Needlestick injuries in a 720-bed tertiary care hospital were analyzed before and after the introduction of a rigid, puncture resistant, needle disposal system. Following implementation of the system, disposal-related injuries decreased from 0.9 per 100 full-time equivalent employees/year to 0.3 per 100 full-time equivalent employees/year (p <.005). However, needlesticks associated with procedures (2.2 vs. 4.4 per 100 full-time equivalent employees/year, p <.0005), and those resulting from loose needles (0.5 vs. 1.9 per 100 full-time equivalent employees/year, p <.0005), increased. Injuries occurring during needle recapping or the carrying of needles were not significantly altered. Total needlestick injuries increased from 6.0 to 8.7 per 100 full-time equivalent employees/year (p <.0005).

We concluded that a rigid, puncture resistant, needle disposal system can reduce disposal-related needlestick injuries, but must also be perceived as convenient to impact substantially upon needlesticks associated with other activities.

During the past 30 years, many important strides have been made in the prevention of nosocomial infections in the United States. Infection control programs have been established in hospitals throughout the country. Techniques for surveillance of nosocomial infections have been developed and utilized extensively. Results of the Study on the Efficacy of Nosocomial Infection Control (SENIC Project) and the experience with surveillance of surgical wound infections have documented the fact that surveillance is an integral component of an effective nosocomial infection control program. In recent years, a number of approaches to nosocomial infection surveillance have been proposed as alternatives to comprehensive or hospital-wide surveillance. In 1986, four surveillance components were introduced in the National Nosocomial Infections Surveillance (NNIS) system to provide participating institutions the option to tailor their surveillance program to their local needs and priorities while continuing to provide information to the national database on nosocomial infections. Infection control practitioners currently face a challenge to develop more meaningful nosocomial infection rates to permit identification of new infection control priorities for their institution and to assess progress toward specific prevention objectives.

We investigated the effect of the following on the sterile integrity of surgical packs: four wrapping materials (two-ply reusable, nonbarrier wovens, both new and previously used; disposable, barrier nonwovens; and polypropylene peel pouches), dustcovers, two storage locations, and storage times ranging from 2 to 50 weeks. Two hundred sixty-three packs containing stainless steel coupons were prepared, wrapped, sterilized, and stored. Half of the packs were dustcovered prior to storage. At monthly intervals for a year, packs of each type were opened in a laminar flow hood, and the coupons inoculated into trypticase soy broth. The coupon contamination probabilities were 0.019 for reusable, woven packs; 0.017 for disposable, nonwoven packs; and 0.016 for peel pouches. These differences were not significant. The probability of finding a contaminated coupon in any pack after 50 weeks was 0.018. No trend toward increased probability of contamination over time was observed for any of the pack types studied.

The correlation of fecal gram-negative bacilli (GNB), neutropenia, and bacteremia was studied in 45 bone marrow transplant recipients. Weekly stool cultures were prospectively monitored for GNB resistant to routine prophylactic and empiric antimicrobial agents. Seven cases of GNB bacteremia occurred in 45 patients described as follows. Twenty-three patients had no fecal or blood GNB. Fifteen patients had fecal GNB and no blood GNB; three of these latter patients had ≤50/mm3 circulating white blood cells (WBC) at the time of isolation of fecal GNB but two of the three were concurrently receiving appropriate empiric antibiotics. Two patients had blood GNB but no fecal GNB: one patient had a trimethoprim/sulfamethoxazole (TMP-SMZ)-sensitive isolate that would not be detectable in the feces by our methodology and one patient had feces analyzed only after the bacteremic event. Five patients had fecal GNB and blood GNB: one of these patients did not have a fecal sample analyzed prior to bacteremia but the remaining four patients had the same species/antibiogram of GNB isolated from the feces two to three days prior to the detection of bacteremia. Thus, the fecal GNB could have been used to predict the antibiogram of the subsequent blood GNB. In addition, all four of these latter bacteremic patients had ≤50/mm3 circulating WBC at the time of documented fecal GNB. Thus, bone marrow transplant recipients with fecal GNB coupled with severe neutropenia (≤50/mm3 circulating WBC) were more likely to develop bacteremia (P<0.02) than were those with fecal GNB and ≤50/mm3 circulating WBC.

We conducted a prospective environmental study for Legionella pneumophila in 15 hospitals in Pennsylvania. Hot water tanks, cold water sites, faucets, and show-erheads were surveyed four times over a one-year period. Sixty percent (9/15) of hospitals surveyed were contaminated with L pneumophila. Although contamination could not be linked to a specific municipal water supplier, most of the contaminated supplies came from rivers. Parameters found to be significantly associated with contamination included elevated hot water temperature, vertical configuration of the hot water tank, older tanks, and elevated calcium and magnesium concentrations of the water (P < 0.05). This study suggests that L pneumophila contamination could be predicted based on design of the distribution system, as well as physicochemical characteristics of the water.

We undertook a study of postdischarge infections to assess the reliability of a surgical wound surveillance program in a 930-bed teaching hospital. During a six-month period, a subset of operations performed each day was randomly selected and patients interviewed by telephone one month postsurgery using a standard set of questions. The infection rate for all patients contacted directly postdischarge was 5.4%, whereas the surgical wound infection rate determined for all procedures through the standard hospital program was 1.5%. For day-surgery patients, who are not routinely followed in the hospital surveillance program, 8 (7.8%) of 103 patients contacted had infection. Thus, the overall surgical infection rate determined in this study was over three times higher than that calculated using standard surveillance. A reliable method for identifying postdischarge wound infections is necessary to ensure accurate surgical wound infection rates.

The use of protein fingerprinting for the establishment of relatedness among isolates of Acinetobacter calcoaceticus subspecies anitratus, isolated from patients in a surgical intensive care unit was examined. Poly-acrylamide gel electrophoresis was used to analyze the cellular proteins from whole cell lysates of 14 intensive care unit A calcoaceticus subspecies anitratus isolates and 11 control strains. Antimicrobial susceptibilities and plasmid profiles were also determined for all isolates. All intensive care unit A calcoaceticus subspecies anitratus isolates exhibited identical cellular protein fingerprints, no detectable plasmids, and minimum inhibitory concentrations within ±1 log2 dilution of the mode value for each of the antimicrobial agents tested. The other clinical isolates demonstrated a range of antimicrobial susceptibilities, various numbers and sizes of plasmids, and distinctly different protein fingerprints. These data indicate that protein fingerprinting may be useful as an epidemiologic tool in A calcoaceticus subspecies anitratus outbreaks and this method deserves further study.

We determined the operative related cerebrospinal fluid (CSF) shunt infection rates for our institution over a 3-year period (1982 to 1984) using strictly defined numerator and denominator data. The minimum post-operative follow-up period was 12 months. The average surgical infection risk for a CSF shunt procedure at our institution during the study period was 13.3%. Annual infection rates were relatively constant (13.8%, 13.2% and 12.9%), however both quarterly (5.7% to 23.3%) and surgeon-specific (5.7% to 22.8%) rates varied widely. Infection rates calculated by using “traditional” numerator and denominator data were considerably lower (6.5% to 9.2%).

Operative related CSF shunt infection rates should be determined by utilizing strictly defined numerator and denominator values in order to allow valid comparisons of published rates.

Herpes simplex viral infection is a common cause of infection involving the eye and skin adjacent to the eye. Acute keratoconjunctivitis is a frequently observed herpetic manifestation often accompanied or exacerbated by stress factors, including fever (especially when associated with respiratory or intestinal infection), stress, trauma, environmental exposure, drugs, and menstruation. Each year approximately 300,000 to 500,000 cases of corneal herpes are reported. Complications such as decreased or lost vision may be associated with attacks of ophthalmic herpes infections. Therefore, effective treatment is imperative.1 Experts estimate that nearly 25% of patients with a primary ocular infection will have a recurrence of the infection, and approximately 50% of these patients will have a recurrence within two years. Herpes viral infections are a significant cause of blindness and a primary indication for corneal transplants.

The initial and cumulative efficacy of two antiseptic handwash preparations in eliminating Serratia marcescens from hands was evaluated on volunteers. Two antiseptics with persistent skin antibacterial activity, 4% chlorhexidine gluconate in detergent and 1.5% triclosan in natural soap, were studied in a new protocol designed according to Food and Drug Administration guidelines. After a single handwash, both preparations exhibited a degerming action statistically superior to the mechanical elimination of the marker organism that was achieved by the nonmedicated controls. Following a further nine hand recontamination sequence with 109 colony-forming units (cfu)/mL S marcescens (mean pre-disinfection baseline, log10 6.6), the efficacy of chlorhexidine and triclosan was significantly augmented: the mean log10 reduction factors were 4.15 and 3.78, respectively. In the absence of internationally accepted testing standards for antiseptic handwash products, the significance of protocol variables is discussed. The advantages to preventative microbiology of antiseptics with persistent skin antibacterial activity are highlighted.

This paper addresses the problems associated with defining and classifying events as nosocomial infections, discusses the methods by which rates of nosocomial infection are calculated and their rationales, and presents some specific rates useful in nosocomial epidemiology. Previously unpublished data demonstrate important differences between antibiotic susceptibility tallies produced by clinical laboratories and similar tallies derived from nosocomial infection surveillance data.

Conversion of real world events into categorical data presents formidable difficulties. Surveillance personnel must classify a given series of clinical events as 0,1, or more infections and make a determination as to whether each infection is nosocomial or community acquired. High-quality research studies to validate these efforts should compare the sensitivity and specificity of methods used to some “gold standard.” The gold standard is usually a review of medical records or patients by an infectious diseases physician. But even the standard is flawed. In clinical practice this flaw presents less of a problem because therapy for infectious diseases is generally quite safe and may be instituted when the probability of infection is 10%, 5%, or even lower. For surveillance purposes a higher standard is required, which is particularly important when surveillance information is used to provide feedback data to physicians who understandably bridle at overestimates of infection rates in their patients. The overestimation of infections based on weak evidence under-cuts feedback efforts.

Human immunodeficiency virus (HIV), the etiological agent of the acquired immunodeficiency syndrome (AIDS), was treated with either Betadine® (povidone-iodine) Solution or Betadine Surgical Scrub®. HIV inactivation was analyzed using the viral reverse transcriptase assay or by observing the cytopathic effect produced in HIV-infected, H-9, T-cell cultures. The minimum effective Betadine dose was 0.25% for complete inactivation of HIV that was treated for various time intervals (immediate vortex to ten minutes). The titer of HIV stocks used in these experiments (105 TCID50 per mL) was greater than amounts generally detected in clinical specimens. Our results provide a rationale for the use of povidone-iodine as a topical antiseptic against HIV in the clinic or laboratory.

Because of the similarities in the spread of hepatitis B virus and the human immunodeficiency virus (HIV), health officials have been concerned about the acquisition of HIV infection by health care workers. This concern has led to numerous cross-sectional and prospective cohort studies during the last 3 years to evaluate the risks involved. The risk of occupationally acquired HIV infection has been shown to be considerably less than that of hepatitis B virus infection, however needlestick transmission has occurred.

Cefixime, a broad-spectrum, orally active cephalosporin, was more active in vitro than ampicillin, cefaclor, cephalothin, and trimethoprim/sulfamethoxazole against 194 nosocomial pathogens of the family Enterobacteriaceae. Activity was especially good against Klebsiella spp, Proteus spp, Serratia spp, and Providencia stuartii. Although gentamicin had equivalent or better activity against Citrobacter spp, Enterobacter spp, Escherichia coli, and Morganella morganii, all 23 of the gentamicin-resistant strains studied were susceptible to Cefixime. Isolates tested were from urinary tract infections, abdominal infections, wounds, vascular infections, and respiratory infections; they were sequentially collected nosocomial pathogens from a single institution. This orally active cephalosporin should be considered for therapy of a variety of nosocomial infections involving gram-negative bacillary pathogens.

Tuberculosis (TB) skin testing practices and the prevalence and inherent risk of TB infection among hospital employees in 167 North Carolina (NC) hospitals were determined from a 79% (132/167) response to a tuberculosis screening questionnaire. Preemployment TB skin testing was performed by 98% of responding hospitals, primarily (87%) by the Mantoux method. TB skin test reactions of ≥ 10 mm were interpreted as significant by 72% and at the appropriate time interval of 48 to 72 hours after administration by 80%. The booster test was routinely performed in 12% of the hospitals. TB infection prevalence among new employees during 1983 was 6.3% (260/4137) in 30 hospitals supplying these data. A positive correlation was noted between employee infection prevalence and county TB case rates (P = .014). Skin test conversion data from 56 hospitals across the state revealed a five year mean conversion rate of 1.14% among 71,253 personnel. There was an association between the incidence of TB in the general population and the frequency of conversions among hospital employees in corresponding geographical regions. Similarly, the incidence of TB among approximately 100,000 NC hospital employees in 1983 and 1984 was less than the incidence in the general population. These associations suggest that the incidence of TB infection among hospital personnel may reflect the prevalence of tuberculosis in the community rather than an occupational hazard. Annual TB skin testing of hospital employees may be justified in eastern North Carolina where the incidence of tuberculosis (22-30 cases/ 100,000) is greater than the national average and where the risk of new TB infection among hospital employees is relatively common (≥1.5%).

Reported are the results of a study on the incidence of nosocomial surgical infections in ten wards of the university hospital A. Gemelli, Rome. One thousand, five hundred five patients were studied and the overall incidence of surgical infections was 8.7%. Factors that influenced infection rates included age, immunosuppressive diseases, and immunosuppressive therapy. We assessed the inutility of antibiotic prophylaxis in clean operations and its usefulness in clean operations with insertion of prostheses or other devices. The importance of the duration of preoperative hospitalization and of the length of the operation were also noted. The most frequent etiological agents proved to be Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. The average hospital stay for patients with surgical infection was more than double that of patients with no infection (25.7 days v 11.7 days).

Aspergillus flavus and Aspergillus fumigatus are important causes of invasive, often fatal, fungal disease in immuno-compromised patients. Sources of aspergilli for hospitalized patients may include window air conditioners, fireproofing materials, dust accumulated above false ceilings and acoustical ceiling tiles, and improperly functioning central ventilation systems. Renovation and construction projects, movement of heavy equipment, and demolition of nearby buildings often occur in or near hospitals. These events may aerosolize dust and soil laden with Aspergillus spores. Immunocompromised patients may acquire invasive aspergillosis in the hospital by inhalation of spores or by direct contact with contaminated intravenous arm boards. We have recently recognized the occurrence of invasive aspergillosis in an area of our hospital that does not contain false ceilings or a central ventilation system. All of the patient rooms in this area contain air conditioners that are attached to ceilings rather than windows, recirculating room air rather than drawing air in from the outside.