Environmental Pollution

Military aviation training noise remains understudied despite its widespread impacts across urban, rural, and wilderness areas. The predominance of low-frequency noise and repetitive training can create pervasive noise pollution, yet past research often fails to capture the full range of health and quality-of-life effects. This study analyzed two complaint datasets related to Whidbey Island Naval Air Station noise: U.S. Navy records (2017-2020) and Quiet Skies Over San Juan County data (2021-2023). We analyzed and mapped sentiment intensity from noise complaints relative to modeled annual noise exposure, developed a typology to classify impacts, and modeled the environmental and operational factors influencing complaints. Findings revealed widespread negative sentiment and anger, often beyond the bounds of estimated noise contours, suggesting that annual cumulative noise models inadequately estimate community impacts. Complaints consistently highlighted sleep disturbance, hearing and health concerns, and compromised home environments due to shaking, vibration, and disruption of daily life. Residents also reported significant social, recreational, and work disruptions, along with feelings of fear, helplessness, and concern for children's well-being. The number of complaints were strongly associated with training schedules, with late-night sessions being the strongest predictor. A delayed response pattern suggests residents reach a frustration threshold before filing complaints. Overall, our findings demonstrate persistent negative sentiment and diverse impacts from military aviation noise. Results highlight the need for improved noise metrics, modeling and operational adjustments to mitigate the most disruptive effects.

Benzalkonium chloride (BAC) is widely used as a disinfectant in cleaning products and is frequently detected in indoor dust. In this study, we assessed dust samples, along with information on cleaning product use, from 24 pregnant participants. Dust samples were analyzed for BAC concentration and microbial tolerance. Different chain lengths of BAC (C12, C14, and C16) were quantified using LC-MS/MS, and bacterial isolates were tested for BAC tolerance using minimum inhibitory concentration (MIC) assays. BAC was ubiquitously detected, with C12 and C14 being dominant. Higher BAC concentrations were associated with reported disinfectant use and increased microbial tolerance. These findings suggest that indoor antimicrobial use may promote microbial resistance, highlighting potential exposure risks in indoor environments and the need for further investigation into health and ecological impacts.

Aims Indoor air pollution resulting from combustion of unclean cooking fuels has been linked to adverse health outcomes, but evidence regarding its association with mental health in low- and middle-income countries remains limited. We investigated the association between household use of unclean cooking fuels, as a proxy for indoor air pollution, and depression symptoms among adults aged 45 years and older in India, and assessed effect modification by age, sex, caste, and rural/urban residence. Methods We conducted a cross-sectional analysis of the first wave (2017-2018) of data from the Longitudinal Aging Study in India (LASI), a nationally representative survey of adults aged [≥]45 years. Cooking fuel type was classified as clean or unclean, and depression symptoms were assessed using the 10-item Centre for Epidemiologic Studies Depression (CES-D-10) scale. We used logistic regression to estimate odds ratios for depression symptoms, and linear regression to compare mean CES-D-10 scores by cooking fuel type, adjusting for sociodemographic and housing characteristics. Results We included 62,650 respondents. Median age was 57 years (IQR: 50-65), 46.7% were women, 47.6% reported using unclean cooking fuels, and 27.6% screened positive on the CES-D-10. After adjusting for sociodemographic and housing characteristics, use of unclean cooking fuels was associated with higher odds of screening positive on the CES-D-10 (aOR: 1.08; 95% CI: 1.02, 1.15), and higher mean CES-D-10 scores (adjusted mean difference: 0.34; 95% CI: 0.24, 0.44). The association was more pronounced among individuals living in urban areas (aOR: 1.36; 95% CI: 1.21, 1.53). Conclusion Use of unclean cooking fuels was associated with depression symptoms among older adults in India, and especially among those living in urban areas.

Wastewater surveillance (WWS) is established as a vital tool for monitoring polio and SARS-CoV-2 with potential to improve surveillance for many other infectious diseases. This study evaluated the feasibility of detecting measles virus (MeV) RNA in wastewater as part of a national WS preparedness trial in Brisbane, Australia, from March to June 2025. Composite and passive sampling methods were employed in parallel at three wastewater treatment plants serving populations between 230,000 and 584,000. Nucleic acids were extracted and analyzed using RT-qPCR targeting MeV N and M genes to distinguish wild-type and vaccine strains. MeV RNA were detected in both 24-hour composite and passive samples on May 26 to 27, 2025 from the largest catchment of 584,000 which also included an international airport. No measles cases were reported in this city or region within 4 weeks of the WS detections. These were confirmed as vaccine-derived measles virus (MeVV) strain via specific RT-qPCR assay. Extraction recoveries varied (11.5% to 70.5%), with passive sampling showing higher efficiency. This is the first report of use of passive samples for detection of MeV. These findings are consistent with other studies reporting WWS results of both MeVV genotype A and wild type genotype B and/or D. It demonstrates the potential for sensitive MeV WWS with rapid differentiation of MeVV from wild type MeV shedding, including in airport transport hubs and with different sample types. Use of WWS could strengthen measles surveillance by enabling rapid detection of MeV RNA and supporting outbreak preparedness and response. This requires optimised methods which are specific to or differentiate wild-type MeV from MeVV. Furthermore, the successful detection of MeV using passive sampling in this study highlights its potential for deployment in diverse global contexts which may include non-sewered settings.

Respiratory infections caused by bacterial pathogens like Mycobacterium tuberculosis and Bordetella pertussis have increased since the COVID 19 pandemic, yet clinical surveillance of both suffers from underreporting and delayed diagnoses. Wastewater monitoring is a valuable public health surveillance tool that can help fill gaps in clinical data yet has rarely been applied to respiratory bacterial pathogens despite evidence of bacterial shedding via excretion types that enter wastewater. In this study, we investigated the possibility for wastewater monitoring of two bacterial respiratory diseases, tuberculosis and pertussis, using two case studies of wastewater monitoring for M. tuberculosis and B. pertussis. We retrospectively measured concentrations of these pathogens in wastewater samples collected longitudinally from communities with and without known outbreaks of these diseases. We designed and validated a novel B. pertussis specific assay for the NAD(P) gene; B. pertussis nucleic acids were detected sporadically in wastewater during an identified outbreak. We used a highly specific, established assay for M. tuberculosis nucleic acids, and found low concentrations of the marker in wastewater that were lag-correlated with clinical incidence rates 5 weeks later. Findings support the potential of wastewater monitoring for M. tuberculosis and B. pertussis to enable identification of communities with outbreaks of tuberculosis and pertussis and provide early warning for tuberculosis.

BackgroundEvidence on the long-term impact of urban green and blue spaces (UGBS) interventions remains limited. This study is a 15-year evaluation of an urban greenway development in Belfast (United Kingdom), assessing the potential effects of this UGBS intervention on physical activity (PA), mental wellbeing and co-benefits. MethodsUsing quasi-experimental design, a repeated cross-sectional survey was conducted in 2010 (baseline), 2017 (post-opening) and 2023 (long-term follow-up) with about 1,200 adults participated each wave. Outcomes included PA, mental wellbeing, general health, quality of life, social capital and environmental perception. Multilevel mixed-effect regressions were performed to examine within-group changes at long-term follow-up. Difference-in-differences analysis investigated the between-group changes that might be attributed to the greenway. Additional comparative analyses included distance-decay analysis and comparison with population trends in Northern Ireland. ResultsAt six years after completion, the greenway intervention appears to buffer a decline in duration of PA - mainly from moderate-intensity activity (decline lower by 118.6 min/week, 95%CI: 3.9-232.2) but with no significant impact on the proportion of the population meeting the recommended PA level. The intervention is associated with a smaller decline in self-rated health (4.98 units; 95%CI: 0.62-9.34) relative to control group. Intervention association with mental wellbeing was positive but not significant (p=0.30). The greenway also showed positive effects on social capital and environmental perceptions, with impacts most evident in improving safety and trust in the local area. ConclusionThis study provides evidence to support the public health impact of UGBS and its long-term health and social benefits.

Infectious disease surveillance systems in tropical countries show that respiratory disease incidence generally manifests as year-round activity with weak fluctuations and irregular seasonality. Previously, using a ten-year time series of influenza-like illness (ILI) collected from outpatient clinics in Ho Chi Minh City (HCMC), Vietnam, we found a combination of nonannual and annual signals driving these dynamics, but with unknown mechanisms. In this study, we use seven stochastic dynamical models incorporating humidity, temperature, and school term to investigate plausible mechanisms behind these annual and nonannual incidence trends. We use iterated filtering to fit the models and evaluate the models by comparing how well they replicate the combination of annual and nonannual signals. We find that a model including specific humidity, temperature, and school term best fits our observed data from HCMC and partially reproduces the irregular seasonality. The estimated effects from specific humidity and temperature on transmission are nonlinearly negative but weak. School dismissal is associated with decreased transmission, but also with low magnitude. Under these weak external drivers, we hypothesize that stochasticity makes a strong sub-annual cycle more likely to be observed in ILI disease dynamics. Our study shows a possible mechanism for respiratory disease dynamics in the tropics. When the external drivers are weak, the seasonality of respiratory disease dynamics is prone to the influence of stochasticity.

BackgroundThe rapid growth of the worlds urban population has contributed to the expansion of informal urban settlements in many cities across the world. In these settings, lack of safe sanitation combined with high population density and poverty contributes to heightened health risks for often vulnerable populations. The aim of this study was to evaluate the effect of a shared, onsite sanitation intervention on the nutritional status of children in Maputo, Mozambique. MethodsThe Maputo Sanitation (MapSan) trial was a controlled before-and-after study to evaluate the effect of a shared, onsite sanitation intervention on child health in Maputo, Mozambique. Here, we report the effects on childhood stunting, wasting and underweight, and height-for-age, weight-for-height and weight-for-age z-scores. Children were enrolled aged 1-48 months at baseline and outcomes were measured before and 12 and 24 months after the intervention, with concurrent measurement among children in a comparable control arm. The primary analysis was intention-to-treat. The trial was registered at ClinicalTrials.gov, number NCT02362932. ResultsWe enrolled 757 and 852 children in the intervention and control groups respectively. There was no evidence for an effect of the intervention on any outcome at 12 or 24 months of follow-up except for wasting where there was very weak evidence for an effect (adjusted prevalence ratio: 0.497; 95% CI: 0.22-1.11; p=0.09). In two exploratory analyses - one including only those children born into compounds post-intervention and a second excluding children in control compounds which had independently improved their sanitation facilities during follow-up - we found that stunting increased in the intervention group whilst wasting decreased. ConclusionsThis study contributes to the growing evidence on the role of sanitation in shaping child health outcomes in informal urban settlements. We found no evidence for an effect on stunting and weak evidence for an effect on wasting. More research is needed to understand how sanitation can reduce childhood undernutrition in complex urban environments.

Background: Reusable menstrual products provide sustainable and cost effective alternatives to disposable sanitary products; however, their adoption remains limited, even among healthcare professionals. Objectives: To assess awareness, knowledge, perceptions, and utilisation of reusable menstrual products among female medical students and healthcare professionals, and to identify predictors of willingness and use. Design: Cross sectional analytical study. Setting: An online survey was conducted among female medical students and healthcare professionals in Nigeria. Participants: A total of 203 female respondents aged 15 to 55 years. Intervention: Not applicable. Primary Outcome Measures: Utilisation of reusable menstrual products and willingness to adopt their use. Secondary Outcome Measures: Awareness, knowledge, perceptions, and barriers. Methods: Data were collected using a structured questionnaire and analysed using descriptive statistics, chi square tests, and logistic regression. Results: Awareness was high (96.06%), but utilisation was low, with 5.42% ever using and 4.43% currently using reusable products. About 31.53% were willing to use them. Respondent type was not associated with willingness (p = 0.735), although healthcare professionals had higher knowledge (p = 0.024). Positive perception predicted willingness (AOR = 7.58, 95% CI: 3.18 to 18.03, p < 0.001). Good knowledge (AOR = 14.96, p = 0.014) and increasing age (AOR = 1.28, p = 0.004) predicted utilisation. Conclusion: Despite high awareness, utilisation remains low. Perception influences willingness, while knowledge drives use. Targeted behavioural and educational interventions are needed. Keywords: Menstrual hygiene, reusable menstrual products, menstrual cup, sustainability, healthcare professionals

Loneliness--the perceived discrepancy between desired and actual social connection--is a common and aversive psychological state associated with a range of adverse health outcomes. Several theoretical models suggest that these associations may operate partly through health behaviors. In this preregistered study, we used data from the All of Us Research Program to evaluate associations of loneliness and functional rurality (FR), a study-specific contextual index of reduced neighborhood accessibility, with Fitbit-derived physical activity and sleep outcomes. Final samples included 16,912 participants for physical activity analyses and 13,937 for sleep analyses. In adjusted models, higher FR was associated with greater loneliness ({beta} = 0.061, 95% CI [0.045, 0.077], p = 9.63 x 10-14). FR and loneliness were independently associated with fewer daily steps and lower moderate-to-vigorous physical activity. Loneliness was also associated with shorter sleep duration, greater sleep duration variability, higher odds of short sleep, and higher odds of low sleep efficiency. FR was not associated with sleep duration or sleep duration variability but showed a small positive association with mean sleep efficiency and lower odds of low sleep efficiency. Interaction analyses provided little evidence that FR modified the associations of loneliness with most outcomes, although the FR x loneliness interaction was significant for sleep duration variability, indicating that loneliness was more strongly associated with irregular sleep duration in higher-FR contexts. Sensitivity analyses using stricter valid-day thresholds, winsorization, quartile-based exposure coding, and a backward 30-day window yielded directionally similar findings. These results suggest that FR and loneliness are independently associated with lower physical activity, whereas loneliness shows a more consistent relationship with adverse sleep patterns.

This study investigated retirement adjustment in retired police officers in the UK (N = 289), examining how time since leaving the service moderates the relationship between perceived organisational support and retirement adjustment while accounting for resilience. Results indicated a developmental trend: organisational support remains stable initially but becomes increasingly influential in later life. Using Johnson-Neyman analysis, a threshold of 32.07 years was identified, after which the association reaches statistical significance. These findings suggest an organisational legacy effect; for the older generation, the retrospective perception of being valued by the service acts as a durable psychological resource. This study offers a novel conceptualisation of long-term organisational influence by identifying a temporally delayed legacy effect that extends beyond existing models of retirement adjustment. The study advocate for lifelong wellbeing strategies that extend, recognising that the organisational relationship continues to shape adjustment outcomes decades after the conclusion of active duty.

BackgroundIn long-term care facilities (LTCFs), close-contact identification often relies on staff recall and monitoring records because residents may be unable to self-report reliably. How these different record-generation processes relate to proximity-based sensor measurements in routine LTCF workflow remain unclear, and how such differences may influence contact-based decision-making in outbreak response is not well understood. MethodsWe conducted a five-day observational study in a Japanese LTCF using ultra-wideband (UWB) indoor positioning. Twenty-seven participants wore UWB tags, including 16 residents and 11 staff members; 10 staff members completed questionnaires. We compared UWB-derived proximity with questionnaire-derived contacts from staff self-report and monitoring-based proxy records, and assessed directional discrepancies under multiple distance-time thresholds. ResultsQuestionnaire-based records and UWB-derived proximity showed different patterns of discrepancy across contact types. Within this facility, resident-related monitoring-based proxy records showed relatively small directional discrepancies, whereas staff self-reports tended to identify additional resident-staff contacts under the baseline threshold ([&le;]1.0 m for [&ge;]15 min). Several alternative thresholds were associated with discrepancies closer to zero than the baseline, although the apparent ranking varied by summary metric. ConclusionsIn this single-facility observational study, different contact-list generation processes were associated with different patterns of discrepancy relative to a proximity-based operational measure. These findings support interpretation in terms of workflow-specific contact-list generation rather than a single universally optimal threshold and may help inform facility-level review of contact identification practices in LTCFs. These findings support aligning contact identification strategies with facility-specific workflows to improve the feasibility and effectiveness of IPC practices in LTCFs.

Standard in vitro antimicrobial susceptibility testing (AST) using Mueller-Hinton broth (MHB) does not reflect infection-site conditions, and its results often do not correlate with therapeutic outcomes. Here, we compared the antibiotic susceptibility of methicillin-resistant Staphylococcus aureus (MRSA), a common chronic wound pathogen, in simulated wound fluid (SWF) resembling wound exudate versus MHB, revealing discordant AST results across six of nine tested antibiotic classes. The most significant were 128-fold increased resistance to tetracyclines and 256-fold sensitization to {beta}-lactams in SWF. Tetracycline resistance was mediated by MntC, an extracellular manganese-binding protein, whereas {beta}-lactam sensitization was driven by cell envelope remodelling in SWF. Galleria mellonella wound infection results matched the SWF susceptibility phenotypes, suggesting SWF better predicts in vivo wound infection therapeutic outcomes. These comprehensive phenotypic and mechanistic insights into MRSA antibiotic responses under wound-infection-mimetic conditions with direct in vivo validation identify a potential new antibiotic adjuvant target and may guide improved antibiotic therapy for MRSA wound infections.

Colorectal cancer (CRC) is the second leading cause of cancer death globally and the number one cause of cancer death in people under 50 years old. The reasons for the rise of early-onset CRC are unknown, and while anatomically distinct subtypes of CRC have substantial clinical and molecular associations, the etiology of region-specific disease, such as early-onset CRC's enrichment in the distal colon, remains unclear. Understanding regional mutagenesis may identify risk factors for this public health concern and CRC more broadly. To evaluate mutational dynamics across the premalignant colon, we performed whole-genome sequencing of 125 individual colon crypts taken from six standardized regions biopsied during colonoscopy, collected from 11 donors without polyps and 10 with polyps. We observed mutation spectra and accumulation rates consistent with previous whole-organ studies, with greater subclonal mutation capture enabled by experimental design. T>[A,C,G] mutations, which are associated with colibactin genotoxicity from pks+ Escherichia coli, were significantly enriched in the rectum of donors with and without polyps (adjusted p-values < 0.01). Moreover, when comparing findings to crypts from individuals with CRC and sequenced CRC tumors, we observed consistent enrichment of the colibactin-associated mutational signature "ID18" in the rectum in both normal colon crypts and CRC tumors, without significant difference in colibactin-specific single nucleotide variant or insertion-deletion burden in crypts across the three clinical groups (i.e., no polyp, polyp, and CRC). These findings argue against a causal or prognostic role for colibactin in CRC, instead indicating that the proposed association with early-onset disease reflects anatomic specificity rather than cancer-specific clinical relevance.

HighlightsO_LIHealth inequalities have widened over 15 years, favouring high-income groups C_LIO_LIInequality in physical activity & mental health widened the most pre-intervention C_LIO_LIPost-intervention, inequalities persisted but stayed relatively unchanged. C_LIO_LILong-term illness and unemployment were key drivers of inequality C_LIO_LIThe greenway may have slowed down the inequality widening but the impact is limited C_LI BackgroundEvidence concerning health inequalities following urban green and blue space UGBS) interventions is limited. This study examined the changes in health inequalities after a major urban regeneration project, the Connswater Community Greenway (CCG), in Belfast, UK. MethodCross-sectional household surveys were conducted in 2010/11 (baseline), 2017/18 (immediately after completion), and 2023/24 (long-term follow-up) with a sample of approximately 1,000 adults each wave. Using concentration indices (CI), income-related health inequalities for three outcomes (physical activity, mental wellbeing and quality of life) were measured. A regression-based decomposition of concentration index examined the contribution of sociodemographic factors to the observed inequalities underpinning each outcome over time. ResultsAcross three waves, there was widening of inequalities over the 15-year period across all three health outcomes, with those from high-income groups reported higher levels of physical activity (CI=0.33, SE=0.026), better mental wellbeing (CI=0.03, SE=0.003), and better quality of life (CI=0.09, SE=0.008). The widening inequalities mainly occurred during the construction phase of CCG (2010-2017) and remained stable post-intervention (2017-2023). Decomposition analysis revealed that the pro-poor concentration of long-term illness and unemployment was the key driver that together explained approximately 51%-76% of the inequalities. ConclusionThe CCG was limited in reducing health inequalities which were mainly driven by long-term illness and unemployment - factors beyond the direct scope of the UGBS intervention - resulting in low-income groups likely to fall further behind the wealthier groups. The widening of inequality is consistent with findings from other public interventions that did not have a primary equity focus.

BackgroundCommercial motorcycle riders are among the most vulnerable road users in low- and middle-income countries and contribute substantially to the burden of road traffic injuries. The use of personal protective equipment (PPE), including helmets and protective clothing, reduces injury severity; however, uptake remains suboptimal. This study evaluated the effectiveness of a theory-driven health education intervention in improving knowledge, attitudes, and use of PPE among commercial motorcycle riders in Cameroon. MethodsA quasi-experimental, non-randomized controlled before-and-after study was conducted in Limbe (intervention) and Tiko (control) Health Districts between August 4, 2024, and April 6, 2025. Participants were recruited from a cohort of commercial motorcycle riders and followed over an eight-month intervention period. The intervention, guided by the Health Belief Model and developed using the Intervention Mapping framework, combined face-to-face sensitization sessions with mobile phone-based educational messaging adapted to participants literacy levels and communication preferences. Data were collected at baseline and endline using structured questionnaires and direct observation checklists. Intervention effects were estimated using difference-in-differences analysis with generalized estimating equations, adjusting for socio-demographic factors. ResultsA total of 313 riders were enrolled at baseline (183 intervention, 130 control), with 249 retained at endline (149 intervention, 100 control). The intervention was associated with significant improvements in PPE knowledge ({beta} = 2.91; 95% CI: 2.14-3.68; p < 0.001) and attitudes ({beta} = 5.76; 95% CI: 4.32-7.21; p < 0.001) compared with the control group. No statistically significant effect was observed for PPE practice scores ({beta} = 0.21; 95% CI: -0.09-0.52; p = 0.171). Among individual PPE items, helmet use increased significantly in the intervention group relative to the control group (AOR = 2.38; 95% CI: 1.19-9.45; p = 0.036), while no significant effects were observed for gloves, trousers, eyeglasses, or closed-toe shoes. ConclusionThe theory-driven health education intervention significantly improved knowledge and attitudes toward PPE and increased helmet use among commercial motorcycle riders but did not lead to broader improvements in the uptake of other protective equipment. These findings highlight the need for complementary structural and policy interventions to address persistent barriers to PPE use in similar low-resource settings. Trial registrationClinicalTrials.gov Identifier: NCT07087444 (registered July 28, 2025, retrospectively)

BackgroundThe World Health Organization has developed several global template protocols for epidemiological investigations, including for household transmission investigations (HHTIs). These investigations facilitate rapid characterisation of novel or re-emerging respiratory pathogens and support evidence-based public health actions. Beyond technical readiness, community buy-in is central to the feasibility and acceptability of HHTIs. Research is needed to determine the perceived legitimacy among the community to inform local protocol adaptation and development of implementation plans that consider community attitudes and needs. MethodsIn 2025, we conducted a convenience survey of community members living in Victoria, Australia to explore: their understanding of emerging respiratory diseases; their willingness to take part in public health surveillance activities such as HHTIs; the acceptability of clinical and epidemiological data collection and respiratory/blood sample collection as main components of HHTIs, and; participant comfort towards including their companion animals in HHTIs. ResultsWe received 282 survey responses, of which 235 were included in the analysis dataset. Compared to the general Victorian population, our participants included a higher proportion of participants who reported being female, tertiary-educated, of Aboriginal and/or Torres Strait Islander heritage, born in Australia and speaking only English at home. Participants indicated overall high levels of comfort and acceptability towards participation in HHTIs, particularly in relation to clinical and epidemiological data collection, with lesser but still high levels of comfort with providing multiple respiratory specimens in a 14-day period. Participants were least comfortable with other specimens such as urine and blood. Involving companion animals in HHTIs was similarly acceptable as human-focused components. ConclusionsDespite our survey population being non-representative of the general Victorian population, our findings provide valuable descriptive insights into the acceptability of HHTIs in Victoria, Australia from which to benchmark future local and international surveys and community engagement activities.

1.Study questionDo singletons conceived by medically assisted reproduction (MAR) experience an elevated incidence of childhood cancers and are they at a greater risk of such cancers compared to naturally-conceived singletons? Summary answerWe found no strong evidence the adjusted risk of childhood cancers is increased for MAR-conceived singletons. What is known alreadyThere is longstanding concern children conceived via MAR may be at increased risk of childhood cancer. Current epidemiological evidence does not support such a relationship. Study design, size, durationWe conducted a retrospective population-based cohort study of 5,104,121 singletons born in Australia between 1991 and 2019. Median follow-up time varied from 4 to 10 years depending on mode of conception. Participants/materials, setting, methodsWe linked birth records to public medical insurance data of the mother to ascertain MAR conception. We classified treatment as ovulation induction/intrauterine insemination (OI/IUI) or assisted reproductive technology (ART; IVF/ICSI), with ART coded as either fresh embryo transfer or frozen embryo transfer. The cohort included 4,924,354 naturally-conceived singletons and 179,767 singletons conceived via MAR. We calculated standardised incidence ratios (SIRs) to ascertain differences in population incidence of childhood cancer, and generated hazard ratios (HRs) using flexible parametric survival models controlling for key confounders. We report absolute incidence and risk differences for both statistical approaches. Main results and the role of chanceThere was no increase in the incidence or risk of all childhood cancers combined for singletons conceived via MAR, either any MAR or specific MAR types. There was some evidence the incidence of leukemias, myeloproliferative diseases, and myelodysplastic diseases was increased after ART compared to the general population (SIR: 1.32, 95% CI 1.02-1.68; equating to 2.09, 95% CI 0.13-4.44 extra cancers per 100,000 person-years), but no increased risk after adjusting for available confounders (HR: 1.04, 95% CI 0.73-1.46). These cancers showed increased incidence and risk for those conceived via IVF (SIR: 1.54, 95% CI 1.01-2.26; HR: 1.77, 95% CI 1.06-2.95), but not ICSI (SIR: 1.27, 95% CI 0.83-1.85; HR: 0.76, 95% CI 0.48-1.22). Incidence of renal tumours was elevated after IVF (SIR: 2.37, 95% CI 1.02-4.67; equating to 1.83, 95% CI 0.03-3.99 extra cancers per 100,000 person-years) and frozen transfer ART (SIR: 2.52, 95% CI 1.09-4.97; equating to 2.12, 95%CI 0.12-5.53 extra cancers per 100,000 person-years), however risk was not elevated after adjusting for available confounders (HR: 1.06, 95% CI 0.47-2.38; and HR: 1.63, 95% CI 0.73-3.61 respectively). Limitations, reasons for cautionWe did not have information on parental cause of infertility, which could be a confounder for childhood cancer, although we did adjust for parental history of cancer. For many specific cancer types, fewer than 50 cases were observed in total. Given the number of comparisons reported and closeness of the lower-bound confidence interval to 1, we cannot exclude that a significant association between conception via IVF and leukemias, myeloproliferative diseases, and myelodysplastic diseases reflects a type I error. Wider implications of the findingsOur findings align generally with published meta-analyses on the risk of childhood cancers following MAR conception and reinforce the need for very large studies to increase confidence. Parents who have conceived via MAR and their offspring can be reassured there is not strong evidence the treatments increase the overall incidence or risk of childhood cancer. Study funding/competing interest(s)This work was funded by the National Health and Medical Research Council (NHMRC: APP1164852). Dr ARW declares that their involvement in this work was supported by employment at UNSW Sydney. Prof CMV declares payment to their institution from the National Health and Medical Research Council (APP1164852). Prof NH declares payment to their institution from the National Health and Medical Research Council (APP1164852); royalties and licenses for Berek and Hackets Gynecologic Oncology (Walters Kluwer); royalties and licenses for Hacker and Moores Essentials of Obstetrics and Gynecology (Elsevier); consulting fees from Darwin Hospital and Gold Coast University Hospital; support for attending the British Gynaecological Cancer Society meeting in Aberdeen, UK, Jun 2023; support for attending the Symposium on Gynaecological Cancer in Budapest, Hungary, Nov 2023; support for attending the International conference of the Rajiv Gandhi Cancer Centre in Delhi, India, Mar 2025; and membership of the Medical Advisory Committee for TruScreen (Australia and New Zealand). A/Prof SO declares that they received payment to their institution from the National Health and Medical Research Council (APP1164852); they received a grant from the European Society for Human Reproduction and Embryology (Open call 2022) including payment to their institution; and that they are a member of the Advisory Board of the Cervical Screening Program in Norway through The Norwegian Institute of Public Health (NIPH), for which they were reimbursed travel expenses to their institution. Prof MC declares support for Theramex European Society for Human Reproduction and Embryology registration and Fertility Society of Australia and New Zealand registration and accommodation. A/Prof USD declares that her involvement in this work was supported via an Early Career Fellowship from the Cancer Institute NSW (ID: 2020/ECF1163) and employment at UNSW Sydney. A/Prof USD also declares payment to their institution from the National Health and Medical Research Council (APP2035240) and the Medical Research Future Fund (APP2032214; APP2038377), and the Australian Research Council (DP240100072) as well as current grants from NSW Health, Prince of Wales Hospital Foundation, and unpaid involvement as an Associate Editor for the "Journal of Psycho-Oncology Research and Practice". Prof LJ declares payment to their institution from the National Health and Medical Research Council (APP1164852). Prof RJN declares they are the Chair of the Clinical Advisory Committee, Westmead Fertility; External mentor at VinMec hospital; Editorial Editor at the journal "Fertility and Sterility"; and has received funding from the National Health and Medical Research Council (NHMRC) for the NHMRC Centre for Research Excellence in Womens Health in Reproductive Life (CRE WHiRL). A/Prof CS declares stock or stock options associated with CSL Ltd, Sigma Healthcare Ltd, Resmed Inc, Medical Developments International Ltd, Vitrafy Life Sciences Ltd, Intuitive Surgical, and Steris PLC. Prof GMC declares payment to their institution from the National Health and Medical Research Council (APP1164852). Prof CV declares payment to their institution from the National Health and Medical Research Council (APP1164852); research grants receive from Merck KGaA and Ferring; payments for honoraria from Merk Ltd, Merk Sharpe & Dohme, Ferring, Organon, Gedeon-Richter for being an invited lecturer in scientific meetings/conferences on multiple occasions as well as member of advisory boards for these companies who have a commercial portfolio in the field of assisted reproduction technology (ART); and speaking fees from IBSA, Vianex, Sonapharm; travel support for their participation in scientific meetings/conferences both nationally and internationally, usually as an invited speaker for the following companies - Merck Ltd, Merck Sharpe & Dohme, Ferring, Organon, Gedeon-Richter; unpaid involvement as a Board member of the Hellenic Society of Fertility and Sterility, Member of the Editorial Board of the journal "Human Reproduction", Senior Deputy of the Coordination Committee of the Special Interest Group "Reproductive Endocrinology" of the European Society for Human Reproduction and Embryology, Member of the Editorial Board of the journal "F&S Reviews", Member of the Editorial Board of the journal "RBM Online", Member of the Editorial Board of the journal "Reproductive Biology & Endocrinology", Member of the Editorial Board of the journal "Frontiers in Endocrinology", and Member of the Editorial Board of the journal "Reproductive Sciences". SubjectReproductive epidemiology

We used 2492 whole genome sequences from Laos to investigate the molecular epidemiology of SARS-CoV-2 from 2021 through 2024, covering the major waves of COVID-19 disease in Laos including time periods of travel restrictions and after relaxation of travel across international borders. We identify successive waves of COVID-19 caused by shifts in the dominant lineage, beginning with the Alpha variant in April 2021 and continuing through the Delta and Omicron variants. We quantify a shift from a small number of viral introductions responsible for widespread transmission in early waves to a larger number of introductions for each variant after travel restrictions were lifted, and identify potential routes of introduction into the country. Our study underscores the importance of genomic surveillance to public health responses to characterize viral transmission dynamics during pandemics.

BackgroundTimely cancer diagnosis in children and adolescents is critical to improving outcomes, yet substantial variation in diagnostic intervals persists across cancer types and care settings. We aimed to quantify time to diagnosis and assess variations by patient, demographic, and system-level factors. MethodsWe conducted a retrospective population-based study of children and adolescents aged 0-19 years diagnosed with one of 12 common cancers between 2010 and 2022 in Quebec, Canada. The diagnostic interval was defined as the time from first cancer-related healthcare encounter to diagnosis. We calculated medians and interquartile ranges (IQR) overall and by cancer type and used multivariable quantile regression to identify factors associated with time to diagnosis at the 25th, 50th, and 75th percentiles. ResultsAmong 2,927 individuals with cancer, diagnostic intervals varied by cancer type and age. Median intervals were longest for carcinomas (100 days; IQR 33-192) and shortest for leukemias (8 days; IQR 3-44). Compared with children living in Montreal, living in regional areas and other large urban centres was associated with longer 50th and 75th percentiles of time to diagnosis for hepatic and central nervous system (CNS) tumours. Diagnostic intervals were shorter in the post-pandemic period (2020-2022) across several cancer sites, with CNS tumours showing reductions across all quantiles. InterpretationDiagnostic timeliness differed by cancer type, age, and rurality, but not by sex, material, or social deprivation. The shorter diagnostic intervals observed in the post-pandemic period suggest that pandemic-related changes in care pathways may have expedited diagnosis for some cancers.