The contemporary infection control program, whether independent or fully integrated into a hospital-wide quality assurance (QA) program, has a very broad scope including surveillance, outbreak management, education, policy/procedure development, environmental/construction surveillance, program evaluation and research (Table). The greatest problem organizing an infection control program has been identified as integration of its components so as to establish supervision and feedback among its participants, with the purpose of achieving steady progress.

Programs have historically been “centralized” with the hospital epidemiologist, infection control practitioner and hospital infection control committee responsible directly or indirectly for the maintenance of the system.’

To improve the efficiency of nosocomial infection detection, a highly structured system combining initial reporting by the bedside night nurse of symptoms possibly related to infection with follow-up by the infection control nurse (ICN) was developed: The Infection Control Sentinel Sheet System (ICSSS).

Between July 1, 1987 and February 28, 1988, a prospective comparison of results obtained through ICSSS and daily bedside observation/chart review by a full-time trained intensivist was undertaken in the pediatric intensive care unit (PICU). Ratios of nosocomial infections and nosocomially-infected patients were 15.8 and 7.0 respectively among 685 admissions; included are seven infections identified only through the ICSSS so that the “gold standard” became an amalgamation of the two systems. The sensitivity for detection of nosocomially-infected patients by bedside observation/chart review and ICSSS was 100% and 87% respectively. The sensitivity for detection of standard infections (blood, wound and urine) was 88% and 85% respectively. The sensitivity for detection of nosocomial infections at all sites was 94% and 72% respectively. Missed infections were minor (e.g., drain, skin, eye), required physician diagnosis (e.g., pneumonia), were not requested on the sentinel sheet (SS) (e.g., otitis media), related to follow-up of deceased patients or were minor misclassifications or failures to associate with device (e.g., central-line related). Daily PICU surveillance by the ICN required only 20 minutes a day. The ICSSS appears highly promising and has many unmeasured benefits.

This review of the use of surveillance by infection control practitioners (ICPs) in nosocomial infection control programs has identified key components that have led to and supported its continued application and success. These include:

◾ Surveillance targeting of events (diseases);

◾ Early development of standardized definitions;

◾ Wide acceptance of these criteria;

◾ Advocacy, leadership and education of methodology and;

◾ A high level of effectiveness in program practice.

Personnel concerned with instrument processing have searched for decades for the ultimate machine to effectively decontaminate dirty instruments, a machine that could take heavily soiled instruments— even instruments with dried debris—and turn them out spotlessly clean. The machines previously available simply do not tit this bill.

Case-control studies (sometimes referred to as case-referent studies) have long been important in epidemiologic research. This technique has been instrumental in allowing researchers to discover the associations between cigarettes and lung cancer, thromboembolism and oral contraceptives, and stilbesterol and vaginal cancer, just to cite a few examples. The case-control method is also a very useful technique for studies in hospital epidemiology. This article will briefly review this technique, its advantages, and some of its potential pitfalls.

We report an outbreak of Enterobacter sakazakii infection and colonization in neonates related to an infant formula contaminated during the manufacturing process. The outbreak occurred in a 2O-bed neonatal intensive care unit during a six-week period in 1988, and involved a total of four infants. Three infants had sepsis and three had bloody diarrhea; all patients responded to intravenous antibiotics and recovered without complications. The E sakazakii isolated from the formula had the same plasmid and multilocus enzyme profile as those isolated from patients. This outbreak demonstrates the significance of commercially contaminated formulas and emphasizes the need to limit contamination and multiplication of bacteria in enteral formulas.

A prospective study was performed over a two-year period to determine whether computer-generated reminders of perioperative antibiotic use could improve prescribing habits and reduce postoperative wound infections. During the first year, baseline patterns of antibiotic use and postoperative infection rates were established. During the second year, computer-generated reminders regarding perioperative antibiotic use were placed in the patient's medical record prior to surgery and patterns of antibiotic use and postoperative wound infections monitored.

Hospitalized patients undergoing non-emergency surgery from June to November 1985 (3,263 patients), and from June to November 1986 (3,568) were monitored with respect to indications for perioperative antibiotic use, timing of antibiotic use and postoperative infectious complications. Perioperative antibiotic use was considered advisable for 1,621 (50%) patients in the 1985 sample and for 1,830 (51%) patients in the 1986 sample. Among these patients, antibiotics were given within two hours before the surgical incision in 638 (40%) of the 1985 sample and 1,070 (58%) of the 1986 sample (p<0.001). Overall, postoperative wound infections were detected in 28 (1.8%) of 1,621 patients in 1985 compared with 16 (0.9%) of 1,830 such patients in 1986 (p<0.03).

We conclude that computer-generated reminders of perioperative antibiotic use improved prescribing habits with a concurrent decline in postoperative wound infections.

Group B streptococci are the most frequent cause of life-threatening infections in newborn infants in the United States. The reservoir of this organism is thought to be the mother's vaginal or rectal microflora or both. Prevalence surveys have documented arriage rates ranging from 8% to 31%. Increased rates of vertical transmission are seen in infants born to women with dense vaginal colonization at delivery. In most cases, early onset group B streptococcal disease in neonates is diagnosed during the first day of life.' While the carrier rate may approach 30% in pregnant women, the incidence of serious disease in neonates is 0.2% to 0.4% with a mortality rate approaching 50% in some studies. Risk factors prominently associated with early onset group B streptococcal disease have been identified as premature labor, prolonged rupture of amniotic membranes and intrapartum fever.

The cross-sectional study, also called the prevalence survey, is one of the most popular epidemiologic methods. It has been employed in up to one-third of published studies. This survey method has two primary applications: describing population characteristics and analyzing potential etiologic agents or risk tactors for diseases or other population attributes. Studies of the prevalence of rheumatoid arthritis and the association between smoking and chronic bronchitis are two examples of the cross-sectional method applied at the population-based level.

One of the more important aspects of nosocomial infections is that they often are caused by bacterial strains resistant to many antimicrobial agents. Despite over 50 years in the development and use of a wide variety of antibiotics, bacterial resistance mechanisms have not been defeated and are playing an increasingly important role in the therapy of infections.

The mechanisms of bacterial resistance, moreover, are constantly changing, but our understanding of these resistance mechanisms at a molecular level is rapidly increasing.” Yet importantly, a detailed knowledge and understanding of the genetic basis for bacterial resistance is of great importance for the proper evaluation and control of nosocomial infections caused by resistant pathogens. The purpose of this discussion is to provide insights into the genetic basis for bacterial resistance and to describe some newer mechanisms of bacterial resistance that influence the therapeutic approach to nosocomial infections.

Life expectancy has been the most popular outcome measurement for decision analyses. The effectiveness, or utility, of a strategy is expressed in years of life gained over a baseline state. This is particularly useful from a public health standpoint when a fixed budget must be used to serve a diverse population. For example, should money be spent on influenza vaccination programs or cholesterol screening? A decision analysis to answer this question might use cost per year of life gained as the primary outcome. Essentially, the public health provider is seeking to minimize cost while maximizing life expectancy. Strategies could be ordered and priority given according to rank.

Environmental surface and personnel hand impression cultures were obtained during 13 sampling periods in the University of Virginia Pediatric Intensive Care Unit to document potential reservoirs of nosocomial pathogens. In 78 environmental cultures Staphylococcus aureus was found eight times and gram-negative bacilli ten times. The patient chart cover was the most commonly contaminated surface. Acinetobacter calcoaceticus was found in five of ten cultures positive for gram-negative bacilli. Thirty of 59 hand cultures were positive for S aureus and gram-negative bacilli; nurses and residents had both, respiratory therapists only gram-negative bacilli, and A calcoaceticus was the most commonly isolated bacterium of potentially nosocomial significance (14/30). Laboratory investigation of bacterial survival revealed that gramnegative bacilli survived on a dry formica surface from a few hours up to three days but Acinetobacter survived up to 13 days. Since A calcoaceticus has been implicated in many nosocomial infections, its long survival on a dry surface may be an additional factor in its transmission in hospitals and suggests that more attention be paid to environmental surfaces as a source of significant nosocomial pathogens.

The use of glycoprotein G (gG) from the herpes simplex virus has made possible an immunoprecipitation test that distinguishes prior infection with herpesvirus type 1 (HSV-I), herpesvirus type 2 (HSV-2) or both. The test is more sensitive than previously available tests. A national study employing this new immunologic test suggests great differences in prevalence of antibodies to each of these two viruses at different ages in different ethnic groups. For example, in the 20-to 25-year age group, about 5% of Caucasians have antibody to HSV-2, while the frequency of antibody to HSV-2 in blacks is about four times that high. This study also suggests a higher prevalence of HSV infection in the population of women of childbearing age than was previously estimated with less sensitive testing methods. Since HSV disease in newborns is closely related to the frequency of herpes simplex infection in the mother, estimates of the likelihood of nosocomial infection with HSV in newborns must take these new data into account. The specificity of the new test was not discussed.

A case of primary and recurrent herpes simplex virus (HSV) infection resulting from a bite wound' occurring in a pediatric nurse is presented. HSV infection as an occupational hazard among hospital, personnel is briefly reviewed.

Herpes simplex virus occurring as herpes whitlow is a well-known hazard among dentists and dental technicians. There is one report in the literature of a large series of nurses in a neurosurgical unit contracting herpetic whitlow. There is one case in the literature of a physician contracting primary herpes simplex infection from mouth-to-mouth resuscitation of a patient with herpes simplex pneumonia. Three days after performing mouth-to-mouth resuscitation, the physician developed painful papulovesicular lesions over the beard area, which subsequently ulcerated and crusted. One year after the resuscitation, the physician experienced cervical lymphadenop-and a recurrence of herpetic lesions in the same areas as the original infection. We report a case of primary and recurrent herpes simplex type 1 infection with disabling causalgia in a licensed practical nurse resulting from a bite wound received from a child hospitalized with pneumonia.

In 1972 the Council of Europe, in which most of the Western European countries are represented, adopted a resolution aimed at the improvement of hospital hygiene and the promotion of the prevention of nosocomial infections. The member states were invited to take the required measures, but each country was free to implement the resolution according to its own needs and particularities. In Belgium, the first legal regulations were issued in 1974—every hospital was obliged to set up a committee for hospital hygiene.

Although similar regulations were issued in most other member states. the actual infection control policies adopted can vary. This article highlights some of the particularities for Belgium.

Protozoans of genus Cryptosporidium cause infections of the mucosal epithelium of a variety of animals, including humans. Infections by these coccidian parasites were once considered rare in animals. In humans, infections were thought to be the result of an opportunistic occurrence in immunosuppressed persons. Recently however, the concept of this intracellular protozoan parasite has changed markedly in that this parasite is now thought to be an important cause of widespread gastrointestinal (GI) illness commonly seen in several species, including humans. Infections in animals are common in newborn livestock and often are fatal. At least one species of this protozoan genus may cause mild to severe diarrhea in immunocompetent humans; this diarrheal illness may last from several days to a month or more. In immunosuppressed persons seen with acquired immunodeficiency syndrome (AIDS), cryptosporidiosis may cause a prolonged life-threatening diarrheal illness.” Recent descriptions of respiratory and biliary infections by Cryptosporidium species demonstrate that this parasite is not confined to the GI tract of immunosuppressed persons. Unfortunately, antiprotozoan therapy for cryptosporidiosis is ineffective. Persons with normal host defenses or those with restored immune balance are able to control the infection.

Our earliest memories include the games played with friends and parents, sometimes for fun, sometimes for education. Similarly, the roots of decision analysis can be traced to game theory. Game theory is the study of probabilities and outcomes that occur when two or more players interact in a fixed setting. Although not widely applied to health care, an understanding of game theory is fundamental to decision analysis.

We have all attempted game theory at an informal level. In a game of chess, players try not only to see which move is best, but also to predict how an opponent will react to the move. In Monopoly, a player might have to decide if it is profitable to buy Boardwalk if he or she does not own Park Place. In the latter situation, the player must estimate the probability that the random role of the dice will enable him or her to land on Park Place before his or her opponents or that an opponent would not elect to buy the property if given the opportunity.