Comparison of rivaroxaban and low molecular weight heparin in the treatment of cancer-associated venous thromboembolism: a Swedish national population-based register study

BACKGROUND

Treating cancer-associated venous thromboembolism (CAT) with anticoagulation prevents recurrent venous thromboembolism (rVTE), but increases bleeding risk.

OBJECTIVES

To compare incidence of rVTE, major bleeding, and all-cause mortality for rivaroxaban versus low molecular weight heparin (LMWH) in patients with CAT.

METHODS

We developed a cohort study using Swedish national registers 2013-2019. Patients with CAT (venous thromboembolism within 6 months of cancer diagnosis) were included. Those with other indications or with high bleeding risk cancers were excluded (according to guidelines). Follow-up was from index-CAT until outcome, death, emigration, or end of study. Incidence rates (IR) per 1000 person-years with 95% confidence interval (CI) and propensity score overlap-weighted hazard ratios (HRs) for rivaroxaban versus LMWH were estimated.

RESULTS

We included 283 patients on rivaroxaban and 5181 on LMWH. The IR for rVTE was 68.7 (95% CI 40.0-109.9) for rivaroxaban, compared with 91.6 (95% CI 81.9-102.0) for LMWH, with adjusted HR 0.77 (95% CI 0.43-1.35). The IR for major bleeding was 23.5 (95% CI 8.6-51.1) for rivaroxaban versus 49.2 (95% CI 42.3-56.9) for LMWH, with adjusted HR 0.62 (95% CI 0.26-1.49). The IR for all-cause mortality was 146.8 (95% CI 103.9-201.5) for rivaroxaban and 565.6 (95% CI 541.8-590.2) for LMWH with adjusted HR 0.48 (95% CI 0.34-0.67).

CONCLUSIONS

Rivaroxaban performed similarly to LMWH for patients with CAT for rVTE and major bleeding. An all-cause mortality benefit was observed for rivaroxaban which potentially may be attributed to residual confounding.

TRIAL REGISTRATION NUMBER

NCT05150938 (Registered 9 December 2021).

Challenges and lessons learned from a long-term postauthorisation safety study programme of rivaroxaban in Europe

OBJECTIVES

To describe opportunities and challenges experienced from the four pharmacoepidemiological database studies included in the rivaroxaban post authorisation safety study (PASS) programme and propose ways to maximise the value of population-based observational research when addressing regulatory requirements.

DESIGN

PASS programme of rivaroxaban carried out as part of the regulatory postapproval commitment to the European Medicines Agency.

SETTING

Clinical practice in Germany, the Netherlands, Sweden and the UK (electronic health records)-undertaken by pharmacoepidemiology research teams using country-specific databases with different coding structures.

PARTICIPANTS

355 152 patients prescribed rivaroxaban and 338 199 patients prescribed vitamin K antagonists.

RESULTS

Two major challenges that were encountered throughout the lengthy PASS programme were related to: (1) finalising country-tailored study designs before the extent of rivaroxaban uptake was known, and (2) new research questions that arose during the programme (eg, those relating to an evolving prescribing landscape).

RECOMMENDATIONS

We advocate the following strategies to help address these major challenges (should they arise in any future PASS): conducting studies based on a common data model that enable the same analytical tools to be applied when using different databases; maintaining early, clear, continuous communication with the regulator (including discussing the potential benefit of studying drug use as a precursor to planning a safety study); consideration of adaptive designs whenever uncertainty exists and following an initial period of data collection; and setting milestones for the review of study objectives.

Safety profile of rivaroxaban in first-time users treated for venous thromboembolism in four European countries

BACKGROUND

The European rivaroxaban post-authorization safety study evaluated bleeding risk among patients initiated on rivaroxaban or vitamin K antagonists for the treatment and secondary prevention of venous thromboembolism in routine clinical practice.

METHODS

Cohorts were created using electronic healthcare databases from the UK, the Netherlands, Germany and Sweden. Patients with a first prescription of rivaroxaban or vitamin K antagonist during the period from December 2011 (in the UK, January 2012) to December 2017 (in Germany, December 2016) for venous thromboembolism indication, with no record of atrial fibrillation or recent cancer history, were observed until the occurrence of each safety outcome (hospitalization for intracranial, gastrointestinal, urogenital or other bleeding), death or study end (December 2018; in Germany, December 2017). Crude incidence rates of each outcome per 100 person-years were computed.

RESULTS

Overall, 44 737 rivaroxaban and 45 842 vitamin K antagonist patients were enrolled, mean age, 59.9-63.8 years. Incidence rates were similar between rivaroxaban and vitamin K antagonist users with some exceptions, including higher incidence rates for gastrointestinal bleeding in rivaroxaban users than in vitamin K antagonist users. Among rivaroxaban users, mortality and bleeding risk generally increased with age, renal impairment and diabetes.

CONCLUSIONS

This study provides further data from routine clinical practice that broadly support safety profile of rivaroxaban for VTE indication and complement findings from previous randomized clinical trials.

Incidence of hospital-acquired acute kidney injury and trajectories of glomerular filtration rate in older adults

BACKGROUND

In older adults, epidemiological data on incidence rates (IR) of hospital-acquired acute kidney injury (AKI) are scarce. Also, little is known about trajectories of kidney function before hospitalization with AKI.

METHODS

We used data from biennial face-to-face study visits from the prospective Berlin Initiative Study (BIS) including community-dwelling participants aged 70+ with repeat estimated glomerular filtration rate (eGFR) based on serum creatinine and cystatin C. Primary outcome was first incident of hospital-acquired AKI assessed through linked insurance claims data. In a nested case-control study, kidney function decline prior to hospitalization with and without AKI was investigated using eGFR trajectories estimated with mixed-effects models adjusted for traditional cardiovascular comorbidities.

RESULTS

Out of 2020 study participants (52.9% women; mean age 80.4 years) without prior AKI, 383 developed a first incident AKI, 1518 were hospitalized without AKI, and 119 were never hospitalized during a median follow-up of 8.8 years. IR per 1000 person years for hospital-acquired AKI was 26.8 (95% confidence interval (CI): 24.1-29.6); higher for men than women (33.9 (29.5-38.7) vs. 21.2 (18.1-24.6)). IR (CI) were lowest for persons aged 70-75 (13.1; 10.0-16.8) and highest for ≥ 90 years (54.6; 40.0-72.9). eGFR trajectories declined more steeply in men and women with AKI compared to men and women without AKI years before hospitalization. These differences in eGFR trajectories remained after adjustment for traditional comorbidities.

CONCLUSION

AKI is a frequent in-hospital complication in individuals aged 70 + showing a striking increase of IR with age. eGFR decline was steeper in elderly patients with AKI compared to elderly patients without AKI years prior to hospitalization emphasising the need for long-term kidney function monitoring pre-admission to improve risk stratification.

Time Trends in Patient Characteristics of New Rivaroxaban Users with Atrial Fibrillation in Germany and the Netherlands

BACKGROUND

Use of the direct oral anticoagulant rivaroxaban has strongly increased in Europe since its market approval for non-valvular atrial fibrillation in 2011. Patients characteristics of rivaroxaban initiators may have changed over time but this has not been investigated so far.

OBJECTIVE

We aimed to describe time trends of patient baseline characteristics among new rivaroxaban users with non-valvular atrial fibrillation from 2011 to 2016/17 in two European countries.

METHODS

We used data from Germany (German Pharmacoepidemiological Research Database) and the Netherlands (PHARMO Database Network). We included new rivaroxaban users with (i) a first dispensing between 2011 and 2016/17, (ii) ≥ 2 years of age, and (iii) a diagnosis of non-valvular atrial fibrillation and described their baseline medication and comorbidity prior to starting rivaroxaban stratified by year of inclusion.

RESULTS

Overall, 130,652 new rivaroxaban users were included during the study period (Germany: N = 127,743, the Netherlands: N = 2909). The sex ratio and median age remained relatively stable over time. The proportion of patients without prior use of oral anticoagulants before initiation of rivaroxaban increased in both countries between 2011 and 2016/17 (Germany: from 51 to 76%, the Netherlands: from 57 to 85%). In Germany, we observed a relative decrease by 27% in the proportion of new rivaroxaban users with a history of ischemic stroke and by 18% in the proportion with a transient ischemic attack at baseline. No such a pattern was observed in the Netherlands. The proportion of patients with heart failure at baseline showed a three-fold increase in the Netherlands, while there was a relative decrease by 12% in Germany.

CONCLUSIONS

Patient characteristics of new rivaroxaban users with non-valvular atrial fibrillation changed between 2011 and 2016/17, but changes differed between countries. These patterns have methodological implications. They have to be considered in the interpretation of observational studies comparing effectiveness and safety of oral anticoagulants, especially regarding potential bias due to unmeasured confounding.

Safety and effectiveness of rivaroxaban for prevention of stroke in patients with nonvalvular atrial fibrillation: analysis of routine clinical data from four countries

BACKGROUND

The safety and effectiveness of rivaroxaban versus vitamin K antagonists (standard of care [SOC]) for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF) was evaluated in Europe.

RESEARCH DESIGN AND METHODS

Observational studies were conducted in the UK, the Netherlands, Germany, and Sweden. Primary safety outcomes were hospitalization for intracranial hemorrhage, gastrointestinal bleeding, or urogenital bleeding among new users of rivaroxaban and SOC with NVAF; outcomes were analyzed using cohort (rivaroxaban or SOC use) and nested case-control designs (current vs nonuse). Statistical analyses comparing rivaroxaban and SOC cohorts were not performed.

RESULTS

Overall, 162,919 rivaroxaban users and 177,758 SOC users were identified. In the cohort analysis, incidence ranges for rivaroxaban users were 0.25-0.63 events per 100 person-years for intracranial bleeding, 0.49-1.72 for gastrointestinal bleeding, and 0.27-0.54 for urogenital bleeding. Corresponding ranges for SOC users were 0.30-0.80, 0.30-1.42, and 0.24-0.42, respectively. In the nested case-control analysis, current SOC use generally presented a greater risk of bleeding outcomes than nonuse. Rivaroxaban use (vs nonuse) was associated with a higher risk of gastrointestinal bleeding, but a similar risk of intracranial or urogenital bleeding, in most countries. Ischemic stroke incidence ranged from 0.31 to 1.52 events per 100 person-years for rivaroxaban users.

CONCLUSIONS

Incidences of intracranial bleeding were generally lower with rivaroxaban than with SOC, whereas incidences of gastrointestinal and urogenital bleeding were generally higher. The safety profile of rivaroxaban for NVAF in routine practice is consistent with findings from randomized controlled trials and other studies.

Acute Kidney Injury in Patients with Non-Valvular Atrial Fibrillation Treated with Rivaroxaban or Warfarin: A Population-Based Study from the United Kingdom

PURPOSE

To compare the risk of acute kidney injury (AKI) among users of rivaroxaban vs warfarin.

PATIENTS AND METHODS

We identified two cohorts of patients with non-valvular atrial fibrillation (NVAF) who initiated rivaroxaban (15/20 mg/day, N = 6436) or warfarin (N = 7129) excluding those without estimated glomerular filtration rate values recorded in the year before oral anticoagulant (OAC) initiation and those with a history of end-stage renal disease or AKI. We used two methods to define AKI during follow-up (mean 2.5 years): coded entries (method A) and the Aberdeen AKI phenotyping algorithm (method B) using recorded renal function laboratory values during the study period to identify a sudden renal deterioration event. Cox regression was used to calculate hazard ratios (HRs) for AKI with rivaroxaban vs warfarin use, adjusted for confounders.

RESULTS

The number of identified incident AKI cases was 249 (method A) and 723 (method B). Of the latter, 104 (14.4%) were also identified by method A. After adjusting for age, sex, baseline renal function and comorbidity, HRs (95% CIs) for AKI were 1.19 (0.92-1.54; p=0.18) using method A and 0.80 (0.68-0.93; p<0.01) using method B. Estimates stratified by baseline level of chronic kidney disease were largely consistent with the main estimates.

CONCLUSION

Our results support a beneficial effect of rivaroxaban over warfarin in terms of AKI occurrence in patients with NVAF. More research into how best to define AKI using primary care records would be valuable for future studies.

Pre- and post-stroke oral antithrombotics and mortality in patients with ischaemic stroke

BACKGROUND

Reducing stroke occurrence requires the effective management of cardiovascular and other stroke risk factors.

PURPOSE

To describe pre- and post-stroke medication use, focusing on antithrombotic therapy and mortality risk, in individuals hospitalised for ischaemic stroke (IS) in the United Kingdom.

METHOD

Using primary care electronic health records from the United Kingdom, we identified patients hospitalised for IS (July 2016-September 2019) and classed them into three groups: atrial fibrillation (AF) diagnosed pre-stroke, AF diagnosed post-stroke, and non-AF stroke (no AF diagnosed pre-/post-stroke). We determined use of cardiovascular medications in the 90 days pre- and post-stroke and calculated mortality rates.

RESULTS

There were 3201 hospitalised IS cases: 76.2% non-AF stroke, 15.7% AF pre-stroke, and 8.1% AF post-stroke. Oral anticoagulant (OAC) use increased between the pre- and post-stroke periods as follows: 54.3%-78.7% (AF pre-stroke group), 2.3%-84.8% (AF post-stroke group), and 3.4%-7.3% (non-AF stroke group). Corresponding increases in antiplatelet use were 30.8%-35.4% (AF pre-stroke group) 38.5%-47.5% (AF post-stroke group), and 37.5%-87.3% (non-AF stroke group). Among all IS cases, antihypertensive use increased from 66.8% pre-stroke to 78.8% post-stroke; statin use increased from 49.6%-85.2%. Mortality rates per 100 person-years (95% CI) were 17.30 (14.70-20.35) in the AF pre-stroke group and 9.65 (8.81-10.56) among all other stroke cases.

CONCLUSION

Our findings identify areas for improvement in clinical practice, including optimising the level of OAC prescribing to patients with known AF, which could potentially help reduce the future burden of stroke.

Risk of venous thromboembolism in men with prostate cancer compared with men in the general population: a nationwide population-based cohort study in Sweden

OBJECTIVE

To estimate the additional risk of venous thromboembolism (VTE) in men with prostate cancer compared with men without prostate cancer in Sweden.

DESIGN

Nationwide cohort study following 92 105 men with prostate cancer and 466 241 men without prostate cancer (comparison cohort) matched 5:1 by birth year and residential region.

SETTING

The male general population of Sweden (using the Nationwide Prostate Cancer data Base Sweden).

PRIMARY AND SECONDARY OUTCOME MEASURES

Crude incidence proportion ratios (IPRs) comparing the incidence of VTE in men with prostate cancer and men in the comparison cohort. Cox regression was used to calculate HRs for VTE adjusted for confounders.

RESULTS

2955 men with prostate cancer and 9774 men in the comparison cohort experienced a first VTE during a median of 4.5 years' follow-up. Deep vein thrombosis (DVT) accounted for 52% of VTE cases in both cohorts. Median time from start of follow-up to VTE was 2.5 years (IQR 0.9-4.7) in the prostate cancer cohort and 2.9 years (IQR 1.3-5.0) in the comparison cohort. Crude incidence rates of VTE per 1000 person-years were 6.54 (95% CI 6.31 to 6.78) in the prostate cancer cohort (n=2955 events) and 4.27 (95% CI 4.18 to 4.35) in the comparison cohort (n=9774 events). The IPR decreased from 2.53 (95% CI 2.26 to 2.83) at 6 months to 1.59 (95% CI 1.52 to 1.67) at 5 years' follow-up. Adjusted HRs were 1.48 (95% CI 1.39 to 1.57) for DVT and 1.47 (95% CI 1.39 to 1.56) for pulmonary embolism after adjustment for patient characteristics.

CONCLUSIONS

Swedish men with prostate cancer had a mean 50% increased risk of VTE during the 5 years following their cancer diagnosis compared with matched men free of prostate cancer. Physicians should be mindful of this marked increase in VTE risk in men with prostate cancer to help ensure timely diagnosis.

Renal decline in patients with non-valvular atrial fibrillation treated with rivaroxaban or warfarin: A population-based study from the United Kingdom

BACKGROUND

Reports suggest that renal decline is greater among patients with non-valvular atrial fibrillation (NVAF) treated chronically with warfarin vs. some non-vitamin K antagonist oral anticoagulants.

METHODS AND RESULTS

Using primary care electronic health records from the United Kingdom we followed adults with NVAF and who started rivaroxaban (20 mg/day, N = 5338) or warfarin (N = 6314), excluding those with estimated glomerular filtration rate (eGFR) <50 ml/min/1.73m², end-stage renal disease (ESRD) or no eGFR or serum creatinine (SCr) values recorded in the previous year. Outcomes were: doubling SCr levels, ≥30% decline in eGFR and progression to ESRD. We calculated adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for each outcome. Average eGFR slope was estimated using mixed model regression. After a mean follow-up 2.5 years, the number of incident cases of adverse renal events within the two cohorts was: doubling SCr (n = 322), ≥30% decline in eGFR (n = 1179), and progression to ESRD (n = 22). Adjusted HRs (95% CIs) for the renal outcomes among rivaroxaban vs. warfarin users were: doubling SCr, 0.63 (0.49-0.81); ≥30% decline in eGFR, 0.76 (0.67-0.86); ESRD, 0.77 (0.29-2.04). Similar results were observed among patients with diabetes or heart failure. Estimated mean decline in renal function over the study period was 2.03 ml/min/1.73 m²/year among warfarin users and 1.65 ml/min/1.73 m²/year among rivaroxaban users (p = 0.03).

CONCLUSIONS

We found clear evidence that patients with NVAF, preserved renal function at baseline and treated with rivaroxaban had a markedly reduced risk and rate of renal decline compared with those treated with warfarin.

Population-based study of long-term anticoagulation for treatment and secondary prophylaxis of venous thromboembolism in men with prostate cancer in Sweden

Background

Epidemiological data on anticoagulation for venous thromboembolism (VTE) in prostate cancer are sparse. We aimed to investigate associations between anticoagulation duration and risks of VTE recurrence after treatment cessation and major on-treatment bleeding in men with prostate cancer in Sweden.

Methods

Using nationwide prostate cancer registry and prescribing data, we followed 1413 men with VTE and an outpatient anticoagulant prescription following prostate cancer diagnosis. Men were followed to identify cases of recurrent VTE, and hospitalized major bleeding. We calculated adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) to quantify the association between anticoagulation duration (reference ≤ 3 months) and recurrent VTE using Cox regression. We estimated 1-year cumulative incidences of major bleedings from anticoagulation initiation.

Results

The outpatient anticoagulation prescribed was parenteral (64%), direct oral anticoagulant (31%), and vitamin K antagonist (20%). Median duration of anticoagulation was 7 months. Adjusted HRs (95% CI) for off-treatment recurrent pulmonary embolism (PE) were 0.32 (0.09–1.15) for > 3–6 months’ duration, 0.21 (0.06–0.69) for > 6–9 months and 0.16 (0.05–0.55) for > 9 months; corresponding HRs for deep vein thrombosis (DVT) were 0.67 (0.27–1.66), 0.80 (0.31–2.07), and 1.19 (0.47–3.02). One-year cumulative incidences of intracranial, gastrointestinal and urogenital bleeding were 0.9%, 1.7%, 3.0% during treatment, and 1.2%, 0.9%, 1.6% after treatment cessation.

Conclusion

The greatest possible benefit in reducing recurrent VTE risk occurred with > 9 months anticoagulation for PE and > 3–6 months for DVT, but larger studies are needed to confirm this. Risks of major bleeding were low overall.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12894-022-00967-z.

Evaluating patient and physician knowledge of risks and safe use of rivaroxaban: a survey across four countries

BACKGROUND

At the request of the European Medicines Agency, a Prescriber Guide and Patient Alert Card were developed to increase awareness and understanding about the initiation of rivaroxaban and potential bleeding risk associated with its use. This study evaluated physician and patient awareness and understanding of key safety messages in these educational materials in three waves.

RESEARCH DESIGN AND METHODS

Three cross-sectional surveys were administered to physicians and one survey was administered to patients (wave 1 only) with recent rivaroxaban experience in France, Germany, Spain, and the United Kingdom.

RESULTS

Patient and physician knowledge of key safety information in the educational materials was generally high. Patients' knowledge was high for questions related to bleeding risk (80% responded correctly), indication (96%), consulting their doctor (86%-91%), and informing other physicians they are taking rivaroxaban (95%). Physicians' knowledge was particularly high for questions related to bleeding risk (92%-94% across waves), populations at increased risk of serious side effects (76%-94%), contraindications (70%-92%), and invasive procedures (76%-82%).

CONCLUSIONS

Among patients and physicians, the highest levels of knowledge were on the most important risks, as expected. The Prescriber Guide and Patient Alert Card were found to be useful sources of information.

Renal decline in patients with atrial fibrillation treated with rivaroxaban or warfarin: a population-based cohort study in the United Kingdom

Background

A recent observational study (1) has suggested that renal decline among patients with non-valvular atrial fibrillation (NVAF) could be faster in users of warfarin vs. rivaroxaban.

Purpose

To estimate renal decline in patients with NVAF and preserved renal function who started oral anticoagulant (OAC) therapy with rivaroxaban 20 mg or warfarin.

Methods

Using primary care electronic health records (EHRs) from the United Kingdom (UK), we identified patients with NVAF who initiated rivaroxaban (20 mg/day, N=5338) or warfarin (N=6314) from January 2014–March 2019. Patients were excluded if they had no estimated glomerular filtration rate (eGFR) or serum creatinine (sCr) values recorded in the year before OAC initiation, a history of end-stage renal disease (ESRD), or baseline eGFR &lt;50 ml/min/1.73m2.

We identified three renal decline outcomes during follow-up: a) doubling of sCr levels, b) ≥30% decline in eGFR (confirmed by a subsequent measurement), and c) ESRD (code for ESRD/stage 5 CKD/chronic dialysis, or eGFR &lt;15 ml/min/1.73m2 confirmed by subsequent measurement). To identify incident cases of each outcome, we followed patients from OAC initiation to the earliest of a renal decline event, death, or the end of the study period (September 2019). Cox regression was used to calculate adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for each outcome with rivaroxaban vs. warfarin use, overall and among heart failure and diabetes patient subgroups. We estimated the average eGFR slope using a mixed model regression among the subset of individuals with at least two eGFR measurements during follow-up, where the first was recorded within 120 days of the start of follow-up, and the last was recorded &gt;180 days after the first eGFR measurement (rivaroxaban n=2054, warfarin n=2464).

Results

After a mean follow-up of 2.5 years, the number of incident cases was: doubling sCr (n=322), ≥30% decline in eGFR (n=1179), and ESRD (n=22). As shown in the Table, after adjusting for age, sex, baseline renal function and comorbidity, HRs for the renal outcomes with rivaroxaban vs. warfarin users were: doubling sCr, 0.63 (95% CI: 0.49–0.81); ≥30% decline in eGFR, 0.76 (95% CI: 0.67–0.86); ESRD, 0.77 (95% CI: 0.29–2.04). Similar results were observed among patients with diabetes or heart failure. Estimated mean loss in renal function during the study period was 2.03 ml/min/1.73 m2 per year among warfarin users and 1.65 ml/min/1.73 m2 among rivaroxaban initiators (p=0.03).

Conclusion

The risk of renal decline events and rate of decline in renal function among patients with baseline eGFR &gt;50 ml/min/1.73m2 was lower in patients using rivaroxaban 20 mg vs. warfarin. As residual confounding could have been present, further research is needed to confirm/refute our findings.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Bayer AG

FC 046INCIDENCE OF NOSOCOMIAL ACUTE KIDNEY INJURY (AKI) IN A COHORT OF COMMUNITY-DWELLING OLDER ADULTS OVER 8 YEARS OF OBSERVATION

Background and Aims

Acute kidney injury (AKI) is amongst the most common in-hospital complications especially in old age. Epidemiological data on incidence rates (IR) of nosocomial AKI in individuals aged 70+ years, stratified by age, gender and pre-existing diseases are scarce because older adults are usually underrepresented in clinical research.

Method

We used data from the Berlin Initiative Study (BIS), a longitudinal, population-based cohort of adults aged ≥70 with biennial follow-up visits (including blood and urine tests) in combination with claims data from the AOK Nordost insurance fund to complement information on diagnoses and in-hospital procedures (based on ICD-10 and OPS coding). Nosocomial AKI was defined as documented in-hospital diagnosis (ICD-10: N17.xx) excluding cases with AKI as admission diagnosis. Incidence rates (IR) and 95% confidence intervals (CI) of the first nosocomial AKI were calculated with the number of incident cases during observation divided by the total person-years of follow-up, for AKI cases truncated at the first incidence of nosocomial AKI. IR are reported by age strata, sex and preexisting diseases (diabetes, arterial hypertension, atrial fibrillation, heart failure, angina pectoris, peripheral artery disease and impaired kidney function).

Results

In 2020 individuals (mean age 80.5 years; 52.6% women), 383 developed nosocomial AKI over the median [IQR] follow up time of 8.8 [5.9-9.3] years (Fig.1). The IR of nosocomial AKI was 26.8 (95%CI 24.1-29.6) per 1000 person years among all patients, with higher IR in men compared to women, and - when stratified by age - lowest IR in age category 70-75 versus the highest IR in age category of ≥ 90 years (Fig.1).

Conclusion

Nosocomial AKI is an in-hospital complication common in older adults with IRs rising continuously with age above the age of 70 years. IR of AKI are considerably higher in patients with cardiovascular comorbidities. A better understanding of the patient population at risk is of great clinical relevance when aiming to improve prevention strategies.

Discontinuation of oral anticoagulation in atrial fibrillation and risk of ischaemic stroke

OBJECTIVE

To evaluate associations between oral anticoagulant (OAC) discontinuation and risk of ischaemic stroke (IS) among patients with atrial fibrillation (AF).

METHODS

We undertook a population-based cohort study with nested case-control analysis using UK primary care electronic health records (IQVIA Medical Research Data-UK) and linked registries from the Region of Southern Denmark (RSD). Patients with AF (76 882 UK, 41 526 RSD) were followed to identify incident IS cases during 2016-2018. Incident IS cases were matched by age and sex to controls. Adjusted ORs for OAC discontinuation (vs current OAC use) were calculated using logistic regression.

RESULTS

We identified 616 incident IS cases in the UK and 643 in the RSD. ORs for IS with any OAC discontinuation were 2.99 (95% CI 2.31 to 3.86, UK) and 2.30 (95% CI 1.79 to 2.95, RSD), for vitamin K antagonist discontinuation they were 2.38 (95% CI 1.72 to 3.30, UK) and 1.83 (95% CI 1.34 to 2.49, RSD), and for non-vitamin K antagonist oral anticoagulant discontinuation they were 4.59 (95% CI 2.97 to 7.08, UK) and 3.37 (95% CI 2.35 to 4.85, RSD). ORs were unaffected by time since discontinuation and duration of use. Annually, up to 987 IS cases in the UK and 132 in Denmark could be preventable if OAC therapy is not discontinued.

CONCLUSIONS

Our results suggest that patients with AF who discontinue OAC therapy have a significant twofold to threefold higher risk of IS compared with those who continue therapy. Addressing OAC discontinuation could potentially result in a significant reduction in AF-attributed IS.

Biomarkers of treatment success in fully sensitive pulmonary tuberculosis patients: a multicenter longitudinal study

Aim: Novel biomarkers that are able to accurately monitor tuberculosis (TB) treatment effectiveness are needed to adjust therapy and identify a need for a regimen change. Materials & methods: In our study, conducted on a cohort comprising 100 pulmonary TB patients, we analyzed the role of plasma cytokines and Toll-like receptors expression as biomarkers of treatment response. Results: Changes in toll-interacting protein (TOLLIP) and lymphocyte antigen 96 (LY96) gene expression as well as nine cytokine levels over the first 2 months were significantly associated with successful treatment outcome. Successful treatment was associated with higher serum concentration of Toll-like receptor-2. Conclusion: Our results suggest that differential expression of specific effector molecules and dynamics of selected cytokines may help to identify those responding to TB treatment early.

Rationale and design of a European epidemiological post-authorization safety study (PASS) program: rivaroxaban use in routine clinical practice

BACKGROUND

Rivaroxaban is a highly selective factor Xa inhibitor approved for use in Europe for multiple indications.

STUDY DESIGN AND METHODS

The European rivaroxaban epidemiological post-authorization safety study (PASS) program consists of seven complementary observational studies. For four of the studies, data are obtained from health-care databases in the UK, the Netherlands, Germany, and Sweden. These database studies describe patterns of rivaroxaban use and patient characteristics over time, and investigate safety and effectiveness outcomes in new users of rivaroxaban using a cohort analysis and nested case-control analysis. To put these results in context, safety outcomes are also analyzed in new users of standard of care. In addition, a modified prescription event monitoring study conducted in the early post-launch phase in primary care, and two specialist cohort event monitoring studies that investigated rivaroxaban use in the secondary care hospital setting, systematically collected drug utilization and safety data via questionnaires completed by health-care professionals in the UK.

DISCUSSION

The European rivaroxaban epidemiological PASS is a comprehensive program of complementary studies generating evidence from patients treated in routine clinical practice that will expand our understanding of the risk-benefit profile of rivaroxaban.

Discontinuation of non-Vitamin K antagonist oral anticoagulants in patients with non-valvular atrial fibrillation: a population-based cohort study using primary care data from The Health Improvement Network in the UK

OBJECTIVE

To determine discontinuation rates, patterns of use and predictors of discontinuation of non-vitamin K antagonist oral anticoagulants (NOACs) among patients with non-valvular atrial fibrillation (NVAF) in the first year of therapy.

DESIGN

Population-based cohort study.

SETTING

UK primary care.

POPULATION

11 481 patients with NVAF and a first prescription (index date) for apixaban, dabigatran or rivaroxaban (January 2012 to December 2016) with at least 1 year of follow-up and at least one further NOAC prescription in the year following the index date were identified. 1 year rates and patterns of discontinuation were described.

PRIMARY AND SECONDARY OUTCOME MEASURES

Outcome measures were the percentage of patients who, in the first year from starting NOAC therapy, discontinued with their oral anticoagulant (OAC) therapy (discontinuation was defined as a gap in OAC therapy of >30 days); switched OAC within 30 days; discontinued and reinitiated OAC therapy. Predictors of discontinuation were also evaluated.

RESULTS

1 year discontinuation rates according to the index NOAC were 26.1% for apixaban, 40.0% for dabigatran and 29.6% for rivaroxaban. Reinitiation rates were 18.1% for apixaban, 21.7% for dabigatran and 17.3% for rivaroxaban, and switching rates were 2.8% for apixaban, 8.8% for dabigatran and 4.9% for rivaroxaban. More than 93% of reinitiations were with the index NOAC. Patients starting on dabigatran were more likely to switch OAC therapy than those starting on apixaban; ORs 4.28 (95% CI 3.24 to 5.65) for dabigatran and 1.89 (95% CI 1.49 to 2.39) for rivaroxaban. Severely reduced renal function was a predictor of any discontinuation, OR 1.77 (95% CI 1.28 to 2.44).

CONCLUSION

While the majority of patients with NVAF in the UK initiating NOAC treatment received continuous therapy in the first year of treatment, a substantial proportion of patients experienced gaps in treatment leaving them less protected against thromboembolism during these periods.

Appropriateness of initial dose of non-vitamin K antagonist oral anticoagulants in patients with non-valvular atrial fibrillation in the UK

OBJECTIVE

To evaluate the appropriateness of the initial prescribed daily dose of non-vitamin K antagonist oral anticoagulants (NOACs) according to label in patients with non-valvular atrial fibrillation (NVAF) in the UK.

DESIGN

Population-based cross-sectional study.

SETTING

UK primary care.

POPULATION

30 467 patients with NVAF and a first prescription for apixaban, dabigatran or rivaroxaban between January 2011 and December 2016.

MAIN OUTCOME MEASURES

Percentage of patients prescribed a NOAC dose according to the European Union (EU) labels (appropriately dosed), and not according to the EU labels (inappropriately dosed-including both underdosed and overdosed patients); percentage of patients prescribed an initial NOAC dose according to renal function status.

RESULTS

A total of 15 252 (50.1%) patients started NOAC therapy on rivaroxaban, 10 834 (35.6%) on apixaban and 4381 (14.4%) on dabigatran. Among patients starting NOAC therapy on rivaroxaban, 17.3% were eligible to receive a reduced dose compared with 12.8% of patients starting on apixaban and 53.8% of patients starting on dabigatran. The majority of patients were prescribed an appropriate dose according to the EU labels: apixaban 74.9 %, dabigatran, 74.4%; rivaroxaban, 84.2%. Underdosing occurred in 21.6% (apixaban), 8.7% (dabigatran), 9.1% (rivaroxaban). Overdosing was more frequent for dabigatran (16.9%) than for rivaroxaban (6.6%) or apixaban (3.5%). There was a trend towards dose reduction with increasing renal impairment. Among patients with severe renal impairment, the majority received a reduced dose NOAC: apixaban, 91.1%, dabigatran, 80.0%, rivaroxaban, 83.0%.

CONCLUSION

Between 2011 and 2016, the majority of patients starting NOAC therapy in UK primary care were prescribed a daily dose in line with the approved EU drug label. Underdosing was more than twice as common among patients starting on apixaban than those starting on dabigatran or rivaroxaban. Research into the patient characteristics that may influence inappropriate underdosing of NOACs in UK primary care is warranted.

Tuberculosis cases caused by heterogeneous infection in Eastern Europe and their influence on outcomes

INTRODUCTION

Mycobacterium tuberculosis superinfection is known to occur in areas with high rates of tuberculosis (TB) and has a significant impact on overall clinical TB management.

AIM

We aimed to estimate the superinfection rate in cohorts of drug sensitive and multi-drug resistant tuberculosis (MDR TB) patients from Eastern Europe and the potential role of a second MDR TB strain infecting a patient with active non-MDR TB in treatment outcome.

METHODS

The study population included 512 serial M. tuberculosis isolates obtained from 84 MDR- and 136 non-MDR TB patients recruited sequentially at sites in Lithuania, Latvia and Russia in 2011-2013. Strains were genotyped using standardized 24-loci Mycobacterial Interspersed Repetitive Unit-Variable Number Tandem Repeat (MIRU-VNTR) typing.

RESULTS

Changes in two or more MIRU-VNTR loci suggesting superinfection were detected in 13 patients (5.9%). We found 4 initially non-MDR TB patients superinfected with an MDR TB strain during treatment and 3 of them had an unsuccessful outcome.

CONCLUSIONS

An unsuccessful treatment outcome in patients initially diagnosed with drug sensitive TB might be explained by superinfection with an MDR TB strain. Bacteriological reversion could be indicative of superinfection with another strain. Archiving of all serial isolates and their genotyping in case of culture reversion could support therapeutic strategies in high MDR TB burden settings if resources are available.

Survival of patients with multidrug-resistant TB in Eastern Europe: what makes a difference?

BACKGROUND

The quality of care for patients with TB in Eastern Europe has improved significantly; nevertheless drug resistance rates remain high. We analysed survival in a cohort of patients with multidrug-resistant and extensively drug-resistant (MDR-/XDR-) TB from Latvia, Lithuania, Estonia and Bucharest city.

METHODS

Consecutive adult new and retreatment patients with culture-confirmed pulmonary MDR-TB registered for treatment in 2009 (and in 2007 in Latvia) were enrolled; prospective survival information was collected.

RESULTS

A total of 737 patients were included into the cohort. Of all MDR-TB cases, 46% were newly diagnosed; 56% of all MDR-TB cases had no additional resistance to fluoroquinolones or injectable agents, 33% had pre-XDR-TB and 11% XDR-TB. Median survival was 5.9 years in patients with MDR-TB and XDR-TB; 1.9 years in patients coinfected with HIV. Older age, male gender, alcohol abuse, retirement, co-morbidities, extrapulmonary involvement and HIV coinfection independently worsened survival. Inclusion of fluoroquinolones and injectable agents improves survival in patients with MDR-TB. Pre-XDR and XDR status did not significantly shorten survival as long as fluoroquinolones and injectable agents were part of the regimen. Moxifloxacin seems to improve survival in ofloxacin-susceptible patients when compared with older generation fluoroquinolones.

CONCLUSIONS

The burden of additional resistances in patients with MDR-TB is high likely due to primary transmission of resistant strains. Social and programmatic factors including management of alcohol dependency, expansion of HIV testing and antiretroviral treatment need to be addressed in order to achieve cure and to interrupt transmission. The role of last generation fluoroquinolones and injectable agents in treatment of patients with pre-XDR and XDR-TB needs to be further investigated.

Bacteriological confirmation of pulmonary tuberculosis in children with gastric aspirates in Germany, 2002-2010

OBJECTIVE

To assess bacteriological confirmation of pulmonary tuberculosis (TB) in children using nucleic acid amplification tests (NAAT) and culture of gastric aspirates in Germany.

DESIGN

We analysed 2002-2010 TB notification data to determine the use of gastric aspirates, NAAT and culture performance, including test agreement among pulmonary TB patients aged <15 years (grouped into <1, 1-4, 5-9 and 10-14 years).

RESULTS

Gastric aspirates were used among 59% (769/1307) of the patients with available diagnostic information. For 454 patients, gastric aspirates were the only reported specimen, and both NAAT and culture were performed. Among these, culture was positive in 53% (95%CI 48-58), NAAT in 48% (95%CI 44-53) and either test in 63% (95%CI 59-68), with an overall test agreement of 74% (95%CI 70-78). Infants < 1 year had the highest positivity rate (79%, 95%CI 68-88, either test). Test agreement was the highest among 10-14 year olds (79%, 95%CI 67-89).

CONCLUSIONS

Routine notification data document a wide use of gastric aspirates and high yield of both NAAT and culture for bacteriological confirmation of TB with gastric aspirates, particularly in infants. Imperfect test agreement supports the combined use of molecular assays and culture-whenever available-in the diagnosis of childhood TB.

Laboratory diagnosis of paediatric tuberculosis in the European Union/European Economic Area: analysis of routine laboratory data, 2007 to 2011

Laboratory confirmation of paediatric tuberculosis (TB) is frequently lacking. We reviewed the range of routine laboratory tests and their performance in different biological samples used to diagnose active TB in children. A questionnaire-based survey was conducted among the European Reference Laboratory Network for TB followed by collection of routine laboratory data on 10,549 paediatric samples tested in 2007 to 2011 at six reference laboratories (in Croatia, Germany, Italy, Latvia, Lithuania and the United Kingdom (UK)). The questionnaire showed that all laboratories used rapid assays. Non-respiratory samples were collected more often in Germany (135/275, 49.1%) and the UK (490/2,140, 22.9%) compared with Croatia (138/2,792, 4.9%), Latvia (222/2,401, 9.2%) and Lithuania (76/1,549, 4.9%). Overall laboratory positivity rates (isolation of Mycobacterium tuberculosis complex and/or identification of its nucleic acids in a sample) were higher in lymph node and gastric aspirate samples (14/203 (6.9%) and 43/1,231 (3.5%)) than in sputum samples (89/4,684 (1.9%)). Pooled sensitivity, specificity, positive and negative predictive values and accuracy of molecular assays assessed against solid or liquid culture were 79.2%, 93.6%, 67.1%, 96.5% and 91.6%, respectively. A more intensive approach in obtaining gastric aspirate and non-respiratory samples may increase laboratory confirmation of paediatric TB. Major effort is needed in optimisation and validation of molecular tests in these samples.

Evolution and transmission of drug-resistant tuberculosis in a Russian population

The molecular mechanisms determining transmissibility and prevalence of drug-resistant tuberculosis in a population were investigated through whole genome sequencing of 1,000 prospectively-obtained patient isolates from Russia. Two-thirds belonged to the Beijing lineage, which was dominated by two homogeneous clades. MDR genotypes were found in 48% of isolates overall and 87% of the major clades. The most common rifampicin-resistance rpoB mutation was associated with fitness-compensatory mutations in rpoA or rpoC, and a novel intragenic compensatory substitution was identified. The proportion of MDR cases with XDR-tuberculosis was 16% overall with 65% of MDR isolates harboring eis mutations, selected by kanamycin therapy, which may drive the expansion of strains with enhanced virulence. The combination of drug resistance and compensatory mutations displayed by the major clades confer clinical resistance without compromising fitness and transmissibility, revealing a biological contribution to the tuberculosis program weaknesses driving the persistence and spread of M/XDR-tuberculosis in Russia and beyond.

Serological evidence of asymptomatic infections during Escherichia coli O104:H4 outbreak in Germany in 2011

Introduction

The largest known outbreak caused by a rare hybrid strain of Shiga toxin-producing E.coli (STEC) and enteroaggregative E. coli (EAEC) (E.coli O104:H4) of serotype O104:H4 occurred in Germany in 2011. Fenugreek sprouts acted as a transmission vehicle and were widely consumed in the outbreak area at the time of the epidemic. In total 3,842 people developed a clinical illness caused by this strain; however the rates of asymptomatic infections remain unclear. We aimed to develop a serological assay for detection of E.coli O104 LPS specific antibodies and to establish the post-outbreak levels of seropositivity among people with documented exposure to contaminated sprouts.

Results and Discussion

Developed serological assays (ELISA with 84% sensitivity, 63% specificity and Western Blot with 100% sensitivity, 82.5% specificity) identified 33% (16/49) level of asymptomatic infection. Relatively small sample size and a significant time- lapse between the onset of symptoms and serum samples collection (appr. 8 weeks) might explain the assay variability. No association was found between clinical or demographic characteristics and assay positivity. Larger studies are needed to understand the complexity of human immune response and factors influencing development of clinical symptoms. Development of intra-outbreak research plans will substantially aid the conduct of more thorough scientific investigation during an outbreak period.

Rapid diagnostics of tuberculosis and drug resistance in the industrialized world: clinical and public health benefits and barriers to implementation

In this article, we give an overview of new technologies for the diagnosis of tuberculosis (TB) and drug resistance, consider their advantages over existing methodologies, broad issues of cost, cost-effectiveness and programmatic implementation, and their clinical as well as public health impact, focusing on the industrialized world. Molecular nucleic-acid amplification diagnostic systems have high specificity for TB diagnosis (and rifampicin resistance) but sensitivity for TB detection is more variable. Nevertheless, it is possible to diagnose TB and rifampicin resistance within a day and commercial automated systems make this possible with minimal training. Although studies are limited, these systems appear to be cost-effective. Most of these tools are of value clinically and for public health use. For example, whole genome sequencing of Mycobacterium tuberculosis offers a powerful new approach to the identification of drug resistance and to map transmission at a community and population level.

Diagnosis of tuberculosis and drug resistance: what can new tools bring us?

This is an exciting time for tuberculosis (TB) diagnostics. The technology for rapid diagnosis of TB and rifampicin (RMP) resistance in pulmonary sputum smear-positive specimens is well advanced, and assays have high specificity with good sensitivity. Nevertheless, the current sensitivity of TB detection means that these assays still cannot replace the standard diagnostic methods for TB or conventional drug susceptibility testing (DST). In extra-pulmonary specimens, the performance of molecular tools varies and should be considered separately for each specimen type. Evidence for the use of these assays for TB and drug resistance detection in individuals co-infected with TB and the human immunodeficiency virus (HIV) is limited. As the positive predictive value for RMP resistance reaches ≥ 90% only when the prevalence of RMP resistance in new TB patients is >15%, which is rare globally, many cases with such resistance will be false-resistant, emphasising the need for a secondary confirmative test. Similarly, increased (or incorrect) diagnosis of TB may compromise programme effectiveness by increasing the numbers of individuals requiring anti-tuberculosis treatment, unless it is carefully planned. For the future, 1) assays with greater sensitivity for TB detection are needed; 2) rapid diagnostics for paediatric TB are important, and there is a need for carefully designed studies, including those involving HIV-positive children; 3) more clinical data need to be obtained from longitudinal studies, especially related to the influence of rapid diagnostics on disease outcome; and 4) point-of-care tests using untreated sputum, blood or urine and little or no equipment would be of immeasurable benefit. Although great progress has been made, we are not there yet.

The Colour Test for drug susceptibility testing of Mycobacterium tuberculosis strains

SETTING

Tartu, Estonia.

OBJECTIVE

To assess the performance and feasibility of the introduction of the thin-layer agar MDR/XDR-TB Colour Test (Colour Test) as a non-commercial method of drug susceptibility testing (DST).

DESIGN

The Colour Test combines the thin-layer agar technique with a simple colour-coded quadrant format, selective medium to reduce contamination and colorimetric indication of bacterial growth to simplify interpretation. DST patterns for isoniazid (INH), rifampicin (RMP) and ciprofloxacin (CFX) were determined using the Colour Test for 201 archived Mycobacterium tuberculosis isolates. Susceptibilities were compared to blinded DST results obtained routinely using the BACTEC™ Mycobacteria Growth Indicator Tube™ (MGIT) 960 to assess performance characteristics.

RESULTS

In all, 98% of the isolates produced interpretable results. The average time to positivity was 13 days, and all results were interpretable. The Colour Test detected drug resistance with 98% sensitivity for INH, RMP and CFX and 99% for multidrug-resistant tuberculosis. Specificities were respectively 100% (95%CI 82-100), 88% (95%CI 69-97) and 91% (95%CI 83-96) and 90% (95%CI 74-98). Agreement between the Colour Test and BACTEC MGIT 960 were respectively 98%, 96%, 94% and 97%.

CONCLUSION

The Colour Test could be an economical, accurate and simple technique for testing tuberculosis strains for drug resistance. As it requires little specialist equipment, it may be particularly useful in resource-constrained settings with growing drug resistance rates.

Common variants at 11p13 are associated with susceptibility to tuberculosis

After imputation of data from the 1000 Genomes Project into a genome-wide dataset of Ghanaian individuals with tuberculosis and controls, we identified a resistance locus on chromosome 11p13 downstream of the WT1 gene (encoding Wilms tumor 1). The strongest signal was obtained at the rs2057178 SNP (P = 2.63 × 10(-9)). Replication in Gambian, Indonesian and Russian tuberculosis case-control study cohorts increased the significance level for the association with this SNP to P = 2.57 × 10(-11).

Microevolution of extensively drug-resistant tuberculosis in Russia

Extensively drug-resistant (XDR) tuberculosis (TB), which is resistant to both first- and second-line antibiotics, is an escalating problem, particularly in the Russian Federation. Molecular fingerprinting of 2348 Mycobacterium tuberculosis isolates collected in Samara Oblast, Russia, revealed that 72% belonged to the Beijing lineage, a genotype associated with enhanced acquisition of drug resistance and increased virulence. Whole-genome sequencing of 34 Samaran isolates, plus 25 isolates representing global M. tuberculosis complex diversity, revealed that Beijing isolates originating in Eastern Europe formed a monophyletic group. Homoplasic polymorphisms within this clade were almost invariably associated with antibiotic resistance, indicating that the evolution of this population is primarily driven by drug therapy. Resistance genotypes showed a strong correlation with drug susceptibility phenotypes. A novel homoplasic mutation in rpoC, found only in isolates carrying a common rpoB rifampicin-resistance mutation, may play a role in fitness compensation. Most multidrug-resistant (MDR) isolates also had mutations in the promoter of a virulence gene, eis, which increase its expression and confer kanamycin resistance. Kanamycin therapy may thus select for mutants with increased virulence, helping preserve bacterial fitness and promoting transmission of drug-resistant TB strains. The East European clade was dominated by two MDR clusters, each disseminated across Samara. Polymorphisms conferring fluoroquinolone resistance were independently acquired multiple times within each cluster, indicating that XDR TB is currently not widely transmitted.

A genome wide association study of pulmonary tuberculosis susceptibility in Indonesians

Background

There is reason to expect strong genetic influences on the risk of developing active pulmonary tuberculosis (TB) among latently infected individuals. Many of the genome wide linkage and association studies (GWAS) to date have been conducted on African populations. In order to identify additional targets in genetically dissimilar populations, and to enhance our understanding of this disease, we performed a multi-stage GWAS in a Southeast Asian cohort from Indonesia.

Methods

In stage 1, we used the Affymetrix 100 K SNP GeneChip marker set to genotype 259 Indonesian samples. After quality control filtering, 108 cases and 115 controls were analyzed for association of 95,207 SNPs. In stage 2, we attempted validation of 2,453 SNPs with promising associations from the first stage, in 1,189 individuals from the same Indonesian cohort, and finally in stage 3 we selected 251 SNPs from this stage to test TB association in an independent Caucasian cohort (n = 3,760) from Russia.

Results

Our study suggests evidence of association (P = 0.0004-0.0067) for 8 independent loci (nominal significance P < 0.05), which are located within or near the following genes involved in immune signaling: JAG1, DYNLRB2, EBF1, TMEFF2, CCL17, HAUS6, PENK and TXNDC4.

Conclusions

Mechanisms of immune defense suggested by some of the identified genes exhibit biological plausibility and may suggest novel pathways involved in the host containment of infection with TB.

Analysis of undiagnosed tuberculosis-related deaths identified at post-mortem among HIV-infected patients in Russia: a descriptive study

Background

Tuberculosis remains a serious public health threat and economic burden in Russia with escalating rates of drug resistance against a background of growing HIV-epidemic. Samara Oblast is one of the regions of the Russian Federation where more than 1% of the population is affected by the HIV-epidemic; almost half of the cases are concentrated in the largely-industrial city of Togliatti with a population of 800 000.

Methods

We conducted a retrospective analysis of errors leading to death of HIV-positive patients in general health care hospitals in Togliatti, Russia, in 2008. All (n = 29) cases when tuberculosis was established at autopsy as a cause of death were included.

Results

Median length of hospital stay was 20 days; in 11 cases the death occurred within the first 24 hours of admission. All cases were known to be HIV-positive prior to admission, however HAART was not initiated for any case, and no relevant tests to assess severity of immunosupression were performed despite their availability. No appropriate diagnostic algorithms were applied to confirm tuberculosis. Major gaps were identified in the work of hospital and consulting physicians including insufficient records keeping. In almost all patients earlier regular HIV-relevant tests were not performed due to poor compliance of patients, many of whom abused alcohol and drugs.

Conclusions

We conclude that introduction of prompt and accurate diagnostics tests, adequate treatment protocols and intensive training of physicians in management of AIDS and TB is vital. This should include reviewing standards of care for HIV-positive individuals with accompanying social problems.

Communicable diseases prioritized for surveillance and epidemiological research: results of a standardized prioritization procedure in Germany, 2011

Introduction

To establish strategic priorities for the German national public health institute (RKI) and guide the institute's mid-term strategic decisions, we prioritized infectious pathogens in accordance with their importance for national surveillance and epidemiological research.

Methods

We used the Delphi process with internal (RKI) and external experts and a metric-consensus approach to score pathogens according to ten three-tiered criteria. Additional experts were invited to weight each criterion, leading to the calculation of a median weight by which each score was multiplied. We ranked the pathogens according to the total weighted score and divided them into four priority groups.

Results

127 pathogens were scored. Eighty-six experts participated in the weighting; “Case fatality rate” was rated as the most important criterion. Twenty-six pathogens were ranked in the highest priority group; among those were pathogens with internationally recognised importance (e.g., Human Immunodeficiency Virus, Mycobacterium tuberculosis, Influenza virus, Hepatitis C virus, Neisseria meningitides), pathogens frequently causing large outbreaks (e.g., Campylobacter spp.), and nosocomial pathogens associated with antimicrobial resistance. Other pathogens in the highest priority group included Helicobacter pylori, Respiratory Syncytial Virus, Varicella zoster virus and Hantavirus.

Discussion

While several pathogens from the highest priority group already have a high profile in national and international health policy documents, high scores for other pathogens (e.g., Helicobacter pylori, Respiratory syncytial virus or Hantavirus) indicate a possible under-recognised importance within the current German public health framework. A process to strengthen respective surveillance systems and research has been started. The prioritization methodology has worked well; its modular structure makes it potentially useful for other settings.

Evaluation of two molecular assays for rapid detection of mycobacterium tuberculosis resistance to fluoroquinolones in high-tuberculosis and -multidrug-resistance Settings

The Russian Federation is a high-tuberculosis (TB)-burden country with high rates of drug resistance, including multidrug and extensive drug resistance to TB (M/XDRTB). Rapid diagnosis of resistance to fluoroquinolones (FQs) using molecular assays is essential for the implementation of appropriate drug regimens and prevention of the transmission of XDR strains. A total of 51 individual MDRTB strains were tested by pyrosequencing of the quinolone resistance determining region of the gyrA gene and the GenoType MTBDRsl assay (Hain Lifescience, GmbH, Nehren, Germany), and the results were evaluated against those obtained by phenotypic drug susceptibility testing (DST). Mutations were detected in 25 (78.1%) FQ-resistant strains, with the majority of mutations (n = 19 [73.0%]) found in codon 94 of the gyrA gene; the novel mutation 1457 C→Τ was found in the gyrB gene. Three mixed allelic variants were detected, which is a well-known phenomenon in areas with high TB and drug-resistant TB rates. The sensitivity and specificity of pyrosequencing (86.2 and 100%, respectively) and MTBDRsl (86.2 and 100%, respectively) were high; however, the results for 5.9% of the analyzed strains were unreadable when MTBDRsl was used. The MTBDRsl and pyrosequencing assays offer a rapid and accurate means for diagnosing resistance to FQs in high-TB-burden areas.

Survival of civilian and prisoner drug-sensitive, multi- and extensive drug- resistant tuberculosis cohorts prospectively followed in Russia

Objective and Methods

A long-term observational study was conducted in Samara, Russia to assess the survival and risk factors for death of a cohort of non-multidrug resistant tuberculosis (non-MDRTB) and multidrug resistant tuberculosis (MDRTB) civilian and prison patients and a civilian extensive drug-resistant tuberculosis (XDRTB) cohort.

Results

MDRTB and XDRTB rates of 54.8% and 11.1% were identified in the region. Half (50%) of MDRTB patients and the majority of non-MDRTB patients (71%) were still alive at 5 years. Over half (58%) of the patients died within two years of establishing a diagnosis of XDRTB. In the multivariate analysis, retreatment (HR = 1.61, 95%CI 1.04, 2.49) and MDRTB (HR = 1.67, 95%CI 1.17, 2.39) were significantly associated with death within the non-MDR/MDRTB cohort. The effect of age on survival was relatively small (HR = 1.01, 95%CI 1.00, 1.02). No specific factor affected survival of XDRTB patients although median survival time for HIV-infected versus HIV-negative patients from this group was shorter (185 versus 496 days). The majority of MDRTB and XDRTB strains (84% and 92% respectively) strains belonged to the Beijing family. Mutations in the rpoB (codon 531 in 81/92; 88.8%), katG (mutation S315T in 91/92, 98.9%) and inhA genes accounted for most rifampin and isoniazid resistance respectively, mutations in the QRDR region of gyrA for most fluroquinolone resistance (68/92; 73.5%).

Conclusions

Alarmingly high rates of XDRTB exist. Previous TB treatment cycles and MDR were significant risk factors for mortality. XDRTB patients' survival is short especially for HIV-infected patients. Beijing family strains comprise the majority of drug-resistant strains.

Survival of drug resistant tuberculosis patients in Lithuania: retrospective national cohort study

Objective To establish risk factors influencing survival of patients with multidrug-resistant and extensively drug-resistant tuberculosis (MDR/XDRTB). Design All MDR/XDRTB cases (n=1809) reported from 2002 to 2008 in Lithuania with a known outcome were included in the survival analysis. Results Median survival for MDRTB and XDRTB patients was 4.1 (95% CI 3.7 to 4.4) and 2.9 (95% CI 2.2 to 3.9) years. In a multivariable analysis adjusting for other patient characteristics, the difference in survival between MDRTB and XDRTB patients was not significant (HR=1.29 (0.91 to 1.81)). Older age (HR=4.80 (3.16 to 7.29)) for 60+ vs <30 years, rural living (HR=1.20 (1.02 to 1.40)), alcohol use (HR=1.49 (1.13 to 1.96)) for alcoholic versus moderate use, unemployment (HR=1.79 (1.31 to 2.46)), lower education levels (HR=1.50 (1.08 to 2.07)) for primary level versus tertiary level, cavitary disease (HR=1.54 (1.29 to 1.83)) and being smear positive at the time of MDR/XDRTB diagnosis (HR=1.47 (1.19 to 1.82)) were associated with poorer survival. HIV positivity significantly affected survival (HR=3.44 (1.92 to 6.19)) for HIV positive versus HIV negative; HR=1.60 (1.28 to 2.01) for HIV not tested versus HIV negative). There was no difference in survival of patients who acquired MDR/XDRTB during treatment compared with patients with primary MDR/XDRTB (HR=1.01 (0.85 to 1.19)). Treatment with a second-line drug improved survival (HR=0.40 (0.34 to 0.47)). In a subgroup with genotyped TB strains, a Beijing family of strains was associated with poorer survival (HR=1.71 (1.19 to 2.47)). Conclusions Social factors, rural living, HIV infection and Beijing strain family impact on survival. Survival of MDR/XDRTB patients is short. Rapid drug resistance identification, early administration of appropriate treatment and achieving high cure rates, expansion of HIV testing and antiretroviral treatment are necessary for optimal management of MDR/XDRTB.

Association analysis of the LTA4H gene polymorphisms and pulmonary tuberculosis in 9115 subjects

Immunoregulatory eicosanoids have been implicated in protection from mycobacterial infection in cell and animal models. Recently, a study of the zebrafish embryo demonstrated that mutants of the lta4h gene, which encodes the leukotriene A4 hydrolase (LTA4H) enzyme of the eicosanoid pathway, have hypersusceptibility to Mycobacterium marinum infection. It also reported that heterozygosity at the two single nucleotide polymorphisms rs1978331 and rs2660898 located in introns of the LTA4H gene, a human homologue of lta4h, is associated with protection from pulmonary tuberculosis. To replicate this association we genotyped six LTA4H gene polymorphisms in samples from 3703 pulmonary tuberculosis patients and 5412 healthy controls collected in Russia. We found no evidence of the protective effect of heterozygosity at the polymorphisms rs1978331 and rs2660898 (P = 0.29 and 0.49) and no association of the alleles of any of the six polymorphisms (P = 0.13-0.81). These results suggest that common polymorphisms in the LTA4H gene do not play any major role in susceptibility to clinical pulmonary tuberculosis.

An integrated approach to rapid diagnosis of tuberculosis and multidrug resistance using liquid culture and molecular methods in Russia

OBJECTIVE

To analyse the feasibility, cost and performance of rapid tuberculosis (TB) molecular and culture systems, in a high multidrug-resistant TB (MDR TB) middle-income region (Samara, Russia) and provide evidence for WHO policy change.

METHODS

Performance and cost evaluation was conducted to compare the BACTEC MGIT 960 system for culture and drug susceptibility testing (DST) and molecular systems for TB diagnosis, resistance to isoniazid and rifampin, and MDR TB identification compared to conventional Lowenstein-Jensen culture assays.

FINDINGS

698 consecutive patients (2487 sputum samples) with risk factors for drug-resistant tuberculosis were recruited. Overall M. tuberculosis complex culture positivity rates were 31.6% (787/2487) in MGIT and 27.1% (675/2487) in LJ (90.5% and 83.2% for smear-positive specimens). In total, 809 cultures of M. tuberculosis complex were isolated by any method. Median time to detection was 14 days for MGIT and 36 days for LJ (10 and 33 days for smear positive specimens) and indirect DST in MGIT took 9 days compared to 21 days on LJ. There was good concordance between DST on LJ and MGIT (96.8% for rifampin and 95.6% for isoniazid). Both molecular hybridization assay results correlated well with MGIT DST results, although molecular assays generally yielded higher rates of resistance (by approximately 3% for both isoniazid and rifampin).

CONCLUSION

With effective planning and logistics, the MGIT 960 and molecular based methodologies can be successfully introduced into a reference laboratory setting in a middle incidence country. High rates of MDR TB in the Russian Federation make the introduction of such assays particularly useful.

Performance of the Genotype MTBDRPlus assay in the diagnosis of tuberculosis and drug resistance in Samara, Russian Federation

Background

Russia is a high tuberculosis (TB) burden country with a high prevalence of multidrug resistant tuberculosis (MDRTB). Molecular assays for detection of MDRTB on clinical specimens are not widely available in Russia.

Results

We performed an evaluation of the GenoType^® MTBDRplus assay (HAIN Lifescience GmbH, Germany) on a total of 168 sputum specimens from individual patients at a public health laboratory in Central Russia, as a model of a middle income site in a region with high levels of drug resistance. Phenotypic drug resistance tests (DST) were performed on cultures derived from the same sputum specimens using the BACTEC 960 liquid media system.

Interpretable GenoType^® MTBDRplus results were obtained for 154(91.7%) specimens with readability rates significantly higher in sputum specimens graded 2+ and 3+ compared to 1+ (RR = 1.17 95%CI 1.04–1.32). The sensitivity and specificity of the assay for the detection of rifampicin (RIF) and isoniazid (INH) resistance and MDR was 96.2%, 97.4%, 97.1% and 90.7%, 83.3%, 88.9% respectively. Mutations in codon 531 of the rpoB gene and codon 315 of the katG gene dominated in RIF and INH resistant strains respectively. Disagreements between phenotypical and molecular tests results (12 samples) could be explained by the presence of rare mutations in strains circulating in Russia and simultaneous presence of resistant and sensitive bacilli in sputum specimens (heteroresistance).

Conclusion

High sensitivity, short turnaround times and the potential for screening large numbers of specimens rapidly, make the GenoType^® MTBDRplus assay suitable as a first-line screening assay for drug resistant TB.

Stigma and HIV infection in Russia

Few studies have examined the personal and social consequences of stigma associated with HIV infection in Russia, a country with one of the most rapidly advancing HIV epidemics globally. By May 2005, Samara Oblast, Russia had 24,022 notified seropositive individuals. Focus-group discussions with randomly sampled seropositive and seronegative individuals, matched by age, gender and education were selected from the general population and used to provide an informal forum for discussion of attitudes to HIV and potentially stigmatizing behavior. The results demonstrated that the perception that HIV was associated with immoral behaviour underpinned stigma. Discriminating attitudes are strongly associated with misperceptions regarding transmission and frequent over-estimation of risks from casual contact. The general population was unforgiving to those who had become infected sexually or through drug use. Infection through a medical procedure or from an assault was perceived as a likely route of infection. Knowledge of population attitudes and perceptions, as well as those who are HIV-positive, is critical for successful interventions and to encourage people to come forward for HIV testing. This research offers insights into the distance that needs to be traveled if stigma is to be addressed in wider efforts to control HIV in Russia.

Rates of latent tuberculosis in health care staff in Russia

BACKGROUND

Russia is one of 22 high burden tuberculosis (TB) countries. Identifying individuals, particularly health care workers (HCWs) with latent tuberculosis infection (LTBI), and determining the rate of infection, can assist TB control through chemoprophylaxis and improving institutional cross-infection strategies. The objective of the study was to estimate the prevalence and determine the relative risks and risk factors for infection, within a vertically organised TB service in a country with universal bacille Calmette-Guérin (BCG) vaccination.

METHODS AND FINDINGS

We conducted a cross-sectional study to assess the prevalence of and risk factors for LTBI among unexposed students, minimally exposed medical students, primary care health providers, and TB hospital health providers in Samara, Russian Federation. We used a novel in vitro assay (for gamma-interferon [IFN-gamma]) release to establish LTBI and a questionnaire to address risk factors. LTBI was seen in 40.8% (107/262) of staff and was significantly higher in doctors and nurses (39.1% [90/230]) than in students (8.7% [32/368]) (relative risk [RR] 4.5; 95% confidence interval [CI] 3.1-6.5) and in TB service versus primary health doctors and nurses: respectively 46.9% (45/96) versus 29.3% (34/116) (RR 1.6; 95% CI 1.1-2.3). There was a gradient of LTBI, proportional to exposure, in medical students, primary health care providers, and TB doctors: respectively, 10.1% (24/238), 25.5% (14/55), and 55% (22/40). LTBI was also high in TB laboratory workers: 11/18 (61.1%).

CONCLUSIONS

IFN-gamma assays have a useful role in screening HCWs with a high risk of LTBI and who are BCG vaccinated. TB HCWs were at significantly higher risk of having LTBI. Larger cohort studies are needed to evaluate the individual risks of active TB development in positive individuals and the effectiveness of preventive therapy based on IFN-gamma test results.

Differentiation of tuberculosis strains in a population with mainly Beijing-family strains

A new panel of 25 VNTR-MIRU loci differentiates Beijing-family TB strains better than a panel of 15.

A high prevalence of tuberculosis (TB) isolates that are genetically homogenous and from the Beijing family has been reported in Russia. To map TB transmission caused by these strains, new genotyping systems are needed. Mycobacterial interspersed repetitive units (MIRUs) offer the possibility of rapid PCR-based typing with comparable discrimination to IS6110 restriction fragment length polymorphism techniques. Spoligotyping and detection of IS6110 insertion in the dnaA-dnaN region were used to identify Beijing strains in 187 Mycobacterium tuberculosis isolates from Samara, Russia. The Beijing isolates were analyzed by using 12-MIRU and 3–exact tandem repeats (ETR) loci and by an expanded set of 10 additional variable number tandem repeats loci. The expanded set of 25 MIRUs provided better discrimination than the original set of 15 (Hunter-Gaston diversity index 0.870 vs 0.625). Loci MIRU 26, 1982, and 3232 were the most polymorphic in Beijing isolates.

Resequencing and association analysis of the SP110 gene in adult pulmonary tuberculosis

Recently, the Intracellular pathogen resistance 1 (Ipr1) gene was shown to control susceptibility to Mycobacterium tuberculosis in mice. We examined whether common sequence variants of its human orthologue, the SP110 gene, are associated with susceptibility to tuberculosis in a human population. We resequenced SP110 exons in 96 individuals and identified new polymorphisms. Then, we combined our sequence and HapMap data for 83 distinct polymorphisms and selected tags that capture information for all common variants in the 100 kb region around SP110. We genotyped 29 single nucleotide polymorphisms including seven amino-acid changing variants in 1,912 HIV-negative culture-confirmed adult pulmonary tuberculosis patients and 2,104 adult healthy controls from Russia and found no evidence of association. Our results indicate that common polymorphisms of the SP110 gene have no major effect on susceptibility to tuberculosis in this population.

Costs and outcomes of tuberculosis control in the Russian Federation: retrospective cohort analysis

We analysed costs and outcomes of tuberculosis care for patients in a traditional Russian tuberculosis control system, using 3-year retrospective cohort data. Of 1749 cases at 3 years of follow-up, 65% were cured, 11.3% (198/1749) still had 'active' or 'chronic' disease, 10.3% had transferred out of the local civilian health care system and 12.7% had died. The mean cost of managing one case over 3 years was 886 US dollars: 1,078 US dollars for bacteriologically confirmed (BK+) cases and 718 US dollars for bacteriologically unconfirmed (BK-) cases. Approximately 60% of treatment costs were incurred in the first 12 months and 40% incurred in the remaining 2 years. Around 60% of the total cost was accounted for by hospital inpatient care. The cost, treatment and outcome of BK+ and BK- cases differed substantially. The cost of treating BK+ cases was 50% higher than treating BK- cases due to higher hospitalization rates and the additional cost of managing BK+ cases that become 'chronic'. While BK+ cases accounted for 55% of total health expenditure on tuberculosis, the share of BK- cases was 45% of the total - due to hospitalization and lengthy periods of follow up. The costs of treating tuberculosis in the Russian tuberculosis control system are very high compared with other high-burden countries due to hospitalization policies and lengthy case management periods. Much of this expenditure can be avoided if the WHO-recommended DOTS strategy is implemented. In particular, the proportion of expenditure for BK- cases is surprisingly high and can be avoided as most of these patients do not need hospitalizing or lengthy periods of follow-up.