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Biomedical subjects

W R Jarvis

Publications and source records attributed to W R Jarvis.

At least 19 recordsLinked to original sources
PubMed1992

Hospital outbreak of multidrug-resistant Mycobacterium tuberculosis infections. Factors in transmission to staff and HIV-infected patients.

OBJECTIVE: To describe transmission of multidrug-resistant (MDR) Mycobacterium tuberculosis infection among patients and health care workers (HCWs) in a ward and clinic for human immunodeficiency virus (HIV)-infected patients in a hospital, four studies were conducted. METHODS: Case patients and control patients were persons who had been treated in the HIV ward or clinic, whose clinical course was consistent with tuberculosis and who had at least one positive culture for M tuberculosis between January 1, 1988, and January 31, 1990, resistant to at least isoniazid and rifampin (case patients), or whose isolates were susceptible to all drugs tested (control patients). In the first study, case patients and control patients were compared to identify risk factors for MDR tuberculosis. In the second study, inpatient and outpatient days of MDR tuberculosis case patients were compared to determine whether acid-fast bacillus (AFB) smear-positivity or aerosolized pentamidine use was associated with higher numbers of subsequent MDR tuberculosis cases among exposed patients. In the third study, restriction fragment length polymorphism analysis was performed on available MDR and sensitive M tuberculosis isolates. In the fourth study, skin test conversion rates among HCWs in the HIV ward and clinic were compared with those of HCWs in another ward, and the strength of the associations between skin test conversions among HCWs on the HIV ward and the number of person-days that AFB smear-positive case patients and control patients were on this ward was estimated. RESULTS: Case patients were more likely than control patients to have been exposed on the HIV ward or clinic to an AFB smear-positive case patient (P less than .001). Inpatient and outpatient days of MDR tuberculosis case patients were associated with more subsequent cases of MDR tuberculosis if exposing case patients were smear-positive or if they received aerosolized pentamidine (P less than or equal to .01). Of 13 MDR isolates, all had one of two restriction fragment length polymorphism patterns; 10 sensitive isolates had restriction fragment length polymorphism patterns that were different from each other. The HCW skin test conversion rate was higher on the HIV ward and clinic than on the comparison ward (P less than .01). The risk of occupational acquisition of infection increased in direct proportion to the number of person-days that AFB smear-positive case patients were on the HIV ward (r = .75; P = .005), but did not increase in proportion to the number of person-days that AFB smear-positive control patients were there (r = -.36; P = NS). After isolation measures for AFB smear-positive tuberculosis patients were improved, MDR tuberculosis cases decreased to seven of 214 tuberculosis patients. CONCLUSIONS: Nosocomial transmission of MDR M tuberculosis infection to patients and HCWs occurred on the HIV ward and clinic. Infectiousness of MDR tuberculosis case patients was associated with AFB sputum-smear positivity. Case patients with MDR tuberculosis created a greater risk of skin test conversion for HCWs on the HIV ward than drug-susceptible control patients.

Adult↗
PubMed1992

Nosocomial transmission of multidrug-resistant Mycobacterium tuberculosis. A risk to patients and health care workers.

OBJECTIVE: To determine the factors associated with the development of multidrug-resistant tuberculosis among patients at a New York City Hospital and to investigate possible nosocomial transmission. DESIGN: A retrospective case-control study and tuberculin skin test survey. PATIENTS: Twenty-three patients with tuberculosis whose isolates were resistant to at least isoniazid and rifampin (case patients) were compared with patients with tuberculosis whose isolates were susceptible to all agents tested (controls). Tuberculin skin test conversion rates were compared among health care workers assigned to wards where patients with tuberculosis were frequently or rarely admitted. SETTING: A large, teaching hospital in New York City. MEASUREMENTS: Mycobacterium tuberculosis isolates from case patients and controls were typed by restriction fragment length polymorphism analysis. RESULTS: Case patients were younger (median age, 34 compared with 42 years; P = 0.006), more likely to be seropositive for HIV (21 of 23 compared with 11 of 23 patients; odds ratio, 11.5; 95% CI, 1.9 to 117), and more likely to have had a previous hospital admission within 7 months before the onset of tuberculosis (19 of 23 compared with 5 of 23 patients; odds ratio, 17.1; CI, 3.3 to 97), particularly on one ward (12 of 23 compared with 0 of 23 patients; odds ratio, undefined; P = 0.002). Health care workers assigned to wards housing case patients were more likely to have tuberculin skin test conversions than were health care workers assigned to other wards (11 of 32 compared with 1 of 47 health care workers; P less than 0.001). Few (6 of 23) case patients were placed in acid-fast bacilli isolation, and no rooms tested had negative pressure. Of 16 available multidrug-resistant isolates obtained from case patients, 14 had identical banding patterns by restriction fragment length polymorphism analysis. In contrast, M. tuberculosis isolates from controls with drug-susceptible tuberculosis had patterns distinct from each other and from those of case patients. CONCLUSIONS: These data suggest nosocomial transmission of multidrug-resistant tuberculosis occurred from patient to patient and from patient to health care worker and underscore the need for effective acid-fast bacilli isolation facilities and adherence to published infection control guidelines in health care institutions.

Adult↗
PubMed1992

Nosocomial transmission of tuberculosis in a hospital unit for HIV-infected patients.

OBJECTIVE: To assess nosocomial transmission of tuberculosis (TB). DESIGN: A historical cohort study of hospitalized patients with the human immunodeficiency virus (HIV) and a purified protein derivative (PPD) tuberculin skin test survey of health care workers (HCWs). SETTING: A large public teaching hospital in San Juan, Puerto Rico. PATIENTS: For the cohort study, a case patient was defined as any patient in the HIV unit at the hospital who developed culture-positive TB from 31 days or more after admission through December 31, 1989. For the PPD survey, of 1420 HCWs from the hospital, 908 agreed to participate and had sufficient data for analysis. MAIN OUTCOME MEASURES: For the cohort study, to compare the risk of developing active TB among patients who were exposed to hospital roommates with infectious TB and the risk among nonexposed patients. For the HCW PPD survey, to determine the prevalence of and risk factors for tuberculous infection. RESULTS: Eight of 48 (9.7/10,000 person-days) exposed case patients vs four of 192 (0.8/10,000 person-days) nonexposed case patients developed active TB (relative risk [RR] = 11; 95% confidence interval [CI], 2.3, 50.3). Positive PPDs (greater than or equal to 10 mm of induration) in HCWs were associated with older age (P = .0001) and with history of community TB exposure (P = .0002). In a multivariable logistic model that adjusted for these variables, HIV unit nurses (nine of 19) and nurses in the internal medicine ward (45 of 90) had a higher proportion of positive PPDs than the reference group (clerical personnel on other floors: 35 of 188, P = .0005). CONCLUSIONS: These data suggest that patient-to-patient transmission of TB in HIV units can occur and that HCWs are at risk of acquiring TB infection.

Adolescent↗
PubMed1992

Aspergillus fumigatus sternal wound infections in patients undergoing open heart surgery.

During a 21-month period (July 1986-April 1988), six patients who underwent open heart surgery at Holston Valley Hospital and Medical Center in Kingsport, Tennessee, developed sternal would infections caused by Aspergillus fumigatus. All patients required sternectomy, reconstructive surgery, and long term amphotericin B therapy; no patient died. By univariate analysis, the following were significantly associated with A. fumigatus sternal would infection: chronic lung disease, a recent history of pneumonia, a greater mean number of admission diagnoses, and a particular surgeon. However, multivariate analysis identified chronic lung disease as the only independent risk factor and the best predictor of A. fumigatus sternal wound infections. No factors related to the surgical procedure or operating room personnel were associated with infection. A review of the characteristics of the patients undergoing open heart surgery showed that since 1985, there had been a trend for these patients at Holston Valley Hospital and Medical Center to be older and sicker, which may have contributed to the occurrence of infections never observed before. Despite an extensive investigation, no environmental source for A. fumigatus was identified. A. fumigatus, however, grew from the bronchial washing of one patient at the time the sternal wound infection was diagnosed, and a prospective study showed that the rate of A. fumigatus colonization among open heart surgery patients was the same as the rate of sternal wound infections caused by A. fumigatus. These data suggest that patients with chronic lung disease and respiratory colonization with A. fumigatus are at increased risk for A. fumigatus sternal wound infections after open heart surgery.

Aged↗
PubMed1992

Prevalence of serotypes of Xanthomonas maltophilia from world-wide sources.

Since its development in 1988, a serologic typing scheme for Xanthomonas maltophilia, based on 31 O antigens, has been successfully used to serotype isolates involved in nosocomial outbreaks in the United States. To determine if this serotyping scheme would be useful in typing X. maltophilia isolates from world-wide sources, we obtained additional isolates from 10 countries; of 900 isolates tested, 795 (88.3%) were typable. In order of predominance, the three most common serotypes were 10, 3 and 19. These three serotypes were most frequently associated with respiratory and blood isolates. This serotyping system is useful as an epidemiologic screening method for universal typing of outbreaks of X. maltophilia infections.

Global Health↗
PubMed1992

Anaphylactoid reactions associated with reuse of hollow-fiber hemodialyzers and ACE inhibitors.

From July 18 through November 27, 1989, 12 anaphylactoid reactions (ARs) occurred in 10 patients at a hemodialysis center in Virginia. One patient required hospitalization; no patients died. ARs occurred within minutes of initiating dialysis and were characterized by peripheral numbness and tingling, laryngeal edema or angioedema, facial or generalized sensation of warmth, and/or nausea or vomiting. All 12 ARs occurred with dialyzers that had been reprocessed with an automated reprocessing system. A cohort study, including all patients undergoing dialysis sessions on the six days when an AR occurred, showed that the patients who experienced ARs were significantly more likely than patients who did not to be treated with angiotensin-converting enzyme (ACE) inhibitors (7/10 vs. 3/33; relative risk = 7.9; 95% confidence interval = 2.5 to 25.2) and to have been exposed to reused dialyzers rather than to new dialyzers (12/70 sessions vs. 0/31; P = 0.016). In those sessions using a reused dialyzer, the mean number of dialyzer uses in case-sessions was significantly higher than for noncase-sessions (10.3 vs. 6.2; P = 0.016). After reuse of dialyzers was discontinued at the center, no further ARs occurred, despite the continued administration of ACE inhibitors. This is the first report of an outbreak of ARs associated exclusively with reused dialyzers. We hypothesize that interactions between a dialyzer that has been repeatedly reprocessed and reused, blood, and additional factors, such as ACE inhibitors, increased the risk of developing ARs.

Ambulatory Care Facilities↗
PubMed1992

Risk factors for epidemic Xanthomonas maltophilia infection/colonization in intensive care unit patients.

OBJECTIVE: To determine risk factors for and modes of transmission of Xanthomonas maltophilia infection/colonization. DESIGN: Surveillance and cohort study. SETTING: A 470-bed tertiary trauma-referral community hospital. PATIENTS: From January 1, 1988 to March 17, 1989, 106 intensive care unit patients developed X maltophilia infection/colonization. We defined a case as any intensive care unit patient who, from July 15, 1988, through March 17, 1989 (epidemic period), had X maltophilia infection/colonization greater than or equal to 48 hours after intensive care unit admission. We identified 45 case patients and 103 control patients (persons in the shock-trauma intensive care unit for greater than or equal to 72 hours during the epidemic period who had no X maltophilia-positive culture). RESULTS: Cases were significantly more likely to occur in the shock-trauma intensive care unit than in all other intensive care units combined. Mechanical ventilation, tracheostomy, being transported to the hospital by airplane, and receipt of a higher mean number of antimicrobials were risk factors for X maltophilia infection/colonization. Risk of X maltophilia infection/colonization was significantly greater among cases exposed to a patient with a X maltophilia surgical wound infection than among those without such exposure (relative risk = 1.3, p = .03). Animate and inanimate cultures revealed X maltophilia contamination of the hospital room of a patient with an X maltophilia surgical wound infection, of respiratory therapy equipment in this patient's room, of respirometers shared between patients, and of shock-trauma intensive care unit personnel's hands. Related environmental and clinical isolates were serotype 10. CONCLUSIONS: Mechanically ventilated patients receiving antimicrobials in the shock-trauma intensive care unit were at increased risk of X maltophilia infection/colonization. Patients with draining X maltophilia surgical wound infections served as reservoirs for X maltophilia, and contamination of the respirometers and the hands of shock-trauma intensive care unit personnel resulted in patient-to-patient transmission of X maltophilia.

Cohort Studies↗
PubMed1992

A cluster of severe postoperative bleeding following open heart surgery.

OBJECTIVE: To investigate a cluster of postoperative bleeding following open heart surgery. DESIGN: A cohort and case/control study. SETTING: Palo Alto Veterans Administration Medical Center, Palo Alto, California. PARTICIPANTS: Six (21.4%) of 28 patients undergoing open heart surgery who developed severe, nonsurgical, postoperative bleeding from July 1 through August 30, 1988 (outbreak period). All case-patients had chest tube drainage of greater than or equal to 1000 ml within 4 hours of surgery but did not have identifiable bleeding vessel(s) on exploration. RESULTS: Upon comparison of the pre-outbreak (January 1986 through June 1988) and the outbreak period, a significant increase was found in the incidence of postoperative nonsurgical bleeding (5/440 versus 6/28, p = .0006), but not of postoperative surgical bleeding (8/440 versus 0/28, p = 1.0). Of all patients undergoing open heart surgery during the outbreak period, case patients were found to be older (67.8 versus 60.6, p = .02) and to have received a larger volume of hetastarch (HES), a synthetic colloidal plasma-volume expander (mean = 19.4 ml/kg versus 14.1 ml/kg, p = .02). CONCLUSIONS: We conclude that the use of large volumes of HES during surgery in the elderly open heart surgery patient may increase the risk for severe, nonsurgical postoperative bleeding, probably caused by alterations of the coagulation system. As the incidence of open heart surgery increases among the elderly, surgeons and anesthesiologists should be alert to possible adverse reactions from exposures not associated with adverse reactions in younger patients.

Aged↗
PubMed1992

Outbreak of surgical wound infections associated with total hip arthroplasty.

OBJECTIVES: Describe an outbreak of surgical wound infections associated with total hip arthroplasty; identify risk factors for surgical wound infection during the pre-outbreak and outbreak periods. SETTING: A 100-bed hospital. From May 1 to September 30, 1988, 7 of 15 patients who underwent total hip arthroplasty developed surgical wound infections from Staphylococcus aureus (5), Enterobacter cloacae (1), beta-hemolytic streptococci (1), enterococci (1), coagulase-negative staphylococci (1), and Escherichia coli (1) (attack rate = 46.7%). DESIGN: Retrospective cohort studies comparing surgical wound infection rates by patient- and procedure-related risk factors during the pre-outbreak and outbreak periods were conducted. Drop plate quantitative air culturing was conducted in 10 consecutive total hip arthroplasties in the subsequent 6 months. RESULTS: Rates of surgical wound infection were surgically higher for arthroplasties in which no intraoperative prophylactic antimicrobials were given (44% versus 8%, relative risk [RR] = 5.4, p = .01), or in which the posterior approach (20% versus 3%, RR = 6.7, p = .04) or a specific prosthesis (39% versus 5%, RR = 6.3, p = 0.01) was used. The surgical wound infection rate was highest when one circulating nurse, Nurse A, assisted (47% versus 4%, RR = 12.8, p less than .001). Logistic regression analysis identified use of the posterior approach (RR = 1.8, p = .04) and Nurse A's participation (RR = 5.0, p less than .001) as independent risk factors for surgical wound infection. Interviews of the nursing supervisor indicated that Nurse A had recurrent dermatitis on her hands. During 6 months following Nurse A's reassignment, the rate declined significantly (from 7/15 to 0/10, p = .01). Drop plate culturing yielded 2 to 10 colonies per plate of organisms that did not match outbreak organisms. CONCLUSIONS: Outbreaks associated with personnel generally involve only 1 species. In this outbreak, Nurse A (possibly because of her dermatitis), technique, the posterior approach, and/or other undetermined factors were the primary predictors of surgical wound infection.

Adult↗
PubMed1992

Outbreak of pseudoinfection with Tsukamurella paurometabolum traced to laboratory contamination: efficacy of joint epidemiological and laboratory investigation.

From January 1988 to May 1989, one hospital in South Carolina reported 12 isolates of Tsukamurella paurometabolum from 10 patients. There were no common risk factors among the patients. Case-control studies revealed that the positive specimens were significantly more likely to have been processed in the TB/fungal room, to have been tissue samples, and to have been handled by one technician. Typing on the basis of biochemical, antimicrobial resistance, Southern blot, and ribotype profiles showed that the isolates from the outbreak were essentially identical and that they were distinguishable from each of two isolates obtained after the outbreak and from two type strains. These findings support the hypothesis of a common-source outbreak of pseudoinfection. There are reasons to believe that T. paurometabolum is present both in the environment and as a culture contaminant more often than has been recognized and that it is very rarely the true cause of infection in humans. Typing results show differences between one type strain and all of the other isolates studied in terms of colonial morphology, biochemistry, antimicrobial susceptibility, and ribotyping; these differences suggest that the nomenclature of T. paurometabolum may require further clarification.

Actinomycetales↗
PubMed1992

Predominant pathogens in hospital infections.

To determine the distribution of pathogens causing nosocomial infections in United States hospitals, we analysed data from the National Nosocomial Infections Surveillance (NNIS) System. From October 1986 to December 1990, amongst hospitals conducting hospital-wide surveillance, the five most commonly reported pathogens were Escherichia coli (13.7%), Staphylococcus aureus (11.2%), enterococci (10.7%), Pseudomonas aeruginosa (10.1%), and coagulase-negative staphylococci (9.7%). The commonest pathogens reported by site included, bloodstream: coagulase-negative staphylococci, S. aureus, enterococci, E. coli, and Candida spp.; lower respiratory tract infection: S. aureus, P. aeruginosa and Enterobacter spp.; surgical wound infection: S. aureus, enterococci and coagulase-negative staphylococci; and urinary tract infection: E. coli, enterococci, and P. aeruginosa. Among hospitals conducting intensive care unit (ICU) surveillance, the commonest pathogens were P. aeruginosa (12.4%), S. aureus (12.3%), coagulase-negative staphylococci (10.2%), Candida spp. (10.1%), Enterobacter spp. and enterococci (8.6% each). In the ICUs, the commonest pathogens found in the bloodstream were coagulase-negative staphylococci, S. aureus, and enterococci; in lower respiratory tract infections P. aeruginosa, S. aureus, and enterococci; in surgical wound infections enterococci, coagulase-negative staphylococci, and Enterobacter spp. and in urinary tract infections Candida spp., E. coli, enterococci, P. aeruginosa, and Enterobacter spp. These data show that S. aureus, E. coli and P. aeruginosa remain important nosocomial pathogens, that coagulase-negative staphylococci, enterococci and C. albicans are pathogens of increasing importance, and that the distribution of pathogens differs by site and hospital location.

Adult↗
PubMed1992

Antimicrobial susceptibility patterns of common and unusual species of enterococci causing infections in the United States. Enterococcal Study Group.

We collected 705 isolates of enterococci (1 per patient) from cultures of a variety of anatomic sites from patients at eight tertiary-care hospitals in six geographic regions of the United States. A total of 632 (90%) Enterococcus faecalis, 58 (8%) E. faecium, 5 E. gallinarum, 4 E. avium, 3 E. casseliflavus, 1 E. raffinosus, and 1 E. hirae isolate and 1 biochemical variant of E. faecalis were identified; 606 (86%) of these isolates were associated with clinical infections. The most common sites of isolation were the urinary tract (402 [57%]), nonsurgical wounds (94 [13%]), the bloodstream (74 [10%]), and surgical wounds (62 [9%]). High-level resistance to gentamicin or streptomycin or both was detected in 265 (38%) of the isolates. We identified two E. faecalis isolates resistant to vancomycin (MICs, 32 and 128 micrograms/ml) and 11 beta-lactamase-producing E. faecalis isolates. E. faecium isolates were significantly more resistant than E. faecalis isolates to penicillin, ampicillin, piperacillin, imipenem, and ciprofloxacin (P less than 0.001). The MICs for the 15 non-E. faecalis, non-E. faecium enterococci indicated variable resistance to ciprofloxacin and the penicillins. Antimicrobial susceptibility patterns vary among species of enterococci, and these organisms, while commonly resistant to high-level aminoglycosides, can also acquire resistance to vancomycin or the ability to produce beta-lactamase. Because of these diverse antimicrobial resistance mechanisms, successful treatment and control of enterococcal infections with current antimicrobial agents are becoming increasingly difficult.

Adolescent↗
PubMed1992

Pyrogenic reactions in patients receiving conventional, high-efficiency, or high-flux hemodialysis treatments with bicarbonate dialysate containing high concentrations of bacteria and endotoxin.

High-efficiency (HE) and high-flux (HF) hemodialysis are becoming increasingly popular methods for treating patients with chronic renal failure because they reduce the time required for dialysis treatment. HF and HE dialyzers require bicarbonate dialysate, often prepared from concentrates that can support bacterial growth with endotoxin production. There is a concern that endotoxins or bacteria may cross or interact at the membranes of these dialyzers, triggering the release of endogenous pyrogens (cytokines) by peripheral blood mononuclear cells to cause pyrogenic reactions (PR). To determine the incidence of PR and to examine the association between PR and levels of bacteria and endotoxin in dialysate, a cohort of patients receiving conventional, HE, or HF hemodialysis with bicarbonate dialysate and reprocessed dialyzers at three dialysis centers during a 12-month period was studied prospectively. All dialyzers underwent a test of membrane integrity before use. A total of 19 PR were identified among 18 patients in 26,877 hemodialysis treatments (0.7 PR/1,000 treatments). There was no significant difference in PR rates by treatment modality: conventional, 0.5 per 1,000 (7 PR/13,123 treatments) versus HE, 0.9 per 1,000 (9 PR/11,345) versus HF, 1.2 per 1,000 (3 PR/2,409) (P = 0.21; chi 2 test). Throughout the study period, bacterial counts for dialysate at each center significantly exceeded the Association for the Advancement of Medical Instrumentation's (AAMI) microbiologic standards for dialysate of less than 2,000 CFU/mL (mean, 19,000 CFU/mL), but water used in the reuse of dialyzers tested less than 200 CFU/mL.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

A prospective study of pyrogenic reactions in hemodialysis patients using bicarbonate dialysis fluids filtered to remove bacteria and endotoxin.

Pyrogenic reactions (PR) are a well-recognized complication of hemodialysis and have been associated with dialyzer reuse, high-flux dialysis, and bicarbonate dialysate. However, the roles of bacteria and endotoxin in dialysate for producing PR are not well defined. To determine the effect of removing most bacteria and endotoxin from the dialysate on the incidence of PR, a cohort of chronic hemodialysis patients receiving high-flux, high-efficiency, or conventional hemodialysis at three centers with bicarbonate dialysis fluids that had been filtered with a polysulfone high-flux hemodialyzer was prospectively studied. Unfiltered bicarbonate concentrate had median bacterial and endotoxin concentrations of 479,000 CFU/mL and 39,800 pg/mL, respectively. After filtration of the bicarbonate concentrate at the central proportioner, dialysate had a median 9.2 CFU/mL of bacteria and 17.8 pg/mL of endotoxin. Dialysate filtered at individual proportioning dialysis machines had a median 0.001 CFU/mL of bacteria and 0.19 pg/mL of endotoxin. Nine PR were identified among 303 patients after 28,007 hemodialysis treatments (0.3 PR/1,000 treatments). The rate of PR was similar for the three hemodialysis treatment modalities and for first-use compared with reused dialyzers. Although the PR rate in this study was lower (P = 0.046) than the PR rate of a previous study with unfiltered dialysis fluids (0.7 PR/1,000 treatments), it represents a difference of only 10 PR in over 28,000 treatments. It was concluded that filtration of hemodialysis fluids is efficacious in removing bacterial and endotoxin contamination and can result in a lower incidence of PR in patients receiving high-flux, high-efficiency, or conventional hemodialysis.

Adult↗