminated, did not represent a significant reservoir of gram-negative organisms, and therefore, would be unlikely to be a vehicle of transmission of gram-negative bacteria from the hands of one staff member to another under routine circumstances. Surveillance and disinfection of telephones and related hand-contact items in the hospital appear unnecessary.

Twenty-three episodes of pseudobacteremia occurring over a seven-month period were traced to cross-contamination by the automated blood culture analyzer (BACTEC 460) used in the microbiology laboratory. An epidemiologic investigation of an unusual cluster of three patients with pseudobacteremia caused by oxacillin-resistant Staphylococcus aureus led to the identification of the problem. Mock trials of the blood culture procedure confirmed that the blood culture analyzer was the source of contamination. After the needle sterilizer was replaced by the manufacturer, the problem of cross-contamination abated. Contamination of sterile blood cultures by an instrument intended to identify bacteremia rapidly may lead to incorrect diagnosis, unnecessary administration of antibiotics and prolonged hospitalization. Because of the widespread use of automated blood culture analyzers in the US, physicians, microbiologists, and infection control personnel should be alert to the possibility of cross-contamination and the subtle way in which it may present.

From September 14, 1981 to February 28, 1982, an epidemic of bullous impetigo caused by a penicillin/tetracycline resistant strain of Staphylococcus aureus, phage type 3A/3C, occurred in a newborn nursery in Louisville, Kentucky. Twenty of 1,181 (1.7%) infants at risk developed disease during the six-month epidemic period. Clinically all case-infants had bullous impetigo skin lesions. One infant developed staphylococcal septicemia. No infant died. An epidemiologic investigation identified a nurse as having significantly greater contact with case-infants than control-infants (p=0.0013). She was also found to be a nasal carrier of the epidemic strain. Infection control measures appeared to decrease infant-to-infant transmission via the hands of non-colonized nurses, but did not affect transmission from the nurse carrying the epidemic strain to infants. No cases of bullous impetigo have occurred since this nurse was temporarily removed from the nursery for treatment.

Human rotavirus (HRV) epidemics have not been reported in normal full-term newborn nurseries in the US. This report describes an epidemic from April 27 to May 6, 1982 in which 23 infants were infected. Diagnosis was confirmed with Rotazyme (Abbott) in 82% (23/28 ) of the neonates screened. Five were asymptomatic; in the remaining 18 cases, the symptoms were usually mild and self-limited. Transient shedding of the virus was found in 8% (4/52) of personnel screened, and only one of them was symptomatic. Control measures included the following: strict cohorting, closure of transitional nursery, enteric precautions and wiping of horizontal surfaces with 95% ethyl alcohol which has been shown to be an effective virucidal agent for rotavirus in laboratories. Follow-up in 80 of 108 contact neonates born during the epidemic showed only two mildly symptomatic cases after discharge. During an 11-month period of surveillance, 33% of neonates (1,688/5,054) born at Cook County Hospital were screened for excretion of virus in stools; only 3.6% of infants (61/1,688) were positive by Rotazyme and none were symptomatic. This report suggests that strict measures are helpful in control of HRV epidemic gastroenteritis and asymptomatic shedding need not be as high as the previously reported incidence of 40% to 50%.

Male patients with spinal cord injury are frequently colonized with P. aeruginosa and K. pneumoniae on the perineum. Regular bathing with bar soap has not influenced this colonization. We have attempted to remove these bacteria using antiseptic agents. The number of P. aeruginosa, K. pneumoniae and total aerobic bacteria on the perineum and the penile shaft was determined before and after cleaning with bar soap, chlorhexidine, povidone-iodine and pHresh. Povidone-iodine and chlorhexidine had no advantage over bar soap or pHresh in the removal of P. aeruginosa or K. pneumoniae from the perineum of patients with spinal cord injury.

Coagulase-negative staphylococci (CONS) have only recently gained notoriety as pathogens. Several reports have established their pathogenicity in bacterial endocarditis, prosthetic heart valve endocarditis, intraventricular shunts for treatment of hydrocephalus and intravenous catheters. One difficult decision for physicians is determining whether a particular CONS isolate is pathogenic or contaminant. The differentiation of pathogenic and contaminant CONS has recently been noted, but further studies are needed to aid in this differentiation. Data on antimicrobial susceptibilities of positive blood culture isolates were recently compiled at this institution. This report compares antimicrobial susceptibilities of pathogenic and contaminant CONS and Staphylococcus aureus blood culture isolates from 1961-1981 at this institution.

One hundred fifty Hickman right atrial catheters were inserted into 143 patients and were followed prospectively until removal. Primary indications for their use were: cancer chemotherapy (45), parenteral nutrition (35), antibiotic therapy (63), and miscellaneous (7). The overall catheter-associated infection rate was 12.0%. Since the mean duration of catheterization was 125 days, the infection/duration rate was 1.0/1,000 days of use. The risk of infection differed significantly according to the primary indication for catheterization: parenteral nutrition > antibiotic therapy > cancer chemotherapy. The increased risk of catheter-associated infection attributable to duration of catheterization was additive, and the per day risk of such infections remained constant regardless of duration. Nearly two-thirds of patients were discharged home with catheters in place, without adversely affecting infection risk.

The role of pre-operative disinfection of the surgeon's hands and the skin of the operative site in the prevention of wound infection remains uncertain. The normal resident skin flora, consisting mainly of coagulase-negative staphylococci and aerobic and anaerobic diphtheroids, is an uncommon cause of infection except in prosthetic operations. Staphylococcus aureus is rarely a resident on normal skin other than the perineum, and is mostly present on the hands as a transient acquired from the nose. Nevertheless, it seems rational to kill or remove all transients on the hands of the surgeon and reduce residents to low levels.

Surgical skin disinfection is usually assessed by measuring the reduction in organisms on the hands immediately after disinfection, after repeated applications of the disinfectant and after wearing gloves for two to three hours. The hands are commonly sampled in a bowl or plastic bag containing Ringer's or a similar solution and relevant neutralizers, or by the use of glove washings. A standardized technique is necessary to provide a statistical comparison between agents. Antiseptic detergents, chlorhexidine or povidone iodine show immediate reductions in bacterial counts of 70% to 80%, increasing to 99% after repeated application. Hexachloraphene and triclosan detergents show a lower immediate reduction but a good residual effect. Seventy percent ethyl or 60% propyl alcohol, with or without an antiseptic, show an immediate reduction of over 95%, and in excess of 99% on repeated application. Residual levels of organisms tend to be lower after repeated alcohol treatment than following the use of antiseptic detergents. A two to three-minute application of the antiseptic to the hands, without a scrubbing brush, is commonly recommended in the UK, but possibly in routine surgery an application time of 30 seconds is sufficient, killing or removing transients and superficial residents.

This report describes the results of a prospective study of nosocomial infection in 7,714 patients hospitalized during a 24-month period at a cancer treatment center. An overall nosocomial infection rate of 9.3% was observed with site-specific infection rates of 2.6% for urinary tract, 1.9% for surgical wound, 2.2% for bacteremia and 1.9% for respiratory tract infection. Within specific patient groups, the overall nosocomial infection rates observed were: 8.2% in medical patients, 14.9% in surgical patients and 1.5% in pediatric patients. Despite the markedly elevated nosocomial infection rate in surgical patients (P < 0.001), surgical wound infection rates were not unlike those observed in general hospitals: clean—2.4%, clean contaminated—5.8%, contaminated—13.2%, and dirty—11.8%. These observations provide evidence that institutions which provide medical care predominantly for cancer patients can expect to observe higher nosocomial infection rates than general care hospitals.

Nosocomial (hospital-associated) infection continues to represent a major problem for hospitals. Gram-negative aerobic bacilli continue to be identified most frequently as etiologic agents, but a number of new pathogens now are recognized to play a role. The persons responsible for infection control efforts and in charge of the clinical microbiology laboratory (frequently the same person) must cooperate closely to attack this problem. The role of the laboratory in attempts to minimize occurrence of nosocomial infection involves six aspects: 1) accurate identification of responsible organisms, 2) timely reporting of laboratory data, 3) provision of additional studies, when necessary, to establish similarity or difference of organisms, 4) provision, on occasion, of microbiologic studies of the hospital environment, 5) training of infection control personnel, and 6) participation in activities of the hospital infection control committee.