The cumulative risk of human immunodeficiency virus (HIV) infection over a healthcare career has rarely been estimated, but is more relevant to the description of an occupational hazard than the risk of seroconversion from a single exposure. We describe a model for assessing the individualized risk for HIV infection after multiple potential exposures over many years for surgeons and other operating room personnel, a high-risk group. For the average surgeon operating over a 30-year career on patients with an HIV seroprevalence of 0.01, the cumulative risk is estimated at 1%. The same surgeon operating on patients with a seroprevalence of 0.10 has an estimated cumulative risk of 10%. These risks may vary dramatically depending on the assumed rate of skin punctures during surgery. Healthcare workers need to be aware of the cumulative risk from multiple exposures to infectious blood and body fluids, to follow proposed suggestions for the reduction of percutaneous blood exposures and to assist in developing new technology to further reduce these risks. Failure to protect these professionals could result in the reduction of services for the approximately 1 to 1.5 million HIV-infected persons in the United States.

The reported prevalence of nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) by hospital personnel averages 2.5%. From August 1985 to September 1987, 155 patients at our Veterans' Affairs Medical Center (VAMC) were colonized or infected with MRSA. In December 1986, only two (2.1%) of 94 healthcare workers were identified as nasal carriers. Prompted by a sharp increase in the number of patients with MRSA in early 1987, contact tracing identified 450 employees, of whom 36 (8%) were nasal carriers. Thirty-five percent of surgical residents (7 of 20) were nasal carriers. Prior to being identified as a nasal carrier, one surgical resident was associated with the inter-hospital spread of the VAMC MRSA strain to the burn unit of the affiliated university hospital. Three family members of two employee carriers were also found to harbor the epidemic strain. All 36 carriers were decolonized with various antimicrobial combinations. Vigorous infection control measures were effective in controlling the epidemic. The frequency of MRSA carriage by hospital personnel at our medical center during the epidemic proved higher than previously appreciated. Thus, healthcare workers may comprise a sizable MRSA reservoir. During an MRSA epidemic, infection control should attempt to identify and decolonize this hospital reservoir, as these individuals can disseminate MRSA both within the hospital as well as into the community.

The first two articles in this series reviewed the reasons for widespread acceptance of surveillence and control methods in hospital infection control programs, and discussed important factors contributing to the successes and failures in applying this approach to noninfectious nosocomial events. The quality assurance program ‘targets of surveillence” identified in these articles are referred to as “quality indicators” by other authors and have been defined as “a quantitative measure that can be used as a guide to monitor and evaluate the quality of important patient care and support service activities.” This article highlights those attributes of quality indicators that should be critiqued prior to implementation in a patient care review environment and discusses methods of improving quality indicator performance with ongoing monitoring and evaluation.

Methicillin-resistant Staphylococcus aureus (MRSA) has been an endemic nosocomial pathogen at the VA medical center (VAMC) in Providence, Rhode Island since 1981. From 1985 to 1987, more than 30% of all unique S aureus isolates were methicillin resistant. To evaluate the frequency of acquisition of MRSA isolates by healthcare workers, we compared the antimicrobial susceptibility patterns, multilocus enzyme genotypes and plasmid profiles of isolates recovered from nasal and hand cultures from VAMC nurses and house staff on rotation at the VAMC with those of clinical isolates from patients at the VAMC and four other affiliated hospitals. Fifty-six percent of ward nurses cultured (n = 112) were colonized with S aureus, of which 65% was methicillin resistant. Six isolates of MRSA were identified on the initial culturing of house staff (n=65); 16 MRSA isolates were recovered at the end of a four-week rotation (p<.02). Phenotypic and genotypic analyses demonstrated that numerous distinct MRSA strains were recovered in the study period. The incidence of MRSA among clinical isolates at the VAMC and affiliated institutions was remarkably constant throughout the three-year study period. Moreover, despite regularly sharing resident physicians, interns and medical students, MRSA isolates were uncommonly recovered at the other university-affiliated hospitals. Our study failed to reveal evidence of significant interhospital transmission of MRSA isolates by healthcare workers. While healthcare workers may contribute to the dissemination of MRSA within institutions, they appear to be less important in spreading MRSA between institutions (Infect Control Hosp Epidemiol. 1990;11:479-485.).

Most intravascular device-related infections are caused by staphylococci, presumably because the microbial flora of the skin surface is the major reservoir of microorganisms colonizing and infecting percutaneously-inserted intravascular cannulas.

Recently, we observed two episodes of group A streptococcal cellulitis and bacteremia related to infection of the subcutaneous tunnel of indwelling catheters. This prompted us to review our experience with nosocomial and community-acquired group A streptococcal bacteremias for the past year, and we identified a third catheter-related case. In our ongoing prospective surveillance of nosocomial bacteremias, we have not previously identified any other cases of intravascular catheter-related bacteremia caused by group A streptococcus. Likewise, in two large prospective studies of Hickman and Broviac catheter-related infections, the investigators did not report infections caused by this organism.

Oxygen wall humidifiers are used regularly in the hospital. Although the humidifiers in mechanical ventilators have been extensively investigated, oxygen wall humidifiers are often neglected in the literature. Both reusable and disposable humidifiers are available, and according to the recommendation from the Centers for Disease Control (CDC), both types of humidifiers are acceptable. For reusable humidifiers however, it is crucial that they be washed daily as recommended and that water left in the reservoir be discarded before refilling.

In the CDC guideline for the prevention of nosocomial pneumonia, it is stated that disposable humidifiers for wall oxygen outlets “may be safe for long periods.” However, studies that actually assess the efficacy of these humidifiers on patients are rarely reported, and, to the best of our knowledge, only one such study has been published.

The emergence and widespread distribution of the acquired immunodeficiency syndrome (AIDS) have clearly signaled the most important epidemic of the 20th century. In responding to this epidemic in a compassionate and rational voice, the infection control practitioners-physicians, nurses and technologists-have played a crucial role in healthcare delivery. A great deal of information has resulted from numerous scientific studies. Because of the volume and complexity of data currently being generated, the Editorial Board of Infection Control and Hospital Epidemiology has invited Dr. David K. Henderson to initiate a new column on AIDS. He is an internationally recognized expert who has agreed to edit this column for the journal. We welcome your responses, and encourage your submissions to Dr. Henderson in this area.

Between June 1985 and March 1986, 14 cases of severe nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infection, including septicemia, were observed in the intensive care unit (ICU) of a 400-bed cancer reference center. Simple control measures including contact isolation of colonized patients and reinforcement of handwashing practices among personnel were followed by a sharp decrease in the rate of infection and colonization. An epidemiological investigation showed that a single serophage variant MRSA strain was involved; peak incidence of infection was 17 per 100 ICU patient discharges; the index case was identified as a patient admitted from another hospital and the epidemic strain was then transmitted from patient-to-patient in the ICU; risk factors for acquiring infection were length of prior hospitalization, invasive procedures and number of antibiotic treatments; dissemination of the strain to other wards was only anecdotal. These results stress the effectiveness of simple measures to control outbreaks of MRSA nosocomial infections even in immunocompromised cancer patients.

Of the more than 200,000 patients who undergo open heart surgery annually in the United States, 2% to 10% will develop a post-operative infectionrelated to their surgery. The economic impact of such infections on hospitals under the prospective payment system is unclear. To study the effect of such infections on hospital costs and reimbursement patterns, we compared case patients with controls of similar age, sex, urgency of surgery and type of surgery. The postoperative stay for cases was significantly longer than for matched controls (26.8 days and 8.3 days, respectively; p = .0002). The mean hospital cost for case admissions ($25,957) was twice as high as for control admissions ($12,795) (p = .0002). Cases resulted in an average net loss to the hospital of $2,344 per patient, while controls yielded an average net gain of $3,196 per patient (p = .02). We conclude that hospitals have substantial financial incentives tominimize the incidence of postoperative wound infections associated with open heart surgery.

This issue of the journal marks the introduction of a new column “Emporiatrics”: the study of diseases in travelers. The editorial board considers this an important aspect of the expanding role of the physician epidemiologist and the infection control practitioner. We plan to put the common issues into a perspective that will be useful for those who are frequently asked questions about the prevention and control of illness in travelers. We hope this will fill the current void and we invite your response in letters to the editor.

How do you envision your ideal vacation? Relaxing on a sunny beach to watch the sun sparkle on the water? Treading ancient streets of living history? Hiking peacefully over hill and dale? Or are you more adventurous; the kind of person who would consider Indiana Jones an ideal traveling companion? The siren call of travel draws us and our patients to exotic places filled with excitement-and disease. Indeed, many of the epidemics that first gave birth to epidemiology are still in full swing in developing countries. To protect the traveler from illness and to minimize the importation of serious diseases, emporiatrics (from the Greek: emporos [one who goes on shipboard as a passenger] and iatrke [medicine]) has been developed.

Why discuss acquired immunodeficiency syndrome (AIDS) in “Topics in Long-Term Care”? It is not because there are large numbers of frail elderly patients afflicted with AIDS, although some have estimated that by 1990 there may be as many as 27,000 AIDS cases in persons over 50, and 1,100 cases in persons over 70 years of age. Nor is it the fact that large numbers of patients in long-term care facilities (LTCFs) may be infected with the human immunodeficiency virus HIV). Rather, it is the growing awareness that hospitals provide only a limited portion of the continuum of care for AIDS patients. In addition, the chronically ill and often severely disabled AIDS patient frequently requires more care than the limited community-based resources can provide. Nursing homes, with their tradition of skilled nursing care targeted toward the chronically ill and older patient, could provide an important missing component to the chronic care needs of younger AIDS patients.

Glove-wearing attitudes of 375 physicians, representing 56% of all physicians surveyed, were ascertained. Although the majority were comfortable with their current glove use, 33% preferred wearing them more frequently. The most common reasons for not wearing gloves were a low likelihood of disease transmission and fear of offending patients. Many physicians felt that more frequent glove use in examining human immunodeficiency virus- (HIV)-positive patients might reduce rapport and diminish the adequacy of physical examination procedures, but only 11% felt that increased glove use would compromise overall care of HIVpositive patients. With regard to all patients, 33% felt that increased glove use in examinations would compromise care. Additionally, 56% of physicians stated that they were somewhat concerned about HIV infection. Glove-wearing preferences were significantly associated with greater concern about infection, a younger age and more frequent exposure to blood and body secretions. Contact with high-risk patient groups was not associated with glove-wearing preferences.

The litany of scatalogical euphemisms describing travelers’ diarrhea sounds more like a line-up for a horse race: turista, Aztec two-step, Ramses’ revenge, Casablanca crud, Bombay runs, Delhi belly and Tokyo trots. While the winner in this race is uncertain, the loser is the poor traveler whose most memorable image of an expensive, exotic vacation was a desperate search for bathrooms or confinement to a hotel room while others were enjoying the sights. Though self-limited and relatively mild compared to some diseases acquired abroad, the impact of travelers’ diarrhea on the traveler should not be underestimated.