A community outbreak of measles prompted a serologic survey of personnel in a hospital serving that community. Two hundred sixty-six personnel, primarily physicians (129) and nurses (100), voluntarily participated. Serum specimens were initially tested by the immunofluorescent antibody and enzyme-linked immunosorbent assay (EIA) methods. Specimens with negative results by either test were further examined using the hemagglutination inhibition and plaque neutralization (PN) methods. If EIA and PN results were negative, an individual was considered susceptible. Only one of the 98 participants born during or after 1957 and none of the 168 participants born before 1957 were serosusceptible. The low rate of serosusceptibility, in contrast to previous studies of young adults, appears attributable to the sensitivity of the testing methods used. Based on our experience, institutions considering a measles serologic testing and immunization program should expect to identify very few serosusceptible personnel, even among those born during or after 1957.

The endemic R-plasmids mediating resistance to gentamicin and multiple other antibiotics among many species of Enterobacteriaceae from the Minneapolis and Cleveland Veterans Administration Medical Centers were compared by restriction endonuclease digestion profiling and by phenotype expressed in sensitive E. coli recipients. Southern hybridizations were also performed. Our data indicate that these plasmids demonstrate some microheterogeneity, but are very closely related. Both are self-transferable and mediate resistance to ampicillin, carbenicillin, chloramphenicol, gentamicin, tobramycin, neomycin and kanamycin. These results suggest the dissemination of a conjugal R-plasmid or of Enterobacteriaceae bearing the plasmid between two midwestern Veterans Administration Medical Centers. The most likely mechanism of transmission may be the frequent transfer of patients between midwestern Veterans Administration Medical Centers.

Candida species are seldom considered as a cause of suppurative peripheral thrombophlebitis. During a 15-month period in a 291-bed acute-care hospital, candidal suppurative peripheral thrombophlebitis developed in seven patients. All patients had fever, a tender palpable cord, and Candida species isolated from resected veins and/or pus expressed at the catheter entrance site. Four patients had candidemia. None were neutropenic or recipients of corticosteroids. All had concomitant or preceding bacterial infections, and had received a median of 5 antibiotics (range 3 to 9) for at least 2 weeks. Five of seven had documented preceding candidal colonization associated with broad spectrum antibiotic therapy. Catheter sites had not been routinely rotated and local catheter site care was deficient. Risk factors of antibiotics and duration of hospitalization were fewer in patients with bacterial suppurative thrombophlebitis. Combined segmental venous resection and intravenous amphotericin B appears to be the most rational therapy for this nosocomial fungal infection.

Fifteen rural Wisconsin acute care community hospitals with an average approved bed size of 55 and an average daily census of 28 patients participated in a nosocomial infection control project. Each hospital Infection Control Practitioner (ICP) was trained and conducted prospective nosocomial infection surveillance on all patients admitted to the hospital for 6 consecutive months between May 1,1984 and April 30, 1985. Two hundred twenty nosocomial infections were reported among 13,420 discharged patients for an incidence rate of 1.64 infections per 100 discharged patients. One hundred sixty-four patients had one nosocomial infection. Twenty-three patients had two or more. Infection rates were highest among gynecology— 4.9% and general surgery patients— 4.0%, and lowest among newborns—0.3% and pediatric patients—0%. 39.7% of the infections were of the urinary tract, 27.9% of surgical wounds, 16% pneumonia, and 1.4% primary bacteremia. The other infections were in seven additional sites. Risk factors associated with acquisition of infections included old age, urinary catheterization, and/or a surgical procedure. The overall nosocomial surgical wound infection incidence for inpatient procedures was 1.9%, with incidences of 0.4% for hernia repair, 1.3% for cholecystectomy, 3.3% for appendectomy, 4.0% for total abdominal hysterectomy, and 3.9% for cesarean sections; The incidence of nosocomial infections was 2.7 infections per 100 discharged patients age 65 years or over and 0.9 infections per 100 discharged patients less than 65 years. Two hundred thirty-six microorganisms were cultured from 175 of the infections. Staphylococcus aureus, coagulase-negative Staphylococcus, and Enterococcus were the most common gram-positive organisms. E. coli, Pseudomonas, Proteus, and Klebsiella were the most common gram-negative organisms cultured. The overall nosocomial infection incidence was much lower than reported rates for other groups of hospitals. These data have implications for the review and potential modification of complex guidelines and requirements for infection control in smaller rural hospitals.

The results are reported of a 4-year prospective study of the incidence of primary cytomegalovirus (CMV) infection in the nursing staff of a specialist obstetric hospital. The absence of seroconversion found in personnel attending patients with confirmed CMV-infection justifies reassuring staff members in “high-risk” areas of the adequacy of the methods used to combat cross-infection . On the other hand, a low rate of seroconversion (1.2% per annum) in the staff who nurse normal mothers and “rooming-in” babies emphasizes the need for die rigorous observance of hygienic precautions by all personnel in all areas. The results of this Australian investigation are discussed in relation to the northern hemisphere experience of CMV-seroconversion in pediatric nurses.

A low rate of seroconversion to hepatitis B vaccine is reported. This occurred in healthy hospital employees from two separate institutions. A total of 236 individuals were evaluated in this study and only 53% or 124 persons developed protective levels of antibody to hepatitis B surface antigen following a complete vaccine series. In one hospital, 30% of the vaccine recipients developed antibody but not to a protective level. Employees who received the entire series in the arm or in the arm and buttock (mixed) had a significantly greater number of responders than employees who received the entire series in the buttock (P<.05). Recipients aged 50 to 59 years had a significantly lower response rate to the vaccine (P<.05). There was no correlation with the vaccinee's sex or the timing of the second injection. Vaccine was noted to have frozen in one hospital and accounted for some loss of antigenicity. This failure to respond to the vaccine has necessitated the use of booster injections of vaccine and continued antibody monitoring.

For clean elective surgery, the goal of nosocomial infection control is nothing less than an infection rate of zero. Although infection rates of less than 1% are being posted regularly in selected surgical operations today, infection rates of 2% to 6% persist in many procedures such as coronary artery bypass surgery and vascular surgery. Predictable achievement of a zero infection rate in all of clean surgery will require new directions in both basic and clinical research.

Research into the prevention of infection in clean surgery has, to date, focused upon 1) identifying and controlling the routes of wound contamination, 2) decontamination of a contaminated wound through the prophylactic use of antimicrobials, and 3) modifying the host immune system. The latter is a fascinating area of new research which will not be discussed in detail here.

Routes of contamination are often categorized as endogenous or exogenous. “Endogenous” generally refers to bacterial seeding of the wound from the flora of the patient's own skin, nose, perineum, and GI tract. “Exogenous” contamination has come to mean bacteria originating from the operating room environment or operating room personnel which reach the wound by direct inoculation (eg, improperly sterilized instruments, hands of the surgeon via torn gloves) or by the airborne route. These categories may not be broad enough to satisfy the complexities of the hospital environment, however. The addition of the category “acquired endogenous” may be of help in describing contamination which occurs when patients become colonized with resistant hospital flora and subsequently carry this newly acquired flora into the operating theater.

Seven nurses working in a newborn unit were infested by Microsporum canis, involving the skin of the left forearm. One infant who was treated in the same unit suffered from a similar lesion on the occipital region. Transmission during bottle feeding was suspected. After the introduction of long sleeves for all nurses, no further cases occurred. Data collected on the nurses in the unit suggested that infection correlated with direct exposure to infants.

Kidney lithotripsy patients frequently receive epidural anesthesia via indwelling epidural catheters. In our hospital, patients are immersed in a tub of warm, continuously-flowing tap water. The epidural catheter-entry site is covered by a transparent occlusive dressing. To determine the risk of microbial colonization of the epidural catheter during lithotripsy, we performed quantitative cultures of tub water and semiquantitative cultures of catheters in 63 lithotripsy procedures. Most of the tub water organisms were typical tap water and skin flora isolates. Total colony counts were generally low with no significant progression during the course of serial procedures. Forty-two epidural catheters were cultured; 34 (81%) were sterile, 8 (19%) were colonized with small numbers of flavobacteria or coagulase-negative staphylococci. Only four catheters had organisms present on catheter segments covered by the transparent occlusive dressing (in each case there was a single colony forming unit per semiquantitative plate) and these organisms were probable contaminants. We conclude that with our current lithotripsy procedures, the risk for the development of epidural catheter-associated infection seems to be low.

Adherence mechanisms have been described for some microbes, often in direct association with onset of infection. In other cases, the evidence is vague. This article will summarize modes of attachment, and will focus on each anatomical tract in an effort to outline the relationship between microbial adherence, host cells, foreign bodies, and infection.

Varicella-zoster virus (VZV), one of the most common highly communicable agents of disease, stimulates aggressive infection control measures. In a 1-year period, at one hospital, at least 93 inpatients (82 adult patients, 11 pediatric patients) and 2 hospital staff with active varicella-zoster infections served as potential sources of nosocomial infection. Six incidents of exposure to the virus that occurred without the protection of standard infection control precautions were investigated by the infection control surveillance team. One hundred fifty-six patients and 353 hospital staff were exposed. Fifty-one patients had no history of varicella-zoster infection, but only five were susceptible by serologic testing. One hundred one staff members had no history of varicella-zoster, but only 11 were susceptible by serologic testing. These exposures resulted in three secondary varicella-zoster infections, six courses of varicella-zoster immune globulin prophylaxis and furlough of 13 staff members. Epidemiologic investigation consumed approximately 356 hours of staff time, and management of exposed persons cost approximately $41,500. Prospective knowledge of the immune status of health care workers would vastly decrease the time and effort required to control hospital VZV exposures.

Postoperative infection rates were determined for gynecologic outpatient surgical procedures performed in a traditional operating room environment and a separate, recently opened, surgicenter within the same hospital. Infections were self-reported by attending surgeons responding to computer-generated line listings of their recent surgical procedures. Responses were obtained on 97.9% (612/625) of women having surgery in the operating room and 99.5% (629/632) of women with surgicenter procedures. The overall infection rate for reported women was 0.9% (11/1,241). The difference between operating room and surgicenter rates was not statistically significant. Postoperative infections occurred in 2.5% (3/118) of diagnostic laparoscopies with tubal lavage and 1.4% (3/214) of voluntary abortions by dilatation and evacuation and curettage (D&E&C). The five other infections were scattered among the remaining 25 procedure categories. Ten of the 11 infections were limited to the “clean-contaminated” wounds. No serious or life-threatening infections were encountered. The computer-assisted surveillance system worked well and was easily incorporated into the existing infection surveillance system. The degree of ascertainment of postoperative wound infections is unknown due to reliance on physician self-reporting. However, no patients requiring readmission for infection went unreported by the attending surgeons.

Handwashing practices may be adversely influenced by the detrimental effects of handwashing on skin. A protocol was developed to assess the physiologic and microbiologic effects of frequent handwashing. Fifty-two female volunteers washed their hands 24 times per day for 5 days. Five agents were tested: water alone, non-medicated bar soap, a chlorhexidine-containing antiseptic, and two agents containing povidone-iodine (one currently available on the market and one being tested for possible marketing). Some damage to the outer membrane of skin, the stratum corneum, occurred in all groups. There were significant changes in the amount of evaporation water loss (p=.001) and in self assessments of skin condition (p=.005) from pre-to-post test for the entire group. Skin damage was also assessed by visualizing desquamating stratum corneum cells, which are shed in large aggregates when detergents injure skin. Significantly less such shedding occurred in subjects using water alone, bar soap, and the Chlorhexidine formulation (p=.02). Greater antimicrobial activity of an agent was not correlated with increased skin trauma. We have quantitated, using objective physiologic parameter, the skin damage that occurs during even a short period of frequent handwashing. We recommend that further studies using the methods described be conducted to quantitate skin damage over longer periods of time, more closely resembling handwashing practices of health care personnel.