The scale of the underlying problem is enormous. Rare diseases are individually defined as affecting fewer than 1 in 2,000 people, but more than 7,000 distinct types are currently recognized, and recent estimates suggest the true number may exceed 10,000. Collectively, rare diseases affect roughly 3.5 to 5.9 percent of the global population, equivalent to between 263 and 446 million individuals. Nearly half of all rare diseases are neurological in nature, and around 90 percent of rare childhood diseases involve major neurological manifestations. Approximately 80 percent of rare diseases are genetic in origin, nearly 70 percent of those present during childhood, and about 30 percent of affected children die before their fifth birthday. These figures underscore why rare neurological diseases in children represent a disproportionate share of the global rare disease burden.

To isolate this population, the research team applied three criteria to the GBD 2021 cause hierarchy: relevance to children aged 0 to 14, a prevalence threshold of no more than 50 per 100,000 people, and availability as a distinct disease category permitting population-level estimation. Four groups emerged: motor neuron disease, multiple sclerosis, neuroblastoma and other peripheral nervous cell tumors (NPNCT), and a residual category of other neurological disorders that largely comprises inherited neuromuscular conditions such as muscular dystrophies and myopathies. The team computed age-standardized prevalence, mortality, and disability-adjusted life-year (DALY) rates, stratified by age, sex, and sociodemographic index (SDI), and quantified temporal trends using the average annual percentage change (AAPC).

The headline numbers tell a story of expanding prevalence. Globally, the number of prevalent cases rose by 21.98 percent, from roughly 80,785 in 1990 to 98,541 in 2021. The age-standardized prevalence rate climbed 7.17 percent, from 4.60 to 4.93 per 100,000 population, with an AAPC of 0.21 percent. DALYs increased even faster, rising 30.46 percent from 1.01 million to 1.32 million, with the age-standardized DALY rate up 14.92 percent. In contrast, the age-standardized mortality rate fell 6.98 percent, from 0.43 to 0.40 per 100,000. Children under five carried the heaviest burden in 2021, with the highest prevalence, DALY, and mortality rates of any age group, and prevalence rates rose across all pediatric age groups over the study period.

The four disease groups followed strikingly divergent trajectories. NPNCT had the highest prevalence rate in 2021 at 2.62 per 100,000 and the steepest increase, with an AAPC of 0.54 percent, and it was the only condition whose mortality rate rose. Other neurological disorders, dominated by monogenic neuromuscular diseases, were the leading contributor to disability alongside NPNCT, with a DALY rate AAPC of 0.73 percent. Multiple sclerosis showed a statistically significant but epidemiologically modest rise in prevalence. Motor neuron disease, by contrast, declined across all three measures, with its prevalence rate falling 6.37 percent. The authors attribute this decline partly to advances in prenatal diagnosis, newborn screening, and disease-modifying therapies for conditions such as spinal muscular atrophy, though they caution that uncertainty in GBD estimates for rare pediatric motor neuron diseases is considerable.

Boys consistently bore a higher burden than girls across prevalence, DALYs, and mortality, and the gap widened over time, with boys’ prevalence rate rising faster than girls’. The sex disparity echoes broader GBD 2021 findings across 37 neurological conditions, but this analysis confirms it emerges early in childhood. The authors note that the difference may partly reflect biological factors but also unequal healthcare access and diagnostic ascertainment between boys and girls, particularly in low-SDI countries, and they urge caution in interpretation.

The geographic patterns are perhaps the most consequential finding. High-SDI countries recorded the highest overall rates in 2021, at 9.33 per 100,000 for prevalence, yet all their rates have declined steadily since 1990, plausibly reflecting improvements in early diagnosis, multidisciplinary care, and supportive treatment. The opposite occurred in lower-development settings: middle-, low-middle-, and low-SDI countries all experienced rising prevalence, disability, and mortality, with the pace of increase inversely related to SDI. Low-middle-SDI countries saw the fastest prevalence growth, with an AAPC of 0.87 percent. Across countries, SDI values correlated strongly with prevalence rates, at r = 0.91. South Asia recorded the sharpest regional rise in prevalence, while Western sub-Saharan Africa saw the largest increases in disability and mortality. At the national level, 116 of 204 countries and territories showed rising prevalence, with Guyana experiencing the steepest increase, and India, China, and Pakistan reporting the highest absolute case counts in 2021.

Decomposition analysis revealed what is driving these increases. Population growth accounted for 73.33 percent of the global rise in prevalent cases, with true change in prevalence contributing 35.28 percent. In low- and low-middle-SDI countries, demographic expansion was the dominant force, whereas in middle-SDI regions and several high-case countries, rising prevalence itself played the leading role. The authors interpret the rising recorded prevalence largely as a product of diagnostic progress: newborn screening, next-generation sequencing, and single-molecule sequencing have dramatically improved case ascertainment, with roughly 250 to 280 newly described rare disorders reported annually since 2010. Longer survival among affected children, enabled by expanding targeted therapies, further inflates measured prevalence and DALYs even as mortality falls.

Looking forward, the team built a customized forecasting framework combining Poisson regression on SDI with an autoregressive integrated moving average model applied to regression residuals, integrating four models through root-mean-squared-error-weighted averaging, with ridge regularization and a quadratic SDI term to improve stability. Validated against withheld 2011 to 2021 data, the model achieved a mean absolute percentage error of just 0.62 percent. Its projections indicate that by 2050, prevalent cases will reach approximately 110,200, an 11.83 percent increase from 2021, with the age-standardized prevalence rate climbing to 5.62 per 100,000. Children under five will see the fastest growth, and Western sub-Saharan Africa, Southern sub-Saharan Africa, and South Asia the sharpest regional rises, with 132 countries expected to show increasing prevalence trends. The authors acknowledge that future gene therapies and expanded genomic screening could alter these trajectories in ways the model cannot capture.

To complement the epidemiological picture, the researchers mined ClinVar for genetic evidence of rare monogenic neurological diseases, compiling a curated list of 520 disease-causing genes. Between 1990 and 2024, the database recorded 65,331 pathogenic or likely pathogenic variants in these genes. The acceleration is dramatic: only 1,633 variants were reported between 1990 and 2010, compared with 18,851 in the following decade and 44,847 in just 2021 to 2024, alongside 55 newly reported disease-causing genes in the most recent period alone. The largest genetic evidence base lies within the other neurological disorders category, dominated by inherited neuromuscular diseases, of which more than 600 monogenic forms have now been identified. The authors stress that these figures reflect testing availability and submission practices, which skew toward high-income countries, rather than the true underlying genetic burden. Even so, the convergence of rising prevalence, accelerating genetic discovery, and widening global inequality paints a clear picture: rare childhood neurological diseases are becoming a growing and increasingly tractable global health challenge, one that will demand strengthened surveillance, equitable diagnostic access, and sustained investment in the low- and middle-income countries where the burden is now rising fastest.

Subject of Research: Global epidemiological and genetic burden of rare neurological diseases in children

Article Title: Global epidemiological and genetic burden of rare neurological diseases in children

Article References: Xie, Z., Sun, C., Liang, W., Zhao, X., Miao, L., Liu, X., Lu, Y., Liu, C., Yin, Z., Li, J., & Xie, Z. (2026). Global epidemiological and genetic burden of rare neurological diseases in children. iScience, 29(11), Article 117791. https://doi.org/10.1016/j.isci.2026.117791

Image Credits: AI Generated

DOI: 10.1016/j.isci.2026.117791

Keywords: rare diseases, neurology, pediatrics, Global Burden of Disease, genetics, ClinVar, neuromuscular diseases, neuroblastoma, health inequality, epidemiology, DALYs, disease forecasting

The research team, led by Namita Kaushik and Andreas Tietz, screened 6,983 records and identified 341 studies reporting healthcare resource utilisation or economic outcomes in dengue. Of these, 44 studies reporting hospitalisation rates and 121 studies reporting length of stay met the rigorous feasibility criteria for quantitative synthesis. The work followed PRISMA guidelines, was registered prospectively in the PROSPERO database, and applied the Downs and Black checklist to appraise study quality. Data were drawn from five biomedical databases searched via the Ovid platform, supplemented by citation searches and conference abstracts, with no restriction on country of origin.

The headline result is a pooled global hospitalisation rate of 36.7 percent (95 percent confidence interval 29.0 to 44.4) among patients with dengue irrespective of severity, derived under a random-effects model. The mean length of stay across hospitalised patients was 4.9 days (95 percent CI 4.6 to 5.2). Both outcomes showed very high statistical heterogeneity, with I-squared values approaching 100 percent, reflecting the enormous diversity of settings, designs, and populations represented in the underlying literature. To understand that variation, the authors performed meta-regression across a range of study-level covariates, including geography, outbreak status, data source, and study design.

One variable dominated all others: disease severity. Severity was significantly associated with both higher hospitalisation rates and longer stays, explaining 31.4 percent of between-study variance in hospitalisation and 11.4 percent of the variance in length of stay, with p-values below 0.0001 in both models. Subgroup analyses quantified the gradient precisely. Patients with non-severe dengue without warning signs were hospitalised at a pooled rate of 17.7 percent, rising to 36.9 percent once WHO warning signs such as persistent vomiting, abdominal pain, mucosal bleeding, raised haematocrit, or thrombocytopaenia appeared. Among patients classified as having severe dengue, the pooled hospitalisation rate reached 79.4 percent.

Length of stay followed the same severity gradient. Patients with non-severe disease averaged 4.6 days in hospital, compared with 6.5 days for severe dengue. The most dramatic figures emerged when complications were considered: patients with severe dengue or dengue haemorrhagic fever who developed complications such as shock, renal impairment, platelet-transfusion-requiring thrombocytopaenia, or sepsis stayed a mean of 15.5 days, roughly double the 7.5 days observed in severe cases without complications. Co-infections with pathogens such as SARS-CoV-2 or chikungunya virus, and comorbidities including haematologic malignancies, autoimmune disease, and obesity, each added roughly a day or more to the average stay.

Regional patterns add a further layer of complexity. Hospitalisation rates were numerically higher in Asia, at 35.1 percent, than in Latin America, at 29.3 percent, and length of stay was correspondingly longer in Asian settings, at 5.1 days versus 4.1 days in Latin America. The authors note that this Asian excess echoes the 2016 analysis by Shepard and colleagues, which reported rates of 19.3 to 24.8 percent in Asian subregions against just 3.8 percent in Latin America and the Caribbean. Possible explanations include differing admission thresholds, a higher force of infection, multiple co-circulating serotypes, and demographic differences, but the authors emphasise that the drivers remain unclear and warrant targeted investigation.

The timing of the analysis is significant. Since the last global estimates were published, the world has witnessed record-breaking dengue waves, shifts in circulating serotypes, changing patient demographics, the disruption of the COVID-19 pandemic, and improvements in surveillance and clinical preparedness. The World Health Organization reported a doubling of reported cases from around 7 million in 2023 to approximately 14 million in 2024, while modelling work published in 2025 estimated that annual apparent cases rose from 26.45 million in 1990 to 58.96 million in 2021. Against that epidemiological backdrop, a hospitalisation rate approaching 37 percent implies a demand for inpatient beds, nursing capacity, and supportive care that many endemic health systems are ill-equipped to absorb during peak transmission seasons.

Methodological sensitivity analyses strengthen the central conclusions while exposing their limits. Excluding studies with fewer than 100 participants and those with more than 50,000 yielded a pooled hospitalisation rate of 29.4 percent with narrower confidence intervals, and excluding studies whose data were collected during the pandemic produced an estimate of 25.3 percent, hinting that overwhelmed COVID-era hospitals may have temporarily suppressed dengue admissions. A single exceptionally large nationwide Brazilian cohort dominated the fixed-effects estimate, but random-effects modelling, which the authors favoured given the heterogeneity, attenuated its influence. For length of stay, no evidence of publication bias was detected by Egger’s regression, and the GRADE certainty of evidence was rated low, primarily because of the observational design of the included studies rather than inconsistency or imprecision.

The findings carry immediate practical implications. Hospitalisation is recognised as a key outcome in dengue research: an international Delphi consensus involving experts from more than 30 countries identified the need for hospitalisation as a core endpoint for patients and clinicians. The new benchmarks should therefore help clinical trialists select endpoints and calculate sample sizes, and they align with recently published WHO target product profiles that recommend dengue-related hospitalisation as a secondary efficacy outcome in non-severe disease. For policymakers, the estimates provide a foundation for cost-effectiveness analyses of vaccines, antivirals, and vector-control strategies, and for identifying the regions where preventive investment would relieve the greatest pressure on hospitals.

The authors are careful to frame the pooled figures as average trends across highly diverse settings rather than universal constants. Admission thresholds, clinical practice, healthcare-seeking behaviour, and reporting conventions differ substantially between countries, and the denominator in most studies was skewed towards patients already seeking care, which may inflate the apparent hospitalisation rate relative to all symptomatic infections. The observation that some patients with warning signs or severe disease were nonetheless not hospitalised may reflect symptom misclassification, resource constraints, or emergency department stays that were never recorded as admissions. Even so, the overall message is difficult to escape: dengue’s demand on hospital infrastructure has likely risen considerably over the past decade, and quantifying the associated direct and indirect costs, productivity losses, and caregiver burden is now an urgent priority for global health planning.

Subject of Research: Global hospitalisation rates and length of stay for dengue patients

Article Title: Global burden of dengue on healthcare systems: a meta-analysis of healthcare resource utilisation

Article References: Kaushik, N., Subramanian, S., Gedif, K., Nallagangula, T. K., Singuru, S., Panchal, S., Meyer-Andrieux, I., Gruenberger, J.-B., McBride, A., Yacoub, S., & Tietz, A. (2026). Global burden of dengue on healthcare systems: a meta-analysis of healthcare resource utilisation. eClinicalMedicine, 100, Article 104217. https://doi.org/10.1016/j.eclinm.2026.104217

Image Credits: AI Generated

DOI: 10.1016/j.eclinm.2026.104217

Keywords: dengue, hospitalisation rate, length of stay, meta-analysis, healthcare resource utilisation, systematic review, global health burden, WHO warning signs, severe dengue, Aedes mosquitoes, health systems, eClinicalMedicine

The research team, led by Wenjing Wang and colleagues, searched PubMed, Scopus, and Web of Science for studies published since 2014, applying the rigorous standards of the PRISMA reporting framework and registering the protocol prospectively with PROSPERO under registration number CRD42025648170. Their aim was deceptively simple but methodologically demanding: to estimate pooled incidence and prevalence of urinary tract infections across different healthcare settings, and then to dissect those estimates by geography, infection setting, and host risk profile. The final dataset included 969,476 participants, a scale that lends considerable statistical weight to the pooled estimates.

The headline finding concerns the stark divide between hospital-acquired and community-acquired infections. Hospital-acquired urinary tract infections, abbreviated HAUTIs in the study, showed a pooled incidence proportion of 0.17, with a 95 percent confidence interval of 0.13 to 0.22, and a pooled prevalence of 0.21, with a confidence interval of 0.16 to 0.25. By comparison, community-acquired urinary tract infections showed a pooled incidence of just 0.08, with a confidence interval of 0.06 to 0.10. In practical terms, roughly one in five hospitalised patients in the included studies had or acquired a urinary tract infection, a figure that underscores how the hospital environment itself, with its invasive devices, immunocompromised patients, and dense microbial ecology, amplifies infection risk.

Within the hospital setting, the single most dangerous factor identified was the urinary catheter. Catheter-associated urinary tract infections emerged as a particularly high-risk category, which is consistent with the well-understood biology of these devices. An indwelling catheter provides bacteria with a direct conduit into the bladder, bypassing the natural flushing action of urination and forming a biofilm on its surface that shields microbes from both immune defences and antibiotics. The meta-analysis confirms that this device-related pathway remains a dominant driver of nosocomial urinary infection, and that catheter stewardship, meaning the avoidance, early removal, and meticulous management of urinary catheters, must sit at the centre of any prevention strategy.

Geography mattered as much as setting. The burden of hospital-acquired urinary tract infections was highest in Asia, Africa, and South America, a pattern that likely reflects a combination of factors including differences in healthcare infrastructure, catheterisation practices, antibiotic access, and surveillance capacity across regions. The authors argue that this regional variation exposes a central weakness in current infection control thinking: a uniform, one-size-fits-all prevention approach cannot adequately serve settings whose baseline risks, resources, and microbial ecologies differ so dramatically. Tailored protocols calibrated to local epidemiology, they suggest, are the realistic path forward.

On the microbiological front, the analysis confirmed what clinical microbiologists have long observed: gram-negative bacteria, and particularly Escherichia coli, dominate the etiology of urinary tract infections. Escherichia coli’s specialised adaptations for the urinary tract, including adhesive pili that bind to bladder epithelial cells and an ability to persist intracellularly, make it an exceptionally effective uropathogen. The predominance of gram-negative organisms carries practical consequences, because rising antimicrobial resistance in this bacterial group, particularly extended-spectrum beta-lactamase production, increasingly constrains empiric treatment choices in many regions.

Beyond setting and geography, the study systematically catalogued host-level risk factors, identifying gender, age, comorbidities, and prior disease history as consistent predictors of infection. Some of the most striking quantitative results came from specific vulnerable populations. Among kidney transplant recipients, those who experienced delayed graft function, a complication in which the transplanted kidney does not immediately work properly, faced a risk ratio of 1.63 for urinary tract infection, with a confidence interval of 1.19 to 2.22. This makes biological sense: impaired graft function alters urinary flow and immune regulation, and transplant patients are simultaneously subjected to immunosuppressive drugs that blunt their defences against bacterial invasion.

Pregnant women formed another clearly delineated high-risk group. The analysis found that lower educational attainment among pregnant women was associated with an elevated risk of urinary tract infection, with a pooled effect estimate of 0.40 and a confidence interval of 0.16 to 0.63. Pregnancy itself predisposes to urinary infection through hormonal relaxation of the ureters and mechanical compression of the urinary tract by the growing uterus, which slows urine flow and allows bacteria more time to establish themselves. Untreated infections in pregnancy can escalate to pyelonephritis and are associated with adverse outcomes for both mother and fetus, which is why identifying modifiable social determinants of risk, such as access to health education, carries real public health value.

The study also highlighted the elderly and people with diabetes as key vulnerable groups. Diabetes impairs immune function and, when poorly controlled, glycosuria creates a nutrient-rich environment in the urine that favours bacterial growth. Ageing, meanwhile, brings anatomical and physiological changes, incomplete bladder emptying, and higher rates of catheterisation and institutional care, all of which compound infection risk. By quantifying these risks within a single analytical framework, the review provides clinicians and policymakers with a stratified map of exactly where preventive effort should be concentrated, rather than spreading resources thinly across the entire patient population.

The broader significance of this work lies in its framing. Rather than treating urinary tract infections as a single homogeneous disease, the authors demonstrate that the burden is sharply stratified by where a patient is treated and who the patient is. That insight supports the development of risk-stratified infection control protocols: aggressive catheter reduction programmes and surveillance in hospitals, targeted screening and education for pregnant women, heightened vigilance in transplant units, and tailored prevention for diabetic and elderly patients. As antimicrobial resistance narrows the treatment options available for gram-negative uropathogens, preventing infections in the first place becomes not merely a convenience but a necessity. This meta-analysis, synthesising evidence from nearly a million people across continents and care settings, offers the clearest evidence yet of where that prevention effort must be aimed.

Subject of Research: Global epidemiology and risk-stratified burden of urinary tract infections across healthcare settings and high-risk populations

Article Title: Risk-stratified epidemiology and global burden of urinary tract infections across healthcare and high-risk populations: a systematic review and meta-analysis

Article References: Wang, W., Huo, N., Ma, H., Li, X., & Wang, Y. (2026). Risk-stratified epidemiology and global burden of urinary tract infections across healthcare and high-risk populations: a systematic review and meta-analysis. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14395-z

Image Credits: AI Generated

DOI: 10.1186/s12879-026-14395-z

Keywords: urinary tract infection, hospital-acquired infection, catheter-associated UTI, meta-analysis, Escherichia coli, kidney transplant, pregnancy, diabetes, infection control, antimicrobial resistance, global health burden, risk factors