Willy Peetermans

Risk factors for community-acquired pneumonia in adults in Europe: a literature review

Background Community-acquired pneumonia (CAP) causes considerable morbidity and mortality in adults, particularly in the elderly. Methods Structured searches of PubMed were conducted to identify up-to-date information on the incidence of CAP in adults in Europe, as well as data on lifestyle and medical risk factors for CAP. Results The overall annual incidence of CAP in adults ranged between 1.07 to 1.2 per 1000 person-years and 1.54 to 1.7 per 1000 population and increased with age (14 per 1000 person-years in adults aged ≥65 years). Incidence was also higher in men than in women and in patients with chronic respiratory disease or HIV infection. Lifestyle factors associated with an increased risk of CAP included smoking, alcohol abuse, being underweight, having regular contact with children and poor dental hygiene. The presence of comorbid conditions, including chronic respiratory and cardiovascular diseases, cerebrovascular disease, Parkinsons disease, epilepsy, dementia, dysphagia, HIV or chronic renal or liver disease all increased the risk of CAP by twofold to fourfold. Conclusion A range of lifestyle factors and underlying medical conditions are associated with an increased risk of CAP in European adults. Understanding of the types of individual at greatest risk of CAP can help to ensure that interventions to reduce the risk of infection and burden of disease are targeted appropriately.

Influenza vaccination is efficacious and safe in renal transplant recipients.

Whether influenza vaccination in solid‐organ transplant recipients is efficacious remains a controversial issue. Furthermore, theoretical concerns have been raised regarding the safety of vaccination as it might trigger rejection of the allograft. The present prospective trial is aimed at investigating the antibody response and safety of influenza vaccination in renal transplant recipients (RTR).

Catheter-Tip Colonization as a Surrogate End Point in Clinical Studies on Catheter-Related Bloodstream Infection: How Strong Is the Evidence?

In clinical trials, the incidence of catheter-tip colonization (CTC) is frequently used as a surrogate end point for the incidence of catheter-related bloodstream infection (BSI). It is not clear whether the correlation between CTC and catheter-related BSI is good. We searched the MEDLINE database and conducted a literature search for the years 1990-2002 and retrieved 29 studies (with a total of 60 study groups) with incidence data on predefined CTC and catheter-related BSI definitions. A good linear correlation between CTC and catheter-related BSI was found (r=0.69; r2=0.48; P<.001). The data from the medical literature about catheter-related infection seem to support the use of CTC as a surrogate end point for catheter-related BSI. In evaluations of clinical interventions or new techniques for the prevention of catheter-related BSI, investigation of the prevention of CTC seems to be a logical first step.

(18)F-FDG PET/CT for early detection of embolism and metastatic infection in patients with infective endocarditis.

PurposeIn the acute setting of endocarditis it is very important to assess both the vegetation itself, as well as potential life-threatening complications, in order to decide whether antibiotic therapy will be sufficient or urgent surgery is indicated. A single whole-body scan investigating inflammatory changes could be very helpful to achieve a swift and efficient assessment.MethodsIn this study we assessed whether 18F-FDG can be used to detect and localize peripheral embolism or distant infection. Twenty-four patients with 25 episodes of endocarditis, enrolled between March 2006 and February 2008, underwent 18F-FDG PET/CT imaging on a dedicated PET/CT scanner.ResultsPET/CT imaging revealed a focus of peripheral embolization and/or metastatic infection in 11 episodes (44%). One episode had a positive PET/CT scan result for both embolism and metastatic infection. PET/CT detected seven positive cases (28%) in which there was no clinical suspicion. Valve involvement of endocarditis was seen only in three patients (12%).ConclusionPET/CT may be an important diagnostic tool for tracing peripheral embolism and metastatic infection in the acute setting of infective endocarditis, since a PET/CT scan detected a clinically occult focus in nearly one third of episodes.

Multidrug-Resistant Streptococcus pneumoniae Infections Current and Future Therapeutic Options

Antibacterial resistance in Streptococcus pneumoniae is increasing worldwide, affecting principally β-lactams and macrolides (prevalence ranging between ≈1% and 90% depending on the geographical area). Fluoroquinolone resistance has also started to emerge in countries with high level of antibacterial resistance and consumption. Of more concern, 40% of pneumococci display multi-drug resistant phenotypes, again with highly variable prevalence among countries.Infections caused by resistant pneumococci can still be treated using first-line antibacterials (β-lactams), provided the dosage is optimised to cover less susceptible strains. Macrolides can no longer be used as monotherapy, but are combined with β-lactams to cover intracellular bacteria. Ketolides could be an alternative, but toxicity issues have recently restricted the use of telithromycin in the US. The so-called respiratory fluoroquinolones offer the advantages of easy administration and a spectrum covering extracellular and intracellular pathogens. However, their broad spectrum raises questions regarding the global risk of resistance selection and their safety profile is far from optimal for wide use in the community. For multi-drug resistant pneumococci, ketolides and fluoroquinolones could be considered. A large number of drugs with activity against these multi-drug resistant strains (cephalosporins, carbapenems, glycopeptides, lipopeptides, ketolides, lincosamides, oxazolidinones, glycylcyclines, quinolones, deformylase inhibitors) are currently in development. Most of them are only new derivatives in existing classes, with improved intrinsic activity or lower susceptibility to resistance mechanisms. Except for the new fluoroquinolones, these agents are also primarily targeted towards methicillin-resistant Staphylococcus aureus infections; therefore, demonstration of their clinical efficacy in the management of pneumococcal infections is still awaited.

Quantification of HIV-1 RNA in plasma: comparable results with the NASBA HIV-1 RNA QT and the AMPLICOR HIV monitor test.

We investigated and compared the reproducibility, accuracy, detection limits, and dynamic ranges of two commercial kits for quantification of RNA viral load using a titrated virus stock (laboratory strain HIV-1 IIIB) and 107 plasma samples of 25 HIV-1-infected patients. The high reproducibility of both methods (SD = 0.2-0.3 log for both methods) allowed reliable detection of a 0.5 log change in RNA viral load. Both methods had a similar detection limit (at least 10(3) RNA copies/ml plasma) and a dynamic range that extended over a 5 log (AMPLICOR) or a 6 log (NASBA) range of HIV-1 input. For HIV-1 IIIB, the viral load was compatible with measurements of virus-associated p24 antigen. For 21 patients (91 samples), the RNA viral load was similar with both methods differing by no more than 0.5 log. For four patients, the difference in viral load between the two methods was > 0.5 log for all 16 samples. For three of these patients, this could be explained by mismatches with primers or probes in the gag sequence: there was no correlation to the viral subtype. The RNA viral load determination was highly sensitive compared with p24 antigen measurement (> 95% of patients had a detectable viral load vs. 40% who had a detectable p24 level), but in the p24-positive samples the correlation between the antigen level and the RNA viral load was of only borderline significance. We also found that the viral RNA in whole blood was stable for at least 48 h during transport at room temperature. These observations show that both the NASBA HIV-1 RNA QT test and the AMPLICOR HIV monitor test are reliable parameters of the viral load, with great promise for their use as potential surrogate markers.

Watchful waiting versus immediate catheter removal in ICU patients with suspected catheter-related infection: a randomized trial

Objective To find a subset of patients with suspected central venous catheter (CVC)-related infection (CRI) in whom CVC removal is not needed.Design Randomized controlled trial.Setting Thirty-three-bed ICU.Patients and participants One hundred and forty four patients with suspected CRI in which a change of CVCs was planned were evaluated for inclusion.Interventions Hemodynamically stable patients without proven bacteremia, no insertion site infection, and no intravascular foreign body were randomized to a standard-of-care group (SOC, all CVCs were changed as planned) or a watchful waiting group (WW, CVCs changed when bacteremia was subsequently confirmed or hemodynamic instability occurred).Measurement and results Study groups were compared for incidence of CVC-related bloodstream infection (CR-BSI), resolution of fever, C-reactive protein, SOFA score, duration of ICU stay, and mortality. Of 144 patients with suspected CRI, 80 patients met exclusion criteria. Sixty-four were randomized. Forty-seven of 80 excluded patients were shown to be bacteremic, 20 (25%) of whom had a CR-BSI. Five of 64 (8%) included patients had a CR-BSI during their subsequent ICU stay (two in SOC and three in WW group). All 38 CVCs were changed in the SOC group versus 16 of 42 in the WW group (62% reduction, P<0.01). Resolution of fever, C-reactive protein, SOFA score, duration of ICU stay, and ICU mortality did not differ between SOC and WW group (P>0.1 for all).Conclusions The use of a simple clinical algorithm permits a substantial decrease in the number of unnecessarily removed CVCs without increased morbidity.

Diagnostic Value of Different Adherence Measures Using Electronic Monitoring and Virologic Failure as Reference Standards

Nonadherence to antiretroviral therapy is a substantial problem in HIV and jeopardizes the success of treatment. Accurate measurement of nonadherence is therefore imperative for good clinical management but no gold standard has been agreed on yet. In a single-center prospective study nonadherence was assessed by electronic monitoring: percentage of doses missed and drug holidays and by three self reports: (1) a visual analogue scale (VAS): percentage of overall doses taken; (2) the Swiss HIV Cohort Study Adherence Questionnaire (SHCS-AQ): percentage of overall doses missed and drug holidays and (3) the European HIV Treatment Questionnaire (EHTQ): percentage of doses missed and drug holidays for each antiretroviral drug separately. Virologic failure prospectively assessed during 1 year, and electronic monitoring were used as reference standards. Using virologic failure as reference standard, the best results were for (1) the SHCS-AQ after electronic monitoring (sensitivity, 87.5%; specificity, 78.6%); (2) electronic monitoring (sensitivity, 75%; specificity, 85.6%), and (3) the VAS combined with the SHCS-AQ before electronic monitoring (sensitivity, 87.5%; specificity, 58.6%). The sensitivity of the complex EHTQ was less than 50%. Asking simple questions about doses taken or missed is more sensitive than complex questioning about each drug separately. Combining the VAS with the SHCS-AQ seems a feasible nonadherence measure for daily clinical practice. Self-reports perform better after electronic monitoring: their diagnostic value could be lower when given independently.

Use of Full Sterile Barrier Precautions during Insertion of Arterial Catheters: A Randomized Trial

To investigate whether institution of maximal sterile barrier precautions (SBPs) during arterial catheter (AC) insertion prevents catheter colonization, as is the case for central venous catheters (CVCs), a randomized study was conducted. Three hundred seventy-three patients in whom a radial or dorsalis pedis AC was going to be inserted were randomized to an SBP group or a standard-of-care group. These patients, in addition to all patients who were admitted to the unit with an AC already in place or who were not eligible for the randomized study, were observed for AC-related colonization and infection. Data for 272 randomized patients were available for analysis. The colonization incidence was 20.2 cases per 1000 catheter-days in the SBP group and 15.8 cases per 1000 catheter-days in the control group (P>.1). AC-related infection occurred in 3 patients in the SBP group and in 7 patients in the control group (P>.1). Five episodes of AC-related bloodstream infection were diagnosed (1.5 cases per 1000 catheter-days). Use of SBPs did not prevent AC colonization or infection. The incidence of AC-related infectious complications was comparable to the incidence of CVC-related infection reported in the literature.

Difference in time to positivity of hub-blood versus nonhub-blood cultures is not useful for the diagnosis of catheter-related bloodstream infection in critically ill patients.

ObjectiveThe differential time to positivity (DTTP), defined as the difference in time necessary for the blood cultures taken by a peripheral puncture and through the catheter to become positive has been suggested to be useful in differentiating between catheter-related bloodstream infection (CR-BSI) and other sources of bacteremia. A DTTP of >120 mins was found predominantly in CR-BSI. The objective of our study was to investigate whether DTTP is useful for the diagnosis of CR-BSI in a medical-surgical intensive care unit. DesignProspective clinical study. SettingA 60-bed medical-surgical intensive care unit of a university hospital. PatientsOne hundred consecutive adult patients from whom catheter(s) were to be removed for suspected CR-BSI were studied. InterventionA blood culture (using aerobic and anaerobic culture bottles) was first taken from a new puncture site. Next, a blood culture was taken through every intravascular catheter in place. Measurements and Results DTTP was calculated using the automated BacT/Alert blood culture system. Three patients had CR-BSI and nine patients had noncatheter-related bacteremia. Five patients had catheter-related sepsis without proven bacteremia. There was no significant difference in median DTTP between patients with CR-BSI and noncatheter-related bacteremia (2.1 hrs and 3.3 hrs, respectively;p = .6). Moreover, catheter-related sepsis in patients without bacteremia could not be detected using DTTP. ConclusionDTTP seems not to be useful for the diagnosis of CR-BSI in a medical-surgical intensive care unit.