Subset heterogeneity among gamma delta T cells found in peripheral blood during Plasmodium falciparum malaria.
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Adult↗
Biomedical subjects
D G Maki
Publications and source records attributed to D G Maki.
Comparative study of cefazolin, cefamandole, and vancomycin for surgical prophylaxis in cardiac and vascular operations. A double-blind randomized trial.
Three-hundred twenty-one adults undergoing cardiac or major vascular operations were randomized to receive intravenous cefazolin, cefamandole, or vancomycin for prophylaxis against surgical infection in a double-blind trial. All three regimens provided therapeutic blood levels throughout operation in patients studied undergoing cardiopulmonary bypass. The prevalence of surgical wound infection was lowest with vancomycin (4 infections [3.7%] versus 14 [12.3%] and 13 [11.5%] in the cefazolin and cefamandole groups, respectively; p = 0.05); there were no thoracic wound infections in cardiac operations in the vancomycin group (p = 0.04). The mean duration of postoperative hospitalization was lowest in the vancomycin group (10.1 days; p < 0.01) and highest in the cefazolin group (12.9 days). Prophylaxis with vancomycin or cefamandole, compared with cefazolin, did not prevent nosocomial cutaneous colonization by methicillin-resistant coagulase-negative staphylococci; colonization or infection with vancomycin-resistant staphylococci or enterococci was not detected. Adverse effects attributable to the prophylactic regimen were infrequent in all three groups. Eight patients given vancomycin became hypotensive during administration of a dose, despite infusion during a 1-hour period; however, slowing the rate of administration and pretreating with diphenhydramine allowed vancomycin to be resumed and prophylaxis completed uneventfully in five of the patients. We conclude that administration of vancomycin (approximately 15 mg/kg), immediately preoperatively, provides therapeutic blood levels for surgical prophylaxis throughout most cardiac and vascular operations, resulting in protection against postoperative infection superior to that obtained with cefazolin or cefamandole. Vancomycin deserves consideration for inclusion in the prophylactic regimen (1) for prosthetic valve replacement and prosthetic vascular graft implantation, to reduce the risk of implant infection by methicillin-resistant coagulase-negative staphylococci and enterococci; (2) for any cardiovascular operation if the patient has recently received broad-spectrum antimicrobial therapy; and (3) for all cardiovascular operations in centers with a high prevalence of surgical infection with methicillin-resistant staphylococci or enterococci. Guidelines for dosing and administration of vancomycin for cardiovascular surgical prophylaxis are provided.
Adult↗
A prospective, randomized, double-blind study of trimethoprim-sulfamethoxazole for prophylaxis of infection in renal transplantation. Side effects of trimethoprim-sulfamethoxazole, interaction with cyclosporine.
Questions have been raised regarding the safety of trimethoprim-sulfamethoxazole (TMP-SMZ) in organ transplantation, particularly adverse interactions with azathioprine and cyclosporine. In a prospective randomized, double-blind, trial in 132 patients that encompassed 33,876 patient-days, long-term prophylaxis with TMP-SMZ was found to significantly reduce the incidence of bacterial infection after renal transplantation. Prophylaxis was very well tolerated; none of the 66 recipients of TMP-SMZ, who took the drug for an average of 8.9 months, was withdrawn from the study because of hypersensitivity or toxic side effects. Serial measurements of hematologic parameters and liver function tests after transplantation in the two groups showed no significant differences. Recipients of cadaveric transplants, who were all given cyclosporine, randomized to receive TMP-SMZ had serum creatinine levels approximately 15% higher than those in control patients receiving cyclosporine (p less than 0.01); comparison of renal function by 24-hour endogenous creatinine clearances and technetium 99m-labeled diethylenetriamine-penta-acetic acid glomerular filtration rates in 17 patients crossed over to the alternate treatment group for 7 weeks, however, shows that the observed differences are reversible and represent inhibition of tubular excretion of creatinine by TMP in the presence of cyclosporine. Prophylaxis with TMP-SMZ had no discernable effect on cyclosporine pharmacokinetics: recipients of TMP-SMZ had blood levels of cyclosporine similar to those in patients in the placebo group. Episodes of graft rejection occurred at a similar frequency in the two groups (placebo, 50; TMP-SMZ, 44). We conclude that long-term prophylaxis with TMP-SMZ does not produce discernable hematologic, renal, or hepatic toxicity in renal transplant recipients nor does it augment nephrotoxicity with cyclosporine or increase the risk of rejection. TMP-SMZ may be used safely and is highly cost-beneficial for prophylaxis of infection in renal transplantation.
Creatinine↗
The pathogenesis and epidemiology of catheter-related infection with pulmonary artery Swan-Ganz catheters: a prospective study utilizing molecular subtyping.
To delineate the pathogenesis and epidemiology of catheter-related infection with Swan-Ganz pulmonary artery (PA) catheters, a prospective clinical study of hospitalized adult medical and surgical patients was done. Role of catheter material was assessed by randomizing insertions to heparin-bonded PA catheters made of polyvinylchloride or polyurethane. Sources of infection and pathogenesis were studied by culturing skin, the introducer, the PA catheter tip, all hubs, infusate from each lumen, and the extravascular portion of the PA catheter beneath the external protective plastic sleeve. Concordance between isolates from sources and infected catheters was determined by speciation, antibiogram, and for coagulase-negative staphylococci, plasmid profile analysis. Risk factors for infection were determined by stepwise logistic regression. Overall, 65 (22%) of 297 Swan-Ganz catheters showed local infection of the introducer (58 catheters) or the intravascular portion of the PA catheter (20 catheters); only two catheters (0.7%) caused bacteremia. Eighty percent of infected Swan-Ganz catheters (the introducer or PA catheter) showed concordance with organisms cultured from skin of the insertion site, 17% with a contaminated hub and 18% with organisms contaminating the extravascular portion of the PA catheter beneath the sleeve. Isolates from infected PA catheters were most likely to show concordance with concomitantly infected introducers (71%). Cutaneous colonization of the insertion site with greater than 10(2) cfu/10 cm2 (relative risk [RR] 5.5; p less than 0.001), insertion into an internal jugular vein (RR 4.3; p less than 0.01), catheterization greater than 3 days (RR 3.1; p less than 0.01), and insertion in the operating room using less stringent barrier precautions (RR 2.1; p = 0.03) were each associated with a significantly increased risk of catheter-related infection. The risk of bacteremic infection with Swan-Ganz catheters is now low, in the range of 1%, with reasonable care. Swan-Ganz catheters are vulnerable to contamination from multiple sources, but the patient's skin is the single most important source of organisms causing invasive infection, which in most cases involves the introducer rather than the PA catheter. Heavy colonization of the insertion site, percutaneous insertion in the internal jugular vein rather than subclavian vein, catheterization longer than 3 days, and insertion with less stringent barrier precautions significantly increase the risk of catheter-related infection. These findings hold promise for application to management of Swan-Ganz catheters and research in catheter design to reduce the risk of catheter-related infection.
Adolescent↗
Nosocomial infections from contaminated endoscopes: a flawed automated endoscope washer. An investigation using molecular epidemiology.
Approximately 1 year after purchase of one manufacturer's automated endoscope washing machine, we began to detect heavy contamination of upper gastrointestinal (UGI) endoscopes cultured after cleaning and disinfection in the washer. During the first 6 months of 1988, 77% of surveillance cultures (20-mL flush through the biopsy channel) were positive for gram-negative bacilli (median concentration, 10(5) cfu/mL), most frequently Pseudomonas aeruginosa serotype 10. During the first 19 months of use of the washer, nosocomial post-UGI endoscopy colonization or infections with P. aeruginosa increased 36%. Investigations show that endoscope contamination derives from a flaw in the design of the EW-10 washer: the detergent holding tank, inlet water hose, and air vents cannot be reliably disinfected and contain heavy biofilms that recontaminate the machine after it has been disinfected, as specified by the manufacturer, with glutaraldehyde. Only by rinsing machine-cleansed endoscopes with 70% alcohol followed by forced air drying has reliable disinfection been achieved. Since adaptation of terminal alcohol treatment and drying, post-UGI endoscopy colonization or infection by P. aeruginosa has declined threefold (p less than 0.001). Testing in other centers using the manufacturer's EW-10 or EW-20 washer has shown similar contamination. In three centers, including our own, postendoscopy infections by machine-associated type 10 P. aeruginosa have been confirmed by demonstrating concordance between isolates from contaminated machines or endoscopes and from infected patients by immunoblot of whole cell lysates and by pulsed-field electrophoresis of DraI endonuclease-digested genomic DNA. This problem reaffirms the vulnerability to microbial contamination of water-containing apparatus and equipment in patient care and points up the critical importance of engineering design to prevent contamination.
Cross Infection↗
Epidemiology of hospital sharps injuries: a 14-year prospective study in the pre-AIDS and AIDS eras.
The world pandemic of acquired immunodeficiency syndrome (AIDS) has focused enormous attention on the problem of accidental sharps injuries sustained by health care workers (HCWs) and the risk of occupationally acquired infection by human immunodeficiency virus (HIV). At the 1980 Conference, we reported a 4-year epidemiologic study (1975-1979) of sharps injuries in HCWs at our hospital. Using the same reporting system and analyses, we now report the epidemiology of sharps injuries in our center during the current AIDS era (1987-1988) and assess trends over the 14-year period. Despite greatly increased institutional efforts to prevent sharps injuries, the annual incidence has increased more than threefold (60.4 to 187.0/1,000 HCWs), reflecting better reporting and increased exposure. Reported injuries by house officers have increased ninefold. Adjusting for inflation, the direct costs of sharps injuries has increased sevenfold ($5,354 to $37,271/year). Environmental service HCWs (305.8 sharps injuries per 1,000 employees) now have the highest incidence in our center, followed by nursing personnel (196.5/1,000) and laboratory personnel (169.9/1,000), but as in 1975-1979, two thirds of all injuries occur in nursing personnel. Although phlebotomy team members have a very low risk per procedure (1/26,871 draws), their annual incidence is extraordinarily high, 407.0/1,000. Injuries continue to occur mainly during disposal of waste, linen, or used procedure trays (19.7% of all injuries), administration of parenteral injections or infusion therapy (15.7%), surgery (16.0%), blood drawing (13.3%), or recapping of used needles (10.1%). Making disposal units available at every bedside has reduced injuries from needle disposal two-fold since 1975-1979. With consistent application of a stringent postexposure protocol, and wide acceptance of the hepatitis B vaccine, we have had no sharps injury-related infections during the past 3 years. These data indicate the increasing risk, complexity and cost of sharps injuries in HCWs and the need for more innovative--ideally, technology-based--approaches to prevention. Certain groups of HCWs are at very high risk. Comprehensive postexposure protocols that are uniformly applied can provide substantial protection to exposed HCWs.
Accidents, Occupational↗
Prospective randomised trial of povidone-iodine, alcohol, and chlorhexidine for prevention of infection associated with central venous and arterial catheters.
More than 90% of all intravascular device-related septicaemias are due to central venous or arterial catheters. To assess the efficacy of cutaneous antisepsis to prevent catheter-associated infection, we prospectively studied three antiseptics for disinfection of patients' central venous and arterial catheter insertion sites in a surgical intensive care unit. 668 catheters were randomised to 10% povidone-iodine, 70% alcohol, or 2% aqueous chlorhexidine disinfection of the site before insertion and for site care every other day thereafter. Chlorhexidine was associated with the lowest incidence of local catheter-related infection (2.3 per 100 catheters vs 7.1 and 9.3 for alcohol and povidone-iodine, respectively, p = 0.02) and catheter-related bacteraemia (0.5 vs 2.3 and 2.6). Of the 14 infusion-related bacteraemias (4 due to contaminated infusate or catheter hub, 10 due to infected catheters), 1 was in the chlorhexidine group and 13 were in the other two groups (odds ratio 0.16, p = 0.04). We conclude that use of 2% chlorhexidine, rather than 10% povidone-iodine or 70% alcohol, for cutaneous disinfection before insertion of an intravascular device and for post-insertion site care can substantially reduce the incidence of device-related infection.
1-Propanol↗
Risk factors for infusion-related phlebitis with small peripheral venous catheters. A randomized controlled trial.
OBJECTIVE: To identify risk factors for infusion-related phlebitis with peripheral intravenous catheters. DESIGN: A randomized trial of two catheter materials, with consideration of 21 potential risk factors. SETTING: A university hospital. PATIENTS: Hospitalized adults without granulocytopenia who received a peripheral intravenous catheter. INTERVENTIONS: House officers or ward nurses inserted the catheters, and each insertion was randomized to a catheter made of tetrafluoroethylene-hexafluoropropylene (FEP-Teflon) or a novel polyetherurethane without leachable additives (PEU-Vialon). MEASUREMENTS: Research nurses scored insertion sites each day for inflammation and cultured catheters at removal. RESULTS: The Kaplan-Meier risk for phlebitis exceeded 50% by day 4 after catheterization. intravenous antibiotics (relative risk, 2.00), female sex (relative risk, 1.88), prolonged (greater than 48 hours) catheterization (relative risk, 1.79), and catheter material (PEU-Vialon: FEP-Teflon) (relative risk, 0.73) strongly predicted phlebitis in a Cox proportional hazards model (each, P less than 0.003). The best-fit model for severe phlebitis identified the same predictors plus catheter-related infection (relative risk, 6.19), phlebitis with a previous catheter (relative risk, 1.54), and anatomic site (hand: forearm, relative risk, 0.71; wrist:forearm, relative risk, 0.60). The low incidence of local catheter-related infection was comparable with the two catheter materials (5.4% [95% CI, 3.8% to 7.6%] and 6.9% [CI, 4.9% to 9.6%]); none of the 1054 catheters prospectively studied caused bacteremia. CONCLUSIONS: Multiple factors, including the infusate and the duration of cannulation, contribute to the development of infusion-related phlebitis. The use of peripheral intravenous catheters made of PEU-Vialon appears to pose the same risk for catheter-related infection as the use of catheters made of FEP-Teflon, and PEU-Vialon can permit longer cannulation with less risk for phlebitis. The risk for catheter-related bacteremia with FEP-Teflon and PEU-Vialon catheters is sufficiently low that it no longer seems justifiable to recommend the use of small steel needles for most peripheral intravenous therapy.
Catheterization, Peripheral↗
Nosocomial Pseudomonas pickettii bacteremias traced to narcotic tampering. A case for selective drug screening of health care personnel.
Three patients in a university hospital developed nosocomial infusion-related Pseudomonas pickettii bacteremia. Investigation identified six additional patients who had received intravenous fluid contaminated by P pickettii but did not become ill. All nine patients had had surgery, and each of these patients but only nine of 19 operated-on control patients had received intravenous fentanyl citrate in the operating room; the mean dose given to the nine case patients was far greater than that given to control patients. Fentanyl in 20 (40%) of 50 predrawn 30-mL syringes was shown to be contaminated by P pickettii. Contamination was caused by theft of fentanyl from predrawn synringes and replacement by distilled water contaminated by P pickettii. Narcotic theft by health care personnel may cause patients to suffer pain needlessly and can also result in dire unanticipated consequences, such as nosocomial bacteremia. Whereas drug testing in the workplace is highly controversial, we believe that testing of health care personnel is indicated when drug abuse or theft is suspected.
Adult↗
A prospective, randomized, double-blind study of trimethoprim-sulfamethoxazole for prophylaxis of infection in renal transplantation: clinical efficacy, absorption of trimethoprim-sulfamethoxazole, effects on the microflora, and the cost-benefit of prophylaxis.
PURPOSE: To determine the efficacy of long-term prophylaxis with trimethoprim-sulfamethoxazole (TMP-SMZ) for prevention of bacterial infection following renal transplantation, the absorption of TMP-SMZ in transplant patients, the effects of prophylaxis on the microflora, and the cost-benefit of prophylaxis. PATIENTS AND METHODS: One hundred thirty-two adult patients selected to undergo renal transplantation participated in a randomized, double-blind, placebo-controlled trial. RESULTS: Patients randomized to receive TMP-SMZ experienced fewer hospital days with fever (3.3% versus 7.7%, p less than 0.001) and significantly fewer bacterial infections during the transplant hospitalization after removal of a urethral catheter (0.76 versus 1.88 per 100 days, p less than 0.005) and following discharge from the hospital (0.08 versus 0.30 per 100 days, p less than 0.001). During the transplant hospitalization, a daily dose of 320/1,600 mg was highly effective for prophylaxis whereas 160/800 mg daily gave unexpectedly low blood levels and was effective only for prevention of urinary tract infections after catheter removal. Prophylaxis was most effective in prevention of infections of the urinary tract (24 versus 54, p less than 0.005) and bloodstream (one versus nine, p less than 0.01) and infections caused by enteric gram-negative bacilli (four versus 46, p less than 0.001), enterococci (six versus 22, p = 0.006), or Staphylococcus aureus (one versus nine, p = 0.01). Prophylaxis did not prevent urinary tract infection associated with urethral catheters in the early posttransplant period, but after catheter removal, reduced the risk of urinary tract infection threefold (p less than 0.001). No significant differences in colonization by TMP-SMZ-resistant gram-negative bacilli were identified between the two groups; patients given TMP-SMZ were, paradoxically, less likely to become colonized by candida, probably because of less exposure to antibiotics for treatment of infection. Recipients of prophylaxis did not have a higher rate of infection caused by TMP-SMZ-resistant bacteria or Candida; however, their infections were more likely to be caused by resistant bacteria than infections in patients in the placebo group (62% versus 18%, p less than 0.001). CONCLUSIONS: Prophylaxis with TMP-SMZ, which is well tolerated, significantly reduces the incidence of bacterial infection following renal transplantation, especially infection of the urinary tract and bloodstream, can provide protection against Pneumocystis carinii pneumonia, and is cost-beneficial. Subnormal absorption of TMP-SMZ in the early posttransplant period mandates 320/1,600 mg daily for optimal benefit. Prophylaxis has little discernible effect on the microflora.
Absorption↗
Duplicate publication of a manuscript.
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Communication↗
Bacterial pneumonia in solid organ transplantation.
Approximately 4% of recipients of solid organ transplants in the United States develop bacterial pneumonia in the posttransplant period, often in the first 3 months following transplantation. The incidence of bacterial pneumonia is highest in recipients of heartlung (22%) and liver transplants (17%), intermediate in recipients of heart transplants (5%), and lowest in renal transplant patients (1 to 2%). The crude mortality of bacterial pneumonia in solid organ transplantation has exceeded 40% in most series. Beyond those risk factors identified for nosocomial pneumonia, the occurrence of primary cytomegalovirus (CMV) infection, graft rejection, maintenance antirejection therapy with prednisone, azathioprine, and antilymphocyte globulin, antirejection therapy with high-dose corticosteroids or OKT3 and splenectomy have been associated with a significantly increased risk of bacterial pneumonia in these patients. In the first 3 months posttransplant, gram-negative bacilli, Staphylococcus aureus and Legionella predominate and mortality is very high, in excess of 60%. Thereafter, bacterial pneumonias are caused primarily by Streptococcus pneumoniae and Hemophilus influenzae, with considerably lower mortality. Bacterial pneumonia must be suspected in any transplant patient presenting with fever and cough, especially associated with dyspnea or infiltrates on chest radiograph. If large numbers of bacteria and polymorphonuclear leukocytes are not visualized in respiratory secretions the work-up should proceed directly to fiberoptic bronchoscopy with bronchoalveolar lavage and/or protected brush specimen to establish the microbiologic diagnosis as accurately as possible. For presumptive gram-negative bacillary pneumonia, the initial regimen must be effective against Pseudomonas aeruginosa. Prevention of bacterial pneumonia in transplant patients must begin with immunization against S pneumoniae and Influenza A, and include precautions taken to prevent nosocomial pneumonia. It further may include measures to prevent CMV infection and the use of trimethoprim/sulfamethoxazole prophylaxis during the first year posttransplantation. Ultimately, novel technologies such as selective antimicrobial decontamination and/or protective isolation during the early postoperative period may prove effective.
Anti-Bacterial Agents↗
OKT3 salvage therapy in a quadruple immunosuppressive protocol in cadaveric renal transplantation.
Since the introduction of OKT3 at our center in January 1986, we have performed 246 cadaveric renal transplants (220 primary, 26 nonprimary). All patients received quadruple immunosuppression consisting of prednisone, azathioprine, and the sequential use of Minnesota antilymphoblast globulin (MALG) and cyclosporine. OKT3 (Orthoclone OKT3) therapy was reserved for corticosteroid- and/or ALG-resistant rejection. Of the 246 patients, 138 developed one or more rejection episodes (56.1%). Ninety-seven (70.3%) were successfully reversed with prednisone and/or ALG, whereas 41 (29.7%) required additional treatment with OKT3. Initial graft salvage occurred in 34 (82.9%) patients treated with OKT3, but rejection recurred in 18 (52.9%) and was successfully reversed in only 6 patients. However, the rate of recurrent rejection was much lower in patients given OKT3 early (14%), shortly after it was apparent that high-dose corticosteroid therapy was proving ineffective, than in patients who received OKT3 after a prolonged or second course of corticosteroids (64%) or ALG (60%). Graft survival after a mean follow-up interval of 11 months in all OKT3-treated patients was 54%. One or more infections occurred in 19 (46%) patients treated with OKT3. Patients developing infections following OKT3 therapy received significantly larger total doses of prednisone during graft rejection (46.3 mg/kg vs. 27.9 mg/kg, P less than .05) than OKT3-treated patients who did not develop infectious complications. Our experience shows that use of OKT3 for treatment of corticosteroid- and/or ALG-resistant rejection is associated with a high rate of recurrent rejection, except when given early, as soon as it is clear that high-dose corticosteroid therapy is not reversing the rejection episode. It further suggests that prolonged administration of high-dose corticosteroids and possibly ALG for the treatment of rejection prior to beginning OKT3 greatly increases the rate of infection following OKT3 therapy.
Adult↗
Single-antibiotic therapy for streptococcal endocarditis.
Ninety-nine patients treated with penicillin G potassium, cephalothin sodium, or vancomycin hydrochloride were studied to evaluate single-drug therapy for nonenterococcal streptococcal endocarditis. Eighty-six patients survived; of these, 66 received penicillin alone. The maximum serum bactericidal titer obtained at the expected nadir of serum antibiotic concentration was 1:8 or greater in 70 (95%) of the 74 patients studied. No relapse occurred among the 66 patients treated wih penicillin. Only one patient experienced a relapse that occurred following therapy with suboptimal doses of vancomycin. Distinct second episodes of endocarditis occurred in five patients. While 13 patients died, none died of intractable infection. The treatment of endocarditis due to penicillin-susceptible streptococci with high-dose parenteral penicillin or a bactericidal penicillin substitute for four weeks or longer results in bacteriologic cure rates comparable with those achieved with combined penicillin-streptomycin regimens.
Administration, Oral↗
Septic endarteritis due to intra-arterial catheters for cancer chemotherapy. I. Evaluation of an outbreak. II. Risk factors, clinical features and management, III. Guidelines for prevention.
A cluster of three cases of staphylococcal septic endarteritis originating from percutaneously inserted brachial artery catheters for regional cancer chemotherapy prompted an epidemiologic and clinical study of bacteremic infections associated with this therapeutic modality. Nine cases were identified over a 3 1/2-year period (1.6% of all catheterizations), all caused by Staphylococcus aureus. The cluster followed discontinuation of hexachlorophene for scrub of the extremity prior to cannulation; phage-typing suggested the three cases were caused by the patients' own strains of Staphylococcus. These infections produced a distinctive clinical syndrome which facilitates implicating the catheter in the genesis of fever occurring in a patient receiving intra-arterial chemotherapy: early localized pain (89%) and hemorrhage (78%), and Osler's nodes distally (44%), later followed by local inflammation (78%), purulence (56%) and signs of systemic sepsis (100%) (each factor, p less than or equal to .005). Duration of cannulation did not influence susceptibility to infection. However, difficult cannulations or need for repositioning the catheter (p = .0096), prior radiation therapy (p = .033), leukopenia (p less than .05) and hypoalbuminemia (p less than .05) were all associated with septicemia. In the 25 months since implementation of specific control measures, there have been no further catheter-related septicemia in 310 catheterization (p less than .001). Guide-lines for prevention and management of these infections are provided.
Adult↗
Infections caused by aterial catheters used for hemodynamic monitoring.
Utilizing a semiquantitative technique for culturing vascular catheters, we prospectively studied the risk and profile of infection caused by arterial catheters used for hemodynamic monitoring in 95 patients with a high risk of nosocomial infection. Of 130 catheters, 23 (18 per cent) produced local infection (larger than or equal to 15 colonies on semi-quantitative culture) and five septicemia (4 per cent). Sixteen of the 23 local infections and all septicemias occurred with catheter placements exceeding four days (p less than 0.001). Other factors associated with an increased risk of infection included insertion by surgical cut-down rather than percutaneously (ninefold increased rate of bacteremia, p = 0.008) and the presence of local inflammation (12-fold increase, p = 0.009). Systemic antimicrobial therapy (given to 80 per cent of the entire group and to four of the five with septicemia) did not protect against catheter-related infection but may account for the predominance of enterococci, Candida and gram-negative bacilli in these infections. Twelve per cent of all nosocomial bacteremias occurring in this critical care unit population originated from an arterial catheter. Indwelling arterial catheters pose a significant risk of bacteremic infection to ctirically ill patients. The percutaneous mode of placement is preferred; when prolonged arterial cannulation is required, the site should be rotated every four days. Local pain or inflammation, or clinical signs of sepsis without an obvious source should prompt removal and culture of the catheter.
Adolescent↗
A semiquantitative culture technic for identifying infection due to steel needles used for intravenous therapy.
Using steel intravneous needles obtained from patients with hematologic malignancies, the authors evaluated the efficacy of a semiquantitative method for culturing vascular cannulas on solid medium, comparing it with conventional broth culture. Of 148 needles studied, 140 (95%) were negative on semiquantitative culture (less than 15 colonies on the plate) although 38 produced growth in broth or on the plate; none of these needles caused septicemia. Eight needles were positive on semiquantitative culture (greater than or equal to 15 colonies), and two of these caused septicemia (P = .002). Positive semiquantitative cultures were associated with local inflammation (P = .02). Semiquantitative culturing was equal to the broth method in sensitivity (100%) in the diagnosis of needle-related septicemia; specificity (96% vs. 92%) and the predictive value of a positive needle culture (25% vs. 14%) were both enhanced with the semiquantitative method. The semiquantitative technic differentiates infection from contamination and offers other major advantages compared with the broth method, and is recommended for culturing steel needles as well as plastic catheters.
Culture Media↗
Indirect sandwich enzyme-linked immunosorbent assay for rapid detection of Haemophilus influenzae type b infection.
We report the development and testing of an enzyme-linked immunosorbent assay with excellent sensitivity for the detection of Haemophilus influenzae type b (HI(b)) antigen in clinical specimens from patients with HI(b) meningitis. The assay, an indirect sandwich technique, uses polystyrene balls as a solid phase and an alkaline phosphatase-labeled goat anti-rabbit globulin conjugate. Specimens are incubated with polystyrene balls armed with burro anti-HI(b) antiserum, and recognition antibody is visualized by addition of alkaline phosphatase-labeled anti-globulin, together with the enzyme substrate p-nitrophenyl phosphate. Concentrations of antigen are determined from standard curves prepared by using purified HI(b) capsular antigen polyribophosphate. The assay reproducibly detects polyribophosphate at concentrations between 1 and 5 ng/ml. Cross-reactions have not as yet been encountered in simulated and authentic clinical specimens containing other species including Escherichia coli, Klebsiella pneumoniae, group B Streptococcus, Pseudomonas aeruginosa, Streptococcus pneumoniae, Staphylococcus aureus, Neisseria meningitidis, and Listeria monocytogenes. In preliminary tests with 11 spinal fluid specimens, 2 serum specimens, and 5 urine specimens from patients with culture-proved HI(b) meningitis, antigen was detected in all specimens in concentrations ranging from 1 to 7,000 ng/ml. Antigen was not detected in any of 62 clinical specimens which were culture negative for HI(b), including 11 spinal fluid specimens from patients with bacterial meningitis caused by microorganisms other than HI(b). The enzyme-linked immunosorbent assay technique described here is considerably simpler than radioimmunoassay and, based on concurrent tests with 14 positive clinical specimens, may be more sensitive than counterimmunoelectrophoresis. It seems, therefore, to hold considerable promise for clinical use in rapid detection of systemic HI(b) infections.
Antigens, Bacterial↗