Publications by authors named "Yohhei Hamada"

Article Synopsis
  • The current tests for identifying TB infection include the Tuberculin Skin Test (TST) and interferon-gamma release assays (IGRA), but access and implementation issues limit their use.
  • Novel skin tests such as Diaskintest and C-TST show potential for better scalability and accuracy, though evidence on their economic impact is still lacking.
  • Systematic reviews indicated that while costs for TBST were generally lower than TST and IGRA, there is limited high-quality evidence for TBST, and the existing studies on TST and IGRA lean towards high-income settings without clear economic consensus.
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Article Synopsis
  • The study aimed to examine the prevalence of non-communicable diseases, particularly diabetes, among household contacts of individuals with tuberculosis (TB).
  • A systematic review identified 39 studies, with 14 providing individual participant data and 25 offering aggregated data; the results showed a pooled diabetes prevalence of 8.8% among those tested properly.
  • Findings indicate that diabetes prevalence among household contacts is likely underestimated, highlighting the importance of targeted interventions during TB contact investigations to identify and address these health issues.
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The provision of tuberculosis preventive treatment is one of the critical interventions to reduce tuberculosis incidence and ultimately eliminate the disease, yet we still miss appropriate tools for an impactful intervention and treatment coverage remains low. We used recent data, epidemiological estimates, and research findings to analyze the challenges of each step of the cascade of tuberculosis prevention that currently delay the strategy implementation. We addressed research gaps and implementation bottlenecks that withhold key actions in tuberculosis case finding, testing for tuberculosis infection, provision of preventive treatment with safer, shorter regimens and supporting people to complete their treatment.

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Background: COVID-19 disrupted the TB prevention programme in the UK, especially for TB infection (TBI) care. We explore whether experience of the COVID-19 pandemic impacted on patients' perceptions of TBI and its treatment.

Methods: Semi-structured interviews were conducted as part of the Research to Improve Detection and Treatment of TBI (RID-TB) programme, exploring perceptual and practical barriers to TBI treatment.

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Tuberculosis (TB) and non-communicable diseases (NCD) share predisposing risk factors. TB-associated NCD might cluster within households affected with TB requiring shared prevention and care strategies. We conducted an individual participant data meta-analysis of national TB prevalence surveys to determine whether NCD cluster in members of households with TB.

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Evidence on the economic impact of novel skin tests for tuberculosis infection (TBST) is scarce and limited by study quality. We used estimates on the cost-effectiveness of the use of TBST compared to current tuberculosis infection (TBI) tests to assess whether TBST are affordable and feasible to implement under different country contexts. A Markov model parametrised to Brazil, South Africa and the UK was developed to compare the cost-effectiveness of three TBI testing strategies: (1) Diaskintest (DST), (2) TST test, and (3) IGRA QFT test.

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Background: An estimated one fourth of the world's population is infected with Mycobacterium tuberculosis, and 5-10% of those infected develop tuberculosis in their lifetime. Preventing tuberculosis is one of the most underutilized but essential components of curtailing the tuberculosis epidemic. Moreover, current evidence illustrates that tuberculosis manifestations occur along a dynamic spectrum from infection to disease rather than a binary state as historically conceptualized.

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Background: Non-communicable diseases (NCDs) and NCD risk factors, such as smoking, increase the risk for tuberculosis (TB). Data are scarce on the risk of prevalent TB associated with these factors in the context of population-wide systematic screening and on the association between NCDs and NCD risk factors with different manifestations of TB, where ∼50% being asymptomatic but bacteriologically positive (subclinical). We did an individual participant data (IPD) meta-analysis of national and sub-national TB prevalence surveys to synthesise the evidence on the risk of symptomatic and subclinical TB in people with NCDs or risk factors, which could help countries to plan screening activities.

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Background: The World Health Organization (WHO) recommends that outpatient people living with HIV (PLHIV) undergo tuberculosis screening with the WHO four-symptom screen (W4SS) or C-reactive protein (CRP) (5 mg·L cut-off) followed by confirmatory testing if screen positive. We conducted an individual participant data meta-analysis to determine the performance of WHO-recommended screening tools and two newly developed clinical prediction models (CPMs).

Methods: Following a systematic review, we identified studies that recruited adult outpatient PLHIV irrespective of tuberculosis signs and symptoms or with a positive W4SS, evaluated CRP and collected sputum for culture.

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Background: A systematic review showed that the accuracy of antigen-based skin tests (TBSTs) for tuberculosis is similar to that of interferon γ release assay, but the safety of TBSTs has not been systematically reviewed.

Methods: We searched for studies reporting injection site reactions (ISRs) and systemic adverse events associated with TBSTs. We searched Medline, Embase, e-library, the Chinese Biomedical Literature Database, and the China National Knowledge Infrastructure database for studies through 30 July 2021, and the database search was updated until 22 November 2022.

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Approximately 10·6 million people worldwide develop tuberculosis each year, representing a failure in epidemic control that is accentuated by the absence of effective vaccines to prevent infection or disease in adolescents and adults. Without effective vaccines, tuberculosis prevention has relied on testing for Mycobacterium tuberculosis infection and treating with antibiotics to prevent progression to tuberculosis disease, known as tuberculosis preventive treatment (TPT). Novel tuberculosis vaccines are in development and phase 3 efficacy trials are imminent.

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Article Synopsis
  • * A study conducted in Nigeria's Enugu, Gombe, Lagos, and Nasarawa states found that seroprevalence of SARS-CoV-2 antibodies ranged from 9.3% to 25.2%, with over 96% of interviewed individuals providing blood samples
  • * Despite a high seroprevalence indicating infection rates much higher than officially reported cases, active SARS-CoV-2 infection was low at 0.2%, suggesting that most of the population remained susceptible to COVID-19
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Introduction: The successful scale-up of a latent tuberculosis (TB) infection testing and treatment programme is essential to achieve TB elimination. However, poor adherence compromises its therapeutic effectiveness. Novel rifapentine-based regimens and treatment support based on behavioural science theory may improve treatment adherence and completion.

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Article Synopsis
  • Scientists compared two tests (TST and IGRA) to see which one is better at predicting active tuberculosis (TB) disease.
  • They looked at data from 13 studies with over 32,000 people to find out which test was more reliable.
  • The IGRA test was found to be better in certain countries, especially where fewer people have TB.
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  • Scientists are finding better ways to use mRNA technology to create tests for tuberculosis (TB) that can help diagnose, monitor treatment, and predict how the disease might progress.
  • Early studies weren't very good because they didn't include many people or use the right methods, but newer research has improved this.
  • Some testing methods are expensive and complicated, and while they can help tell if treatment is working, they can't yet accurately predict who will develop TB over a long time.
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Background: WHO recommends urine lateral-flow lipoarabinomannan (LF-LAM) testing with AlereLAM in HIV-positive inpatients only if screening criteria are met. We assessed the performance of WHO screening criteria and alternative screening tests/strategies to guide LF-LAM testing and compared diagnostic accuracy of the WHO AlereLAM algorithm (WHO screening criteria followed by AlereLAM if screen positive) with AlereLAM and FujiLAM (a novel LF-LAM test) testing in all HIV-positive inpatients.

Methods: We searched MEDLINE, Embase, and Cochrane Library from Jan 1, 2011 to March 1, 2020 for studies among adult/adolescent HIV-positive inpatients regardless of tuberculosis signs and symptoms.

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Objective: There is a need for reliable serological assays to determine accurate estimates of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence. Most single target antigen assays have shown some limitations in Africa. To assess the performance of a multi-antigen assay, we evaluated a commercially available SARS-CoV-2 Multi-Antigen IgG assay for human coronavirus disease 2019 (COVID-19) in Nigeria.

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Background: Since 2011, WHO has recommended that HIV-positive inpatients be routinely screened for tuberculosis with the WHO four-symptom screen (W4SS) and, if screened positive, receive a molecular WHO-recommended rapid diagnostic test (eg, Xpert MTB/RIF [Xpert] assay). To inform updated WHO tuberculosis screening guidelines, we conducted a systematic review and individual participant data meta-analysis to assess the performance of W4SS and alternative screening tests to guide Xpert testing and compare the diagnostic accuracy of the WHO Xpert algorithm (ie, W4SS followed by Xpert) with Xpert for all HIV-positive inpatients.

Methods: We searched MEDLINE, Embase, and Cochrane Library from Jan 1, 2011, to March 1, 2020, for studies of adult and adolescent HIV-positive inpatients enrolled regardless of tuberculosis signs and symptoms.

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Article Synopsis
  • The text talks about a way to check for tuberculosis (TB) in people living with HIV, using a method to look for four symptoms first, then a special test called Xpert if those symptoms are present.*
  • Researchers wanted to see if there are better ways to test for TB, so they looked at a lot of studies and data from several years to compare different testing methods.*
  • They found that the original four-symptom method works pretty well, but there are other tests, like checking for C-reactive protein, that might also be helpful in finding TB.*
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Validated assays are essential for reliable serosurveys; however, most SARS-CoV-2 immunoassays have been validated using specimens from China, Europe, or U.S. populations.

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Background: Novel skin-based tests for tuberculosis infection might present suitable alternatives to current tests; however, diagnostic performance of new tests compared with the purified protein derivative-tuberculin skin test (TST) or interferon-γ release assays (IGRA) needs systematic assessment.

Methods: In this systematic review and meta-analysis, we searched English (Medline OVID), Chinese (Chinese Biomedical Literature Database and the China National Knowledge Infrastructure), and Russian (e-library) databases from the inception of each database to May 15, 2019, (with updated search of the Russian and English databases on Oct, 20 2020) using terms "ESAT6" OR "CFP10" AND "skin test" AND "Tuberculosis" OR "C-Tb" OR "Diaskintest". We included studies reporting on the performance of index tests alone or compared with a comparator.

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Article Synopsis
  • There is growing evidence suggesting a higher risk of tuberculosis (TB) in individuals with chronic airway diseases (CADs) like COPD, but a systematic review of this association had not been conducted before.
  • A systematic review included nine studies published from 1993 to 2021, finding that three cohort studies showed a significant link between COPD and increased TB risk in high-income countries, with hazard ratios between 1.44 and 3.14.
  • The review highlighted significant variability among studies (I2=97.0%) and noted inconsistent findings regarding asthma's effect on TB risk, with limited data on chronic bronchitis or bronchiectasis.
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