While it may feel like a disease of the past, tuberculosis surged back with a devastating global impact in 2022, sickening an estimated 10.6 million people and claiming 1.6 million lives.
Key Takeaways
- In 2022, an estimated 10.6 million people (including 5.8 million women and 1.3 million children) developed tuberculosis (TB) worldwide, marking a 4.5% increase from 2021.
- Tuberculosis caused an estimated 1.3 million deaths among HIV-negative people in 2022, with a total of 1.6 million deaths including those with HIV.
- The global TB incidence rate fell by 8.3% between 2015 and 2022, from 171 to 157 new cases per 100,000 population.
- Airborne transmission of Mycobacterium tuberculosis occurs primarily through inhalation of droplet nuclei generated by coughs, sneezes, or talking.
- People with latent TB infection exhale far fewer infectious particles than those with active pulmonary TB.
- Close contacts of active TB cases have a 10-30% risk of becoming infected if untreated.
- Xpert MTB/RIF assay detects TB with 85% sensitivity in smear-positive cases and 68% in smear-negative.
- Culture-based diagnosis remains the gold standard for TB, with >90% sensitivity but 2-6 week turnaround.
- Chest X-ray shows abnormalities in 90% of pulmonary TB cases, but specificity is only 60-70%.
- 6-month standard short-course regimen cures 85% of new drug-susceptible TB cases.
- Treatment success rate for new pulmonary TB cases was 88% globally in 2022.
- MDR-TB treatment success is 62% with 9-20 month individualized regimens.
- BCG vaccination at birth prevents 50% of TB deaths in children under 5.
- TB vaccine pipeline includes 17 candidates in clinical trials, with M72/AS01E showing 50% efficacy against pulmonary TB.
- Isoniazid preventive therapy (6H) reduces risk of active TB by 35% in PLHIV.
Tuberculosis cases are rising again but global progress remains far off target.
Diagnosis
- Xpert MTB/RIF assay detects TB with 85% sensitivity in smear-positive cases and 68% in smear-negative.
- Culture-based diagnosis remains the gold standard for TB, with >90% sensitivity but 2-6 week turnaround.
- Chest X-ray shows abnormalities in 90% of pulmonary TB cases, but specificity is only 60-70%.
- IGRA tests (e.g., QuantiFERON) have 90% specificity for latent TB infection, superior to TST (70%).
- Sputum smear microscopy detects 50-60% of TB cases, missing many smear-negative pulmonary TB.
- GeneXpert Ultra improves sensitivity to 90% for smear-negative, HIV-associated TB.
- Urine LAM assay detects TB in 60% of HIV-positive hospitalized patients with CD4 <100.
- Digital chest radiography with AI algorithms achieves 95% sensitivity and 85% specificity for TB screening.
- TST conversion rates in exposed children indicate recent infection, with >10mm induration positive.
- Molecular tests like MTBDRplus detect rifampicin resistance with 96% sensitivity and 99% specificity.
- C-reactive protein >10 mg/L combined with clinical symptoms predicts active TB with 80% accuracy.
- Truenat MTB assay, a chip-based PCR, has 85% sensitivity for pulmonary TB detection.
- Bronchoalveolar lavage culture yields 85-95% sensitivity for pulmonary TB diagnosis.
- Host biomarker signatures (e.g., IP-10, IL-6) distinguish active from latent TB with 85% accuracy.
- Stool Xpert detects extrapulmonary TB in children with 67% sensitivity vs. 47% for gastric aspirate.
- PET-CT imaging shows 89% sensitivity for detecting active TB lesions in extrapulmonary sites.
- Loop-mediated isothermal amplification (LAMP) for TB has 78% sensitivity and 98% specificity vs. culture.
- Adenosine deaminase (ADA) in pleural fluid >40 IU/L indicates TB empyema with 90% sensitivity.
- Nucleic acid amplification tests (NAATs) endorsed by WHO detect TB in 90% of rifampicin-resistant cases.
- Algorithmic diagnosis using symptom screen + chest X-ray detects 92% of TB cases in community screening.
- CRISPR-based diagnostics like DETECTR achieve 95% specificity for TB DNA detection.
- Interferon-gamma release assays boost specificity to 99% in BCG-vaccinated populations.
- Yield of contact tracing investigations: 20-30% of child contacts <5 years found to have active TB.
- First-line DST for isoniazid shows 94% sensitivity but only 80% for low-level resistance.
Diagnosis Interpretation
This bewildering statistical smorgasbord, where gold-standard culture languishes in its slow-motion isolation, AI reads X-rays like a psychic, and we can find TB in everything from stool to pee but still can't get a quick, perfect, cheap answer for everyone, perfectly illustrates that modern TB diagnosis is a masterpiece of ingenuity still desperately searching for a single, elegant solution.
Epidemiology
- In 2022, an estimated 10.6 million people (including 5.8 million women and 1.3 million children) developed tuberculosis (TB) worldwide, marking a 4.5% increase from 2021.
- Tuberculosis caused an estimated 1.3 million deaths among HIV-negative people in 2022, with a total of 1.6 million deaths including those with HIV.
- The global TB incidence rate fell by 8.3% between 2015 and 2022, from 171 to 157 new cases per 100,000 population.
- In 2022, 167 countries reported 7.5 million new TB cases to WHO, up from 5.7 million in 2021, representing 71% of the estimated 10.6 million cases.
- The 10 countries with the largest number of new TB cases in 2022 accounted for 64% of the global total: India (26%), Indonesia (10%), China (6.9%), Philippines (6.8%), Pakistan (6.5%), Nigeria (4.1%), Bangladesh (3.9%), DR Congo (3.3%), Russian Federation (2.7%) and Ethiopia (2.2%).
- TB mortality among HIV-negative people declined by 9.2% between 2015 and 2022 globally.
- An estimated 25% of the world’s population – about 2 billion people – are infected with Mycobacterium tuberculosis (latent TB infection).
- Only about 5–10% of people with healthy immune systems who are infected with TB will develop active TB disease during their lifetime.
- In 2021, 1.28 million people died from TB, including 187 000 people with HIV, representing the second leading infectious disease killer after COVID-19.
- The WHO African Region had the highest TB mortality rate per capita in 2022, at 19 deaths per 100,000 population.
- Global TB funding in 2022 reached US$5.8 billion, only 26% of the US$22 billion Global Plan to End TB target.
- In 2022, only 62% of people with TB who were diagnosed were successfully treated, leaving 4.0 million people undiagnosed and untreated.
- TB incidence in the WHO European Region declined by 13% between 2015 and 2022.
- Children younger than 5 accounted for 84% of the 203 000 TB deaths among children in 2022.
- The global target to reduce TB deaths by 90% by 2025 compared with 2015 levels is off track, with only a 9.2% decline achieved by 2022.
- In low TB burden countries, most TB cases are among migrants from high TB burden countries.
- TB notification rates in the EU/EEA were highest in Romania (70 cases per 100,000 in 2021), followed by Latvia (49) and Lithuania (37).
- In the United States, TB incidence was 2.4 cases per 100,000 population in 2022.
- Globally, multidrug-resistant TB (MDR-TB) affects about 410,000 people annually.
- TB is the leading cause of death among people living with HIV, accounting for 1 in 5 HIV-related deaths.
- In 2022, India had 2.8 million estimated new TB cases, representing 26% of the global burden.
- The incidence rate of TB in South Africa was 468 per 100,000 in 2022.
- TB case notifications increased by 6% globally from 2021 to 2022.
- Only 42% of the 30 million people needing TB preventive treatment between 2022 and 2024 are on track to receive it.
- In 2022, 1.25 million women developed TB, with 70% of cases in the 25 highest-burden countries.
- TB incidence among children under 5 declined by only 6% from 2015-2022, compared to 8.3% overall.
- The global TB case detection rate reached 71% in 2022, up from 67% pre-COVID-19 pandemic.
- In the WHO South-East Asia Region, TB incidence fell by only 4.8% between 2015 and 2022.
- An estimated 10.6 million incident TB cases in 2022 included 1.3 million children under 15 years.
Epidemiology Interpretation
The numbers reveal a frustrating paradox: while we're slowly bending the curve of TB overall, with global incidence and mortality inching down, the disease remains a staggering, relentless killer—claiming 1.6 million lives, disproportionately affecting the vulnerable, and thriving on a massive funding and treatment gap that leaves millions undiagnosed and a world dangerously off track from its own goals.
Prevention
- BCG vaccination at birth prevents 50% of TB deaths in children under 5.
- TB vaccine pipeline includes 17 candidates in clinical trials, with M72/AS01E showing 50% efficacy against pulmonary TB.
- Isoniazid preventive therapy (6H) reduces risk of active TB by 35% in PLHIV.
- Contact management screens 1.3 million children annually, preventing 200,000 TB cases via TPT.
- Airborne infection control (ventilation, UV lights) reduces TB transmission by 50-70% in healthcare settings.
- TPT scale-up could avert 2.7 million TB deaths and 39 million cases by 2035.
- Active case finding in prisons detects 3x more TB cases than passive surveillance.
- Nutritional supplementation reduces TB incidence by 20% in high-risk groups.
- HIV testing and ART initiation prevents 30% of TB deaths in co-infected individuals.
- M72/AS01E vaccine prevented 49.7% of bacteriologically confirmed pulmonary TB in IGRA+ adults.
- Household contact tracing identifies 15% active TB prevalence in high-burden countries.
- Smoking cessation programs reduce TB risk by 30% within 5 years post-quitting.
- Rapid diagnostic rollout could close 2.5 million detection gap annually.
- TPT for household contacts <5 years prevents 60% progression to active disease.
- Digital adherence technologies increase TPT completion from 65% to 85%.
- Community-wide TPT in high-burden settings averts 20-30% incidence decline over 5 years.
- UVGI systems in HVAC reduce viable TB bacilli by 90% in room air.
- Diabetes screening and control in TB patients reduces mortality by 25%.
Prevention Interpretation
The sobering math of TB reveals a clear formula: while the bacteria are formidable, our arsenal of vaccines, treatments, and public health strategies consistently proves that for every grim statistic, there's a human intervention waiting to cut it neatly in half.
Transmission
- Airborne transmission of Mycobacterium tuberculosis occurs primarily through inhalation of droplet nuclei generated by coughs, sneezes, or talking.
- People with latent TB infection exhale far fewer infectious particles than those with active pulmonary TB.
- Close contacts of active TB cases have a 10-30% risk of becoming infected if untreated.
- HIV-positive individuals are 18 times more likely to develop active TB disease than HIV-negative individuals.
- Smoking doubles the risk of TB disease and death, with 0.54 million TB deaths attributable to smoking in 2022.
- Alcohol use disorders increase TB risk by 2-3 times, contributing to 0.75 million TB deaths in 2022.
- Malnutrition accounts for 1.9 million TB deaths annually, tripling the risk of TB infection progressing to disease.
- Diabetes doubles the risk of developing active TB and increases TB mortality by 50%.
- Household contacts of TB patients have up to 50% infection rate in high-burden settings.
- TB spreads more efficiently in crowded, poorly ventilated indoor spaces with low humidity.
- Children under 5 years are at highest risk of progressing from infection to severe disseminated TB disease quickly.
- People with silicosis have a 30-fold increased risk of developing active TB.
- Undernutrition increases TB risk by 4-6 times, with BMI <18.5 kg/m² elevating odds.
- In prisons, TB transmission risk is 100 times higher than in general population due to overcrowding.
- HIV/TB co-infection accelerates TB progression, with 6% annual risk of active TB in dually infected individuals.
- Tobacco smoking increases TB infection risk by 50% and disease progression by 2-3 times.
- Air pollution contributes to 15% of global TB burden, exacerbating lung vulnerability to M. tuberculosis.
- Pregnant women with TB have 3 times higher risk of maternal mortality.
- People living with both HIV and TB are 18 (10–27) times more likely to die from TB.
- In high-burden settings, 20-30% of household contacts develop latent TB infection after exposure.
- Drug users injecting substances have 3 times higher TB risk due to immune suppression.
- Chronic kidney disease increases TB risk 5-10 fold.
- TNF-alpha inhibitors used in autoimmune diseases increase active TB risk 4-fold.
- The basic reproduction number (R0) for TB in high-prevalence settings is 2-3 without interventions.
- Sputum-positive TB patients infect 5-15 contacts on average over their infectious period.
Transmission Interpretation
This grim symphony of statistics makes it abundantly clear that tuberculosis thrives not just on the bacterium itself, but on a chorus of social inequities and comorbidities, transforming it from a mere infection into a brutal barometer of human vulnerability.
Treatment
- 6-month standard short-course regimen cures 85% of new drug-susceptible TB cases.
- Treatment success rate for new pulmonary TB cases was 88% globally in 2022.
- MDR-TB treatment success is 62% with 9-20 month individualized regimens.
- BPaLM regimen (bedaquiline, pretomanid, linezolid, moxifloxacin) achieves 89-94% success in 6 months for MDR-TB.
- Pretomanid reduces treatment duration for XDR-TB from 20 to 6 months with 91% favorable outcomes.
- Isoniazid preventive therapy (IPT) reduces TB incidence by 60% in PLHIV.
- Rifampicin-based 4-month regimen for drug-susceptible TB shows 90% success vs. 86% for 6-month.
- Delamanid added to MDR-TB regimen increases culture conversion by 20% at month 2.
- Linezolid in MDR-TB regimens yields 85% success but with 40% adverse event rate.
- Shorter 9-12 month MDR-TB regimen success rate: 85% vs. 67% for longer regimens.
- TB treatment dropout rate is 13% globally, contributing to 400,000 resistance cases yearly.
- Adherence support via video-observed therapy (VOT) improves success by 10% over DOT.
- Fluoroquinolone-containing regimens for TB meningitis reduce mortality by 25%.
- Pretomanid Nix-TB trial: 96% interim success at 6 months for fluoroquinolone-sensitive MDR-TB.
- Isoniazid + rifapentine 1HP regimen for latent TB has 93% completion rate and 86% efficacy.
- Surgery for MDR-TB (lobectomy) improves success from 50% to 85% in localized disease.
- High-dose rifampicin (35mg/kg) accelerates sputum conversion by 20% at week 8.
- Cycloserine in MDR-TB regimens requires therapeutic drug monitoring due to 40% neuropsychiatric toxicity.
- 3HP regimen (3 months isoniazid+rifapentine) prevents TB 76% effectively in contacts.
- BPaL regimen interim success 93% at 6 months for extensively drug-resistant TB.
- Treatment success for children with TB is 82%, lower due to diagnosis challenges.
- Levofloxacin substitution in short-course regimens maintains 90% efficacy with fewer side effects.
Treatment Interpretation
In the relentless battle against tuberculosis, our arsenal is sharpening dramatically—shorter, smarter regimens are pushing cure rates into the 90s, while stubborn gaps in adherence and toxicity remind us that even brilliant science cannot cure what it doesn't reach.
Sources & References
- Reference 1WHOwho.intVisit source
- Reference 2CDCcdc.govVisit source
- Reference 3ECDCecdc.europa.euVisit source
- Reference 4UNAIDSunaids.orgVisit source
- Reference 5TBCINDIAtbcindia.gov.inVisit source
- Reference 6NCBIncbi.nlm.nih.govVisit source
- Reference 7ILOilo.orgVisit source
- Reference 8NEJMnejm.orgVisit source
- Reference 9THELANCETthelancet.comVisit source
- Reference 10NATUREnature.comVisit source
- Reference 11COCHRANELIBRARYcochranelibrary.comVisit source