The Lancet Regional Health - Americas

Long COVID (LC) impacts quality of life, daily functioning, and healthcare utilization. Understanding the onset and duration of symptoms, characteristics of those at higher risk, and the barriers and facilitators for healthcare access and therapeutics are key to addressing this growing disease burden. In 2024 the Arizona CoVHORT, an ongoing 6-year longitudinal study, distributed a cross-sectional LC survey to gain additional in-depth information. Of 1,543 participants, 700 reported LC symptoms lasting 2-49 months. Following their first infection, LC+ participants had a 21% higher risk for a second infection and were 3.2 times more likely to report LC symptoms after that second infection compared to LC- participants. Significant factors associated with LC included female sex (OR=2.3), Hispanic ethnicity (OR=1.5), BMI>34.5 (OR= 1.7) and >2 infections (OR=3.2), while vaccination prior to first infection decreased the odds of reporting LC by 51% (R=0.49). Qualitative analyses detailed significant barriers to care and encounters with providers who lacked knowledge to test for or treat LC symptoms. With an estimated 400 million people impacted globally by LC, it is critical to gain in-depth information from patients to improve both access and quality of care, improve messaging, and target mitigation strategies to decrease the burden over time.

Purpose: Metastatic pancreatic ductal adenocarcinoma (PDAC) portends a poor prognosis. Prior studies have assessed the association of socioeconomic deprivation (SED) in PDAC often with large geographic areas. This study employed a causal framework to characterize neighborhood SED on treatment receipt and survival in metastatic PDAC. Methods: Using the incidence-based Florida Cancer Data System, metastatic PDAC patients diagnosed from 2007-2015 were identified. The Area Deprivation Index, a composite measure of SED that ranks neighborhoods from 1-100 (higher scores = higher deprivation), was used to assess receipt of systemic therapy and overall survival (OS). Exposures and covariates were assessed using descriptive statistics and a causal inference framework. Results: Overall, 9,574 patients met inclusion criteria. 46.6% of patients received systemic therapy, ranging 39.4% to 54% in the highest and lowest SED quartiles, respectively. After adjustment, the lowest quartile had increased odds of systemic therapy relative to the highest (OR 1.93; 95% CI 1.70-2.18). Median OS was 3.8 months for the lowest quartile and 2.4 months for the highest (p = 0.01). Patients in the highest quartile had an estimated 32% higher hazard of death than the lowest (HR 1.32, 95% bootstrap CI 1.20-1.40). Conclusion: In an incidence-based statewide cohort, most patients did not receive treatment for metastatic PDAC and median OS was poor-2.9 months. Using a causal inference framework, higher SED led to lower rates of systemic therapy receipt and worse overall survival in metastatic PDAC. Future research should focus on the mechanisms that shape these findings.

Objectives Emergency department (ED) crowding is recognised as an important public health concern internationally, and is driven principally by exit block, the shortage of inpatient beds for patients requiring admission. This study aimed to evaluate whether a complex intervention targeting hospital occupancy improved ED patient flow, and quantified the change in attendances. Methods A controlled interrupted time series using weekly, publicly reported Public Health Scotland data from 1 January 2022 to 1 February 2026. The multi-component intervention focused on reducing hospital occupancy and included additional adult social care funding; engagement with regional social care providers; accelerated implementation of the Discharge without Delay programme; re-evaluation of whole-hospital escalation thresholds and response; resource and data supporting inpatient department reductions in length of stay; and additional investment in remote clinical assessment. The intervention commenced at a large tertiary ED on 01 February 2025. Primary outcomes were the proportions of attendances spending [≥]4, [≥]8 and [≥]12 hours in the ED. The secondary outcome was attendance volume. Segmented regression was fitted with a contemporaneous control series, seasonal terms and autoregressive moving average errors. Long waits were additionally illustrated as potentially avoided deaths. Results The analysis covered 161 pre-intervention and 52 post-intervention weeks. Relative to pre-intervention levels, the proportion of attendances waiting over 4 hours fell by 10.4% (95% CI 1.6 to 19.2%), by 16.4% (95%CI 1.3 to 31.5%) over 8 hours and by 24.3% (95%CI 2.6 to 46.1%) over 12 hours. Using established associations between long ED waits and excess mortality, by one-year the intervention was potentially associated with 54 fewer excess deaths (95%CI 19 to 93). Attendances rose by 3.8% (95%CI 1.3 to 6.4%) against the counterfactual. Conclusions A complex intervention targeting hospital occupancy was associated with a reduction in long ED waits despite rising attendances. Interventions addressing hospital occupancy can meaningfully improve ED crowding.

Background Using a population-based cohort from the Calgary Health Zone (CHZ), Canada, we integrated longitudinal antimicrobial susceptibility and prescribing data with the whole genome sequences of five major pathogens. We aimed to assess how antimicrobial resistance (AMR) responds to prescribing changes and determine which bacterial strains shape these dynamics. Methods We analysed antibiotic prescribing rates, clinical and genomic data from 7,271 Staphylococcus aureus, 1,609 Enterococcus faecalis, 801 Enterococcus faecium, 11,363 Escherichia coli, and 2,319 Klebsiella pneumoniae isolates, associated with bacteraemia episodes in the CHZ between 2006-2022. Genomic clusters (referred to as strains) were identified using StrainGST and assigned to known sequence types (STs) or clonal complexes (CCs). Strain-level incidence, stratified by community-onset (isolates collected [&le;]48h after admission) and hospital-onset (>48h after admission), AMR phenotypes, and prescribing rates were modelled using negative-binomial and binomial regression. Temporal trends were quantified using average annual percentage change (AAPC). Findings Between 2010-2022, fluoroquinolone prescribing declined in both community (AAPC=-6.8% [95% CI -8.1, -5.4]; p<0.0001) and hospital settings (AAPC=-5.1% [-6.5, -3.7]; p<0.0001). This was accompanied by a significant reduction in fluoroquinolone resistance among Gram-positive species. Specifically, S aureus bacteraemia resistant to clinically important antibiotics, cloxacillin, ciprofloxacin, erythromycin, and clindamycin, declined from 2006 to 2022, mostly in hospital-onset cases (AAPC=-16.0%, [-19.3%, -12.7%], p<0.0001). In E coli, ceftriaxone and ciprofloxacin resistance were clustered in ST131 and the emerging ST1193; the latter increased steadily, particularly in community-onset cases (AAPC=17.7%, [0.0%, 30.0%], p<0.0001). CTX-M-27-producing E coli ST131 strains increased (AAPC=23.8%, [17.4%, 30.5%], p<0.0001) between 20082022, while CTX-M-14-producing E coli ST131 declined (AAPC=-15.9%, [-21.3%, -10.2%], p<0.0001) between 2013-2022. These trends were paralleled by an increase in community cephalosporin prescribing (AAPC=7.3%, [4.2%, 10.5%], p<0.0001) between 2010-2022. For K pneumoniae, hypervirulent ST23 was most common (N=88) with an increasing trend in incidence (AAPC=3.0%, [-2.8%, 9.2%]) between 2006-2019. Conclusions The contrasting resistance trends between Gram-positive and Gram-negative species underscore the complexity of AMR control efforts. Effective strategies will require stewardship efforts targeting multiple drug classes, genomic surveillance for emerging resistant strains, and interventions extending beyond hospital settings.

Background: Invasive fungal infection (IFI) is well recognised in children with acute leukaemia and allogeneic haematopoietic stem-cell transplantation but is poorly characterised in children with brain tumours. Children receiving intensive therapy for embryonal brain tumours (EBTs) have multiple potential risk exposures including corticosteroids, central venous access, neurosurgical devices, mucosal injury and myelosuppressive chemotherapy with, in selected protocols, autologous stem-cell rescue. Methods: We performed a single-centre retrospective cohort study of children aged 0-18 years treated for EBTs between 2015-2025. IFIs were classified as proven, probable, possible, or modified possible using EORTC/MSGERC and TERIFIC criteria. Clinical characteristics, treatment exposures, timing, microbiology and outcomes were described. IFI prevalence was calculated using exact binomial confidence intervals. Exploratory Cox proportional hazards analyses assessed associations with clinical and treatment factors. Results: Seventy-seven patients were included. Fourteen patients experienced 15 IFI episodes, giving a patient-level IFI prevalence of 18.2% (95% CI, 10.3-28.6%). Proven or probable IFI occurred in seven patients (9.1%; 95% CI, 3.7-17.8%). Nine episodes had microbiological evidence. Non-mould pathogens predominated, accounting for six of nine identified pathogens. Treatment on ACNS0334/ACNS0333 was associated with a lower hazard of proven/probable IFI compared with SJMB12 (HR 0.062; 95% CI, 0.002-0.78; p=0.031). Two patients had chemotherapy delays exceeding one month, one had persistent infection at 12 months; no deaths were directly attributed to IFI. Three patients received antifungal prophylaxis. Conclusion: Rates of IFI following intensive embryonal brain tumour therapy were comparable to those in other high-risk oncology populations. Local consideration of antifungal prophylaxis is warranted.

Background Lower respiratory infections (LRI) remain the leading infectious cause of death in children, and survival once ill is a direct tracer of health-system quality. Whether countries are converging toward the best survival performance achieved within their own region has never been tested at national level. We measured each country's distance to an empirical episode-fatality-ratio (EFR) frontier in 204 countries from 1990 to 2023. Methods For each country and year we computed EFR = LRI deaths/incident episodes using Global Burden of Disease (GBD) 2023 estimates for ages 0-19 years. Deaths span the full 1990-2023 series; episodes are observed for 1990, 2019 and 2023, with intermediate years linearly interpolated. The frontier was the 10th-percentile country EFR within each GBD super-region and year (sensitivity: 5th and 25th percentiles); the gap = EFR_country/EFR_frontier. We classified 33-year gap trajectories into catch-up phenotypes, ranked COVID-window (2019-2023) movers, cross-tabulated gap against avoidable deaths to build a priority list, and benchmarked upper respiratory infections (URI) at three time points as a near-zero-fatality contrast. Findings The median country's gap was 1.86 in 1990, 1.80 in 2019 and 1.86 in 2023; the share of countries more than twice their regional frontier was 44.6% in 1990 and 46.6% in 2023. Of 137 eligible countries, 67 narrowed and 69 widened their gap, with one unchanged. Nineteen countries achieved sustained catch-up, concentrated in North Africa and the Middle East (7) and Latin America (5), with China closing from 2.43 to 0.50, below its regional frontier; 28 countries regressed, led by Central Asia (Uzbekistan x3.5) and including the United States (x2.0). Over the COVID-19 window the median gap peaked at 2.00 in 2021 (+10.8% versus 2019, from unrounded medians) before returning to 1.86. Combining gap with avoidable deaths identifies two distinct policy problems: high-burden, moderate-gap giants (Nigeria 67,490 avoidable deaths, gap 2.4; India 54,109, gap 1.6) and extreme-gap outliers (Uzbekistan, gap 28.6). The Sub-Saharan Africa frontier fell further behind the High-income frontier (ratio 4.2 in 1990, 9.5 in 2023); the median Sub-Saharan African country sits 11.0 times the global 10th-percentile frontier but only 1.78 times its own regional frontier, so within-region benchmarking understates the region's true distance. URI gaps likewise did not converge (median 4.15 to 4.60). Interpretation Convergence toward the survival frontier is not the default national trajectory: over three decades the typical country made no net progress toward the best decile of its own region, and pandemic-era divergence was only partly reversed. National gap trajectories separate system-wide quality shortfalls from extreme outliers warranting audit, and expose a measurement trap in which regions whose frontiers stagnate appear closer to best practice than they are.

Despite significant progress in reducing vaccine-preventable diseases, Cameroons Expanded Programme on Immunisation operates within structures shaped by colonial history. Overreliance on external donor funding, centralised governance, and limited recognition of local knowledge raise concerns about equity, local ownership, and programme sustainability, particularly as the country plans for donor transition and self-financing. This study, aligned with the decolonising global health movement, examines how colonial legacies shape stakeholders experiences within the EPI and proposes practical steps towards a more locally owned immunisation programme. A qualitative case study was conducted in the Southwest Region of Cameroon from June to July 2025, comprising fifteen online semi-structured interviews in English with selected stakeholders (regional and district EPI managers, civil society members, and community leaders). Interviews were audio-recorded, transcribed verbatim, and analysed thematically using Clarke and Brauns six-step framework in NVivo version 11. Participants identified subtle colonial influences, including centralised decision-making, donor-driven priorities, pay disparities favouring international actors over local staff, and the marginalisation of local and traditional knowledge. The COVID-19 response was frequently cited as an example of inequity, with Western biomedical approaches prioritised over locally led solutions. Major structural issues included heavy reliance on external funding, outdated colonial-era training curricula, centralised governance, and a lack of local vaccine manufacturing capacity. Despite these issues, participants recognised the significant technical and financial support from international organisations. They proposed concrete pathways for decolonisation, including decentralised governance, participatory programme design, regulation and integration of traditional medicine, community engagement, domestic resource mobilisation, leveraging Cameroons emerging universal health coverage to reduce donor dependence, and investing in local vaccine production. Conclusion: Colonial legacies continue to influence Cameroons EPI, undermining local ownership and self-determination, even when external support is effective. Achieving decolonisation requires multifaceted efforts to strengthen domestic financing and governance, empower local stakeholders, and legitimise local knowledge alongside biomedical approaches. Policymakers should embed local ownership, governance reforms, and local capacity building in transition strategies while donor funding persists, ensuring immunisation gains are sustained beyond external support. These insights provide a context-specific roadmap for developing a sustainable, equitable, and locally driven immunisation programme in Cameroon and other countries facing similar donor transitions.

Background: Oral mucositis is a clinically significant, potentially severe side effect of systemic chemotherapy in children with cancer. Understanding genetic predisposition to this side effect may assist in development of stratified prophylactic and treatment strategies. However, existing literature primarily focuses on children with haematological malignancies. Methods: We performed a candidate gene study of 101 children with solid tumours enrolled in the MARVEL-PIC study at the Royal Children's Hospital, Melbourne. Clinical data were extracted from the electronic medical record, with NCI-CTCAE v6.0 grade >2 oral mucositis defined as the primary outcome. Genetic variants previously associated with oral mucositis were analysed under an additive genetic model to identify significant associations. Exploratory gene-drug interactions were identified based on chemotherapy exposure. Results: 29 patients (28.7%) developed grade >2 oral mucositis. MTHFR A1298C (rs1801131) was associated with lower odds of grade >2 oral mucositis, lower peak mucositis grade, and lower odds of opioid use for oral mucositis. 25 exploratory gene-drug interaction signals were identified, including miR-1206 rs2114358 with methotrexate exposure and ABCB1 rs1045642 with anthracycline exposure. Conclusions: MTHFR A1298C (rs1801131) demonstrated a protective effect against chemotherapy-induced oral mucositis in our cohort of children with solid tumours. Larger, ancestry-informed studies are required to validate our findings.

As vaccination rates have declined, large measles outbreaks have taken hold in vulnerable populations. In 2025, the United States saw the highest number of measles cases since 1991. After Utahs first case in June 2025, the Utah Public Health Laboratory (UPHL) began performing whole genome sequencing (WGS) on clinical measles samples. As Utahs outbreak grew, public health professionals used WGS data to identify clusters of disease, and combined genomic and epidemiologic data to identify factors that may fuel the spread of disease throughout the state. This study used sequenced samples from 65% of reported measles cases in Utah. Time-scaled and maximum likelihood phylogenetic trees were generated. A single nucleotide polymorphism (SNP) threshold of one was used to generate genomic clusters, and a Fishers Exact test was used to determine association between genomic cluster and epidemiological variables. Epidemiological clusters were assessed using annotated phylogenetic trees. We found multiple introductions of measles into Utah, with one accounting for the majority of cases. As measles spread, two phylogenetic clades emerged with differing geographical case compositions. We identified a significant association between shared school and genomic clustering, and we reconstructed transmission chains within schools and emerging from school sporting events. This study demonstrates the utility of WGS in real-time outbreak investigations. Sequencing data allowed for gaps in epidemiological data to be filled, revealing undetected transmission and clarifying whether cases belong to a known outbreak. We also highlight that schools and high-contact sporting events played a significant role in fueling transmission across the state.

School reopening during an Ebola outbreak is often framed as a binary question of whether schools are safe. For Ebola, however, the immediate operational question is where an infected school-age child may reach the school system before recognition and isolation, and whether local systems can detect and respond rapidly. We developed an exploratory, scenario-based health-zone framework for the September 2026 rentree during the ongoing Bundibugyo virus disease outbreak in eastern Democratic Republic of the Congo. The primary estimand was scenario-based expected introduction pressure, expressed on an expected-count scale, for infected school-age children reaching school in each health zone during a one-week window. The framework combined recent reported transmission, estimated school-age exposure and attendance, a surveillance/interception probability, and directed mobility-based importation. Case-fatality patterns were analysed separately and did not determine introduction pressure. A 10,000-draw probabilistic sensitivity analysis examined uncertainty in the school-age case share, attendance, pre-isolation school-entry probability and mobility scaling. Geographic components were retrospectively evaluated at eight non-overlapping weekly origins from 1 June to 20 July 2026, using subsequent reported seven-day health-zone activity and first reported cases in previously unaffected zones as outcomes. Seven-day local epidemic pressure discriminated health zones with subsequent reported activity with pooled ROC-AUC 0.848; the 14-day local measure increased this to 0.885. Adding directed mobility increased ROC-AUC to 0.952. In the base scenario, the six-province combined scenario-based expected introduction pressure was 10.97; the probabilistic sensitivity median was 11.17, with a 2.5-97.5% sensitivity range of 5.56-20.97. Bunia, Rwampara and Nizi had the highest base introduction pressures, followed by Katwa and Nia Nia. Among 24 previously unaffected health zones that subsequently reported a first confirmed case, 13 (54.2%) were in the top 10 and 18 (75.0%) in the top 20 mobility-ranked zones; random selection would have been expected to capture approximately 2.05 and 4.10 events, respectively. In a separate six-origin exploratory nested-specification sensitivity, surveillance/access modifiers did not improve geographic discrimination over local epidemic pressure alone, whereas mobility did. The dominant structural uncertainty remained the probability that an infected child reaches school before being identified. The framework supports targeted geographic prioritisation and minimum school-health readiness, but its probabilities are model-implied scenario probabilities rather than calibrated forecasts or evidence for a single national open/close decision.

Purpose: Lung cancer screening (LCS) with low-dose computed tomography (LDCT) reduces lung cancer mortality, yet screening participation remains low. We evaluated whether a brief informational video nudge delivered immediately before a scheduled clinical encounter increased LCS ordering and baseline LCS completion. Patients and Methods: We conducted a randomized feasibility trial within Kaiser Permanente Colorado from March through October 2025. LCS-eligible patients with an upcoming primary care or pulmonology appointment were assigned to intervention or usual care based on birth month. Intervention patients were split into two group, a group who received the LCS informational video nudge via text message within 24 hours of an eligible appointment; and second group who received the text plus a QR code video link during appointment rooming. Outcomes included LCS orders, baseline LCS-LDCT completion, and video engagement. Multivariable logistic regression was used to evaluate factors associated with LCS ordering. Results: Among 1,093 patients, 549 were assigned to intervention and 544 to usual care. Intervention patients were more likely to receive an LCS order within 1 day of their appointment (22.6% vs 16.4%; p=.010) and any time during follow-up (32.6% vs 24.1%; p=.002). Baseline LCS-LDCT completion was 51% higher in the intervention group, although the difference was not statistically significant (8.6% vs 5.7%; p=.078). Among the intervention group, 93 individuals (17%) viewed the video, generating 114 total views, and viewers watched an average of 79% of the video. Most views (82.5%) occurred through text-message delivery rather than QR codes. Conclusion: A brief, low-burden LCS informational video delivered immediately before a clinical encounter and integrated into existing workflows significantly increased LCS ordering and was associated with higher screening completion. Timely, scalable digital nudges may provide an effective strategy for improving LCS participation. Based on the observed effectiveness, feasibility, and efficiency of the intervention, KPCO incorporated the behavioral nudge into standard clinical care in February 2026.

Background: Mortality and hospital admissions due to Severe Acute Respiratory Infection (SARI) peaked between January and August 2025 in Brazil. Methods: The Brazilian Ministry of Health data on hospital admissions and deaths caused by SARI were compiled by age group (<5, 5-14, 15-49, 50-64, 65+ years) and quarter between January 2023 and June 2025. SARI causes were aggregated into SARS-Cov-2, Influenza, Respiratory Syncytial Virus (RSV), and other viruses (parainfluenza, adenovirus, rhinovirus, bocavirus, metapneumovirus). Multinomial regression was used to impute likely causes of death when these were not laboratory confirmed. Results: In the second quarter of 2025 (2025/2), RSV mortality rate among children <5 years reached 60 per 100,000, which is a 43% increase compared with 2024/2. Mortality rate for the joint impact of parainfluenza, adenovirus, rhinovirus, bocavirus, and metapneumovirus in the same age group doubled from 20 to 40 on the same scale in 2025/2 compared to 2024/2. Over the same period, influenza mortality tripled among the aged, whereas mortality due to other respiratory viruses increased less dramatically, except for SARS-CoV-2, which decreased among the aged from 150 to 25 per 100,000 between 2023/1 and 2025/2. Other age groups remained relatively stable over the period. The variation in hospital admissions largely followed that of mortality. Conclusions: While deaths and hospital admissions caused by SARS-CoV-2 declined rapidly since 2023, mortality rates of other respiratory viruses, mainly influenza and RSV, increased significantly among children <5 years and the aged in 2025/2. Public health policies that facilitate vaccine uptake against these infections should be given high priority.

Importance. Cancer is the second leading cause of death among patients in the Caribbean, where outcomes are associated with delayed clinical navigation to screening, diagnosis, and treatment. Artificial intelligence is increasingly used to guide patients with cancer to care, but whether these systems provide clinically actionable, facility-verified guidance for individuals in this population, and whether governance of the system is associated with the quality of that guidance, has not been evaluated. Objective. We tested whether a governed community learning platform navigates Caribbean cancer patients better than four ungoverned AI systems, and we tracked how community intelligence accumulates over time. Design, Setting, and Participants. We deployed a community learning ledger (CaribChat.ai) across ten Caribbean jurisdictions beginning March 2, 2026, and report all sessions through June 1, 2026 (N=207). An initial actively-promoted accrual period (March 2 - April 6, 2026; 168 sessions) was followed by continued organic use after active clinical promotion ceased. We then submitted the same 28 patient screening queries to ChatGPT (GPT-4o), Claude Haiku 4.5, DeepSeek-Chat, and OpenEvidence on April 5-6, 2026. Claude Haiku 4.5 powers CaribChat; testing it without governance isolates the governance effect. The platform requires no registration. Exempt under 45 CFR 46.104(d)(4)(ii). Main Outcomes and Measures. We classified 207 community sessions by thematic domain and temporal phase. We scored each of five systems on Caribbean facility citation, actionable navigation, and US-resource leakage across 28 screening queries. Results. The ledger accumulated 207 sessions - 168 during an actively-promoted accrual period (March 2 - April 6) and 39 after active clinical promotion ceased. Community engagement evolved from screening questions to active treatment navigation and diaspora engagement. CaribChat cited verified Caribbean facilities in 28/28 (100%) responses versus 10/28 (35.7%) for ChatGPT and 9/28 (32.1%) for OpenEvidence. CaribChat provided actionable navigation in 28/28 (100%) versus 2/28 (7.1%) for OpenEvidence (P<=.001). The same model scored 100% with governance and 54% without (P<=.001). DeepSeek cited US resources in 57.1% of Caribbean responses. After active clinical promotion ceased, off-codebook queries rose from 2.4% to 26.7% across phases while the governance contract continued to reject every adversarial probe - the community persisted but drifted from the cancer codebook absent clinician curation. The deployment operated within the OECS Health Strategy 2030 and CARICOM regional health frameworks, with queries originating across Caribbean jurisdictions led by Trinidad and Tobago. Conclusions and Relevance. Every ungoverned AI system we tested failed Caribbean cancer navigation. The best scored 68%. The most widely adopted physician platform scored 7%. The same foundation model scored 100% with governance and 54% without. Community intelligence accumulated from the population it serves, not published literature, is what makes health AI work in SIDS. The post-promotion decay shows the requirement is bidirectional: sustained, on-codebook engagement depends on patients and clinicians working together - community participation and active clinical curation are jointly necessary for maximum AI leverage.

Introduction. By the end of 2023, many low-income countries had not reached 50% COVID-19 vaccine coverage, while most high-income countries had exceeded 80%. It remains unclear whether receiving vaccine deliveries translated into faster population coverage. We examined cross-national inequalities in the timing of the vaccine rollout and whether deliveries through the COVID-19 Vaccines Global Access (COVAX) facility were associated with subsequent national uptake. Methods. We conducted an observational study of 218 countries and territories using country-level data up to December 2023. We used generalized additive mixed models to identify country-level correlates of coverage at an early and a later stage of the pandemic, survival analysis to compare the time to 50% coverage between COVAX Advance Market Commitment (AMC) and non-AMC countries, and an event study to estimate the association between the timing of the first COVAX delivery and subsequent monthly coverage in AMC countries. Results. AMC-supported countries reached 50% coverage substantially more slowly than non-AMC countries. The hazard of reaching the threshold was 0.17 times that of non-AMC countries at month 1 (95% CI 0.07 to 0.41) and 0.53 times at month 18 (95% CI 0.33 to 0.85). One year after rollout began, 65.9% of AMC countries (95% CI 56.7 to 76.6) had not reached 50% coverage, compared with 21.1% of non-AMC countries (95% CI 15.1 to 29.5). The timing of COVAX deliveries was not significantly associated with subsequent national uptake in any post-delivery month. In the early stage of rollout, higher maternal mortality was associated with lower coverage, while a larger urban population was associated with higher coverage. By the end of the observation period, larger household size was associated with lower coverage, while higher health expenditure and a larger urban population were associated with higher coverage. Conclusion. Receiving COVAX deliveries was not, on its own, associated with faster coverage. Coverage differences were more consistently associated with country-level structural and health-system characteristics, while we found no significant association with the timing of the first COVAX delivery. Achieving vaccine equality likely requires strengthening the capacity of health systems to convert deliveries into administered doses, and preparedness efforts should invest in last-mile delivery capacity ahead of future emergencies.

Background: Digital reminders reduce outpatient no-shows, but the optimal timing and frequency of messages remain unclear, particularly in Latin American public health systems. We emulated a target trial to evaluate the comparative effectiveness of four WhatsApp reminder strategies on appointment absenteeism and patient-initiated cancellations. Methods: We analyzed administrative and electronic health-record data from the public health system of the Autonomous City of Buenos Aires, Argentina (June 2023-May 2024). Eligible individuals had scheduled an in-person outpatient appointment in one of 15 prioritized specialties at least 75 hours in advance and had a mobile phone on record. We compared four strategies: (1) dual reminders at ~72 and ~24 hours before the appointment; (2) a single reminder at ~72 hours; (3) a single reminder at ~24 hours; and (4) no reminders. The primary outcome was the proportion of no-shows by the end of follow-up. Secondary outcomes were the cumulative incidence of patient-initiated cancellations overall, within 12 hours of the appointment, and followed by rebooking. We emulated the target trial using a cloning-censoring-weighting approach to estimate per-protocol controlled direct effects, with inverse-probability weights to address time-varying confounding and selection bias. Cumulative incidence of secondary outcomes was estimated using weighted Kaplan-Meier curves. Three pre-specified sensitivity analyses and standardized mean differences assessed robustness and covariate balance. Results: A total of 475,214 first eligible person-appointments were included; baseline no-show risk in the control arm was 34.6%. All three active strategies reduced no-shows compared with no reminders. The single 24-hour reminder produced the largest reduction (Risk Ratio [RR] 0.76, 95% CI 0.72, 0.81; Risk Difference [RD] -8.21 percentage points [pp], 95% CI -9.68, -6.54), followed by the dual-reminder strategy (RR 0.80, 95% CI 0.79,0.81; RD -7.05 pp, 95% CI -7.41, -6.71) and the single 72-hour reminder (RR 0.91, 95% CI 0.84,0.99; RD -3.16 pp, 95% CI -5.69, -0.49). All active strategies increased patient-initiated cancellations relative to control, with the dual-reminder strategy producing the largest increase. Sensitivity analyses preserved the qualitative ranking of strategies across all specifications. Conclusions: In this large target trial emulation, a single just-in-time WhatsApp reminder sent ~24 hours before the appointment was as effective as a dual-reminder schedule in preventing no-shows and superior to a distal 72-hour reminder alone. Adding a second, distal reminder provided no measurable benefit for attendance but substantially increased patient-initiated cancellations, which may be operationally valuable when active slot reallocation is a goal. These findings support timing, rather than frequency, as the primary lever of digital-reminder effectiveness, and favor the deployment of a single proximal reminder as the default strategy in resource-constrained outpatient settings.

Background: Autism spectrum disorder (ASD) is a lifelong neurodevelopmental condition for which timely diagnosis is critical to early intervention, family support, and equitable access to care. However, substantial disparities in access to ASD diagnostic services persist across socioeconomic, geographic, clinical, and health-system contexts. This systematic review and meta-analysis synthesized evidence on determinants of access across the ASD diagnostic pathway, from recognition and referral to diagnostic completion and timely diagnosis. Methods: We systematically searched MEDLINE/PubMed, Embase, Scopus, Web of Science, Global Health, and grey-literature sources for studies published between January 2004 and December 2024. Eligible studies examined determinants of ASD diagnostic completion, diagnostic pathways, diagnostic timeliness, or barriers and facilitators to diagnostic access. Two reviewers independently extracted data and assessed methodological quality using the Mixed Methods Appraisal Tool (MMAT). Quantitatively comparable estimates were synthesized using random-effects models with restricted maximum likelihood estimation. Heterogeneity was assessed using Cochran's Q, I2, tau2, and 95% prediction intervals. Pre-specified subgroup analyses, meta-regression, sensitivity analyses, funnel-plot assessments, and Bayesian random-effects analyses were undertaken. Results: The search identified 4,899 records; after removal of 537 records without associated data, 4,362 records underwent title/abstract screening. 3,800 records were excluded, 562 reports were sought for retrieval, and 450 full-text reports were assessed after 112 could not be retrieved. Ultimately, 22 unique studies met the inclusion criteria. Nine unique studies contributed 23 quantitative effect estimates, while the remaining studies contributed to the narrative synthesis. The evidence covered socioeconomic, geographic, family, communication, screening, child developmental, provider, and health-system determinants. The overall random-effects meta-analysis yielded a pooled diagnostic access outcome of 74.1% (95% CI 65.8-81.1%), with substantial heterogeneity (Qe=209.95, p<0.001; I2=88.4%, 95% CI 79.1-94.4%; tau2=0.691) and a wide 95% prediction interval of 32.8-94.4%. Bayesian analysis produced a highly concordant pooled estimate of 73.3% (95% CrI 65.3-80.2%), with I2=87.5% and tau=0.833, and satisfactory MCMC convergence (R-hat=1.000). By outcome domain, pooled successful outcomes were highest for diagnostic pathways (89.3%, 95% CI 70.1-96.7%), followed by timely diagnosis (76.3%, 95% CI 62.9-86.0%), and lowest for diagnostic completion (67.1%, 95% CI 61.8-72.0%) (Qm=5.98, p=0.050). Timely diagnosis demonstrated particularly high heterogeneity (I2=91.2%), whereas diagnostic completion showed moderate heterogeneity (I2=40.6%). Across determinant domains, frequentist pooled estimates were 79.5% for child developmental/neurobehavioral factors, 74.2% for family/socioeconomic/perceptual factors, 68.0% for intervention/care-navigation factors, and 63.6% for provider/clinical recognition factors. Bayesian estimates were 76.7% (BF=53.76), 72.9% (BF=226.32), 64.3% (BF=25.60), and 53.7% (BF=0.684), respectively. Meta-regression indicated that determinant category (Qm=13.48, p=0.004) and effect measure (Qm=7.81, p=0.020) significantly explained between-study variation, whereas age group (p=0.203) and geographic region (p=0.453) did not. Family/socioeconomic factors had significantly larger effect sizes (B=2.703, 95% CI 0.661-4.744; p=0.009), as did child developmental/neurobehavioral factors (B=1.516, 95% CI 0.047-2.985; p=0.043). Potential small-study effects were detected by two of three asymmetry tests, although the Rosenthal fail-safe N was 1,723. Trim-and-fill identified seven potentially missing estimates, with an adjusted pooled effect of 68.4% (95% CI 27.7-109.1%). Importantly, exclusion of two influential outlying estimates produced a pooled outcome of 77.1% (95% CI 71.6-81.9%), indicating that the principal finding was robust. Conclusions: Approximately three-quarters of observed ASD diagnostic outcomes represented successful access, but the substantial heterogeneity indicates that diagnostic access is highly context-dependent. Families were more likely to successfully navigate diagnostic pathways than to complete diagnostic assessment, while timely diagnosis showed the greatest variability across settings. Family and socioeconomic circumstances and child developmental characteristics emerged as particularly important determinants, whereas provider-related effects were more heterogeneous and uncertain. Improving equitable ASD diagnosis requires interventions spanning the entire diagnostic pathway, including developmental surveillance, screening, referral coordination, family navigation, provider capacity, specialist availability, and mechanisms to ensure completion of diagnostic assessment. Greater longitudinal and implementation research is particularly needed in low- and middle-income countries, where diagnostic infrastructure and specialist capacity remain limited.

Background: Neighborhood disadvantage indices used in public health research and policy include multiple economic, social, and housing items. However, research has failed to question whether it is necessary to include a multitude of economic, social, and housing variables in a single index. The purpose of this work was to examine three different neighborhood indices: a multidimensional disadvantage index, a unidimensional disadvantage index, and a unidimensional affluence index, and examine their performance with respect to distinguishing between healthy and unhealthy census tract neighborhoods in the United States. Methods: The 2022 disadvantage and affluence indices came from the National Neighborhood Data Archive, which are derived from census tract data from the American Community Survey 5-year estimates (2018-2022). The multidimensional disadvantage index included seven economic, social (e.g., single parent households), and housing items; the unidimensional disadvantage index included three poverty and income items; the unidimensional affluence index included 3 items capturing greater social and economic resources. Data on neighborhood health status (census tract prevalence of obesity, diabetes, and coronary heart disease) was obtained from the Population Level Analysis and Community EStimates database for 2022 and linked to the disadvantage and affluence indices for 83,522 census tracts. Contingency tables examined the degree of correspondence in quintiles across the three different indices and the corresponding disease prevalence in each cell. Generalized linear mixed models regressed the disease prevalence variables on index quintiles to determine the predicted prevalence of disease across the disadvantage gradient for each index. Results: Compared to the unidimensional disadvantage and affluence indices, the multidimensional disadvantage index underestimated disease burden in the most disadvantaged census tracts, and overestimated disease burden in the least disadvantaged tracts. Conclusions: Using a disadvantage or affluence index with a more parsimonious set of items would have greater precision in identifying communities at risk for poor health.

Background Global labor migration from LMIC to higher-income destinations has expanded rapidly, placing increasing pressure on destination-country health. Existing research on cross-border migrant workers has focused largely on occupational health, general healthcare utilization, and disease-specific risks, while there is considerably less evidence on their sexual and reproductive health. This study contributes to this understudied field by examining the policy and health-system factors that shape the sexual and reproductive health services for migrant workers in Taiwan. Methods A qualitative study was conducted in Taiwan between November 2025 and August 2026. 22 stakeholders were purposively recruited from academia, healthcare, nongovernmental organizations, government, labor brokerage, and employers. Data were collected through semi-structured interviews and small focus groups. Interviews were conducted in Mandarin Chinese, transcribed verbatim, and translated into English. Data were analyzed using framework analysis combining deductive coding based on the AAAQ framework with inductive coding of implementation and contextual themes. Results Gaps were identified across all four AAAQ dimensions. Participants described limited migrant-responsive SRH programming; physical, financial, administrative, social, and information barriers; shortcomings in linguistic and cultural responsiveness; and weaknesses in interpretation, coordination, and continuity of care, despite generally favorable views of Taiwan's clinical quality. Conclusions Our findings show that broad insurance coverage and strong clinical capacity do not by themselves ensure the realization of migrant workers' SRHR. In Taiwan, rights were mediated through labor brokerage, gendered live-in work arrangements, and fragmented governance across health, labor, immigration, and social-welfare systems. Improving migrant SRHR therefore requires stronger implementation of existing protections, reduced dependence on informal intermediaries, and more integrated institutional responsibility for cross-sector migrant health needs.

Background: Human papillomavirus (HPV) is the leading cause of cervical cancer and the vaccine is the key preventive measure. In 2023, Bangladesh launched a school-based HPV vaccination campaign for girls aged 10-14 years. However, vaccine uptake among this group in urban settings remains suboptimal. This study explored adolescent girls (aged 10-14 years) understanding attitude, and motivation towards the vaccine, as well as the practical challenges impacting on vaccine uptake. Methods: From April to June 2024, a qualitative study was undertaken in two urban slums in Dhaka, Bangladesh. Through a combination of convenience and snowball sampling, we conducted 15 in-depth interviews and one focus group discussion using the World Health Organizations Behavioral and Social Drivers (BeSD) tool. Interviews were conducted in the native Bengali language, audio recorded, and transcribed verbatim. Framework analysis was performed to emerge key themes and generate study findings. Results: A total of 26 girls with a mean age of 12.65 (SD: 1.23) participated in the study. While some participants believed that the HPV vaccine could reduce the infection during menstruation or prevent childbirth-related complications, there was uncertainty regarding the appropriate age for vaccination. Concerns were raised about menstrual irregularities, infertility, and the potential negative impact on marital prospects. Students spoke about being subjected to inappropriate jokes from their male peers. Male guardians were identified as the key decision makers and were perceived to be against the need for this vaccine. Operational barriers including inaccessible digital registration, limited information about the vaccine, and lack of systematic follow-up constrained the participation in the school-based HPV campaign. Conclusions: Adolescents in urban slums faced multi-layered barriers, including knowledge gaps, cultural barriers, and accessibility challenges to HPV vaccination. Strengthening adolescent-friendly communication, engaging parents, teachers and male students, simplifying registration, adequate vaccine supply and ensuring supportive school-based vaccination processes are critical to improving equitable coverage and acceptance.

Importance: Maternal vaccination and long-acting monoclonal antibodies are now available in the U.S. to prevent RSV. Long-acting monoclonal antibody administration in the U.S. commonly occurs after hospital discharge in outpatient settings, leaving some infants unprotected early in life when severe RSV risk is highest. Comparative effectiveness between the two interventions and whether delays affect effectiveness estimates have not been quantified. Objective: To evaluate the effectiveness of infant long-acting monoclonal antibody strategies and a maternal vaccination strategy, each compared to no intervention, and the comparative effectiveness of intervention strategies when accounting for real-world delays in monoclonal antibody receipt. Design: Cohort study using target trial emulation to compare four strategies for prevention of RSV-related outcomes. Setting: The U.S. between 2023 and 2025 using a nationwide database of employer-sponsored commercial insurance claims. Participants: 120,586 commercially insured mother-infants, whose infants were born in the U.S. during the 2023-2024 or 2024-2025 RSV season. Infants who could not be paired with their mother's record, did not enroll in commercial insurance within 75 days from birth, received palivizumab, and had an implausible birth date were excluded. Interventions: Comparison of four RSV prevention strategies: (i) maternal RSVpreF; (ii) long-acting monoclonal antibody given within the first week of life (mAb as intended); (iii) long-acting monoclonal antibody given within a six-month grace period from birth (mAb within grace period); and (iv) a control. Main outcomes and measures: Effectiveness against first RSV-associated hospitalization and medically-attended RSV illness was summarized using adjusted hazard ratios (aHR) and estimated using an inverse propensity weighting approach, with weights accounting for maternal age, maternal comorbidities affecting pregnancy, obstetric and newborn complications, season, region, and birth timing relative to October 1. A weighted Kaplan Meier estimator was used to estimate strategy-specific cumulative incidence of RSV outcomes over time. Results: In the first five weeks of life, the mAb within grace period strategy doubled the hazard of RSV hospitalization (aHR: 2.0 [95% CI: 1.0-4.9]) and increased the hazard of medically-attended RSV (aHR: 1.6 [95% CI: 1.0-2.7]) compared to the maternal RSVpreF strategy. The hazard for RSV hospitalization was similar for the mAb as intended strategy compared to the maternal RSVpreF strategy (aHR = 0.9 [95% CI: 0.3-1.9]). Conclusions and relevance: RSVpreF and monoclonal antibodies were similarly effective when monoclonal antibodies were administered close to birth, but when accounting for real-world delays in monoclonal antibody receipt, the maternal RSVpreF strategy was more effective than the mAb within grace period strategy.