Showing papers in "Infection Control and Hospital Epidemiology in 1985"

Habitat association of Klebsiella species.

Abstract: The genus Klebsiella is seemingly ubiquitous in terms of its habitat associations. Klebsiella is a common opportunistic pathogen for humans and other animals, as well as being resident or transient flora (particularly in the gastrointestinal tract). Other habitats include sewage, drinking water, soils, surface waters, industrial effluents, and vegetation. Until recently, almost all these Klebsiella have been identified as one species, ie, K. pneumoniae. However, phenotypic and genotypic studies have shown that “K. pneumoniae” actually consists of at least four species, all with distinct characteristics and habitats. General habitat associations of Klebsiella species are as follows: K. pneumoniae—humans, animals, sewage, and polluted waters and soils; K. oxytoca—frequent association with most habitats; K. terrigena— unpolluted surface waters and soils, drinking water, and vegetation; K. planticola—sewage, polluted surface waters, soils, and vegetation; and K. ozaenae/K. rhinoscleromatis—infrequently detected (primarily with humans).

The Epidemiology of Nosocomial Infections Caused by Klebsiella pneumoniae

Abstract: Klebsiella pneumoniae causes serious epidemic and endemic nosocomial infections We conducted a literature review to characterize the epidemiology of epidemic K pneumoniae outbreaks Eighty percent of the outbreaks (20/25) involved infections of the bloodstream or urinary tract Person-to-person spread was the most common mode of transmission, and nearly 50% of the outbreaks occurred in neonatal intensive care units No one serotype predominated, and no association was found between serotype and either the site of infection or antimicrobial susceptibility pattern We used data reported to the Centers for Disease Control (CDC) by hospitals participating in the National Nosocomial Infections Study (NNIS) to describe the epidemiology of endemic K pneumoniae infections In the 8-year period from 1975 through 1982 the nosocomial K pneumoniae infection rate was 167 infections per 10,000 patients discharged The rate of infection at medical school-affiliated hospitals was significantly greater than at nonaffiliated hospitals; furthermore, the rate of infection at large affiliated hospitals was greater than at small affiliated hospitals The rate of infection varied by service, with the highest rate found on the medicine service During the 8-year period, 184 deaths were caused by nosocomial K pneumoniae infections (184 deaths/16,969 infections, case-fatality ratio 11%), with higher ratios in pediatrics (5%) where there was a 12% mortality in children infected with an aminoglycoside-resistant strain

Occupational risk of hepatitis B infection in hospital workers.

Abstract: To estimate the risk of hepatitis B virus (HBV) infection among hospital workers, we measured the prevalence of HBV infection in employees in five hospitals in different parts of the country and examined the effect of occupational and non-occupational factors on HBV prevalence. Among 5,697 persons studied, serologic markers of HBV infection were found in 807 (14%). Prevalence of infection was strongly related to race (Asian greater than Black greater than White), sex (male greater than female) and increasing age. Risk related to health occupation, studied by examining the change in HBV prevalence with duration in occupational group, was most strongly correlated with frequency of contact with blood during work. Workers having frequent blood contact had the highest estimated infection rate (1.05 per 100 person-years) and those with moderate contact an intermediate infection rate, compared to a negligible infection rate in workers with no blood contact. Frequency of needle accidents had an independent, positive effect on HBV infection rates, while degree of patient contact had no effect. Infection risk was uniform among all hospitals for groups with frequent blood contact. Among different occupation groups, risk of HBV infection also correlated closely with degree of blood-needle contact during daily work. This study provides a general approach to assessing risk of HBV infection in hospital personnel, and indicates that risk may be most easily estimated by quantitating degree of blood-needle contact during daily work.

Evidence for the non-infectious etiology of early postoperative fever.

Abstract: In a prospective study of infections in 871 general surgery patients, we identified 81 patients who developed unexplained postoperative fevers. The majority of these episodes (72%) occurred early (within the first 48 hours) following surgery. Patients who developed early, unexplained fevers differed significantly from patients who developed documented postoperative infections. Patients with unexplained fevers were younger, had less severe underlying disease and underwent less extensive surgeries than patients who subsequently developed infections. In these respects, they were more similar to non-infected, non-febrile patients. We concluded that episodes of early, unexplained postoperative fever occur frequently in a wide range of general surgery patients. Most of these episodes are non-infectious in origin. Patients with early postoperative fevers should be evaluated to identify any obvious sources of infection. If no focus is identified, empiric antibiotic therapy should not be initiated nor should prophylactic antibiotics be extended for prolonged durations. Unexplained fevers will resolve in time without specific therapeutic interventions.

Epidemiology and clinical significance of blood cultures positive for coagulase-negative staphylococcus.

Abstract: Coagulase-negative staphylococci are frequently isolated from blood cultures. As these organisms may occasionally cause serious disease, differentiating bacteremia from contamination is very important but often difficult. Over a 26-month period, of 29,542 blood cultures processed at the University of Michigan Medical Center, 2,875 (9.7%) were positive, and of those, 694 (from 527 patients) grew coagulase-negative staphylococci. Isolates from the 439 patients with only one blood culture positive for coagulase-negative staphylococci and those from the 18 patients with two positive cultures 10 days or more apart were deemed contaminants. Review of the records of the remaining 70 patients with multiple isolates indicated that 33 had had an episode of true bacteremia, 29 (87.9%) of which were associated with intravascular catheters or prosthetic valves. Overall, 85% of all coagulase-negative staphylococci isolated during the study period were judged to be contaminants. Seventy-one percent of the blood cultures drawn during the episodes of bacteremia were positive for coagulase-negative staphylococci as opposed to only 34% in the patients with contaminated cultures (p less than 0.01). Moreover, coagulase-negative staphylococci grew in both aerobic and anaerobic bottles in 85% of blood culture sets drawn during episodes of bacteremia, but in only 30% of the cultures thought to be contaminated (p less than 0.001). Growth of coagulase-negative staphylococci in less than 48 hours was also significantly associated with bacteremia (p less than 0.01). Antibiotic sensitivity patterns were not useful in differentiating bacteremia from contamination.(ABSTRACT TRUNCATED AT 250 WORDS)

Nosocomial fungal infection during hospital renovation.

Abstract: Nosocomial fungal pulmonary infections (Zygomycetes, Aspergillus sp.) developed in two premature infants in a special care unit (SCU) adjacent to an area of renovation. Inspection showed that inadequate barriers permitted the passage of airborne particles between the two areas, and cultures confirmed a significantly higher (p≤0.05) density of mold spores in the SCU (0.88 cfu per hour per settling plate) compared to a construction-free comparison area (0.22 cfu per hour per settling plate). The major source of mold was the dust above the hospital's false ceiling. In another construction area, impervious barriers were shown to effectively restrict the dispersal of mold. Our experience adds Rhizopus to Aspergillus as a possible cause of construction-related nosocomial infection. Sporadic episodes will continue to occur until the hazards of renovation are appreciated and effective preventive measures are routinely instituted.

Handwashing and skin. Physiologic and bacteriologic aspects.

Abstract: Handwashing practices are often based on tradition and belief. To develop sound rationale for handwashing practices, the physiologic and bacteriologic effects of handwashing must be examined. The purposes of this article are to review the three major microenvironments of the skin with their bacterial flora, to discuss physiologic and bacteriologic characteristics of the skin with particular reference to handwashing, and to describe current handwashing recommendations and practices.

An outbreak of invasive aspergillosis among allogeneic bone marrow transplants: a case-control study.

Abstract: Between April 1982 and March 1983, 10 of 26 (38.4%) allogeneic bone marrow transplant recipients housed on a newly opened bone marrow transplant unit developed invasive aspergillosis. By contrast, between September 1977 and March 1982, only 3 of 46 (6%) transplant recipients developed invasive aspergillosis. A case-control study to identify host factors related to Aspergillus infection found that aspergillosis was more common in patients with chronic myelogenous leukemia and aplastic anemia, older patients, patients having cytomegalovirus disease, patients who experienced prolonged granulocytopenia, patients conditioned with ara-C (100-200 mg/day), and patients who received longer duration of antimicrobial therapy. A series of logistic regression analyses revealed that underlying disease was the single best predictor of Aspergillus infection. This study demonstrates that underlying disease is an important risk factor for aspergillosis and that special measures may be warranted when transplanting certain patients.

The relationship between intravenous fluid contamination and the frequency of tubing replacement.

Abstract: Medical patients receiving IV therapy were randomly assigned to one of two IV tubing change groups. One group had a 48-hour tubing change and the other had no tubing change for the remainder of the cannula placement. A daily IV fluid specimen was processed microbiologically. To complete the study, a minimum of 3 continuous days of therapy and three fluid specimens was required. There were two contaminated specimens, one in each tubing change group. The contamination rate in the 48-hour change group was 0.87% and 0.96% in the no change group. The rate difference of 0.09% has a 95% confidence interval (-0.035 to +0.036) which includes zero. Survival analysis also revealed no significant difference in the cumulative probability of survival, however the mean duration of continuous tubing use of 4.3 days in the no change group and 1.8 days in the 48 hour change group were significantly different (p less than 0.05). The cumulative probability of surviving contamination free was 0.988 in the 48-hour group and 0.987 in the no-change group. We conclude that it is safe to change IV tubing at intervals up to but not exceeding 4 days.

Klebsiella pneumoniae: selected virulence factors that contribute to pathogenicity.

Abstract: Klebsiella pneumoniae infections occur in humans of all ages, however the highest risk groups appear to be infants, the elderly and the immunocompromised. One or more virulence factors may contribute to pathogenicity in humans. In this article we review three factors that may mediate virulence: cell wall receptors, capsular polysaccharide, and endotoxin. First, the presence of cell wall receptors enables K. pneumoniae to attach to the host cell, thereby altering the bacterial surface so that phagocytosis by polymorphonuclear leukocytes and macrophages is impaired and invasion of the non-phagocytic host cell is facilitated. Second, invasion of the host cell is also facilitated by the large polysaccharide capsule surrounding the bacterial cell; in addition this capsule acts as a barrier and protects the bacteria from phagocytosis. Third, K. pneumoniae produces an endotoxin that appears to be independent of factors that determine receptors and capsular characteristics. Marked interspecies differences in endotoxin production may correlate with virulence. Although some or all of these factors may ultimately determine virulence, the interaction of these factors in vivo has made it difficult to assess the relative contribution of any one of these virulence factors. The pathogenic mechanisms of K. pneumoniae that ultimately determine virulence remain unclear and will require further study.

How frequent are outbreaks of nosocomial infection in community hospitals

Abstract: A statistical algorithm was used to identify potentially important clusters among nosocomial infections reported each month by 7 community hospitals. Epidemiologic review and on-site investigations distinguished outbreaks of clinical disease from factitious clusters. In 1 year, 8 outbreaks were confirmed. They involved 82 patients--approximately 2% of patients with nosocomial infections and 0.09% of all discharges. One true outbreak occurred for every 12,000 discharges--at least 1 outbreak per year for the average community hospital. Five (63%) outbreaks were recognized independently by the hospitals' infection control personnel. Four (50%) resolved spontaneously; the hospitals' own control measures were necessary in 2; and 2 resolved only after an outside investigation. Organized surveillance appears necessary to detect some outbreaks, and control measures are needed to stop many. Since, however, outbreaks account for such a small proportion of nosocomial infections, infection control programs should be sufficiently staffed and managed so that most of the effort is directed toward the surveillance and control of endemic infection problems, but with adequate resources remaining to respond to outbreaks when they occur.

A prospective study of postoperative fever in a general surgery department.

Abstract: During a 4-month period, 693 patients undergoing surgical procedures were prospectively studied to investigate the etiology of postoperative fever (greater than or equal to 38 degrees C during 48 hours or more). The overall rate of fever was similar for the three categories of surgical procedures studied (14%, 13.4% and 13.1% respectively after clean, clean contaminated and contaminated surgical procedures). No cause of fever was found in 5%, 2.7% and 1.7% of patients who underwent clean, clean contaminated and contaminated surgical procedures. Several episodes of fever were observed for 12 patients after clean surgery; for 11 of them this was due to infection. The mean interval between febrile episodes was 4.7 days. After clean wound surgery, fever documented as infectious began significantly later (2.7 vs 1.6 days) and lasted significantly longer (5.4 vs 3.5 days) than fever for which no source was determined. Only half of the infections were associated with fever.

Evaluation of H2O2 prophylaxis of bacteriuria in patients with long-term indwelling Foley catheters: a randomized controlled study.

Abstract: Since the long-term catheterized patient is at significant risk of urinary tract infection, and the catheter drainage bags of these patients are at significant risk of becoming reservoirs for nosocomial pathogens, we carried out a randomized, controlled study to determine the efficacy of intermittent drainage bag instillation of hydrogen peroxide (H2O2) in patients requiring indwelling Foley catheters for 5 days or more. Herein we report the effects of this technique on the rates of catheter and bag bacteriuria, the duration to positive culture, the temporal relationships observed, and the spectrum of organisms recovered. Bag source bacteriuria was found with the same frequency in both control and H2O2 groups. H2O2 did reduce contamination of the drainage bag but did not reduce catheter-associated bacteriuria or frequency of symptomatic urinary tract infection. Furthermore, H2O2 did not reduce the frequency of bag contamination with most of the common nosocomial urinary pathogens.

A randomized study comparing a transparent polyurethane dressing to a dry gauze dressing for peripheral intravenous catheter sites.

Abstract: We studied rates of peripheral intravenous (IV) catheter tip and insertion site colonization after randomly assigning patients to transparent polyurethane (TP) dressings (N = 316) or dry gauze (DG) dressings (N = 421). The study was conducted during both summer and fall seasons, in a facility which lacked air conditioning. All patients had a teflon plastic catheter inserted, maintained and cultured by a member of the IV therapy team; no antibiotic or antiseptic ointments were used. Colonization rates were higher in the summer than in the fall for both catheter tips (9.0% vs 3.5%, p = 0.005) and sites (21.6% vs 7.0%, p = 0.001). During the summer season, the rate of catheter tip colonization with TP dressings was nearly twice that of DG dressings (12.4% vs 6.8%, p = 0.04). Logistic regression analysis indicated that catheter tip colonization was associated with the summer season (odds ratio = 3.0, 95% CI 1.4-6.2) and TP dressings (odds ratio = 1.8, 95% CI 1.1-3.2), and that site colonization was associated with both summer (odds ratio = 4.0, 95% CI 2.2-7.1) and receipt of antibiotics (odds ratio = 1.9, 95% CI 1.1-3.2). Coagulase-negative staphylococci were isolated from 55.5% of the colonized catheter tips and insertion sites. The data suggest that bacterial colonization of peripheral IV catheters is increased in summer, and that use of TP dressings may increase both tip colonization and cost nearly twofold.

Infection control programs in twelve North Carolina extended care facilities.

Abstract: To assess the scope of infection control programs in extended care facilities, 1-day surveys were conducted in 12 North Carolina facilities over an 8-month period using a standardized questionnaire. All 12 facilities had a designated infection control practitioner (ICP), although none had attended an infection control education course. Eleven had an Infection Control Committee of which 8 (73%) met regularly. The Director of Nurses generally (58%) was the ICP and spent about 2 hr/wk on infection control. Ten (83%) facilities conducted infection surveillance among residents but did not accurately compute nosocomial infection rates. Eleven (92%) facilities had employee health programs that included preemployment and annual tuberculosis screening. None had a comprehensive resident health program. Infection control aspects of patient care practices often varied from facility to facility. Nosocomial infection surveillance among 336 residents in 9 facilities using modified CDC criteria revealed an overall prevalence rate of 5.4%. Additional infections were suspected but not included because of limitations of laboratory data and chart documentation.

Isolation of Legionella pneumophila from the cold water of hospital ice machines: implications for origin and transmission of the organism.

Abstract: Although the mode of transmission of L. pneumophila is as yet unclear, the hot water distribution system has been shown to be the reservoir for Legionella within the hospital environment. In this report we identify a previously unrecognized reservoir for L. pneumophila within the hospital environment, ie, the cold water dispensers of hospital ice machines. The cold water dispensers of 14 ice machines were cultured monthly over a 1-year period. Positive cultures were obtained from 8 of 14 dispensers, yielding from 1 to 300 CFU/plate. We were able to link the positivity of these cold water sites to the incoming cold water supply by recovering L. pneumophila from the cold water storage tank, which is directly supplied by the incoming municipal water line. This was accomplished by a novel enrichment experiment designed to duplicate the conditions (temperature, sediment, stagnation, and continuous seeding) of the hot water system. Our data indicate that significant contamination of cold water outlets with L. pneumophila can occur. Although no epidemiologic link to disease was made, the fact that the primary source of a patient's drinking water is from the ice machines warrants further investigation of these water sources as possible reservoirs.

The rapidly growing mycobacteria--Mycobacterium fortuitum and Mycobacterium chelonei.

Abstract: In summary, rapidly growing mycobacteria, M. fortuitum and M. chelonei, are pathogens of increasing importance which are often hospital-acquired and can infect patients with iatrogenic immunosuppression. They readily grow on routine mycobacterial culture media and must be distinguished from non-pathogenic rapidly growing species and slowly growing mycobacteria. Widely distributed in nature, they are often present in hospital environments, especially in water. Compared to M. tuberculosis they are weak pathogens, and infected patients are not considered contagious. Disease is probably acquired from environmental sources by direct entry of the organisms through traumatized skin or mucous membranes or by aspiration into previously abnormal lungs. They are usually resistant to antituberculous agents but are susceptible to several commonly used antibacterial agents. Treatment generally requires one or more active antibiotics plus adjunctive surgery in many cases. Prevention of nosocomial infection lies in proper disinfection of potentially contaminated medical devices and elimination of contaminated water.

Hospital Usage of Parenteral Antimicrobial Agents: A Gradated Utilization Review and Cost Containment Program

Abstract: Forty percent to 60% of antimicrobial agents administered in hospitals without effective antimicrobial review and control programs are not needed. Excessive use of antimicrobial agents in the hospital promotes colonization of patients with resistant organisms, needlessly exposes them to the risk of an adverse drug reaction, and increases the cost of care. A gradated antimicrobial utilization review program is presented that determines hospital usage, develops guidelines for appropriate cost-effective drug administration, provides several options for implementation, and monitors outcome so that measures can be modified for specific situations. The techniques used are basic epidemiologic measures currently used to assess hospital infections.

Lack of nosocomial spread of Varicella in a pediatric hospital with negative pressure ventilated patient rooms.

Abstract: All patients at the new British Columbia's Children's Hospital with chickenpox or Herpes zoster are nursed with appropriate precautions in single-bed rooms provided with negative pressure ventilation. Over a period of 1 year, no nosocomial infections were detected on follow-up of 110 susceptible patients who had been on wards at the same time as six cases of chickenpox and one immunocompromised patient with cutaneous dissemination of Varicella zoster. In a preceding study at the previous hospital, with similar staff, control measures, and patient population, in an isolation facility without negative pressure ventilation, nosocomial infections occurred in seven out of 41 susceptible patients who were on the same ward as two patients with chickenpox. These findings suggest that a simple negative pressure ventilation system without air locks is a useful adjunct in the control of cutaneous Varicella infections. [Infect Control 1985; 6(3):120-121.]

Methicillin-resistant Staphylococcus aureus (MRSA): risk and outcome of colonized vs. infected patients.

Abstract: A retrospective study of 204 patients culture positive for methicillin-resistant Staphylococcus aureus compared infected and colonized patients. Seventy-eight patients were colonized and never developed infection (C), 24 were colonized and subsequently infected (C----I), and 102 patients had 1 or more nosocomial infections with MRSA at time of first culture (I). The most prevalent sites of infection were wound (26.5%) and blood-stream (20.7%), whereas the respiratory tract and surgical wounds were both frequent sites of colonization. Stepwise discriminant analysis found the most important factors in differentiating likelihood of colonization vs. infection were recent prior hospitalization, history of wound debridement, and number of invasive procedures. Ten percent of (C) died and 25.5% of (I) died. MRSA contributed to death in 57.6% of the (I) deaths (p less than .05). These results underscore the importance of differentiating (C) vs. (I) in hospitals where MRSA is endemic so that early specific treatment may be initiated. Risk factors for infection should be discriminated from those for acquisition of the organism.

Prospective payment and infection control.

Abstract: Under prospective payment utilizing the diagnostic related groups (DRG) classification, hospital administrators have begun to rethink accepted hospital procedures. It is now necessary to consider every factor that contributes to the cost of care, because those costs will be borne more and more by the hospital rather than the patient. Administrators must determine if an expenditure really improves the quality of care and shortens the length of stay. Unfortunately, in many cases there are no mechanisms or criteria for such an evaluation. The health care industry is in danger of cutting away tissue when the fat is being trimmed away. An effort tojustify and quantify the benefit of an infection control program in a 270-bed acute care general hospital led to eye-opening results, and a decision to expand the program rather than reduce it. The expanded program is expected to recover cost two-fold.

Nosocomial rubella--consequences of an outbreak and efficacy of a mandatory immunization program.

Abstract: An outbreak of rubella in a large metropolitan hospital is described Nineteen cases among employees and three secondary cases in family members occurred Nosocomial cases occurred among the 3,900 employees of an adult medical-surgical unit where a voluntary program of rubella immunization was in effect No cases occurred among the 1,400 employees of the women's and pediatric units with mandatory policies, despite interfacility and community exposure Ten pregnant women were among the 377 contacts of the cases Five were sero-negative to rubella Two who developed clinical rubella, one asymptomatic sero-conversion and one other, all elected to terminate their pregnancies The remaining woman, exposed in her third trimester delivered a normal infant We conclude a policy requiring new employees to be rubella immune is more effective in preventing nosocomial rubella than a voluntary program and is desirable in view of the potential consequences of an outbreak to pregnant employees

Acceptance of hepatitis B vaccine by hospital personnel

Abstract: Personnel at high risk of acquiring hepatitis B in two university-affiliated teaching hospitals were offered immunization against this disease. Of the 1,193 employees, 454 (38%) requested immunization. Individuals who declined or deferred immunization were sent questionnaires requesting the reasons for their decisions. Responses to the questionnaire were received from 487 of 674 personnel (72%). Most respondents (greater than 90%) indicated that they: 1) were aware of being at risk of acquiring hepatitis B, and 2) recognized the potential danger of the disease. A majority of respondents (56%) indicated that they had decided not to be immunized because they wanted to wait until more was known about the vaccine. Concern about specific side effects (eg, Guillain-Barre syndrome or acquired immunodeficiency syndrome) was cited much less often as a reason for declining immunization. Nearly one-fifth of questionnaire respondents either did not know the date of their last tetanus-diphtheria immunization or had not received a booster within the past decade.

Recommended precautions for patients undergoing hemodialysis who have AIDS or non-A, non-B hepatitis.

Abstract: Precautions used for dialysis patients who have acquired immunodeficiency syndrome or non-A, non-B hepatitis are based on infection control strategies developed for the control of hepatitis B in dialysis centers. Specificially, these recommendations include identifying infected patients; isolating (except for non-A, non-B hepatitis patients) patients, and separating staff, and equipment; applying blood precautions and aseptic techniques; and using good environmental control procedures. AIDS patients can be safely dialyzed by either hemodialysis or peritoneal dialysis in hospital-based or free-standing centers, or at home without risk of AIDS transmission to other patients or to staff members, if precautions that have been developed for the control of hepatitis B infection in dialysis units are employed. Further, the type of dialysis treatment, or modality, should be based on the needs of the patient and not on a fear of risk of disease transmission.

A comparison of pneumonia caused by gentamicin, methicillin-resistant and gentamicin, methicillin-sensitive Staphylococcus aureus: epidemiologic and clinical studies.

Abstract: We investigated an outbreak of nosocomial pneumonia due to gentamicin, methicillin-resistant Staphylococcus aureus (GMRSA). We compared the predisposing factors for pneumonia due to GMRSA to those for pneumonia due to gentamicin, methicillin-sensitive Staphylococcus aureus (GMSSA). Seventeen of 29 patients with staphylococcal pneumonia were infected with GMRSA. Risk factors and associated diseases which selected for infection with GMRSA as opposed to GMSSA included prior antibiotic therapy for a prolonged period of time (p = 0.0001), number of risk factors per patient (p = 0.0001), days hospitalized prior to diagnosis of pneumonia (p = 0.002) and number of associated diseases per patient (p = 0.002). Despite the epidemiologic differences between GMSSA and GMRSA pneumonia, there were no differences in the clinical presentation, course of illness, complications, response to appropriate therapy or outcome between the two groups. Survival was adversely affected by age only among the GMSSA patients (p = 0.02) and by the number of associated diseases (p = 0.005).

A Multi-Hospital Hepatitis B Vaccine Program: Prevalence of Antibody and Acceptance of Vaccination Among High-Risk Hospital Employees

Abstract: In July 1982, five Hartford hospitals embarked on a joint hospital-sponsored program to immunize high-risk employees against hepatitis B virus (HBV). The program included a questionnaire to characterize relative risk, serology for anti-HBs, vaccination and a follow-up survey of vaccine non-recipients. Of 2,065 employees who were considered to be at high-risk for infection with HBV, 1,894 (91.7%) responded to the screening questionnaire and 1,279 (67.5%) were tested for anti-HBs serology. The prevalence of antibody varied from hospital to hospital; the highest prevalence (10.9%) was observed at one of the urban university-affiliated community hospitals and the lowest prevalence (4.1%) was reported from the smaller, rural hospital. The prevalence of antibody also varied greatly within the high-risk groups; the highest prevalence of antibody was seen among surgical house officers (15%). The rate of acceptance of vaccine among hospitals ranged from 57.5% to 23.7%. Reasons for vaccine non-acceptance included fear of as yet unknown side effects, perceived low risk of hepatitis acquisition and possible effects on present or future pregnancies. Our experience illustrates some of the epidemiologic and practical aspects that must be addressed in administering a hospital-based HBV vaccine program. Among the five hospitals, we saw marked inter- and intra-hospital variations in the prevalence of anti-HBs among high-risk employees. More significantly, we observed unexpectedly low rates of vaccine acceptance among high-risk personnel.

Characteristics of Pseudomonas aeruginosa isolated from whirlpools and bathers.

Abstract: Pseudomonas aeruginosa is the most frequently isolated microorganism from whirlpool water and lesions associated with outbreaks of dermatitis and folliculitis related to whirlpool exposure. Strains were selected from 19 outbreaks of P. aeruginosa infections (1977 to 1983) associated with whirlpool use; they were examined to determine if the strains possessed unique virulence factors or characteristics that might aid in their selection in the environment. P. aeruginosa, 011, was the predominant serotype isolated from whirlpool water as well as from bathers with dermatitis or folliculitis, followed by serotypes 09, 04, and 03. Antimicrobial susceptibility patterns were similar for all strains. Strains of P. aeruginosa from bathers and water demonstrated statistically significant differences in extracellular enzyme production compared with control strains. P. aeruginosa, serotypes 09 and 011, were found to be sensitive to low levels of chlorine. These data suggest that, if adequate levels of free available chlorine are maintained, P. aeruginosa should have little opportunity to persist in whirlpools. A bather's risk of P. aeruginosa dermatitis or folliculitis appears to be affected primarily by three factors: 1) immersion in water colonized by P. aeruginosa, 2) skin hydration with altered skin flora, and 3) toxic reactions to extracellular enzyme or exotoxins produced by P. aeruginosa. Although a single virulence factor was not identified from the results of this study, there are some indications that the enzymes produced by these microorganisms play an important role in the pathogenesis of disease associated with whirlpool use.

Lessons from the Roswell Park bone marrow transplant aspergillosis outbreak.

Abstract: Between April 1982 and March 1983 an outbreak of aspergillosis occurred among bone marrow transplant patients in a newly opened bone marrow transplant unit (BMTU) at the Roswell Park Memorial Institute. Rotstein and his colleagues, in an article in this issue, present the first scientific data about this important event.1 Their primary contribution is a case-control analysis of risk factors predisposing to aspergillosis comparing the 10 BMTU patients who developed aspergillosis with the 16 who did not. Since the number of analyzed variables surpasses the number of patients involved, these authors can be said to have mined the material close to its limits.