Medical instruments that come in contact with patients' blood and body fluids during invasive procedures should be sterilized after use. Some instruments, however, are too delicate to tolerate auto-clave temperatures, even the lower temperature required by ethylene oxide sterilization. Chemical sterilants are an acceptable alternative but present a different problem because they require prolonged soaking time from six and three-quarters to ten hours. This long exposure to liquids may adversely affect the components of some instruments. Therefore, the manufacturer should always be consulted when prolonged soaking is contemplated.

Another disadvantage to prolonged sterilization cycles is the increased number of instruments that may be required to compensate for the lag in availability. As an acceptable alternative, the Centers for Disease Control (CDC) and others have divided instruments into three categories: instruments that enter normally sterile tissue and the vascular system (these must be sterilized); instruments that contact nonintact skin and mucous membranes (these should receive high-level disinfection); and items that contact only intact skin such as blood pressure cuffs (these require a lower level of disinfection and will not be discussed here). Importantly, it should be noted that the Environmental Protection Agency (EPA), which registers chemical disinfectants/sterilants, does not recognize these categorizations. They register solutions for sterilization or disinfection.

Infection control guidelines are now widely used in controlling nosocomial infection. For instance, the guidelines published by the Centers for Disease Control (CDC) are now successfully diffused and available in over 80% of the hospitals in the United States.

Before introducing any guideline, it should be carefully reviewed and evaluated. Because guidelines can only benefit patients after they are successfully implemented, the review should focus on the implementation process. A review scheme focusing on implementation was developed. In this scheme, an attempt was made to identify the guideline recommendations already being practiced in the hospital, recommendations requiring extra resources before they could be implemented and recommendations resisted by the hospital staff. We describe the review scheme and a study to assess its validity when used by infection control nurses (ICNs) in Hong Kong

Intravascular catheter tip colonization was prospectively evaluated in critically ill neonates to determine its relationship to the type of device used, duration of catheterization, insertion site and nosocomial bloodstream infection. Sixty-one percent (376 of 621) of all intravascular catheter tips were retrieved from 91 infants. Thirteen percent (41 of 310) of peripheral intravenous, 14% (6 of 42) of umbilical, 21% (3 of 11) of central venous, 36% (4 of 11) of peripheral arterial and 100% (2 of 2) of femoral catheters were colonized. Duration of catheterization was significantly longer for colonized lines (p < .001). Eight of 26 (30.8%) peripheral intravenous catheters remaining in place for more than three days were colonized, compared with 33 of 284 (11.6%) at three days or less (p = 0.012). Coagulase-negative staphylococcus was the organism most frequently isolated from catheter tips and bloodstream infections. Catheter colonization rates in this population were higher than those found in adults. Heavily manipulated devices and those in place for longer periods of time were the most frequently colonized.

Toxoplasma gondii is an obligate intracellular parasite that is a worldwide cause of infections in virtually all mammalian species, including humans. Although toxoplasmosis is extremely common in humans, most cases are subclinical and are revealed only by the presence of antibodies to this parasite. Prior to the use of immunosuppresive therapy and the recognition of the acquired immune deficiency syndrome (AIDS), the most devastating consequence of toxoplasmosis was seen in children of women who acquired acute toxoplasmosis in their first trimester of pregnancy.

In the past two decades, this pathogen has become increasingly recognized in immunocompromised patients as a common cause of encephalitis. The tragedy of toxoplasmosis is that it is a preventable disease. French investigators, have clearly defined the risk and range of severity of congenital toxoplasmosis, the value of systemic screening and patient education, and the value of treatment of the mother during pregnancy to prevent transmission to the fetus. Prevention of a large portion of cerebral toxoplasmosis cases in immunocompromised patients might be possible if congenital toxoplasmosis was better controlled in the United States. The first step in controlling toxoplasmosis in the United States is a better appreciation of this infection.

Although we think of malaria as a disease of the tropics, it is sobering to recall that in the beginning of this century, more than two-thirds of the earth's population lived in areas where malaria was endemic. The United States and Europe were both rife with malaria, and the disease changed the course of world history many times. Indeed, in Western Africa during 1942, the incidence of malaria was as high as 1,071 cases per 1,000 soldiers per year.

Eight patients in two surgical units developed systemic candidosis during a 40-day period from June 5 to July 13, 1987 (in five cases Candida albicans was identified). Three of them died. All cases belonged to a group of 27 patients receiving parenteral nutrition (PN), while among the 108 patients who did not receive PN, no cases were observed (p = .000001). Candida was cultured from two PN bags administered to the cases. A specialized nutrition nurse was responsible for the PN compounding and for maintaining administration sets in the two wards involved.

An epidemiological investigation in which 19 uninfected patients who had had PN were used as controls, showed no significant difference between cases and controls except that lipids were more frequently added to bags administered to cases (p = .0005). Furthermore, the bags administered to cases contained a higher average number of multidose constituents (p = .0008) when the comparison was focused on the two days before the onset of symptoms.Given the favorable medium provided by lipids, even a low level contamination of PN solutions during compounding and/or administration could have been responsible for the outbreak. The finding of a more frequent exposure of cases to multidose vials suggests, although not conclusively, that an extrinsic contamination occurred during compounding. Six isolates of C albicans were available from four cases. C albicans was cultured from the pharyngeal swabs of two physicians and three nurses, including the specialized nutrition nurse. According to DNA restriction pattern analysis, a single strain was responsible for all the cases of systemic candidosis, with only the specialized nutrition nurse harboring the same strain. DNA fingerprinting provided a reliable system for typing C albicans strains. This was the first outbreak of C albicans systemic infection associated with PN.

Aztreonam, the first licensed monobactam in the United States, is a β-lactam antimicrobial agent with a unique structure and in vitro spectrum of activity. The drug is active only against gram-negative aerobic bacteria in vitro, thus resembling the spectrum of aminoglycosides, but displays the safety profile typical of β-lactam agents. Due to these properties, aztreonam may prove useful in the therapy of various nosocomial infections. This review outlines the salient features of aztreonam and suggests areas of appropriate usage.

Three different sequentially applied post-varicella zoster virus (VZV) exposure management strategies were employed over a 43-month period. We began by using a standard post-exposure protocol in which 50 susceptible healthcare workers (HCW) involved in hospital exposures were furloughed from work at a loss to the hospital of 424 workdays and $46,000. Of the eight nosocomial cases of VZV infection in HCWs, four (50%) caused future HCW and patient exposure. In trial I, we substituted a post-exposure screening procedure for the standard work furlough procedure. We screened 77 exposed staff resulting in one nosocomial VZV infection that was the source of another exposure incident. No secondary cases of varicella resulted from this exposure and only 20 days of furlough time were used during trial I. As VZV resulting from a home exposure source was responsible for most hospital exposures in which HCWs were the source, our trial II protocol added the Centers for Disease Control's (CDC) off-duty procedure, but limited its use to susceptibles exposed at home. The 43-month overall attack rate of nosocomial varicella was 4.7%, while the true home exposure attack rate was 79% (p < .00001). There was an average of 42.4 lost workdays charged to the hospital per incident under the standard protocol and three days per incident in the combined experience of trials I and II (p < .0001). Both trial protocol periods saved the hospital many potentially lost HCW days, 592 and 401, respectively, but the trial I protocol led to an observed increase in hospital exposure incidents. While the trial II protocol resulted in more lost workdays (120 of 521) than the trial I protocol, it prevented 18 additional HCW exposures. We conclude that the trial II protocol is safe and the most cost-effective of the three management strategies.

The first article in this series reviewed the type of surveillance currently used by most of the infection surveillance and control programs in acute care hospitals in the United States. Five components were identified as critical to the widespread acceptance and continuing success of this surveillance methodology: targeting of events (diseases); early development of standardized definitions; wide acceptance of the criteria for these definitions; advocacy, leadership and education in methodology; and a high level of effectiveness in program practice. Using the framework of these key components, this article will discuss the potential for the application of similar methodology to noninfectious nosocomial adverse events and explore some current successes and problems associated with surveillance for such events.

The data collection form (also referred to as a questionnaire, case report form or interview guide) is the focal point of any research project. It contains the data used to test the research hypotheses. If errors are made in translating the questions of interest into items on the form, or in coding those items, the answers sought might not be available. Designing an excellent data collection form may be more art than science. However, there are certain principles that, if followed, will generally result in an easy-to-use, efficient and reliable instrument for gathering and coding data.

The recent emphasis on outcome assessment has required hospitals not only to practice high quality care but also to prove that they do so. In search of leadership, many hospitals have turned to epidemiologists and infection control practitioners (ICPs), arguing that there are strong parallels between their activities and those of quality assurance. Both have the same ultimate goal of improving the health of the patient. The principles of surveillance, data management and problem solving used in epidemiology apply also to quality assurance. As advisers, participants or leaders, epidemiologists and ICPs are being drawn irresistibly into the field of quality assurance.

The need for leadership has arisen because the assessment of quality is a surprisingly complex task. Initial approaches are often unstructured and designed to fulfill the requirements of various regulatory agencies rather than to improve the delivery of care. In addition, quality assurance is costly, and financial restrictions on medicine are increasing. It is time to take a serious look at the cost-effectiveness of quality assurance and apply the techniques of medical decision analysis to combat the inefficiency and ineffectiveness that often dominate the field.

Pseudomonas aeruginosa previously has been reviewed in “Topics in Clinical Microbiology.” However, the increased importance of this micro-organism in nosocomial infections as well as new information on pathogenic mechanisms is such that this topic should be “revisited.” For example, the ubiquitous presence of this bacterium in nature and its ability to survive in hostile environments has been recently emphasized by episodes of P aeruginosa peritonitis, bacteremia and pseudobacteremia that have been linked to contaminated povidone-iodine. Clearly, P aeruginosa is an important pathogen and is deserving of careful and deliberate consideration.

The role of P aeruginosa as a nosocomial pathogen in hospitalized patients with critical illness is rapidly increasing. Recent data from the Centers for Disease Control (CDC) have shown that while nosocomial infections from Escherichia coli and Klebsiella have remained relatively constant from 1975 to 1984, the proportion of such infections caused by Pseudomonas has risen from 6.3% in 1975 to 11.4% in 1984. The frightening aspect of this epidemiologic data is the extremely high rate of mortality associated with hospital-acquired Pseudomonas infections. For example, the mortality rate for Pseudomonas bacteremia often ranges from 67% to 90% for neutropenic cancer patients. Among more general hospital patient populations, the mortality rate for Pseudomonas bacteremia can be similar depending on the underlying condition of the host.

Strongyloides stercoralis is a common nematode causing helminthic infections in humans. Strongyloidiasis is principally distributed in the tropics and subtropics. In the United States, a prevalence of 0.4% to 4% has been estimated in southeastern states. Like many other parasitic infections, strongyloidiasis most often is asymptomatic unless the patient becomes immunosuppressed. Immunosuppression can lead to an overwhelming autoinfection, which is highly fatal. This hyperinfection often occurs in hospitalized patients and may be confused with other nosocomial infections. This report will review the salient aspects of strongyloidiasis.