The findings come from Start4All, a four-year partnership funded by Unitaid and led by LSTM together with the Stop TB Partnership and research collaborators in seven countries with high TB burdens. According to the study team, pooled sputum testing, in which specimens from multiple individuals are examined in one molecular test cartridge, halves the number of cartridges required to achieve successful diagnoses. The team’s paper on the performance and costs of pooled testing for molecular detection of TB has been published in The Lancet Global Health, and the results have already directly informed World Health Organization guidelines on pooled testing issued earlier this year, which recommend the technique for adolescents and adults in resource-constrained settings.

The scale of the evidence base is what sets this work apart. Between November 2023 and February 2025, more than 14,000 people with symptoms of TB took part in the study across Bangladesh, Brazil, Cameroon, Kenya, Malawi, Nigeria and Vietnam. Participants were recruited through screening in communities as well as at primary health centres and district hospitals, meaning the data reflect the realities of routine health systems rather than idealised research clinics. Each person’s sputum was tested individually and again as part of a pool of up to four specimens on Xpert MTB/RIF Ultra, the most widely used rapid molecular TB test in the world.

Technically, pooled testing borrows a logic long used in other screening contexts: instead of running one cartridge per person, specimens from up to four people are combined into a single cartridge. If the pooled result is negative, all members of that pool can be confidently ruled out with a single test. If the pooled result is positive, individual retesting of the constituent specimens identifies who requires treatment. Because the large majority of symptomatic screens are expected to be negative, the arithmetic favours pooling strongly, and the Start4All results confirmed this in practice. Pooled testing used just over 7,000 cartridges instead of the roughly 14,000 that individual testing would have required, a 51 percent reduction. That efficiency cut the cost of each test from nearly US$8 to less than US$4.

Crucially, the study is the first to measure pooled testing against culture, the reference standard for TB diagnosis, rather than only against individual molecular testing. This matters because diagnostic accuracy studies that compare a new approach only to an existing test can inherit and mask the limitations of that comparator. By anchoring the evaluation to culture, the researchers were able to characterise pooled testing’s true performance. The trade-off they found was modest: a slight drop of 3.1 percent in sensitivity, meaning the number of people with TB correctly identified, compared with individual testing. That loss was concentrated mostly in specimens containing a very low TB bacterial load, a category in which even individual molecular testing can struggle.

Dr Tushar Garg, the study’s first author, said the findings demonstrate that the technique could increase access to accurate, rapid and low-cost TB testing, enabling thousands more people to be diagnosed around the globe. The framing is significant because the central bottleneck in global TB diagnosis is not the existence of good tests but their reach. Chronic underinvestment has produced limited and inequitable access to WHO-recommended molecular rapid diagnostic tests, and globally only one in two people receive such a test as their initial diagnostic. In many high-burden countries, cartridges and the GeneXpert machines that run them are in chronically short supply, forcing clinicians to fall back on sputum smear microscopy, a century-old method that misses a large share of cases, including many in people living with HIV.

Dr Tom Wingfield, deputy director of LSTM’s Centre for Tuberculosis Research and chief investigator on Start4All, said the evidence took pooled testing from a promising idea to a WHO recommendation, and that it came from routine laboratories and clinics in the countries that need it most, not from a research setting. He emphasised that pooling needs no new technology, and that it makes smarter use of the machines and cartridges laboratories already have, so that many more people can receive a rapid molecular test from the same budget. That, he said, is what reaching the missed millions looks like in practice. The point underscores why the approach has resonated with national programmes: it requires no capital investment, no new procurement streams and no retraining beyond modest laboratory workflow adjustments.

Voices from the collaborating institutions reinforce the operational case. Cyrille Mbuli, a researcher from the Bamenda Center for Health Promotion and Research, Start4All’s collaborating partner in Cameroon, said TB programmes have been asking a simple question: what do programmes give up when they pool tests, and what do they gain. He said the Start4All results confirm what laboratories have observed, namely that pooling lets them test almost twice as many people for the same investment. For national TB programmes operating under fixed budgets, that arithmetic can translate directly into more cases found, more treatment courses started and fewer onward infections, all without a single additional dollar of diagnostic spending.

The research is already producing practical tools beyond the headline paper. A new toolkit for healthcare professionals and National TB Programmes has been created, alongside a test cost calculator and decision tool developed by the Stop TB Partnership, allowing programme managers to model what pooling would save in their own laboratories. The Lancet Global Health paper is also one of a series of Start4All outputs on pooled testing. These include an explanation of the role of pooled sputum testing in the global TB diagnostic landscape published in The Lancet Respiratory Medicine; a multicountry qualitative study in BMJ Open, led by Dr Vibol Iem at LSTM, which found that laboratory staff, programme managers and people with TB in the seven countries considered pooled sputum testing feasible and acceptable; and a cross-sectional study in Clinical Microbiology and Infection that reported the diagnostic accuracy and potential resource savings of pooled testing among adults in Vietnam.

The next phase of Start4All points toward further simplification and scale. Pooled testing will be combined with computer-aided chest X-ray triage, an artificial intelligence-assisted screening approach that can help prioritise who is most likely to benefit from molecular testing, and will be expanded to tongue swab specimens, a less invasive sample type that could widen testing to people who struggle to produce sputum. Together, these steps support simpler and scalable approaches that can expand access to molecular TB testing. For a disease that has been declared a global emergency repeatedly since 1993 and that still claims more than a million lives annually, the prospect of doubling diagnostic throughput with existing machines and cartridges offers one of the most immediately actionable opportunities in the TB response, turning a laboratory logistics trick into a route toward finding the millions the world keeps missing.

Subject of Research: Pooled sputum testing for rapid, low-cost molecular diagnosis of tuberculosis in high-burden countries

Article Title: Rapid low-cost diagnosis within reach for TB ‘missed millions’ researchers find

Article References: Rapid low-cost diagnosis within reach for TB ‘missed millions’ researchers find. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: tuberculosis, pooled testing, Xpert MTB/RIF Ultra, diagnostics, Liverpool School of Tropical Medicine, Start4All, WHO guidelines, The Lancet Global Health, sputum, global health, Unitaid, molecular testing

The study’s central conclusion is stark: the majority of hospitalisations and deaths among children in their first two years of life are caused by infectious diseases that are, in principle, preventable. Malaria alone accounted for 54.3 percent of all hospital admissions recorded during the follow-up period, dwarfing every other cause of severe illness. Lower respiratory infections ranked second at 16.7 percent of admissions, followed by diarrhoeal disease at 9.6 percent, undernutrition at 7.4 percent and sepsis at 4.8 percent. Among deaths that occurred in hospitals with available medical records, malaria was responsible for 50.6 percent, meaning that one in every two in-hospital deaths in this age group was attributable to a single parasitic disease transmitted by mosquitoes.

The burden extends beyond hospital walls. For children who died outside medical facilities, the research team reconstructed probable causes of death through standardised interviews with family members and caregivers, a well-established epidemiological technique known as verbal autopsy. This analysis likewise identified malaria as the most frequent cause of death, followed by respiratory infections and diarrhoea. The researchers caution, however, that verbal autopsy is likely to underestimate malaria mortality, because the fever and generalised symptoms characteristic of severe malaria overlap considerably with those of other common infectious diseases, making it difficult for bereaved caregivers to distinguish between them when recalling a child’s final illness.

The scale and precision of the study distinguish it from previous efforts to characterise early childhood disease burden in the region. Routine surveillance systems in Sierra Leone and many other countries typically group all children under five into a single reporting category, a practice that obscures the distinct epidemiology of infancy and early toddlerhood and makes it difficult to identify precisely which conditions drive hospitalisation and death at different ages. To close this gap, the ICARIA team combined continuous health facility surveillance with household visits, telephone follow-up and a network of community informants, creating an unusually complete record of both severe illness and mortality across the first two years of life.

“To address this important knowledge gap, we followed 20,560 infants up to 24 months of age across 14 health centres in three districts of Sierra Leone,” explained Kwabena Owusu-Kyei, an ISGlobal researcher based in Sierra Leone and first author of the study. “By combining health facility surveillance with household visits, telephone follow-up and community informants, we were able to build a much more complete picture of childhood hospitalisations and deaths.” During the follow-up period, the cohort recorded 2,688 hospital admissions and 859 deaths, figures that translate into an extraordinary concentration of severe disease in a population of children who had, by the study’s design, access to facilities offering free healthcare.

The context of Sierra Leone’s public health landscape makes the findings all the more consequential. Over the past decade and a half, the country has introduced a series of major initiatives aimed at reducing child deaths, including a policy of free healthcare for children under five, malaria chemoprevention programmes, pneumococcal vaccination and, more recently, the rollout of the malaria vaccine. Yet until now, it has been difficult to assess how these interventions are affecting survival during the first two years of life, the period when children are most vulnerable to the infectious diseases that dominate the region’s disease burden. The new study provides the granular evidence base that such assessments require.

Beyond quantifying the burden of disease, the study identified several factors strongly associated with a child’s chances of survival, offering concrete targets for intervention. Children who had received all the routine vaccines of the Expanded Programme on Immunization (EPI) due for their age had a 35 percent lower risk of overall mortality compared with incompletely vaccinated children. Complete vaccination was also associated with a 29 percent lower likelihood of dying during a hospital admission and, strikingly, a 44 percent lower risk of death in the period after discharge from hospital, a finding that underscores how vaccination status shapes resilience well beyond the immediate protection conferred against specific vaccine-preventable pathogens.

Malaria chemoprevention also emerged as a powerful protective factor. Children who received all scheduled doses of sulfadoxine–pyrimethamine, the preventive antimalarial treatment delivered through Sierra Leone’s immunisation programme, had a 40 percent reduction in mortality risk compared with those who missed doses. Conversely, undernutrition significantly increased the risk of dying during hospitalisation, a result that reinforces long-standing calls to integrate nutritional support into paediatric care rather than treating malnutrition and infectious disease as separate clinical problems. Taken together, these associations suggest that the tools needed to save young lives largely already exist within the health system, but that coverage, adherence and integration remain insufficient.

The study arrives at a moment of broader concern for global child health. Worldwide, child mortality has declined substantially over recent decades, one of the great public health achievements of the modern era, but the progress achieved up to 2015 has since stalled. In many countries across sub-Saharan Africa, infectious diseases remain among the greatest threats to survival during the first years of life, and the stagnation of mortality declines suggests that existing strategies are not reaching their full potential. Sierra Leone, still rebuilding its health system after decades of civil war and the 2014 Ebola epidemic, exemplifies the challenge facing the world’s most vulnerable settings.

“These findings show that there is still a substantial unfinished agenda in global health, and that strengthening vaccination, malaria prevention, community-based care and post-discharge follow-up are essential to reducing child mortality in the world’s most vulnerable settings and meeting the Sustainable Development Goals,” concluded Clara Menéndez, Director of ISGlobal’s Maternal, Child and Reproductive Health Programme and principal investigator of the study. With the Sustainable Development Goal target of ending preventable deaths of newborns and children under five by 2030 drawing closer, the Sierra Leone cohort offers both a warning and a roadmap: the diseases killing the youngest children are known, the preventive tools are available, and the decisive variable is whether they reach every child who needs them.

Subject of Research: Causes of hospitalisation and death from malaria and other infectious diseases in children under two in Sierra Leone

Article Title: Malaria remains the leading cause of hospital admission and in-hospital death in children under two in Sierra Leone

Article References: Malaria remains the leading cause of hospital admission and in-hospital death in children under two in Sierra Leone. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: malaria, child mortality, Sierra Leone, The Lancet Global Health, ISGlobal, ICARIA project, vaccination, chemoprevention, sulfadoxine-pyrimethamine, undernutrition, respiratory infections, verbal autopsy

The study, conducted by the NIHR-funded Global Health Group on Equitable Access to Quality Health Care for Injured People in Four Low- or Middle-Income Countries, known as Equi-injury, followed 8,858 injury patients treated at nineteen hospitals across Ghana, Pakistan, Rwanda and South Africa. The hospitals included both urban and rural facilities, giving the researchers an unusually broad picture of how injured people move through very different healthcare environments. It is the first large multi-country study to examine both mortality and disability outcomes among hospitalised injury patients across low- and middle-income settings, and its scale allows conclusions that smaller, single-country studies could not support.

The headline numbers are stark. Within three months of hospital discharge, 47.6 per cent of patients had either died or were living with moderate-to-severe disability. Six point one per cent died while still in hospital, 9.7 per cent had died by the three-month mark, and 40.6 per cent were surviving with moderate-to-severe disability. Behind those figures lies a patient population that mirrors the global pattern of injury: the median age was just 31 years, 76.8 per cent were male, road traffic collisions accounted for half of all injuries recorded, and orthopaedic injuries were the most common type, affecting 39.2 per cent of patients. These are overwhelmingly young people in the prime of working life, which means the economic and social ripple effects of death and disability extend far beyond the individuals themselves.

Perhaps the most provocative finding concerns ambulances. Patients who arrived at hospital by ambulance had significantly worse outcomes than those who arrived by other means, with 86 per cent higher odds of death or disability and more than double the odds of mortality within three months. The researchers are careful to stress what this does and does not mean. Lead author Professor Justine Davies, of the University of Birmingham, said that one of the most surprising findings was that measures often assumed to improve outcomes, such as ambulance transport and rapid transfer to major hospitals resembling highly centralised trauma services, were not consistently linked with better recovery or survival. She emphasised that this does not mean ambulances cause worse outcomes, but rather suggests that investment in ambulance systems alone is unlikely to improve outcomes unless services are coordinated and appropriately resourced.

Corresponding author Dr Leila Ghalichi, also of the University of Birmingham, reinforced the point. She said the finding does not mean ambulances or specialist trauma centres are ineffective; rather, it suggests that simply investing in expensive emergency systems is not enough. In her view, low- and middle-income countries should be cautious about investing heavily in ambulance services and specialist, centralised trauma centres without ensuring they are well coordinated, properly staffed, and supported by strong health systems. Better data and further research, she argued, are needed to understand which trauma-care investments actually improve patient outcomes. The message is a direct challenge to the assumption that healthcare models developed in wealthier countries can simply be transplanted elsewhere and expected to work.

One of the study’s most counterintuitive results concerns time. The researchers found no evidence that reaching a hospital more quickly reduced the risk of death, and patients who experienced some delays were actually less likely to be disabled later. This runs against the deeply entrenched belief, reinforced by trauma systems in high-income countries, that faster treatment always leads to better outcomes after injury. The study also found that stopping first at a nearby hospital for emergency stabilisation may sometimes be beneficial, particularly when a specialist hospital is far away, while going directly to a major trauma hospital may improve outcomes when such a hospital is close by. In other words, the optimal route to definitive care depends heavily on geography and local capacity, not on a universal formula.

The pattern of who recovers and who does not also shifted depending on where patients were in the healthcare journey. Age was linked to worse outcomes, but gender, wealth and education had little effect on survival while patients were in hospital. Once patients left hospital, however, the picture changed: wealthier and better-educated patients tended to recover better, suggesting that access to rehabilitation and follow-up care plays an important role in long-term recovery. This split between in-hospital and post-discharge outcomes points to a neglected phase of trauma care. A health system may perform adequately in the operating theatre yet fail its patients in the weeks and months afterward, when disability is either mitigated through rehabilitation or allowed to harden into permanent impairment.

Country-level differences were striking and underline the study’s central argument that context matters. Patients in South Africa had the lowest odds of disability but the highest odds of mortality, while patients in Rwanda experienced the lowest odds of mortality. Patients in Pakistan, meanwhile, experienced substantially higher odds of the combined outcome of death or disability than those in Ghana. These divergent profiles suggest that different health systems fail in different ways: one country may keep people alive but leave them disabled, another may achieve better survival overall. No single imported template can address such varied failure modes, which is why the study argues that countries should develop trauma and injury-care systems based on local evidence, local resources, and the actual needs of their patients.

The broader context makes the findings urgent. Injuries are estimated to account for around ten per cent of the global burden of disease, yet trauma care receives far less attention than infectious diseases or chronic conditions in global health policy. As road traffic volumes grow across Africa and South Asia, the burden of injury is likely to rise, and the population studied here, young, predominantly male, and injured largely on the roads, represents the face of that coming wave. The Equi-injury study provides something the field has lacked: rigorous, multi-country evidence about which parts of the care pathway actually determine whether injured people survive and recover. Its conclusion is uncomfortable but constructive. Money spent on ambulances and trauma centres without coordination, staffing, and strong underlying health systems may buy impressive infrastructure without saving lives. The path forward, the researchers argue, lies in understanding how people actually move through their local healthcare systems, and in building trauma care around that reality rather than around imported blueprints.

Subject of Research: Mortality and disability outcomes among hospitalised injury patients in low- and middle-income countries

Article Title: Global injury crisis highlights urgent need for smarter trauma care

Article References: Global injury crisis highlights urgent need for smarter trauma care. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: trauma care, injury, global health, low- and middle-income countries, ambulances, disability, mortality, The Lancet Global Health, University of Birmingham, health systems, road traffic collisions, rehabilitation

The scale of exposure is striking. Researchers estimate that 241 million people aged 15 years and older were chewing tobacco users in 2023, a global prevalence of 3.9 percent, with use more than twice as common among males as among females. Despite decades of progress in tobacco control that has driven down smoking rates in many parts of the world, the global prevalence of chewing tobacco use has remained essentially unchanged. No country recorded a significant decrease in the number of users between 1990 and 2023, while 24 countries saw significant increases in the size of their chewing tobacco populations. That stagnation stands in sharp contrast to the trajectory of smoked tobacco and suggests that chewing products have largely escaped the taxation, advertising bans, and public awareness campaigns that have reshaped cigarette consumption.

Geographically, the burden maps onto a narrow band of the planet. South Asia had the highest regional concentration of use, with 14.6 percent of people aged 15 and older using chewing tobacco in 2023, and the region accounted for an estimated 210,000 chewing tobacco-related deaths, about 84 percent of the global total. At the country level, age-standardized prevalence reached 24.4 percent in Palau, followed by Bangladesh at 23.4 percent and Nepal at 17.5 percent. More than 90 percent of male chewing tobacco-related deaths and disability occurred in just ten countries: India, Bangladesh, China, Pakistan, Myanmar, the United States, Nepal, Sri Lanka, the Philippines, and Madagascar. Among females, more than 90 percent of the burden was concentrated in India, Bangladesh, Pakistan, Indonesia, Myanmar, China, Thailand, Cambodia, Vietnam, and Nepal. The researchers caution that these figures reflect absolute numbers of deaths and disability, so countries with larger populations can account for a greater share of the burden even when their per-capita rates are not the highest.

“Chewing tobacco is not a uniform public health problem, and our findings show that a relatively small number of countries bear an overwhelming share of its health burden,” said Gabriela Gil, lead author and Research Scientist at IHME. “Understanding how patterns of use differ within these populations is critical to designing more effective prevention and tobacco control strategies.” Her point underscores a methodological strength of the new analysis: by disaggregating chewing tobacco from other smokeless products and estimating exposure country by country, the study gives policymakers a far more granular picture of where interventions are likely to yield the greatest returns.

The demographic architecture of chewing tobacco use differs sharply by age and sex, and those differences vary by setting in ways that complicate prevention. Globally, use was more common among males, rising through early adulthood and continuing to climb with age before peaking among people aged 60 to 64. In South Asia, nearly one in five males and one in ten females used chewing tobacco in 2023. Male use in the region peaked at ages 60 to 64, while female use peaked among adults aged 80 and older, a pattern consistent with long-duration, lifelong habits established decades earlier. Bangladesh, however, reverses the broader trend: chewing tobacco use was higher among females than males across all age groups older than 30, even though the products remained common among both sexes. “These findings show why chewing tobacco control cannot take a one-size-fits-all approach,” said Dr. Emmanuela Gakidou, senior author and Professor in the Department of Health Metrics Sciences at IHME. “Prevention and cessation strategies need to reflect how patterns of use differ by country, age, and sex, as well as the cultural and social factors that shape tobacco use in each setting.”

On the health outcomes side, the study employed the Burden of Proof framework, a systematic approach for quantifying the risks associated with a given exposure, to estimate the burden attributable to chewing tobacco across six outcomes: stroke, lip and oral cavity cancer, esophageal cancer, other pharyngeal cancer, laryngeal cancer, and nasopharyngeal cancer. The results challenge the common perception that chewing tobacco is primarily an oral cancer risk. Stroke accounted for the largest share of chewing tobacco-related health loss globally, at 55.9 disability-adjusted life-years, or DALYs, per 100,000 people, followed by lip and oral cavity cancer at 17.4 per 100,000. DALYs are a composite metric that combines years of life lost to premature death with years lived in disability, providing a single measure of total health loss. The prominence of stroke indicates that the cardiovascular consequences of chewing tobacco, likely driven by nicotine absorption and its effects on blood pressure and vascular function, may be as consequential as, or more consequential than, the cancers that dominate public perception of the habit.

The cancer burden remains substantial nonetheless. Chewing tobacco was responsible for 17.3 percent of lip and oral cavity cancer DALYs worldwide, a figure that rose to 30.5 percent in South Asia, where products such as betel quid with tobacco are deeply embedded in social and cultural practice. The concentration of oral cancer risk in the same region that dominates overall chewing tobacco mortality creates a compounding public health challenge: health systems in Bangladesh, India, Nepal, and neighboring countries face elevated rates of both cardiovascular disease and head and neck cancers attributable to a single exposure, straining diagnostic, surgical, and oncology services that are often already under-resourced.

The trajectory of the burden is also alarming. The number of DALYs attributed to chewing tobacco increased by 116 percent between 1990 and 2023, reaching 6.48 million globally. Most of that burden came from premature death, accounting for 6.17 million years of life lost in 2023, a signal that chewing tobacco is killing users early rather than merely adding years of chronic illness. Population growth and aging in high-prevalence countries help explain part of the increase, since even stable prevalence rates translate into more users and more deaths as populations expand, but the finding that no country achieved a significant decline in user numbers means the growth in burden has been met with essentially no counteracting progress in exposure reduction.

Why has chewing tobacco escaped the attention devoted to cigarettes? The study points to a convergence of factors: longstanding cultural and social practices that normalize the habit, widespread misconceptions that chewing products are less harmful than smoking, limited surveillance systems that fail to track smokeless tobacco use separately, and higher rates of use among rural and lower-income populations who may have less access to cessation services and health information. These dynamics have left a gap in global tobacco control, in which smokeless products are frequently absent from taxation schemes, graphic warning requirements, and cessation programs designed around cigarettes.

The authors argue that reducing chewing tobacco-related deaths and disability will require stronger integration of smokeless tobacco prevention and cessation into national tobacco control and noncommunicable disease strategies, with approaches tailored to differences by age, sex, local patterns of use, and socioeconomic context. Given that more than 90 percent of the burden clusters in ten countries for each sex, even modest, well-targeted interventions in those settings could avert a disproportionate share of the global toll. As the GBD 2023 analysis makes clear, the world’s progress against tobacco will remain incomplete until the products tucked in the cheeks of 241 million users receive the same scrutiny as the cigarette.

Subject of Research: The global, regional, and national burden of chewing tobacco use and its attributable deaths and disability from 1990 to 2023

Article Title: Chewing tobacco linked to 251,000 deaths worldwide, with more than 90% of health loss concentrated in 10 countries

Article References: Chewing tobacco linked to 251,000 deaths worldwide, with more than 90% of health loss concentrated in 10 countries. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: chewing tobacco, Global Burden of Disease, smokeless tobacco, stroke, oral cavity cancer, South Asia, DALYs, tobacco control, IHME, public health, prevalence, The Lancet Global Health