The contribution of epidemiology to quality assessment and monitoring: a clear enough subject. But as I approached it, it slipped into ambiguity and confusion. What was quality assessment? What was monitoring? For that matter, what was quality? And the meaning of epidemiology was the deepest mystery of all.

I must begin by defining my terms. Quality shall be taken to mean making a judgment on the goodness of healthcare, based on one or more of the following: the expected or realized ability of the care to achieve the greatest improvement in health that the current science and technology of healthcare can achieve; acceptability to patients (including their families); and acceptability to the community (or the society at large). There are three ways in which we can find out if healthcare has been good in these respects. First is the examination of the process of care, which I take to mean the degree to which what is done for and by patients corresponds to what is known or believed to be most effective in improving health, and most acceptable to patients and to society. Second is the examination of the outcomes of care, meaning the degree to which the care provided is acceptable and has attained achievable improvements in health. Third is the examination of structural attributes, meaning the degree to which the physical and organizational settings in which care is given are conducive to the kind of care that can be expected to improve health and to be acceptable to patients and to the community. So much for quality assessment.

We employed a questionnaire to survey 334 registered nurses regarding their knowledge, perceptions and vaccine acceptance for Hepatitis B virus (HBV) infections. The study population was those persons working in areas considered at high-risk for contracting HBV. The nurses were asked to provide information regarding blood and body fluid exposures and the reporting of these exposures. The questionnaire was completed by 169 nurses (50.6%). Less than half of the respondents (42%) had been vaccinated. We found that 13 of 14 black nurses, compared to 85 of 154 nonblack nurses, had not been vaccinated (p < .01). No other demographic differences between recipients and nonrecipients were noted. Partially or totally incorrect answers regarding transmittal knowledge were given by 108 of 160 (68%) respondents. Reasons for failure to be vaccinated were varied. Fear of side effects of the vaccine, contracting AIDS or hepatitis from the vaccine, or doubt of efficacy of the vaccine were cited by 50 of 88 (58%) respondents as reasons for not being vaccinated. Inability to schedule an appointment or unawareness of the vaccine's availability were expressed by 23% and 17% of the individuals, respectively. Our data allow us to conclude that to improve vaccination compliance, the vaccine must be made more readily available, possibly through workplace on-site administration. Additionally, a concerted effort to educate our staff regarding HBV with particular emphasis on minorities is needed.

Factors predisposing to clinically significant nosocomial infection with Xanthomonas maltophilia were examined in a matched case-control study using multivariate techniques. Sixteen cases occurred among cancer patients in a six-month period, including an apparent cluster of three cases in an intensive care unit. These infections were unusually serious; eight patients had disseminated infection caused by X maltophilia and six died as a result of their infections.

Among the 64 factors that were examined, therapy with broad-spectrum antibiotics and central venous catheterization were found to significantly increase susceptibility to infection. Therapy with imipenem was more than ten times more frequent among cases than among controls (p < .001). All fatal infections occurred in patients who had received imipenem, including two patients who died before the organism could be identified and appropriate therapy instituted.

Infection with X maltophilia should be suspected in patients who develop superinfection while receiving imipenem, and prompt therapy should be instituted to improve chances of survival. Because a common environmental source of X maltophilia was not identified, further study is necessary to determine specific preventive measures.

To test the effects of four surgical scrub products on colonizing hand flora, 60 healthy adult volunteers were assigned by block randomization (12 subjects per group) to use one of the following formulations: 70% ethyl alcohol with 0.5% chlorhexidine gluconate (ALC); a liquid detergent base containing 1% triclosan (TRI); a liquid detergent base containing 4% chlorhexidine gluconate (CHG); a liquid detergent base containing 7.5% povidone-iodine (PI); or a nonantimicrobial liquid soap (control). Using standard protocol, subjects performed a surgical scrub daily for five consecutive days. Hand cultures were obtained at baseline and on test days 1 and 5 immediately after the scrub and following four hours of gloving. After the first and last scrubs, ALC, CHG and PI resulted in significant reductions in colonizing flora when compared to the control. Additionally, by day 5 ALC was associated with an almost 3-log reduction as compared to an approximate 1.5-log reduction for CHG and PI and less than a l-log reduction of TRI and the control (p = .009). After four hours of gloving on both days 1 and 5, microbial counts on hands of subjects using ALC, TRI and CHG were significantly lower than counts for the control (p < .001), whereas there was no significant difference in counts between the PI and control groups (p = .41). Skin assessment by study subjects rated products from least to most harsh as follows: control, TRI, CHG, ALC and PI (p = .00001). It was concluded that ALC could be an efficacious and acceptable alternative for surgical scrubbing.

In the prevention of nosocomial infection, it is important to understand its epidemiology and pathogenesis. Only then are we able to formulate appropriate preventive methods for the various types of infection. However, in recent years there has been growing recognition that the implementation of preventive measures is often only possible when behavioral change occurs. In fact, an appreciation of behavioral change principles is critical for infection control nurses (ICNs) because most preventable nosocomial infections are related to inappropriate patient care practices. Procedures for prevention are often simple (e.g., washing hands), but compliance can be extremely difficult to enforce in the hospital.

In the normal individual, about 100 billion polymorphonuclear leukocytes (neutrophils) enter the bloodstream daily from the bone marrow. About half of the intravascular neutrophils are adherent (marginated) to the endothelium of small vessels and the remainder are circulating. Without unusual disturbances, the half-life of the intravascular neutrophil is about six hours. Although the number of circulating neutrophils seems enormous, it represents only 5% of the total body content of these cells, the major portion residing in the bone marrow.

It is remarkable that quantitation ofpolymorphonuclear leukocytes in a drop of peripheral blood can be highly predictive of an individual's resistance and response to infectious diseases, especially those caused by bacteria. Neutrophil activity is complex and its role in host defense is dependent upon factors other than quantity. Nevertheless, when the absolute neutrophil count is maintained at values less than 1000/cu mm, increased susceptibility to infection occurs and is at a rate that is inversely proportional to the neutrophil count. When the count is decreased to values of 500 neutrophils/cu mm or less, the frequency of serious bacterial infection reaches a point where special attention must be directed to the patient at the earliest sign of infection.

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.