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Katherine Horton @kchorton.bsky.social · 19m

Our analysis highlights underappreciated patterns in #TB exposure and transmission that are directly relevant to efforts to end TB. More systematic analyses to understand the epidemiology of TB transmission should be used to inform context-specific prevention and care strategies.

Katherine Horton @kchorton.bsky.social · 19m

Across age groups, TB exposure typically peaked in adolescence. However, transmission contributions by age varied across regions with the highest proportion from adolescents aged 15-24 in AMR and SEAR, adults aged 35-44 in AFR and EUR, and older adults 65+ in EMR and WPR.

[NOT YET PEER REVIEWED]

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Katherine Horton @kchorton.bsky.social · 19m

Both exposure and transmission were higher in males than in females. We found that a majority of TB transmission was attributable to contact with adult men: 67% (95% UI 62-71%) of transmission to men, 52% (95% UI 49-56%) to women, and 63% (95% UI 58-68%) to children.

[NOT YET PEER REVIEWED]

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Katherine Horton @kchorton.bsky.social · 19m

Understanding patterns of #TB exposure and transmission is needed for targeted prevention strategies. In our latest pre-print, @petedodd24.bsky.social and I estimated the proportion of TB exposure to and transmission from sex and age groups for 177 countries.

bit.ly/4nbV492

A global analysis of patterns of tuberculosis exposure and transmission

Tuberculosis (TB) is a major public health concern and the leading infectious cause of mortality globally. The disease exhibits strong prevalence patterns by age and sex, but the implications of these...

www.medrxiv.org

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Reposted by Katherine Horton

Rein Houben @reinhouben.bsky.social · 5d

In a new preprint (NOT PEER REVIEWED) we continue to explore the challenge of overtreatment in community screening. It seems the benefits of TB treatment far outweigh the harms, especially once we accept that sputum culture is not perfect. Important food for thought. www.medrxiv.org/content/10.1...

Do no harm - re-evaluating the risks of overtreatment in community-wide tuberculosis screening

Background Community-wide screening is a crucial strategy to end tuberculosis (TB), but a common concern is potential harm from overtreatment following false positive diagnoses. However, current refer...

www.medrxiv.org

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Reposted by Katherine Horton

Ruth Bowness @ruthbowness.bsky.social · 15d

PhD opportunity: New approaches to modelling TB transmission in low-incidence settings.
Supervised by Ellen Brooks-Pollock (Bristol), me (Bath) & Rajeka Lazarus (Bristol)
Apply: www.findaphd.com/phds/project...
Deadline 20 Oct
#PhD #Tuberculosis #Epidemiology #InfectiousDisease

New approaches for modelling tuberculosis transmission in low incidence settings at University of Bristol on FindAPhD.com

PhD Project - New approaches for modelling tuberculosis transmission in low incidence settings at University of Bristol, listed on FindAPhD.com

www.findaphd.com

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Katherine Horton @kchorton.bsky.social · 20d

Our systematic review of rural/urban differences in #TB prevalence shows evidence of rapidly urbanising epidemics in many settings, with differences across countries and regions.

Link to preprint below ⬇️

Peter MacPherson @petermacp.bsky.social · 20d

Are there more people with #TB in cities or rural areas?

In a 🚨new🚨 preprint (NOT PEER REVIEWED) we modelled urban-rural TB trends from 2000-2023 in 26 countries with 4.6 billion people.

www.medrxiv.org/content/10.1...

A plot, facetted by country, showing the percentage of TB that is urban and rural between 2000-2023

A forest plot, showing estimates of the urban to rural TB prevalence in 46 studies

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Reposted by Katherine Horton

Madhu Pai, MD, PhD @madhupai.bsky.social · 26d

Sad (but not surprised) to read the latest Global Health 50/50 report, amidst turmoil in global health, erosion of democracy, withdrawal from multi-lateralism, aid cuts, attacks on science, DEI, human rights

@kentbuse.bsky.social @jocalynclark.bsky.social

global5050.org/2025-report/

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Reposted by Katherine Horton

Peter MacPherson @petermacp.bsky.social · 25d

Men are more than twice as likely as women to have prevalent #TB.

We did updated meta-analysis including over 4million people in 99 surveys.

Despite increasing focus on gender equitable TB responses, this gap has widened since we last assessed these data over a decade ago.

Katherine Horton @kchorton.bsky.social · 26d

1/ It’s been 10 years (😮) since we reported that #TB prevalence was twice as high in men as in women.

📢 Our new preprint explores how sex differences have shifted with more recent national prevalence surveys and growing attention to #gender responsive TB prevention and care.

bit.ly/4gqP1LH

Differences in Tuberculosis Prevalence by Sex Over 1993-2024: A Systematic Review and Meta-Analysis

Background: Tuberculosis (TB) prevalence is higher among men than women in low- and middle-income countries (LMICs). However, summary measures of sex difference

bit.ly

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Katherine Horton @kchorton.bsky.social · 26d

6/ @petermacp.bsky.social and I seem to be the only coauthors on Bluesky, but this work comes from a great team across @hsph.harvard.edu @uofglasgow.bsky.social @tb-lshtm.bsky.social @lshtm-tbmod.bsky.social

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Katherine Horton @kchorton.bsky.social · 26d

5/ These findings show that, despite calls for gender responsive TB prevention and care, disparities have increased over the past three decades. Effective strategies to reduce men’s risk of TB and to engage men in TB prevention and care remain essential to end TB.

NOT PEER REVIEWED

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Katherine Horton @kchorton.bsky.social · 26d

4/ The stability of pooled estimates doesn't mean sex ratios have remained consistent. We found evidence that male-to-female ratios likely increased 1.6% (95% CrI -1.0-6.2%) annually over the period 1994–2021, with the greatest increase in the Western Pacific region.

NOT PEER REVIEWED

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Katherine Horton @kchorton.bsky.social · 26d

3/ We fitted multi-level Bayesian regression models to estimate a pooled male-to-female prevalence ratio of 2.21 (95% CrI 1.94-2.50) for bacteriologically-confirmed TB.

That's the same point estimate as our previous review, but the two studies used different analytical methods.

NOT PEER REVIEWED

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Katherine Horton @kchorton.bsky.social · 26d

2/ We updated our systematic review and identified 99 TB prevalence surveys reporting sex-disaggregated results (with >4 million participants) conducted between 1993 and 2024 in 33 low- or middle-income countries.

NOT PEER REVIEWED

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Katherine Horton @kchorton.bsky.social · 26d

1/ It’s been 10 years (😮) since we reported that #TB prevalence was twice as high in men as in women.

📢 Our new preprint explores how sex differences have shifted with more recent national prevalence surveys and growing attention to #gender responsive TB prevention and care.

bit.ly/4gqP1LH

Differences in Tuberculosis Prevalence by Sex Over 1993-2024: A Systematic Review and Meta-Analysis

Background: Tuberculosis (TB) prevalence is higher among men than women in low- and middle-income countries (LMICs). However, summary measures of sex difference

bit.ly

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Katherine Horton @kchorton.bsky.social · 27d

Fantastic work from @aschwalbc.bsky.social now out in @plosglobalpublichealth.org. Check out his thread below for more details!

Alvaro Schwalb @aschwalbc.bsky.social · Sep 11

Our work on modelling population-wide screening in Viet Nam is now available in PLOS Global Public Health! tinyurl.com/3ymhuj5s

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Reposted by Katherine Horton

Matthew Saunders @mjsaunder.bsky.social · Sep 9

Nutritional status is a key determinant of TB. In this updated systematic review and dose-response meta-analysis (43 cohorts inc > 26 million people) we redefined the relationship between body mass index (BMI) and TB. doi.org/10.1093/ije/...

Body mass index and tuberculosis risk: an updated systematic literature review and dose–response meta-analysis

AbstractBackground. The relationship between nutritional status and tuberculosis is critically important but poorly understood. We extended a 2009 review c

doi.org

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Katherine Horton @kchorton.bsky.social · Sep 5

... @arkaprabhagun.bsky.social Tom Sumner @cfmcquaid.bsky.social @raclark18.bsky.social @top-j.bsky.social Roel Bakker @yiranliu.bsky.social Mmamapudi Kubjane, Christian Lienhardt @richardwhite321.bsky.social @reinhouben.bsky.social

@lshtm-tbmod.bsky.social @tb-lshtm.bsky.social 9/9

Katherine Horton @kchorton.bsky.social · Sep 5

This work provides an important update to previous comparisons of #TB interventions across the prevention and care cascade and was made possible by a massive team effort from @aschwalbc.bsky.social Martin Harker @laragosce.bsky.social Elena Venero-Garcia, Lily O'Brien ... 8/9

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Katherine Horton @kchorton.bsky.social · Sep 5

Our results show interventions with meaningful epidemiological impact can also be cost-effective, but need to target populations beyond routinely diagnosed individuals or their households. Achieving such potential requires a priority shift in funding, policy, and product development. 7/9

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Katherine Horton @kchorton.bsky.social · Sep 5

ICERs varied widely by intervention and across countries. Shortened DR-TB treatment was cost-saving in all 3 countries, with the next lowest ICERs for screening in prisons [BRA] (US$72/DALY) and nutritional supplementation [IND] (US$167/DALY). 6/9

Incremental Cost-Effectiveness Ratios, with DALYs averted on x-axis and incremental budget (USD) on y-axis, for 3 countries.

Error bars show 95% uncertainty intervals for DALYs averted (horizontal lines) and incremental budget (vertical lines). Dashed line shows cost-effectiveness thresholds. Vacc = Vaccination, TPT = Tuberculosis Preventive Treatment, Comm Scr = Community-wide screening (low diagnostic cost), Impr Diag = Improved diagnosis in clinics, DST for all = Drug Susceptibility Testing for all clinic-diagnosed individuals, Short DS = Shortened treatment for Drug Susceptible TB, Short DR = Shortened treatment for Drug Resistant TB, Pri Scr = Mass screening in incarcerated individuals, Nutr = Nutritional support for households of individuals receiving TB treatment.

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Katherine Horton @kchorton.bsky.social · Sep 5

Only three interventions prevented >10% of incident TB episodes by 2050: vaccination (median 15-28% across countries), community screening (32-38%), and screening in prisons (23%). Other interventions had limited impact, from 0% (shortened DS-TB treatment) to 5% (nutritional supplementation). 5/9

Percentage of incident symptomatic TB episodes averted (2025-2050) for 9 interventions in 3 countries. Greatest impact for community screening, vaccination, and screening in prisons, followed by nutritional supplementation, improved diagnostics, and tuberculosis preventive treatment.

Vacc = Vaccination, TPT = Tuberculosis Preventive Treatment, Comm Scr = Community-wide screening, Impr Diag = Improved diagnosis in clinics, DST for all = Drug Susceptibility Testing for all clinic-diagnosed individuals, Short DS = Shortened treatment for Drug Susceptible TB, Short DR = Shortened treatment for Drug Resistant TB, Pri Scr = Mass screening in incarcerated individuals, Nutr = Nutritional support for households of individuals receiving TB treatment. BRA = Brazil, IND = India, ZAF = South Africa. Error bars reflect 95% Uncertainty Intervals.

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Katherine Horton @kchorton.bsky.social · Sep 5

For each intervention, we standardised scale-up (2025-2030), coverage (80% of target population), and strength of evidence for epidemiological impact (using published data). Our economic model considered health systems costs for interventions as well as routine diagnosis and treatment. 4/9

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Katherine Horton @kchorton.bsky.social · Sep 5

We simulated vaccination, TPT, community screening, improved diagnostics, expanded DST, shortened DS-TB treatment, and shortened DR-TB treatment interventions, plus screening in prisons [BRA] and nutritional supplementation [IND]. No HIV intervention was modelled for ZAF given high ART coverage. 3/9

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Katherine Horton @kchorton.bsky.social · Sep 5

We developed a deterministic #TB model for a geographically and epidemiologically diverse set of countries, incorporating key structural determinants: incarceration in Brazil, undernutrition in India, HIV in South Africa. We calibrated to epidemiological indicators and trends for each country. 2/9

Epidemiological model structure and subdivisions. Model structure for the natural history of TB, incorporating both general subdivisions and country-specific structural determinants: incarceration (Brazil), undernutrition (India), and HIV (South Africa). Background mortality is assumed for all states but not shown; arrows exiting from the corners of certain states represent specific mortality rates. The model is age-stratified in 5-year bands up to 75+ years. TB states shaded in light grey represent individuals harbouring viable Mycobacterium tuberculosis and are further subdivided by drug resistance; this also applies to those recently treated, assuming relapse would involve the same strain. Dark grey TB states appear only in the previously treated stratum within the treatment subdivisions.

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