Implementation of precision medicine in healthcare-A European perspective

The technical development of high-throughput sequencing technologies and the parallel development of targeted therapies in the last decade have enabled a transition from traditional medicine to personalized treatment and care. In this way, by using comprehensive genomic testing, more effective treatments with fewer side effects are provided to each patient-that is, precision or personalized medicine (PM). In several European countries-such as in England, France, Denmark, and Spain-the governments have adopted national strategies and taken "top-down" decisions to invest in national infrastructure for PM. In other countries-such as Sweden, Germany, and Italy with regionally organized healthcare systems-the profession has instead taken "bottom-up" initiatives to build competence networks and infrastructure to enable equal access to PM. In this review, we summarize key learnings at the European level on the implementation process to establish sustainable governance and organization for PM at the regional, national, and EU/international levels. We also discuss critical ethical and legal aspects of implementing PM, and the importance of access to real-world data and performing clinical trials for evidence generation, as well as the need for improved reimbursement models, increased cross-disciplinary education and patient involvement. In summary, PM represents a paradigm shift, and modernization of healthcare and all relevant stakeholders-that is, healthcare, academia, policymakers, industry, and patients-must be involved in this system transformation to create a sustainable, non-siloed ecosystem for precision healthcare that benefits our patients and society at large.

Biomarker-assisted identification of sepsis-related acute liver impairment: a frequent and deadly condition in critically ill patients

Background The prognostic impact of mild/moderate liver impairment among critically ill patients is not known. We aimed to determine whether acute liver impairment, as measured by several biomarkers, (i) is frequent, (ii) influences prognosis and (iii) to determine whether such an effect is specific for infected critically ill patients. Methods A biomarker and clinical cohort study based on a randomized controlled trial. All-cause mortality was the primary endpoint. Biomarkers hyaluronic acid (HA), bilirubin, albumin, alkaline phosphatase and the international normalized ratio (INR) were determined. Multivariable statistics were applied to estimate risk increase according to liver biomarker increase at baseline and the model was adjusted for age, APACHE II, severe sepsis/septic shock vs. milder infection, chronic alcohol abuse Charlson's co-morbidity index, cancer disease, surgical or medical patient, body mass index, sex, estimated glomerular filtration rate, mechanical ventilation and the other biomarkers. Time-to-event graphs were used. The patients were critically ill patients (n = 1096) from nine mixed medical/surgical intensive care units without known hepatobiliary disease. Results HA levels differed between infected patients (median 210.8 ng/mL [IQR: 93.2-556.6]) vs. the non-infected (median 56.8 ng/mL [IQR: 31.9-116.8], p < 0.001). Serum HA quartiles 2, 3 and 4 were independent predictors of 90-day all-cause mortality for the entire population (infected and non-infected). However, the signal was driven by the infected patients (positive interaction test, no signal in non-infected patients). Among infected patients, HA quartiles corresponded directly to the 90-day risk of dying: 1st quartile: 57/192 = 29.7%, 2nd quartile: 84/194 = 43.3%, 3rd quartile: 90/193 = 46.6%, 4th quartile: 101/192 = 52.3 %, p for trend: <0.0001. This finding was confirmed in adjusted analyses: hazard ratio vs. 1st quartile: 2nd quartile: 1.3 [0.9-1.8], p = 0.14, 3rd quartile: 1.5 [1.1-2.2], p = 0.02, 4th quartile: 1.9 [1.3-2.6], p < 0.0001). High bilirubin was also an independent predictor of mortality. Conclusions Among infected critically ill patients, subtle liver impairment, (elevated HA and bilirubin), was associated with a progressive and highly increased risk of death for the patient; this was robust to adjustment for other predictors of mortality. HA can identify patients at high risk.

Small molecule PGC-1α1 protein stabilizers induce adipocyte Ucp1 expression and uncoupled mitochondrial respiration

Objective

The peroxisome proliferator-activated receptor-γ coactivator-1α1 (PGC-1α1) regulates genes involved in energy metabolism. Increasing adipose tissue energy expenditure through PGC-1α1 activation is potentially beneficial for systemic metabolism. Pharmacological PGC-1α1 activators could be valuable tools in the fight against obesity and metabolic disease. Finding such compounds has been challenging partly because PGC-1α1 is a transcriptional coactivator with no known ligand-binding properties. While, PGC-1α1 activation is regulated by several mechanisms, protein stabilization is a crucial limiting step due to its short half-life under unstimulated conditions.

Methods

We designed a cell-based high-throughput screening system to identify PGC-1α1 protein stabilizers. Positive hits were tested for their ability to induce endogenous PGC-1α1 protein accumulation and activate target gene expression in brown adipocytes. Select compounds were analyzed for their effects on global gene expression and cellular respiration in adipocytes.

Results

Among 7,040 compounds screened, we highlight four small molecules with high activity as measured by: PGC-1α1 protein accumulation, target gene expression, and uncoupled mitochondrial respiration in brown adipocytes.

Conclusions

We identify compounds that induce PGC-1α1 protein accumulation and show that this increases uncoupled respiration in brown adipocytes. This screening platform establishes the foundation for a new class of therapeutics with potential use in obesity and associated disorders.

•

A high-throughput platform to identify PGC-1α1 activators.

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PGC-1α1 protein stabilizers work as activators in brown adipocytes.

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Small molecule PGC-1α1 activators induce Ucp1 expression and cellular respiration.

Prediction of non-recovery from ventilator-demanding acute respiratory failure, ARDS and death using lung damage biomarkers: data from a 1200-patient critical care randomized trial

Background

It is unclear whether biomarkers of alveolar damage (surfactant protein D, SPD) or conductive airway damage (club cell secretory protein 16, CC16) measured early after intensive care admittance are associated with one-month clinical respiratory prognosis. If patients who do not recover respiratory function within one month can be identified early, future experimental lung interventions can be aimed toward this high-risk group. We aimed to determine, in a heterogenous critically ill population, whether baseline profound alveolar damage or conductive airway damage has clinical respiratory impact one month after intensive care admittance.

Methods

Biobank study of biomarkers of alveolar and conductive airway damage in intensive care patients was conducted. This was a sub-study of 758 intubated patients from a 1200-patient randomized trial. We split the cohort into a “learning cohort” and “validating cohort” based on geographical criteria: northern sites (learning) and southern sites (validating).

Results

Baseline SPD above the 85th percentile in the “learning cohort” predicted low chance of successful weaning from ventilator within 28 days (adjusted hazard ratio 0.6 [95% CI 0.4–0.9], p = 0.005); this was confirmed in the validating cohort. CC16 did not predict the endpoint. The absolute risk of not being successfully weaned within the first month was 48/106 (45.3%) vs. 175/652 (26.8%), p < 0.0001 (high SPD vs. low SPD). The chance of being “alive and without ventilator ≥20 days within the first month” was lower among patients with high SPD (adjusted OR 0.2 [95% CI 0.2–0.4], p < 0.0001), confirmed in the validating cohort, and the risk of ARDS was higher among patients with high SPD (adjusted OR 3.4 [95% CI 1.0–11.4], p = 0.04)—also confirmed in the validating cohort.

Conclusion

Early profound alveolar damage in intubated patients can be identified by SPD blood measurement at intensive care admission, and high SPD level is a strong independent predictor that the patient suffers from ARDS and will not recover independent respiratory function within one month. This knowledge can be used to improve diagnostic and prognostic models and to identify the patients who most likely will benefit from experimental interventions aiming to preserve alveolar tissue and therefore respiratory function.

Trial registration This is a sub-study to the Procalcitonin And Survival Study (PASS), Clinicaltrials.gov ID: NCT00271752, first registered January 1, 2006

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-016-0212-y) contains supplementary material, which is available to authorized users.

Acute Infection of Cynomolgus Monkeys with Simian Immunodeficiency Virus (SIVSM) as a Model to Evaluate Antiviral Compounds. Effects of 3′-Azido, 3′-Deoxythymidine, Foscarnet and 2′,3′-Dideoxycytidine

Screening of compounds with potential use in the treatment of human immunodeficiency virus (HIV) infections and acquired immunodeficiency syndrome (AIDS) can currently be made in cell culture systems, but there is a need for relevant animal models. We have infected cynomolgus monkeys with simian immunodeficiency virus of sooty mangabey origin (SIVSM) and investigated the influence of multiplicity of infection (MOI) and the effects of three different anti-HIV compounds, 3′-azido-3′-deoxythymidine (AZT), foscarnet (PFA) and 2′,3′-dideoxycytidine (ddC) on the acute infection. To secure a maximal effect of treatment this was started 8h before challenge with SIVSM and the drugs were given subsequently every 8h for 7–9 days. The appearance of viral antigen and antibodies in serum was determined. In control animals the mean day for SIV antigen appearance was Day 5.9 post-infection, whereas in animals treated with 3 × 25 mg kg−1 day−1 of AZT and 3 × 65 mg kg−1 day−1 of PFA there were significant delays in SIV antigen appearance of 1.0 and 3.6 days, respectively. Some delay in antigen appearance was indicated in animals treated with 3 × 0.2 mg kg−1 day−1 of ddC. A delayed antibody response was only seen in animals treated with PFA. Viral infection was not prevented at the multiplicity used with any of the drugs, despite treatment prior to virus inoculation. The animal model described offers attractive features for in vivo evaluation of potential anti-HIV compounds.

Invasive Candida infections and the harm from antibacterial drugs in critically ill patients: data from a randomized, controlled trial to determine the role of ciprofloxacin, piperacillin-tazobactam, meropenem, and cefuroxime

OBJECTIVE

Use of antibiotics in critically ill patients may increase the risk of invasive Candida infection. The objective of this study was to determine whether increased exposure to antibiotics is associated with increased prevalence of invasive Candida infection.

DESIGN

Substudy using data from a randomized controlled trial, the Procalcitonin And Survival Study 2006-2010.

SETTING

Nine multidisciplinary ICUs across Denmark.

PATIENTS

A total of 1,200 critically ill patients.

INTERVENTION

Patients were randomly allocated to either a "high exposure" antibiotic therapy (intervention arm, n = 604) or a "standard exposure" guided by current guidelines (n = 596).

MEASUREMENTS AND MAIN RESULTS

Seventy-four patients met the endpoint, "invasive Candida infection," 40 in the high exposure arm and 34 in standard exposure arm (relative risk = 1.2; 95% CI, 0.7-1.8; p = 0.52). Among medical patients in the high exposure arm, the use of ciprofloxacin and piperacillin/tazobactam was 51% and 75% higher than in the standard exposure arm; no difference in antibiotic exposure was observed between the randomized arms in surgical patients. Among medical intensive care patients, invasive Candida infection was more frequent in the high exposure arm (6.2%; 27/437) than in standard exposure arm (3.3%; 14/424) (hazard ratio = 1.9; 95% CI, 1.0-3.6; p = 0.05). Ciprofloxacin used at study entry independently predicted invasive Candida infection (adjusted hazard ratio = 2.1 [1.1-4.1]); the risk gradually increased with duration of ciprofloxacin therapy: six of 384 in patients not exposed (1.6%), eight of 212 (3.8%) when used for 1-2 days (hazard ratio = 2.5; 95% CI, 0.9-7.3), and 31 of 493 (6.3%) when used for 3 days (hazard ratio = 3.8; 95% CI, 1.6-9.3; p = 0.002). Patients with any ciprofloxacin-containing antibiotic regimen the first 3 days in the trial had a higher risk of invasive Candida infection than did patients on any antibiotic regimen not containing ciprofloxacin (unadjusted hazard ratio = 3.7; 95% CI, 1.6-8.7; p = 0.003; adjusted hazard ratio, 3.4; 95% CI, 1.4-8.0; p = 0.006).

CONCLUSIONS

High exposure to antibiotics is associated to increased risk of invasive Candida infection in medical intensive care patients. Patients with ciprofloxacin-containing regimens had higher risk of invasive Candida infection. Other antibiotics, such as meropenem, piperacillin/tazobactam, and cefuroxime, were not associated with such a risk.

Profound endothelial damage predicts impending organ failure and death in sepsis

Endothelial damage contributes to organ failure and mortality in sepsis, but the extent of the contribution remains poorly quantified. Here, we examine the association between biomarkers of superficial and profound endothelial damage (syndecan-1 and soluble thrombomodulin [sTM], respectively), organ failure, and death in sepsis. The data from a clinical trial, including critically ill patients predominantly suffering sepsis (Clinicaltrials.gov: NCT00271752) were studied. Syndecan-1 and sTM levels at the time of study enrollment were determined. The predictive ability of biomarker levels on death and organ failures during follow-up were assessed in Cox models adjusted for potential confounders including key organ dysfunction measures assessed at enrollment. Of the 1,103 included patients, 418 died. sTM levels at the time of enrollment independently predicted risk of death in adjusted models (hazard ratio [HR] [highest quartile > 14 ng/mL vs. lowest quartile < 7 ng/mL] 2.2 [95% confidence interval [CI]: 1.2-4.0], p = 0.02, respectively). Conversely, syndecan-1 levels failed to predict death (adjusted HR [> 240 vs. < 70 ng/mL] 1.0 [95% CI: 0.6-1.5], p = 0.67). sTM but not syndecan-1 levels at enrollment predicted risk of multiple organ failure during follow-up (HR [> 14 ng/mL vs. < 7 ng/mL] 3.5 [95% CI: 1.5-8.3], p = 0.005 and 2.0 [95% CI: 0.8-5.0], p = 0.1321, respectively). Profound damage to the endothelium independently predicts risk of multiple organ failure and death in septic patients. Our findings also suggest that the detrimental effect of profound endothelial damage on risk of death operates via mechanisms other than causing organ failures per se. Therefore, damage to the endothelium appears centrally involved in the pathogenesis of death in sepsis and could be a target for intervention.

Outbreak of wound botulism in people who inject drugs, Norway, October to November 2013

Binary file ES_Abstracts_Final_ECDC.txt matches

An abbreviated MLVA identifies Escherichia coli ST131 as the major extended-spectrum β-lactamase-producing lineage in the Copenhagen area

Rapid bacterial typing is a valuable and necessary tool in the prevention and detection of outbreaks. The purpose of this study was to adapt a multilocus variable number of tandem repeats analysis (MLVA) for analysis on a benchtop capillary electrophoresis instrument and compare the modified assay with multilocus sequence typing (MLST) for typing cefpodoxime-resistant Escherichia coli (E. coli). Further, we identified the causative resistance mechanisms and epidemiological type of infection for isolates producing extended-spectrum β-lactamases (ESBLs). A collection of E. coli resistant to cefpodoxime was typed by MLST and a modified MLVA assay using a benchtop capillary electrophoresis instrument. Resistance mechanisms were identified by polymerase chain reaction (PCR) and sequencing. Patient history was examined to establish the epidemiological type of infection for ESBL-producing E. coli. MLVA yielded typing results homologous with MLST and it correctly identified E. coli sequence type (ST) 131 that was accounting for 45 % of all ESBL-producing isolates in the sample collection. The majority (76.7 %) of ESBL-producing isolates was healthcare-related and only 23.3 % of the ESBL-producing isolates were community-onset infections (COI), regardless of the ST. Patients with COI were significantly more often of female gender and younger age compared to healthcare-associated infections (HCAI) and hospital-onset infections (HOI). In conclusion, the modified MLVA is a useful tool for the rapid typing of E. coli and it identified ST131 as the predominating ESBL-producing lineage in Copenhagen. Healthcare-related infections were the predominant infection setting of ESBL-producing E. coli and the demographic characteristics differed between patients with COI and healthcare-related infections.

Escherichia coli clonal group A causing bacteraemia of urinary tract origin

Escherichia coli clonal group A (CgA) causes disease in humans. This is the first study investigating the prevalence of CgA among E. coli from non-urine, extraintestinal infections in a northern European country. E. coli blood (n = 196) and paired urine (n = 195) isolates from the same patients with bacteraemia of urinary tract origin were analysed. The isolates were collected from January 2003 through May 2005 at four hospitals in Copenhagen, Denmark. Pulsed-field gel electrophoresis (PFGE) patterns, antimicrobial resistance and patient characteristics were determined for all CgA isolates; presence of virulence-associated genes (VAGs) and serotypes were determined for the blood CgA isolates. Thirty blood isolates (15%) belonged to CgA. CgA blood isolates were associated with female patients and sulfamethoxazole-trimethoprim resistance and they harboured a distinctive VAG profile. The blood and urine isolates from each pair were found to be related in 26 of 27 CgA blood/urine pairs, confirming a urinary tract origin of infection. Furthermore, a relationship between the PFGE patterns of CgA blood/urine isolates and CgA isolates from UTI patients in general practice and a CgA isolate from a community-dwelling human reported previously, was found, suggesting a community origin of CgA. The finding of CgA strains in 15% of the E. coli bloodstream infections with a urinary tract origin in Denmark suggests that CgA constitutes an important clonal lineage among extraintestinal pathogenic E. coli. A reservoir of this pathogenic E. coli group in the community causing not only UTI but also more severe infections such as bacteraemia has implications for public health.

Kidney failure related to broad-spectrum antibiotics in critically ill patients: secondary end point results from a 1200 patient randomised trial

OBJECTIVES

To explore whether a strategy of more intensive antibiotic therapy leads to emergence or prolongation of renal failure in intensive care patients.

DESIGN

Secondary analysis from a randomised antibiotic strategy trial (the Procalcitonin And Survival Study). The randomised arms were conserved from the primary trial for the main analysis.

SETTING

Nine mixed surgical/medical intensive care units across Denmark.

PARTICIPANTS

1200 adult intensive care patients, 18+ years, expected to stay +24 h.

EXCLUSION CRITERIA

bilirubin >40 mg/dl, triglycerides >1000 mg/dl, increased risk from blood sampling, pregnant/breast feeding and psychiatric patients.

INTERVENTIONS

Patients were randomised to guideline-based therapy ('standard-exposure' arm) or to guideline-based therapy supplemented with antibiotic escalation whenever procalcitonin increased on daily measurements ('high-exposure' arm).

MAIN OUTCOME MEASURES

Primary end point: estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2). Secondary end points: (1) delta eGFR after starting/stopping a drug and (2) RIFLE criterion Risk 'R', Injury 'I' and Failure 'F'. Analysis was by intention to treat.

RESULTS

28-day mortality was 31.8% and comparable (Jensen et al, Crit Care Med 2011). A total of 3672/7634 (48.1%) study days during follow-up in the high-exposure versus 3016/6949 (43.4%) in the 'standard-exposure arm were spent with eGFR <60 ml/min/1.73 m(2), p<0.001. In a multiple effects model, 3 piperacillin/tazobactam was identified as causing the lowest rate of renal recovery of all antibiotics used: 1.0 ml/min/1.73 m(2)/24 h while exposed to this drug (95% CI 0.7 to 1.3 ml/min/1.73 m(2)/24 h) vs meropenem: 2.9 ml/min/1.73 m(2)/24 h (2.5 to 3.3 ml/min/1.73 m(2)/24 h)); after discontinuing piperacillin/tazobactam, the renal recovery rate increased: 2.7 ml/min/1.73 m(2)/24 h (2.3 to 3.1 ml/min/1.73 m(2) /24 h)). eGFR <60 ml/min/1.73 m(2) in the two groups at entry and at last day of follow-up was 57% versus 55% and 41% versus 39%, respectively.

CONCLUSIONS

Piperacillin/tazobactam was identified as a cause of delayed renal recovery in critically ill patients. This nephrotoxicity was not observed when using other beta-lactam antibiotics.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00271752.

Characteristics of Escherichia coli causing persistence or relapse of urinary tract infections: phylogenetic groups, virulence factors and biofilm formation

Recurrent urinary tract infections (RUTIs) pose a major problem but little is known about characteristics of Escherichia coli associated with RUTI. This study includes E. coli from 155 women with community-acquired lower urinary tract infections (UTIs) randomized to one of three dosing regiments of pivmecillinam and aimed to identify associations between the presence of 29 virulence factor genes (VFGs), phylogenetic groups and biofilm formation and the course of infection during follow-up visits at 8-10 and 35-49 days post-inclusion, respectively. E. coli causing persistence or relapse were more often of phylogenetic group B2 and had a significantly higher aggregate VFG score than E. coli that were not detectable at follow-up. Specifically, these E. coli causing persistence or relapse were characterized by a higher prevalence of hemolysis and 12 VFGs (sfa/focDE, papAH, agn43, chuA, fyuA, iroN, kpsM II, kpsM II K2, cnf1, hlyD, malX and usp). KpsM II K2 and agn43a(CFT073) were independently associated with persistence or relapse. No specific combination of presence/absence of VFGs could serve as a marker to predict RUTI. Stratifying for VFGs, seven days of pivmecillinam treatment reduced the prevalence of persistence or relapse of UTI compared with three days. In vitro biofilm formation was not higher among E. coli causing persistence or relapse. The presence of agn43a(CFT073) or agn43b(CFT073) was associated with biofilm forming capacity. In conclusion, our results show potential targets for prevention and treatment of persistence/relapse of UTI and potential markers for selecting treatment lengths and warrant studies of these and new VFGs.

Reactivation of Tuberculosis During Immunosuppressive Treatment in a Patient with a Positive QuantiFERON®-RD1 Test

A patient with polymyositis developed tuberculosis during immunosuppressive treatment. Tuberculin Skin Test and chest X-ray failed to demonstrate latent tuberculosis, whereas a blood sample that was tested with a modified QuantiFERON-TB-assay, using the recombinant ESAT-6 and CFP-10, was positive indicating that this patient was latently infected before immunosuppressive therapy. This case indicates the risk of progressing from latent to active tuberculosis given that the subject is RD1 responsive, and we believe that preventive anti-tuberculous treatment could have prevented this case of tuberculosis. We suggest that RD1 based tests are evaluated further in immunocompromised patients.

Human metapneumovirus and respiratory syncytial virus in hospitalized danish children with acute respiratory tract infection

The newly discovered human metapneumovirus (hMPV) has been shown to be associated with respiratory illness. We determined the frequencies and clinical features of hMPV and respiratory syncytial virus (RSV) infections in 374 Danish children with 383 episodes of acute respiratory tract infection (ARTI). Study material comprised routine nasopharyngeal aspirates obtained during 2 winter seasons (November-May) 1999-2000 and 2001-2002 from children hospitalized at the Departments of Paediatrics, Hvidovre Hospital and Amager Hospital, Denmark. hMPV was detected in 11 (2.9%) and RSV in 190 (49.6%) ARTI episodes by real-time reverse transcription-polymerase chain reaction using primers targeting the hMPV N gene and the RSV L gene. Two children were co-infected with hMPV and RSV. They were excluded from statistical analysis. Hospitalization for ARTI caused by hMPV was restricted to very young children 1-6 months of age. Asthmatic bronchitis was diagnosed in 66.7% of hMPV and 10.6% of RSV-infected children (p < 0.001). Overall symptoms and clinical findings were similar among hMPV and RSV positive episodes, but more RSV-infected children required respiratory support. hMPV is present in young Danish children hospitalized with ARTI although less frequent than RSV and with a tendency to a milder clinical course.

The Procalcitonin And Survival Study (PASS) - a randomised multi-center investigator-initiated trial to investigate whether daily measurements biomarker Procalcitonin and pro-active diagnostic and therapeutic responses to abnormal Procalcitonin levels, can improve survival in intensive care unit patients. Calculated sample size (target population): 1000 patients

BACKGROUND

Sepsis and complications to sepsis are major causes of mortality in critically ill patients. Rapid treatment of sepsis is of crucial importance for survival of patients. The infectious status of the critically ill patient is often difficult to assess because symptoms cannot be expressed and signs may present atypically. The established biological markers of inflammation (leucocytes, C-reactive protein) may often be influenced by other parameters than infection, and may be unacceptably slowly released after progression of an infection. At the same time, lack of a relevant antimicrobial therapy in an early course of infection may be fatal for the patient. Specific and rapid markers of bacterial infection have been sought for use in these patients.

METHODS

Multi-centre randomized controlled interventional trial. Powered for superiority and non-inferiority on all measured end points. Complies with, "Good Clinical Practice" (ICH-GCP Guideline (CPMP/ICH/135/95, Directive 2001/20/EC)). Inclusion: 1) Age > or = 18 years of age, 2) Admitted to the participating intensive care units, 3) Signed written informed consent.Exclusion: 1) Known hyper-bilirubinaemia. or hypertriglyceridaemia, 2) Likely that safety is compromised by blood sampling, 3) Pregnant or breast feeding. Computerized Randomisation: Two arms (1:1), n = 500 per arm: Arm 1: standard of care. Arm 2: standard of care and Procalcitonin guided diagnostics and treatment of infection. Primary Trial Objective: To address whether daily Procalcitonin measurements and immediate diagnostic and therapeutic response on day-to-day changes in procalcitonin can reduce the mortality of critically ill patients.

DISCUSSION

For the first time ever, a mortality-endpoint, large scale randomized controlled trial with a biomarker-guided strategy compared to the best standard of care, is conducted in an Intensive care setting. Results will, with a high statistical power answer the question: Can the survival of critically ill patients be improved by actively using biomarker procalcitonin in the treatment of infections? 700 critically ill patients are currently included of 1000 planned (June 2008). Two interim analyses have been passed without any safety or futility issues, and the third interim analysis is soon to take place. Trial registration number at clinicaltrials.gov: Id. nr.: NCT00271752).

[Infection control standards and accreditation--the way forward?]

Evidence-based guidelines on infection control have existed for the last decade. The infection control guidelines in, "The Danish Health Care Quality Assessment Programme" are based on these guidelines. Experience from Danish health care organisations which have been accredited by Joint Commission International and Health Quality Service is that leadership involvement in infection control improves priority and focus on infection control practice with the aim of preventing nosocomial infections. Therefore, national accreditation will by focus improve infection control in healthcare settings.

Primary pneumocystis infection in infants hospitalized with acute respiratory tract infection

Acquisition of Pneumocystis jirovecii infection early in life has been confirmed by serologic studies. However, no evidence of clinical illness correlated with the primary infection has been found in immunocompetent children. We analyzed 458 nasopharyngeal aspirates from 422 patients hospitalized with 431 episodes of acute respiratory tract infection (RTI) by using a real-time PCR assay. In 68 episodes in 67 infants, P. jirovecii was identified. The odds ratio (95% confidence interval) of a positive signal compared with the first quartile of age (7-49 days) was 47.4 (11.0-203), 8.7 (1.9-39.7), and 0.6 (0.1-6.7) for infants in the second (50-112 days), third (113-265 days), and fourth (268-4,430 days) age quartiles, respectively. Infants with an episode of upper RTI (URTI) were 2.0 (1.05-3.82) times more likely to harbor P. jirovecii than infants with a lower RTI. P. jirovecii may manifest itself as a self-limiting URTI in infants, predominantly those 1.5-4 months of age.

Diagnosis of pulmonary infection with Toxoplasma gondii in immunocompromised HIV-positive patients by real-time PCR

The aim of the study presented here was to evaluate the use of PCR for improving the diagnosis of Toxoplasma gondii infection in immunocompromised hosts. Three hundred thirty-two bronchoalveolar lavage (BAL) fluid samples were analyzed by real-time PCR targeting a 529 bp element of T. gondii. In positive samples, the genotype of the parasite was determined by sequence analysis of the GRA6 gene. Positive results were achieved for 2% (7/332) of the samples tested. Genotyping was possible in two samples and revealed GRA6 type II T. gondii. PCR for detecting T. gondii in BAL samples should be performed in all immunosuppressed HIV-positive patients with symptoms of a systemic infection of unknown etiology. Trimethoprim-sulfamethoxazole prophylaxis does not exclude concomitant infection with T. gondii.

Pulsed-field gel electrophoresis typing of Escherichia coli strains from samples collected before and after pivmecillinam or placebo treatment of uncomplicated community-acquired urinary tract infection in women

The primary infecting Escherichia coli strains from 156 women with community-acquired uncomplicated urinary tract infection (UTI) randomized to pivmecillinam or placebo and the E. coli strains causing UTI at two follow-up visits were typed using pulsed-field gel electrophoresis (PFGE). In the pivmecillinam treatment group PFGE showed that among patients having a negative urine culture at the first follow-up 77% (46/60) had a relapse with the primary infecting E. coli strain and 23% (14/60) had reinfection with a new E. coli strain at the second follow-up. Among patients having E. coli at the first follow-up PFGE showed that 80% (32/40) had persistence with the primary infecting E. coli strain, 15% (6/40) had reinfection with a new E. coli strain, and 5% (2/40) had different E. coli strains at the two follow-up visits (one had reinfection followed by relapse, and the other had persistence followed by reinfection). In the placebo group the majority had E. coli at the first follow-up. PFGE showed that among these patients 96% (50/52) had persistence with the primary infecting E. coli strain and 4% (2/50) had different E. coli strains at the two follow-up visits (both had persistence followed by reinfection). The finding that the majority of UTIs at follow-up are caused by the primary infecting E. coli strain supports the theory of a vaginal and rectal reservoir but could also support the recent discovery that E. coli strains are able to persist in the bladder epithelium despite appropriate antibiotic treatment, constituting a reservoir for recurrent UTI.

Latent tuberculosis in HIV positive, diagnosed by the M. tuberculosis specific interferon-gamma test

Background

Although tuberculosis (TB) is a minor problem in Denmark, severe and complicated cases occur in HIV positive. Since the new M. tuberculosis specific test for latent TB, the QuantiFERON-TB In-Tube test (QFT-IT) became available the patients in our clinic have been screened for the presence of latent TB using the QFT-IT test. We here report the results from the first patients screened.

Methods

On a routine basis the QFT-IT test was performed and the results from 590 HIV positive individuals consecutively tested are presented here. CD4 cell count and TB risk-factors were recorded from patient files.

Main findings

27/590(4.6%) of the individuals were QFT-IT test positive, indicating the presence of latent TB infection. Among QFT-IT positive patients, 78% had risk factors such as long-term residency in a TB high endemic area (OR:5.7), known TB exposure (OR:4.9) or previous TB disease (OR:4.9). The prevalence of latent TB in these groups were 13%, 16% and 19% respectively. There was a strong correlation between low CD4 T-cell count and a low mitogen response (P < 0.001;Spearman) and more patients with low CD4 cell count had indeterminate results.

Conclusion

We found an overall prevalence of latent TB infection of 4.6% among the HIV positive individuals and a much higher prevalence of latent infection among those with a history of exposure (16%) and long term residency in a high endemic country (13%). The QFT-IT test may indeed be a useful test for HIV positive individuals, but in severely immunocompromised, the test may be impaired by T-cell anergy.

[Epidemic increase in methicillin-resistant Staphylococcus aureus in Copenhagen]

INTRODUCTION

We have found an epidemic increase in methicillin-resistant Staphylococcus aureus (MRSA) in Copenhagen. The increase has a complex background and involves hospitals, nursing homes and persons nursed in their own home.

MATERIAL AND METHODS

We found 33 MRSA patients in 2003 and 121 in 2004. All isolates have been spa-typed and epidemiologic information collected.

RESULTS

The number of MRSA cases has a doubling time of about six months. The epidemic has been caused by many different MRSA types and 31 staphylococcus protein A genotypes (spa types). MRSA has caused several hospital outbreaks and is endemic in 10 nursing homes. Five staff members from nursing homes have been infected with MRSA. MRSA commonly causes skin and soft tissue infections (76%), but serious infections such as septicaemia and pneumonia are also found.

CONCLUSION

Treatment of MRSA-infected patients is costly due to isolation regimes, increase in bed-days and treatment with special antibiotics. After treatment of the infection and in cases of MRSA carriage, MRSA is found on the skin and in the nose. Carriage of MRSA can be eradicated by washing with chlorhexidine and nasal administration of mupirocin. The necessary resources for handling the epidemic are not available. Without active intervention, this situation will have serious implications for the health care system.

Zinc deficiency is of limited clinical importance in the elderly (>69 y) of Oslo

BACKGROUND

Zinc is an important trace element, and deficiency can cause disease and impairment of several physiological functions.

OBJECTIVE

To examine s-zinc concentration in a large elderly population (347 subjects), and correlate it to standard biochemical markers, nutritional core indicators, and anamnestic data.

DESIGN

A randomized population survey, studying two groups of elderly; one living at home and the other recently admitted to hospital.

RESULTS

Serum zinc concentration was (Mean SD) in the home group (11.6 1.8 micromoles /L), and in the hospital group (11,5 2.5 micromoles /L). S-zinc was below 8 micromol/L in the hospital group in 22 of 250 patients and in 4 out of 97 of the home group. There was no significant difference in prevalence of zinc deficiency in hospital versus the home living group. Low s-zinc was significantly correlated to diarrhea, but to no other marker used in this study.

CONCLUSION

Zinc deficiency is most probably of limited clinical importance in the elderly of Oslo, and there is no biochemical or nutritional marker that in addition to s-zinc can aid in the diagnosis.

Seminational surveillance of fungemia in Denmark: notably high rates of fungemia and numbers of isolates with reduced azole susceptibility

The aim of this study was to present the first set of comprehensive data on fungemia in Denmark including the distribution of species and range of susceptibility to major antifungal compounds based on a seminational surveillance study initiated in 2003. The catchment area of the participating hospitals had a population of 2.8 million, or 53% of the Danish population. A total of 303 episodes of fungemia were registered (annual rate, 11 of 100,000 people or 0.49 of 1,000 hospital discharges). Candida species accounted for 97.4% of the fungal pathogens. C. albicans was the predominant species (63%), but the proportion varied from 57% to 72% among participating departments of clinical microbiology. C. glabrata was the second most frequent species (20%; range, 8% to 32%). C. krusei was a rare isolate (3%) and occurred only at two of the participating hospitals. Retrospective data retrieved from the Danish laboratory systems documented a continuous increase of candidemia cases since the early 1990s. For the 272 susceptibility-tested isolates, MICs of amphotericin B and caspofungin were within the limits expected for the species or genus. However, decreased azole susceptibility, defined as a fluconazole MIC of >8 microg/ml and/or itraconazole MIC of >0.125 microg/ml, was detected for 11 Candida isolates that were neither C. glabrata nor C. krusei. Including intrinsically resistant fungi, we detected decreased susceptibility to fluconazole and/or itraconazole in 87 (32%) current Danish bloodstream fungal isolates. We showed a continuous increase of fungemia in Denmark and an annual rate in 2003 to 2004 higher than in most other countries. The proportion of bloodstream fungal isolates with reduced susceptibility to fluconazole and/or itraconazole was also notably high.

The rationale behind a vaccine based on multiple HIV antigens

The viral diversity of HIV-1 is likely to require a vaccine strategy that induces broad cellular and humoral anti-HIV-1 immunity. Our strategy is based on multiple HIV-1 DNA immunogens together with adjuvant recombinant granulocyte-macrophage stimulating factor. This article describes pre-clinical and clinical work preceding the initiation of clinical HIV-1 phase I/II trials.

Prospective evaluation of a whole-blood test using Mycobacterium tuberculosis-specific antigens ESAT-6 and CFP-10 for diagnosis of active tuberculosis

A new immunodiagnostic test based on the Mycobacterium tuberculosis-specific antigens CFP-10/ESAT-6(QFT-RD1) has been launched as an aid in the diagnosis of latent tuberculosis (TB) infection (LTBI). The aim of this study was to evaluate this test for the diagnosis of active TB. Eighty-two patients with suspicion of TB and 39 healthy BCG-vaccinated persons were enrolled. Forty-eight had active TB, 25 did not, and 9 were excluded. Sensitivity and specificity of the test for active TB were evaluated in a prospective blinded manner in patients suspected of TB. The sensitivity of the QFT-RD1 was 85% (40/48; confidence interval [CI], 75 to 96), and it was higher than the sensitivity of microscopy, 42% (20/48; CI, 27 to 56; P = 0.001), and culture, 59% (27/46; CI, 44 to 73; P = 0.009). Of patients with extrapulmonary TB, 92% (12/13) were QFT-RD1 positive, whereas only 31% (4/13) were positive by microscopy and 42% (5/12) by culture (P < 0.05), and 87% (13/15) of those who were negative by both microscopy and culture were QFT-RD1 positive. By combining microscopy and culture with the QFT-RD1 test, sensitivity increased to 96% (CI, 90 to 102). Ten of 25 (40%) non-TB patients were QFT-RD1 positive, resulting in a specificity of 60%. However, 80% (8/10) of these had risk-factors for TB, indicating latent infection in this group. In healthy controls, only 3% (1/39) were QFT-RD1 positive. In conclusion, the QFT-RD1 test is sensitive for diagnosis of TB, especially in patients with negative microscopy and culture. The accuracy of the QFT-RD1 test will vary with the prevalence of LTBI. We suggest that the QFT-RD1 test could be a very useful supplementary tool for the diagnosis of TB.

Detection of Mycobacterium tuberculosis complex in formalin-fixed, paraffin-embedded tissue specimens with necrotizing granulomatous inflammation by strand displacement amplification

Rapid, reliable diagnosis of tuberculosis is essential to initiate correct treatment, avoid severe complications, and prevent transmission. Conventional microbiological methods may not be an option if samples are formalin-fixed and paraffin-embedded (FFPE) for histopathological examination. With the demonstration of necrotizing granulomatous inflammation, tuberculosis becomes an important differential diagnosis, although it was not initially suspected. Following paraffin extraction, BDProbeTec ET strand displacement amplification for detection of Mycobacterium tuberculosis complex (MTC) was applied to 47 prospectively and 19 retrospectively collected FFPE samples from various sources with granulomatous inflammation and results were compared to tuberculosis notification. Of the prospective samples, 20 were from patients who were notified as having tuberculosis and the assay was positive in 18 (90%). Specificity was 100%. For 27 of the patients with prospectively collected FFPE specimens, culture was performed on a specimen collected at a later date from the same location. Culture revealed MTC in 14 and nontuberculous mycobacteria in four. BDProbeTec ET was positive in 13 (92.8%) of the patients with positive MTC culture and negative in the remaining. The sensitivity and specificity in 19 archival samples was 40% and 100%, respectively, compared to notification data. The assay provided rapid, correct diagnosis on different sources of FFPE samples collected prospectively and therefore offers an important supplementary method for patients where tuberculosis was not initially suspected.

Rapid, automated, nonradiometric susceptibility testing of Mycobacterium tuberculosis complex to four first-line antituberculous drugs used in standard short-course chemotherapy

The increasing prevalence of drug-resistant tuberculosis necessitates rapid and accurate susceptibility testing. The nonradiometric BACTEC Mycobacteria Growth Indicator Tube 960 (MGIT) system for susceptibility testing was evaluated on 222 clinical Mycobacterium tuberculosis complex isolates for isoniazid, rifampin, and ethambutol. Fifty-seven of the isolates were tested for pyrazinamide. Results were compared to those of radiometric BACTEC 460 system and discrepancies were resolved by the agar proportion method. We found an overall agreement of 99.0% for isoniazid, 99.5% for rifampin, 98.2% for ethambutol, and 100% for pyrazinamide. After resolution of discrepancies, MGIT yielded no false susceptibility for rifampin and isoniazid. Although turnaround times were comparable, MGIT provides an advantage as inoculation can be done on any weekday as the growth is monitored automatically. The automated MGIT system is a rapid and reliable alternative for susceptibility testing of M. tuberculosis complex to first-line drugs.

Strain typing methods and molecular epidemiology of Pneumocystis pneumonia

Several typing methods, with different strengths and weaknesses, are available for studies of Pneumocystis pneumonia.

Pneumocystis pneumonia (PCP) caused by the opportunistic fungal agent Pneumocystis jirovecii (formerly P. carinii) continues to cause illness and death in HIV-infected patients. In the absence of a culture system to isolate and maintain live organisms, efforts to type and characterize the organism have relied on polymerase chain reaction–based approaches. Studies using these methods have improved understanding of PCP epidemiology, shedding light on sources of infection, transmission patterns, and potential emergence of antimicrobial resistance. One concern, however, is the lack of guidance regarding the appropriateness of different methods and standardization of these methods, which would facilitate comparing results reported by different laboratories.

Improved sensitivity of nucleic acid amplification for rapid diagnosis of tuberculous meningitis

Early diagnosis of tuberculous meningitis (TBM) is essential for a positive outcome; but present microbiological diagnostic techniques are insensitive, slow, or laborious. We evaluated the standard BDProbeTec ET strand displacement amplification method (the standard ProbeTec method) for the detection of Mycobacterium tuberculosis complex organisms in parallel with the ProbeTec method with a modified pretreatment procedure with 101 prospectively collected cerebrospinal fluid specimens from 94 patients with suspected TBM. By the modified method, the sample-washing step was omitted. A definitive diagnosis was attained by culture. Thirteen specimens from 12 patients were culture positive for M. tuberculosis complex organisms; three specimens (23%) were microscopy positive for acid-fast bacilli. Among the culture-positive specimens, the standard ProbeTec method was positive for 8 (61.5%) and the modified assay was positive for 10 (76.9%). The overall specificity by both procedures was 98.8% compared to the results of culture. After discrepancy analysis, conducted by reviewing the patients' previous laboratory data, the specificity increased to 100%. If the cutoff value for respiratory specimens was adjusted from the recommended value of 3,400 to 1,000, the sensitivity of the modified procedure increased to 84.7%, with unchanged specificity. Results were obtained in 3 to 4 h. The new pretreatment procedure with the ProbeTec assay described here provides a rapid, simple, and sensitive tool for the diagnosis of TBM.

Serotype-specific mortality from invasive Streptococcus pneumoniae disease revisited

Background

Invasive infection with Streptococcus pneumoniae (pneumococci) causes significant morbidity and mortality. Case series and experimental data have shown that the capsular serotype is involved in the pathogenesis and a determinant of disease outcome.

Methods

Retrospective review of 464 cases of invasive disease among adults diagnosed between 1990 and 2001. Multivariate Cox proportional hazard analysis.

Results

After adjustment for other markers of disease severity, we found that infection with serotype 3 was associated with an increased relative risk (RR) of death of 2.54 (95% confidence interval (CI): 1.22–5.27), whereas infection with serotype 1 was associated with a decreased risk of death (RR 0.23 (95% CI, 0.06–0.97)). Additionally, older age, relative leucopenia and relative hypothermia were independent predictors of mortality.

Conclusion

Our study shows that capsular serotypes independently influenced the outcome from invasive pneumococcal disease. The limitations of the current polysaccharide pneumococcal vaccine warrant the development of alternative vaccines. We suggest that the virulence of pneumococcal serotypes should be considered in the design of novel vaccines.

Mutations in the dihydropteroate synthase gene of Pneumocystis jiroveci isolates from Portuguese patients with Pneumocystis pneumonia

The aim of this study was to evaluate the frequency of mutations of the P. jiroveci dihydropteroate synthase (DHPS) gene in an immunocompromised Portuguese population and to investigate the possible association between DHPS mutations and sulpha exposure. In the studied population, DHPS gene mutations were not significantly more frequent in patients exposed to sulpha drugs compared with patients not exposed (P=0.390). The results of this study suggest that DHPS gene mutations are frequent in the Portuguese immunocompromised population but do not seem associated with previous sulpha exposure. These results are consistent with the possibility of an incidental acquisition and transmission of P. jiroveci mutant types, either by person to person transmission or from an environmental source.

Direct detection of multidrug-resistant Mycobacterium tuberculosis in clinical specimens in low- and high-incidence countries by line probe assay

The INNO-LiPA Rif.TB assay is designed for the detection of rpoB gene mutations causing rifampin resistance in isolates. We applied the method directly to 60 Lithuanian and Danish clinical specimens to detect rifampin resistance rapidly. Results were obtained in 78.3% of clinical specimens, and all were concordant with those obtained by BACTEC 460. The assay could have major impact on the management of multidrug-resistant tuberculosis.

Service screening with mammography. Long-term effects on breast cancer mortality in the county of Gävleborg, Sweden

In the current study the long-term effects of a pilot service screening programme in the Swedish county of Gävleborg were studied. Women aged 40-64 years in 13 sub-areas were followed from start of screening between 1974 and 1979. Two control groups were used for comparison; the neighbouring counties and all of Sweden. A reference period prior to the study period was used to facilitate an adjustment for possible differences in baseline breast cancer mortality. Only deaths from breast cancer diagnosed after the first invitation to screening were analysed. Two outcome measures were used for breast cancer mortality; the underlying cause of death and excess mortality. Using the neighbouring counties as a control group, the relative risk, after 22 years of follow-up, of 10 years of screening was estimated at 0.84 (95% CI 0.71-1.00) using excess mortality. Due to lead time bias the relative risk was overestimated by 4%. Hence, a significant 20% reduction of breast cancer excess mortality was found.

Comparison of three small chamber test methods for the measurement of VOC emission rates from paint

The aim of this study was to demonstrate a correlation between the measurement of emission rates of volatile organic compounds (VOCs) in three different climate chambers. In order to achieve this aim, the early state of the emission process in the three chambers was investigated and the effects of some important factors on the emission rates from paint were determined. The paper presents results of measurements in three different climate chambers. For the study, a 1-m3 chamber, a field and laboratory emission cell (FLEC), and a chamber for laboratory investigation of materials pollution and air quality (CLIMPAQ) were used. The airflow and surface area were selected so that the area-specific ventilation rates were identical in the three chambers. Temperature and relative humidity were identical during all the measurements. The paint examined was a solvent-based alkyd paint intended for indoor, which use contained between 30 and 60% of white spirit in wet condition. The paint was applied to electropolished and cleaned stainless steel plates. After application, the test material was stored for 14 days for drying in a well-ventilated conditioning room before the measurements were made. After 2 weeks storage, the most pronounced emissions were pentanal, hexanal, octanal, and decanol. The period before the emission rate stabilized differed for the three chambers studied. However, all chambers gave similar emission rates within the overall uncertainty used in these experiments.

Detection of Pneumocystis DNA in samples from patients suspected of bacterial pneumonia--a case-control study

BACKGROUND

Pneumocystis jiroveci (formerly known as P. carinii f.sp. hominis) is an opportunistic fungus that causes Pneumocystis pneumonia (PCP) in immunocompromised individuals. Pneumocystis jiroveci can be detected by polymerase chain reaction (PCR). To investigate the clinical importance of a positive Pneumocystis-PCR among HIV-uninfected patients suspected of bacterial pneumonia, a retrospective matched case-control study was conducted.

METHODS

Respiratory samples from 367 patients suspected of bacterial pneumonia were analysed by PCR amplification of Pneumocystis jiroveci. To compare clinical factors associated with carriage of P. jiroveci, a case-control study was done. For each PCR-positive case, four PCR-negative controls, randomly chosen from the PCR-negative patients, were matched on sex and date of birth.

RESULTS

Pneumocystis-DNA was detected in 16 (4.4%) of patients. The median age for PCR-positive patients was higher than PCR-negative patients (74 vs. 62 years, p = 0.011). PCR-positive cases had a higher rate of chronic or severe concomitant illness (15 (94%)) than controls (32 (50%)) (p = 0.004). Twelve (75%) of the 16 PCR positive patients had received corticosteroids, compared to 8 (13%) of the 64 PCR-negative controls (p < 0.001). Detection of Pneumocystis-DNA was associated with a worse prognosis: seven (44%) of patients with positive PCR died within one month compared to nine (14%) of the controls (p = 0.01). None of the nine PCR-positive patients who survived had developed PCP at one year of follow-up.

CONCLUSIONS

Our data suggest that carriage of Pneumocystis jiroveci is associated with old age, concurrent disease and steroid treatment. PCR detection of P. jiroveci has low specificity for diagnosing PCP among patients without established immunodeficiency. Whether overt infection is involved in the poorer prognosis or merely reflects sub-clinical carriage is not clear. Further studies of P. jiroveci in patients receiving systemic treatment with corticosteroids are warranted.

Development of a rapid real-time PCR assay for quantitation of Pneumocystis carinii f. sp. carinii

A method for reliable quantification of Pneumocystis carinii in research models of P. carinii pneumonia (PCP) that is more convenient and reproducible than microscopic enumeration of organisms would greatly facilitate investigations of this organism. We developed a rapid quantitative touchdown (QTD) PCR assay for detecting P. carinii f. sp. carinii, the subspecies of P. carinii commonly used in research models of PCP. The assay was based on the single-copy dihydrofolate reductase gene and was able to detect <5 copies of a plasmid standard per tube. It was reproducibly quantitative (r = 0.99) over 6 log values for standards containing > or =5 copies/tube. Application of the assay to a series of 10-fold dilutions of P. carinii organisms isolated from rat lung demonstrated that it was reproducibly quantitative over 5 log values (r = 0.99). The assay was applied to a recently reported in vitro axenic cultivation system for P. carinii and confirmed our microscopy findings that no organism multiplication had occurred during culture. For all cultures analyzed, QTD PCR assays showed a decrease in P. carinii DNA that exceeded the expected decrease due to dilution of the inoculum upon transfer. In conclusion, a rapid, sensitive, and reproducible quantitative PCR assay for P. carinii f. sp. carinii has been developed and is applicable to in vivo as well as in vitro systems. The assay should prove useful for conducting studies in which quantification of organism burden or growth assessment is critical, such as in vitro antimicrobic susceptibility testing or in vivo immunopathological experiments.

Evaluation of a new commercial assay for diagnosis of pulmonary and nonpulmonary tuberculosis

A new commercial assay for the diagnosis of tuberculosis, the BDProbeTec ET Direct Detection assay (Becton Dickinson, USA), was evaluated using 351 respiratory and 372 nonrespiratory specimens. The results were compared to detection of Mycobacterium tuberculosis complex (MTC) by conventional culture. Among the 351 respiratory specimens, MTC bacteria were identified in 150, of which 85 were positive by both microscopy and the assay. Sixty-five specimens culture positive for MTC were microscopy negative; of these, 39 were positive in the assay. All 26 specimens culture positive for nontuberculous mycobacteria (NTM) were negative by the assay. Of 175 specimens culture negative for MTC, 3 were falsely positive by the assay and 1 yielded inhibition. The overall sensitivity and specificity values were 82.7% and 98.5%, respectively. The sensitivity for microscopy-positive and -negative respiratory specimens was 100% and 60%, respectively. After correction for discrepancies, the specificity was 99% compared with notification data. The BDProbeTec ET assay detected 66 of 67 microscopy-positive and 50 of 125 microscopy-negative nonrespiratory specimens. The result for one specimen was inconclusive. All nine specimens containing NTM were negative by the assay. Of 171 specimens culture negative for MTC, 6 were falsely positive by the assay. The overall sensitivity and specificity values obtained with nonrespiratory specimens were 60.7% and 96.7%, respectively. After examining discrepancies by reviewing the patients' histories, the specificity was 98.9%. The sensitivity was 98.5% in microscopy-positive specimens and 40.3% in microscopy-negative specimens. The overall inhibition rate was 0.3%. The BDProbeTec ET assay is a fast, effective, and user-friendly system that can be used for rapid detection of MTC bacteria in respiratory and microscopy-positive nonrespiratory specimens as an important supplement to smear and culture.

Development of posterior capsule opacification in the rabbit

PURPOSE

The aim of the present study was to characterize the development of after-cataract in the rabbit by measuring its wet weight, protein, DNA and glycosaminoglycan (GAG) contents and using Scheimpflug and slitlamp analysis. Further, aqueous humor (AqH) leukocytes, protein and lens epithelial cell proliferation activity were determined.

METHODS

AqH was collected and capsular bags including after-cataract were dissected free on days 0, 1, 7, 14, 28 and 56 after cataract surgery. The wet weights were determined and the contents of DNA, protein and GAG in the capsular bags including after-cataract were analyzed. AqH was analyzed for leukocytes, protein and proliferative activity. In another set of experiments, rabbit eyes were analyzed by the Scheimpflug technique and slitlamp examination on days 0, 1, 7, 14, 28 and 56 after cataract surgery. The wet weight of the capsular bag with the after-cataract was also determined.

RESULTS

An increase was found in the wet weight (480%) and the contents of protein (221%), DNA (945%) and GAG (336%) of the capsular bags including after-cataract during the experimental period. In the AqH, all 3 variables measured, leukocytes, protein and proliferative activity, reached their highest levels on day 1 after surgery. In the second set of experiments, the wet weight of the capsular bag including after-cataract increased by 391% during the 56-day experimental period. Posterior capsule opacification (PCO), as measured by Scheimpflug analysis, increased from 0.8 to 81.7% and the scores of Elschnig's pearls as well as fibrosis, analyzed by slitlamp, increased from 0.0 to 2.8 and 3.0, respectively.

CONCLUSIONS

This study shows that the same components that are reported to be important in human PCO are also components of PCO in the rabbit. Thus, the rabbit model seems to accurately reflect human PCO development, and because PCO develops much faster in rabbits that would make the rabbit model suitable for studies to elucidate human PCO development.

Anterior chamber depth estimation by Scheimpflug photography

PURPOSE

To obtain a model suitable for evaluation of the anterior chamber depth (ACD) maintaining capacity of viscoelastic substances--a critical parameter in cataract surgery.

METHODS

ACD was estimated using an anterior segment analysis system (EAS-1000, Nidek Co Ltd, Japan). Variation was studied as an effect of batch number and eye within batch, storage, globe fixation, globe position, and repeated analyses of Scheimpflug images.

RESULTS

Considerable variation in ACD was found between eyes, batches, and as a result of prolonged storage (biological factors). Different IOPs before surgery caused significant alterations in ACD after overfilling with a viscoelastic substance. No significant differences were found when the globe position was altered or when the ACD was re-estimated repeatedly from the same photograph.

CONCLUSION

Differences due to biological factors are more important than methodological errors caused by the Scheimpflug instrument. To reduce these variations when viscoelastics are evaluated, all measurements should be calculated as % of ACD before surgery and the anterior chamber should be overfilled with a viscoelastic solution.