Nosocomial transmission of hepatitis A from patients to staff members is an unusual event. Recently, several cases of occupational transmission of hepatitis A to health care workers have been reported in the literature. Most of these have occurred as a result of transmission from an infected child to a staff member involved in his or her care. We report an additional case of transmission of hepatitis A from an infected adult to a staff member and review the literature regarding nosocomial hepatitis A transmission. The review emphasizes several points that nearly all instances of nosocomial transmission of hepatitis A have in common, including the role of asymptomatic infection, the timing of hospitalization, and the fact that index patients often have an underlying illness that obscures the early diagnosis of hepatitis A. In addition, several other areas of controversy with respect to hepatitis A are discussed.

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.

The recent approval of ribavirin aerosol for the treatment of severe respiratory syncytial virus (RSV) in infants and young children is a significant addition to the antiviral drugs available today. When administered as an aerosolized form by face mask or mist tent for 20 to 21 hours per day, ribavirin effectively decreases the symptoms of RSV infection and the shedding of RSV virus.

Studies of other viral infections such as viral hepatitis, influenza A and B, Lassa fever, genital herpes, and herpes zoster have demonstrated promising, but inconclusive results. Further studies are needed to justify ribavirin therapy for these indications.

Since 1981, the Centers for Disease Control (CDC) has been publishing Guidelines for the Prevention and Control of Nosocomial Infections as a useful reference tool in infection control. The extent to which practices recommended by CDC to reduce hospital-acquired infections have been successfully diffused and adopted were evaluated in a stratified random sample of 445 US hospitals that were sent a questionnaire in 1985. The data suggest that over 84% of infection control practitioner respondents (78% response rate) are aware of each guideline, although small hospitals (<50 beds) are least likely to be aware of the guidelines or to have reviewed them thoroughly. Adoption of the recommendations remains far from universal, ranging from 23% to 75% for 16 specific recommendations investigated. Smaller hospitals were significantly less likely than large hospitals to have adopted each suggested policy. Recommendations that carried Category I rankings were more likely to be adopted, as were those procedures that had cost-savings implications.

The Centers for Disease Control's Study on the Efficacy of Nosocomial Infection Control (SENIC) showed that infection surveillance and control activities are associated with a decrease in nosocomial infection rates. Moreover, the intensity of activity correlated with the magnitude of the fall in infection rates. These results, plus the guidelines of regulatory agencies, mandate that infection control programs conduct surveillance activities. However, absolute standards for the content and nature of surveillance programs have not been established, and many descriptions of different types of surveillance programs are available. In this primer, we describe the considerations involved in development of a surveillance program with emphasis on issues concerning data collection.

Langmuir considers surveillance when applied to disease as meaning the collection of data, the analysis of those data, and the distribution of the resulting information to those needing to know. The definition implies that surveillance is observational and that surveillance activities should be clearly separated from other related activities such as control measures. The latter activities, including their initiation, approval, and funding, are administrative matters underpinned by a scientific base that are undertaken by the recipients of the surveillance data and their analyses. They should be clearly separated from surveillance activities per se. There is also the implication that action results from surveillance; surveillance without action should be abandoned.

Between November 1982 and July 1984, five patients at a 110-bed pediatric hospital were diagnosed with invasive filamentous fungal infection; three had invasive aspergillosis (IA) and two had invasive zygomycosis (IZ). All five had underlying hematologic malignancy (HM). In a case-control study, these five HM patients (cases) were compared to 10 autopsied HM patients without evidence of aspergillosis or zygomycosis (controls). Cases and controls did not differ in underlying disease or in the degree of immunosuppression, as measured by duration of granulocytopenia and number of platelet transfusions. However, case-patients were more likely than controls to have been hospitalized during the construction of a hospital addition (p<0.02, Fisher's exact test [FET]). Four (80%) of five HM patients autopsied during the period of construction had IA or IZ compared with one (5%) of 21 autopsied before construction began (p=0.001, FET). These findings suggest that, in a population of comparably immunosuppressed patients, construction activity may represent an independent risk factor for IA or IZ. Hospitals caring for such patients should take precautions which minimize exposure of these patients to construction or renovation activity.

Six cases of acute Staphylococcus aureus mediastinitis after median sternotomy were reported. Five resulted from an asymptomatic disseminator of 5 aureus present in the operating room. Each case was characterized by an acute bacteremic phase, occurring after a mean interval of 8.2 ± 1.7 days after the surgical procedure; within 24 to 36 hours all patients had a temperature above 39°C, toxic appearance, and marked leukocytosis. Pericicatricial inflammation was moderate, instability of the sternum was present in only two patients, and chest roentgenogram was not helpful in making an early diagnosis. No risk factor for mediasinitis in connection with the perioperative or postoperative periods was noted in cases compared with a control group of 103 patients. All strains of S aureus were susceptible in vitro to the antibiotic regimen used in prophylaxis. All patients underwent early surgical reopening of the mediastinum within 47 ± 15 hours after the first sign of acute mediastinitis. Mediastinal debridement and continuous irrigation-suction with dilute povidone-iodine solution were associated with intravenous antistaphylococcal therapy for a period of four to six weeks. All patients survived and no recurrence was observed, a finding we think due to early diagnosis and aggressive medicosurgical therapy.

Most information in hospital epidemiology comes from observational studies of hospitalized patients rather than planned experiments, and in such observational studies the characteristics of study patients may vary widely, even within a single hospital. Any comparison between hospital populations will usually contain additional, unintended contrasts among patients with varying degrees of health. Adult patients, for example, may have vastly different underlying diseases, and infants may be of substantially different birth weights. We used both underlying disease and birth weight as indices of the basic severity of illness in order to adjust for confounding by differences in underlying disease in reanalyses of several published studies. We give an example in which differing birth weights among groups of infants compared artifactually double the apparent effect of nosocomial infections as a cause of mortality, and another example in which differing degrees of severity of underlying illness artifactually halve the apparent effect of appropriate antibiotics in preventing death from bacteremia with gram-negative bacilli. We describe simple intuitive methods based on stratification, adapted from chronic disease epidemiology, to remove confounding effects during analyses.

A simple and inexpensive method to assess the contamination of environmental surfaces and the associated potential risk of exposure of autopsy room personnel to potentially hazardous materials is described. Blood was selected as a marker of contamination and HEMASTIX® reagent strips were used to determine its presence on selected surfaces. The surfaces selected for examination typically do not come into direct contact with cadavers or tissues during a routine postmortem examination and thus are not included in routine cleanup. We documented the presence of blood on a variety of environmental surfaces in the autopsy suite and suggest that the contamination resulted from a breakdown in good work practices, most probably the indiscriminate handling or touching of materials and equipment with contaminated gloves. The risk of exposure to blood by the indirect route was deemed significant. The results of this study underscore the importance of establishing and consistently following good work practices and cleanup procedures to minimize the risk of exposure to blood before, during, and after postmortem examinations.

The purposes of this study were to assess the effect of two quantities (1 mL or 3 mL) of four different handwashing products on reductions in log colony-forming units (CFU) from the hands and to determine the amount of liquid soap used for handwashing by personnel in one hospital. First, 40 subjects were assigned by block randomization to one of four handwashing products (4% chlorhexidine gluconate in a detergent base, two alcohol hand rinses, and a liquid, nonantimicrobial soap) to be used in either 1 mL or 3 mL amounts per wash. Each subject washed his or her hands 15 times per day for five days. After one and five days of handwashing there were significant reductions over baseline in log CFU between handwashing products (P<0.001). Additionally, subjects using 3 mL of antiseptic soap had significantly greater reductions in log CFU than those using 1 mL (P<0.001). Among subjects using control liquid soap there was no such dose response. Second, a survey of 47 members of a hospital nursing staff from nine specialty areas and ten individuals in the general population was conducted to measure amounts of two liquid soaps used for handwashing. Amount of soap ranged from 0.4 to 9 mL per handwash. Personnel working in clinical areas where patients were at high risk for nosocomial infection used significantly more soap than did others (P<0.05). We conclude that quantity of soap used for handwashing is one variable influencing the microbial counts on hands, and that the quantity of soap used by health care personnel varies considerably.

Acute gastroenteritis is a public health problem of global proportions. Worldwide there are more than 700 million cases of diarrheal disease resulting in around 5 million deaths. In the United States the incidence of acute gastroenteritis is 11% each year and it is second only to respiratory infection as a contagious disease in the American family. The etiology of this common syndrome is obscure but it is becoming apparent that much of this disease is viral in origin. Recent research has elucidated a growing number of human pathogens: Norwalk-like agents, adenoviruses, caliciviruses, and astroviruses. The best understood of these agents are among the earlier discoveries in gastrointestinal virology—the rotaviruses. The study of these agents has greatly advanced our understanding of viral gastroenteritis.

The risk of nosocomial pneumonia following emergency or urgent endotracheal intubation was studied prospectively. Pneumonia developed in 35 of 78 (45%) patients within three days of intubation. No differences in age, sex, underlying illness, respiratory infection, or antibiotic use were found between those with or without pneumonia. There were also no differences in the frequency of complications occurring during intubation. Patients developing pneumonia tended to have the same organisms isolated from the sputum at the time of intubation and at the time of diagnosis of pneumonia (9 of 20 were identical, 5 differed by a single organism). Sputum cultures taken at the time of intubation were helpful in predicting the subsequent pathogens in patients who developed pneumonia. There were no differences in mortality between patients with (29%) and without (28%) pneumonia. Emergency endotracheal intubation appears to contribute to the overall incidence of nosocomial pneumonia.

Prior to offering the hepatitis B (HB) vaccine, a prescreen for hepatitis B virus (HBV) antibodies was conducted in a 565 bed hospital in Pasadena, California. Antibodies to the hepatitis B virus were detected in 14.5% of 1,745 employees tested. There was a significantly higher prevalence in those with a previous history of hepatitis, blood transfusions, exposure to nee-dlesticks, number of years in the same occupation, and in the same hospital work area. Employees of Asian extraction (33.3%) and blacks (23.1%) had a higher prevalence of antibodies to the hepatitis B virus than Hispanics (13.7%) and whites (10.2%). Anti-HBs was detected in 92.6% of 865 employees who received three doses of the hepatitis B vaccine. Only 28.6% of nonresponders receiving a fourth dose of hepatitis B vaccine produced anti-HBs. The nonresponders to the HB vaccine were older (average age 64.9 years) when compared to the responders (average age 37.5 years), and more males failed to produce anti-HBs after vaccination than females. Hepatitis B vaccination of the majority of individuals with either “low level” anti-HBs alone or anti-HBc alone did not elicit an anamnestic response after one dose of vaccine, implying that these “low level” antibodies are nonspecific and do not represent antiviral antibodies. Adverse reactions to the hepatitis B vaccine were minor and included a flulike syndrome, sore arm, and rash and swelling at the injection site. The reasons for nonparticipation were obtained from 179 individuals, and the main issue was concern about safety of the hepatitis B vaccine.