BACKGROUND: School health education promotes health knowledge and skills, yet measurement of teens' health skills is limited. We psychometrically assessed the perceptions of skills enhanced through school health education (PSE-SHE) measure. METHODS: Cross-sectional data (n = 471) were collected from teens using Teen and Parent Surveys of Health, conducted through AmeriSpeak Panels. The survey included one 5-item question assessing teens' perceptions of health skills enhanced through school health education-including getting health information and services, and understanding factors influencing health, communication, decision-making, and advocacy. For each PSE-SHE item, a 3-level categorization measure was examined (strongly agree/agree, neither agree nor disagree, and strongly disagree/disagree). Cronbach's alphas and confirmatory factor analysis (CFA) examined PSE-SHE measures' reliability and validity. Structural equation modeling used the CALIS procedure (SAS 9.4). RESULTS: High Cronbach's α = 0.91 was observed for the PSE-SHE measure, indicating internal consistency. Polychoric correlations among PSE-SHE items (0.68-0.81) were found. CFA confirmed substantial factor loadings (0.72-0.84, p < 0.0001) of each item on the latent factor (CFI = 0.98), supporting construct validity. IMPLICATIONS FOR SCHOOL HEALTH POLICY, PRACTICE, AND EQUITY: The reliable and valid PSE-SHE measure may inform skills-focused health education research. CONCLUSIONS: Psychometric results confirm the PSE-SHE measure is valid in capturing perceptions of skills enhanced through school health education.

INTRODUCTION: Sexual violence (SV) affects millions globally and has a well-documented bidirectional association with HIV. Post-exposure prophylaxis (PEP) is a critical, yet often underutilized, HIV prevention tool in post-SV care. Despite its potential impact to reduce HIV transmission, SV care remains an overlooked service delivery point for HIV prevention. The U.S. Centers for Disease Control and Prevention (CDC), as part of the President's Emergency Plan for AIDS Relief (PEPFAR), supports PEP provision within broader post-violence care (PVC) services. Understanding PEP utilization is crucial for optimizing service delivery and HIV prevention efforts. METHODS: Using Monitoring Evaluation and Reporting data from fiscal years 2018-2023, we conducted a descriptive analysis of clients who received PVC and SV services through CDC-supported programming in 14 sub-Saharan African countries. RESULTS: From 2018 to 2023, the annual number of clients receiving any PVC, and specifically SV, services increased by 233% (in 2018, n = 206,764; in 2023, n = 689,349) and 163% (in 2018, n = 42,848; in 2023, n = 112,838), respectively. Fewer than half of SV clients completed PEP (38% in 2018, n = 16,103; 31% in 2023, n = 35,118). Across all years combined, most SV clients (female: 185,414; male: 59,618) were aged 15-19 years. The age band and sex with the lowest proportion of clients completing PEP were males aged 15-19 (4%, n = 2296). CONCLUSIONS: The findings underscore a critical gap between the scaling of SV services and the completion of PEP within violence response programmes. Innovative implementation science approaches may help to identify and address barriers inhibiting effective PEP delivery and uptake within PVC service delivery programmes. Enhancing PEP uptake and completion can support mitigating the bidirectional relationship between violence and HIV acquisition, particularly among vulnerable populations like adolescents and young adults. Low PEP coverage also reflects missed opportunities, particularly among adolescent girls and young women, who experience disproportionate rates of HIV acquisition.

INTRODUCTION: In Eswatini, HIV incidence among adolescent girls and young women (AGYW), aged 15-24 years, is 10 times that of their male peers. Despite the World Health Organization's 2014 recommendation for post-exposure prophylaxis (PEP) to be available for all HIV exposures, it has been underutilized among youth. PEP is an effective prevention method, and a better understanding of the characteristics, risk factors and behaviours that are associated with PEP awareness, as a precursor to effective use, is needed. METHODS: Using data from the 2022 Eswatini Violence Against Children and Youth Survey, we used logistic regression models to explore the relationships between PEP awareness and a set of hypothesized explanatory variables among AGYW aged 13-24 years who had ever had sex (N = 2648). Explanatory variables included socio-demographic characteristics, sexual risk factors and sexual health behaviours. RESULTS: A slight majority (57.3%) of AGYW who had ever had sex were aware of PEP as an HIV prevention method. PEP awareness increased with age (aOR 1.1, 95% CI 1.0, 1.1) and was higher among AGYW who had a sexual partner whose age was 5 or more years older in the past 12 months (aOR 1.4, 95% CI 1.1, 1.9), those who had ever taken part in an HIV prevention programme (aOR 1.6, 95% CI 1.2, 2.3) and those who had ever heard of pre-exposure prophylaxis (aOR 8.1, 95% CI 6.4, 10.2). Participants who were ever married or partnered (aOR 0.7, 95% CI 0.5, 1.0) and those who engaged in inconsistent condom use with non-spouse/main partner or multiple partners in the past 12 months (aOR 0.8, 95% CI 0.6, 1.00) had lower odds of knowing about PEP in the adjusted model. CONCLUSIONS: We identified sub-optimal PEP awareness among Swazi AGYW who had ever had sex. Our findings suggest that engagement in HIV prevention programmes increased PEP awareness and that knowing about pre-exposure prophylaxis (PrEP) was associated with PEP awareness. Future efforts could include tailored PEP awareness activities and campaigns to resonate with AGYW at elevated risk of HIV and integration of PEP education into routine sexual and reproductive service delivery and school-based HIV curriculum.

Background: Rickettsia are neglected, arthropod-borne bacteria causing febrile illness of varying severity. Indonesia is endemic for several Rickettsia species, predominantly from murine and scrub typhus groups. Objective: We described here a potentially novel Rickettsia species in a young adult presenting with acute, undifferentiated, febrile illness at a primary health center in Timika, Papua, Indonesia, in 2021. Methods: Blood tested positive for Rickettsia spp. by a nucleic acid amplification test, 17-kDa and ompB gene fragments were successfully sequenced. Results: The recovered sequences showed the highest similarity to two Rickettsia spp. of mosquito origin, with 90.0% identity for the 17-kDa and 85.6% for the ompB gene. Conclusion: These findings suggest the presence of a divergent Rickettsia lineage in Papua, Indonesia. To our knowledge, this is the first report of Rickettsia DNA sequences obtained from a human case in this region. © 2025

Contact investigation is a fundamental component of tuberculosis (TB) programs that drives prompt diagnosis and treatment of Mycobacterium tuberculosis infection among those exposed. Few studies have examined contact investigation costs for TB. We conducted a systematic review of TB contact investigation costs in the United States by searching English-language articles published during January 1990-August 2024 in electronic databases, including MEDLINE, Embase, CINAHL, and Scopus. We identified 2,920 titles and abstracts; 10 studies met our inclusion criteria. We abstracted costs for labor, diagnostic tests, and chest radiographs. Labor cost per contact was estimated at $175.94 (range $79.97-$293.51); total cost, including diagnostic testing and chest radiography, was $228.93 (range $132.95-$346.49).The overall cost of contact investigation in the United States was $9.94 (range $5.77-$15.04) million in 2022; total cost during 2013-2022 was $137.35 million. Contact investigations are essential to prevent TB and avert TB-related labor and diagnostic costs.

BACKGROUND: Traumatic brain injury is a major cause of death and disability worldwide, with almost half of new cases occurring in children, adolescents, and young adults. However, data on injury characteristics stratified by social determinants of health are scarce. This study explores severity, intent, and mechanism of traumatic brain injury sustained during childhood, adolescence, and young adulthood by social determinants of health. METHODS: This study utilizes a population-based birth cohort of births in publicly funded hospitals in Ontario, Canada, between April 1, 1992 and March 31, 2020 (n = 3,648,760). Individuals experiencing a traumatic brain injury requiring medical attention to the emergency department or acute care between April 1, 2002 and November 20, 2020 (n = 94,514) were identified using International Classification of Diseases Version 10 diagnosis codes. Social determinants of health variables included age, sex, rurality of residence, neighbourhood income quintile, and the following Ontario Marginalization Index variables: households and dwellings, material resources, and racialized and newcomer populations. The primary outcome was percentage of injuries falling under each mechanism, intent, and severity of injury category, stratified by social determinants of health variables. RESULTS: Approximately 50% of injuries were mild and 96.2% of injuries were unintentional. Injury severity and intent of injury significantly varied by social determinants of health; for example, the proportion of traumatic brain injury-related healthcare visits for moderate/severe and intentional injuries was highest in areas with the lowest income quintile (13.3% and 6.1%, respectively), lowest households and dwellings stability (12.2% and 5.7%, respectively), lowest material resources (12.8% and 6.0% respectively), and highest racialized and newcomer populations (13.5% and 4.5% respectively). The percentage of traumatic brain injury-related healthcare visits for a sports-related injury significantly varied by social determinants of health; for example, the proportion of traumatic brain injury-related healthcare visits for sports-related injuries was highest among males (45.5%), those living rural areas (44.0%), and those living in areas with the highest income (47.2%), highest households and dwellings stability (44.0%), highest material resources (45.8%), and lowest racialized and newcomer populations (43.4%). CONCLUSIONS: Characteristics of traumatic brain injury-related healthcare visits vary based on social determinants of health. Targeted prevention of traumatic brain injury beyond the sports settings, including fall prevention among young children, are encouraged, and guidelines to identify and address traumatic brain injury outside of the sports setting must be developed to support early intervention of traumatic brain injury across social determinants of health.

BACKGROUND: Uganda reported a significant reduction in the mortality rate of children under 5 years of age, from 146/1,000 live births in 2000-42/1,000 live births in 2021. With the rollout of Option B+, the vertical transmission rate of HIV decreased from 13.0% (2012) to 6.0% (2019). However, its impact on the mortality rate among children is not well documented. We determined the mortality rate and associated risk factors among infants exposed and not exposed to HIV attending immunization clinics in Uganda. METHODS: We conducted an observational prospective cohort study of mother-infant pairs (MIPs) with infants exposed or unexposed to HIV. We enrolled infants aged 4-12 weeks. The inclusion criteria were biological mothers attending health facilities that provide routine immunization for children and/or postnatal care visits who were able to provide signed written informed consent; mothers or infants who were not severely ill; and those who consented to have their infants tested for HIV antibodies at baseline and follow-up visits every 3 months until the children were aged 18 months. Child-HIV infection and death were censored events. Children lost to follow-up or withdrawn from the study were censored from analyses at the last documented study visit. The outcome of interest was child mortality, and the independent variables were mother's age; infant HIV exposure status; infant sex; family socioeconomic status; marital status; education level; malaria during pregnancy; birth attendee; mother's ART initiation; mode of transport to health facilities; breastfeeding pattern; 4 or more ANC visits; and mother's baseline viral load nonsuppression and place of delivery. We used Kaplan-Meier survival curves to estimate cumulative mortality probability and the Wilcoxon log-rank test to compare differences in cumulative survival functions. We used multivariate Weibull proportional hazards and Weibull accelerated failure time (AFT) regression models with 95% confidence intervals (CIs) to identify factors associated with child death. RESULTS: Among the 16,718 MIPs identified, 11,519 (68.9%) mothers consented to study follow-up. At the 18-month follow-up, 0.7% (79/11,519) of the infants had died, 40.5% (32/79) of whom were exposed to HIV. The overall child mortality rate per 1,000 person-years was 5.0 (95% CI: 4.0--6.2) and was significantly greater among the infants exposed to HIV (14.2; 95% CI: 10.0--20.0) than among the infants not exposed to HIV (3.5; 95% CI: 2.6--4.6). In the adjusted model, the mortality risk factors were HIV exposure status (aHR5.6 95% CI: 3.5--9.4), maternal age < 25 years (aHR1.8; 95% CI: 1.1--2.9), living without a partner (aHR1.8; 95% CI: 1.1--2.9), and delivery at home (aHR2.2; 95% CI: 1.3--4.0). CONCLUSION: Single young mothers living with HIV delivering at home increased the risk of child mortality. Identifying mothers with risk factors early for support could reduce the risk of child mortality.

INTRODUCTION: Since 2016, the US Food and Drug Administration (FDA) has required e-cigarette packaging and advertising to bear the warning: "WARNING: THIS PRODUCT CONTAINS NICOTINE. NICOTINE IS AN ADDICTIVE CHEMICAL." Nicotine has numerous adverse consequences besides addiction, including increased anxiety and depression symptoms that arise from nicotine withdrawal. We tested the effects of exposure to text-only e-cigarette package labels about the psychological consequences of nicotine withdrawal. AIMS AND METHODS: We randomized 1919 US young adults aged 18-24 years to view one of four warning label conditions: a no-message control, the current FDA warning, a message that "nicotine addiction can worsen depression and anxiety symptoms," and a message that "nicotine addiction is a source of stress." We explored associations between condition and intentions to use or quit e-cigarettes and perceived message effectiveness. RESULTS: Label condition was not associated with intentions to use or quit e-cigarettes. Intentions were equivalent among those who viewed the FDA label and those who viewed the no-message control. Compared with the FDA label, the depression/anxiety label and the stress label produced greater agreement among participants that the message "makes me concerned about nicotine addiction" after adjustment for sociodemographic characteristics; those who viewed the depression/anxiety label had greater agreement that the message "discourages me from wanting to use nicotine." CONCLUSIONS: While brief exposure to the warnings tested may not impact young adults' intentions to use or quit vaping, messages about stress, depression, and anxiety arising from nicotine addiction had higher perceived effectiveness among young adults than the FDA's current message about addictiveness. IMPLICATIONS: Findings from this randomized controlled experiment among US young adults suggest that warnings about the mental health consequences of nicotine addiction might be one type of message to consider including in a suite of required e-cigarette warnings and as part of a comprehensive effort to educate the public about the risks of commercial tobacco products.

Our study applied the INSPIRE Framework - the WHO's 2016 technical package of evidence-based interventions for addressing violence against children - to identify accelerators for youth in Namibia. Accelerators are protective factors that contribute toward achieving multiple SDG targets. Using nationally representative data from the 2019 Namibia Violence Against Children & Youth Survey (n = 5167), three hypothesised accelerators (food security, parental support, and gender-equitable attitudes) were investigated for their impact on 12 adolescent outcomes. Associations between the hypothesised accelerators and outcomes were assessed using multivariable logistic regressions, and adjusted probabilities, differences, and ratios. Among girls, food security, gender-equitable attitudes, and parental support were accelerators, being associated with lower odds for 8, 6, and 2 outcomes, respectively. When all three were present, the combination was significantly associated with 10 out of 12 outcomes, including >75% lower prevalences of child marriage; > 50% lower prevalences of child abuse, sexual violence victimisation, early sexual debut/early pregnancy, and peer violence victimisation; and >25% lower prevalences of intimate partner violence (IPV) victimisation, not being in school or paid work, mental health distress, inconsistent condom use, and age-disparate or transactional sex. Among boys, gender-equitable attitudes was an accelerator and was significantly associated with 7 out of 10 outcomes, including approximately 50% lower prevalences of sexual violence victimisation, child abuse, age-disparate or transactional sex, IPV victimisation, multiple sexual partners, peer violence victimisation, and inconsistent condom use. Adolescents (especially girls) with access to INSPIRE provisions experience lower rates of violence and HIV-related risks. Implementing interventions on these priority protective factors could accelerate progress in achieving the SDGs for adolescents and young people in Namibia.

BACKGROUND: Risk factors for severe respiratory syncytial virus (RSV) illness include early infancy, premature birth, and underlying medical conditions. However, the clinical significance of respiratory viral co-detection is unclear. We compared the clinical outcomes of young children with RSV-only detection and those with RSV viral co-detection. METHODS: We conducted active, population-based surveillance of children with medically attended fever or respiratory symptoms at 7 US medical centers (1 December 2016-31 March 2020). Demographic and clinical data were collected through parental interviews and chart abstractions. Nasal swabs, with or without throat swabs, were systematically tested for RSV and 6 other common respiratory virus groups. We compared clinical outcomes, including hospitalization, and among those hospitalized, length of stay, intensive care unit admission, supplemental oxygen use, and intubation, between children aged <2 years with RSV-only detection and those with RSV co-detection. RESULTS: We enrolled 18 008 children aged <2 years. Of 17 841 (99.1%) tested for RSV, 5099 (28.6%) were positive. RSV was singly detected in 3927 children (77.0%) and co-detected in 1172 (23.0%). RSV co-detection with parainfluenza virus or adenovirus was associated with significantly lower odds of hospitalization (adjusted odds ratio, 0.56; 95% confidence interval [CI]: .33-.95; P = .031) and supplemental oxygen use (adjusted odds ratio, 0.66; 95% CI: .46-.95; P = .026), respectively, than RSV-only detection. For all other comparisons, we did not identify a significant association between RSV co-detection and worse clinical outcomes. CONCLUSIONS: Co-detection of RSV with another respiratory virus was not significantly associated with worse clinical outcomes compared with RSV-only detection.

Maternal respiratory syncytial virus (RSV) vaccine and nirsevimab, a long-acting monoclonal antibody for infants aged 0-7 months and children aged 8-19 months who are at increased risk for severe RSV disease, became widely available for prevention of severe RSV disease among infants and young children during the 2024-25 RSV season. To evaluate the association between availability of these products and infant and child RSV-associated hospitalization rates, the rates among children aged <5 years were compared for the 2024-25 and 2018-20 RSV seasons using data from the RSV-Associated Hospitalization Surveillance Network (RSV-NET) and New Vaccine Surveillance Network (NVSN). Among infants aged 0-7 months (eligible for protection with maternal vaccination or nirsevimab), 2024-25 RSV-associated hospitalization rates were lower compared with 2018-20 pooled rates (estimated relative rate reductions of 43% [RSV-NET: 95% CI = 40%-46%] and 28% [NVSN: 95% CI = 18%-36%]). The largest estimated rate reduction was observed among infants aged 0-2 months (RSV-NET: 52%, 95% CI = 49%-56%; NVSN: 45%, 95% CI = 32%-57%) and during peak hospitalization periods (December-February). These findings support Advisory Committee on Immunization Practices' recommendations for maternal vaccination or nirsevimab to protect against severe RSV disease in infants and highlight the importance of implementing the recommendations to protect infants as early in the RSV season as possible, before peak transmission, and for infants born during the RSV season, within the first week of life, ideally during the birth hospitalization.

BACKGROUND AND AIMS: In clinical populations, vitamin B(12) deficiency has been associated with adverse metabolic health (e.g., gestational diabetes). Population-level data among women of reproductive age could inform screening and interventions. The objective of this analysis was to examine the prevalence of adverse metabolic characteristics (elevated adiposity and central adiposity, hypertension, elevated glycated hemoglobin [HbA1c]) and associations of vitamin B(12) status with metabolic characteristics in women as part of a population-based biomarker survey in Southern India. METHODS: Participants (n=980 women 15-40y; not pregnant or lactating) were assessed for total vitamin B(12), holotranscobalamin, methylmalonic acid, homocysteine, and HbA1c. Categorical anthropometry assessments and bioelectrical impedance analysis (e.g., whole body (WF%) and trunk (TF%) fat) were assessed among adults (≥18y). Linear and binomial regressions were used to examine associations of vitamin B(12) status with metabolic characteristics. RESULTS: Overall, 25% of participants had HbA1c ≥5.7% (HbA1c≥5.7-<6.5%: 20.0%; ≥6.5%: 5.0%), and 18.6% had hypertension (Stage 1: 16.4%; Stage 2: 2.2%). Among adults, 23.4% had body mass index of (BMI) 25.0-<30.0 kg/m(2), 9.6% had BMI ≥30.0 kg/m(2), 13.4% had elevated waist circumference (WC; >88.9cm), and 20.8% had elevated waist-hip ratio (WHR; ≥0.85cm). Overall, higher vitamin B(12) concentrations were associated with lower BMI and WC. Among adults, higher vitamin B(12) concentrations were associated with lower WF% and TF%; and lower prevalence of overweight (BMI≥25.0 kg/m(2)) and elevated WC, WHR, and WF%. Similarly, vitamin B(12) <148 pmol/L was associated with higher BMI and WC overall and, among adults, higher WF% and TF%, and increased overweight (BMI≥25.0 kg/m(2); prevalence ratio: 1.31; 95% confidence interval: 1.09-1.58), and elevated WC (>88.9 cm; 1.85[1.32-2.60]), WHR (≥85.0; 1.38[1.07-1.78]), WF% (>35%; 1.29[1.10-1.51]), and TF% (>35%; 1.25[1.06-1.49]). CONCLUSIONS: The burden of adverse metabolic characteristics was substantial in this population of young, apparently healthy women. Among those with vitamin B(12) <148 pmol/L there was increased central adiposity and overweight status. Evaluating vitamin B(12) and metabolic outcomes prospectively could inform screening and interventions to improve women's health. REGISTRATION NUMBER: NCT04048330.

Trichomonas vaginalis (TV) and bacterial vaginosis (BV) are highly prevalent vaginal infections. Both are associated with pelvic inflammatory disease and HIV acquisition and transmission, though the underlying mechanisms are incompletely understood. We characterized the effect of TV and BV infection on inflammatory markers in the vagina among reproductive-aged women in Atlanta, Georgia. Cervicovaginal lavage specimens were collected from HIV seronegative women at a baseline visit and again three months later. Eighteen individual cytokines, 17 T cell subsets, BV, and TV were measured at both timepoints. After natural log transformation, the median cytokine concentration and number of T cells were compared by infection status statistically using the Kruskal-Wallis test. A cytokine inflammation score and a T cell score were created using principal components analysis. The scores were then used as outcomes in separate linear mixed regression models with a random intercept. Sixty women had baseline data and 43 were seen for follow-up. The median age was 30 years, 78% self-reported Black race. TV and BV prevalence at the baseline visit was 15% and 37%, respectively. The concentration of 16 out of 18 cytokines differed by infection status. In multivariable modeling, neither TV nor BV were associated with cytokine score. Most CD4+ T cell subsets (7 out of 9) differed by infection status. In a multivariable model, TV infection was associated with a higher T cell score (1.54; 95%CI 0.00, 3.08). BV was not associated with a higher T cell score. Increased concentration of vaginal mucosal T cells may explain the observed association between TV infection and HIV risk.

Young Black and Latino men who have sex with men are disproportionately affected by the U.S. HIV Epidemic, yet pre-exposure prophylaxis (PrEP) uptake remains low. To understand barriers and facilitators to PrEP uptake and persistence, we used a concurrent mixed methods design (quantitative: online surveys, n = 19; qualitative: individual interviews, n = 15) from providers (e.g., nurse practitioners, clinicians, and social workers) at 4 clinics providing PrEP services in Birmingham, Alabama and New York City. Although all providers were comfortable prescribing daily oral PrEP, they had concerns about on-demand PrEP (e.g., complex dosing schedule) and injectable PrEP (e.g., insurance barriers). Provider training is needed to address barriers to providing PrEP modalities beyond daily oral PrEP and increase uptake among young Black and Latino men who have sex with men. Additionally, in order to increase uptake of injectable PrEP, rising PrEP costs due to changes in the 340B Drug Pricing Program will need to be addressed.

BACKGROUND: Diagnosis of iron deficiency commonly relies on measurement of serum ferritin concentrations. WHO guidelines identify serum ferritin thresholds for iron deficiency among healthy individuals of less than 15 μg/L for women and less than 12 μg/L for children under 5 years, based on expert opinion. We report thresholds for iron deficiency for apparently healthy non-pregnant women and young children based on physiological indicators. METHODS: We performed secondary analyses of cross-sectional data from women (aged 15-49 years) and children (aged 6-59 months) from 12 countries in Africa, Asia, Europe, and central America from available surveys (2007-19). Using haemoglobin and soluble transferrin receptor concentrations as individual-level indicators of iron deficiency, we identified country-specific serum ferritin thresholds. We conducted multivariate meta-analysis using individual participant data to assess multinational heterogeneity and intercountry consistency. FINDINGS: Data were collected from July, 2007 to March, 2019. 18 251 individuals (13 864 women and 4387 children) were included in the final analysis. The thresholds of pooled serum ferritin levels corresponding to the starting point of decline in circulating haemoglobin concentrations were 24·8 μg/L (95% CI 24·4-25·2) for women and 22·1 μg/L (20·8-23·4) for children based on the national survey data from 12 countries. The thresholds were consistent among countries (p(heterogeneity): women=0·73, children=0·43) but median serum ferritin concentrations and lower 5% reference ranges differed. In all countries, the prevalence of iron deficiency was higher using physiologically based thresholds than that using WHO current guidelines for women (36·0% [95% CI 25·3-46·8] vs 20·1% [11·5-28·7], p<0·0001) and for children (34·2% [24·3-44·1] vs 16·6% [11·2-22·0], p<0·0001). INTERPRETATION: These results provide evidence that the prevalence of iron deficiency as indicated by physiological measures is substantially higher than those based on current WHO guidelines. The consistency of physiologically based serum ferritin thresholds in apparently healthy women and young children offers a potential means to achieve evidence-informed coordination in thresholds for iron deficiency across populations. The use of physiologically based serum ferritin thresholds could help in detecting the clinical and functional outcomes of iron deficiency. FUNDING: None.

INTRODUCTION: Chronic conditions are costly and major causes of death and disability. Addressing conditions earlier in adulthood can slow disease progression and improve well-being across the lifespan. We estimated, by life stage, 10-year trends among US adults in the prevalence of 1 or more chronic conditions, multiple chronic conditions (MCC; ≥2 conditions), and 12 selected chronic conditions. METHODS: We analyzed data from the 2013-2023 (odd years) Behavioral Risk Factor Surveillance System (N = 2,673,529). We estimated the prevalence of 1 or more conditions, MCC, and each of 12 conditions, by life stage: young (18-34 y), midlife (35-64 y), and older (≥65 y) adults. We used polynomial contrasts to analyze 10-year trends. RESULTS: In 2023, 76.4% (representing 194 million) of US adults reported 1 or more chronic conditions, including 59.5%, 78.4%, and 93.0% of young, midlife, and older adults, respectively. Moreover, 51.4% (representing 130 million) of US adults reported MCC, including 27.1%, 52.7%, and 78.8% of young, midlife, and older adults, respectively. Among young adults, from 2013 to 2023, prevalence increased significantly from 52.5% to 59.5% for 1 or more conditions and from 21.8% to 27.1% for MCC. CONCLUSION: Approximately 6 in 10 young, 8 in 10 midlife, and 9 in 10 older US adults report 1 or more chronic conditions. Trends in conditions worsened among young adults during 2013-2023. Recognizing the burden of chronic disease throughout life stages, especially earlier in life, practitioners and partners may consider prevention and management approaches critical for addressing costs, care, and health outcomes. Practitioners may also consider tailoring these approaches to unique roles, transitions, and challenges in different life stages.

BACKGROUND: In sub-Saharan Africa, mHealth interventions and phone-based data collection are increasingly popular but little is known about who can be reached by these programmes. We used national probability surveys to examine characteristics of youth (15-24 years) mobile phone owners in seven Southern African countries: Botswana, Eswatini, Lesotho, Malawi, Mozambique, Zambia, and Zimbabwe. METHODS: Population-based HIV Impact Assessment surveys are cross-sectional, nationally representative household-based surveys conducted between November 2019 and February 2022. Data were analysed using multivariable logistic regression. RESULTS: Eighty-four percent of youth in Eswatini, 83% in Botswana, 76% in Lesotho, 61% in Zimbabwe, 47% in Mozambique, 46% in Zambia and 32% in Malawi were mobile phone owners. In all countries, odds of phone ownership were higher amongst persons ages 20-24 (compared to 15-19) and those with secondary education or higher. In the three countries with ownership less than 50%, women had lower odds of owning a phone than men, and all wealth quintiles had higher odds of ownership than the lowest wealth quintile. CONCLUSIONS: Mobile phone ownership was consistently higher among certain demographic groups. Public health practitioners employing mobile phones for youth health programmes in Sub-Saharan Africa may not reach the general youth population.

PROBLEM/CONDITION: Autism spectrum disorder (ASD). PERIOD COVERED: 2022. DESCRIPTION OF SYSTEM: The Autism and Developmental Disabilities Monitoring Network is an active surveillance program that estimates prevalence and characteristics of ASD and monitors timing of ASD identification among children aged 4 and 8 years. In 2022, a total of 16 sites (located in Arizona, Arkansas, California, Georgia, Indiana, Maryland, Minnesota, Missouri, New Jersey, Pennsylvania, Puerto Rico, Tennessee, Texas [two sites: Austin and Laredo], Utah, and Wisconsin) conducted surveillance for ASD among children aged 4 and 8 years and suspected ASD among children aged 4 years. Surveillance included children who lived in the surveillance area at any time during 2022. Children were classified as having ASD if they ever received 1) an ASD diagnostic statement in a comprehensive developmental evaluation, 2) autism special education eligibility, or 3) an ASD International Classification of Diseases, Ninth Revision (ICD-9) code in the 299 range or International Classification of Diseases, Tenth Revision (ICD-10) code of F84.0, F84.3, F84.5, F84.8, or F84.9. Children aged 4 years were classified as having suspected ASD if they did not meet the case definition for ASD but had an evaluator's suspicion of ASD documented in a comprehensive developmental evaluation. RESULTS: Among children aged 8 years in 2022, ASD prevalence was 32.2 per 1,000 children (one in 31) across the 16 sites, ranging from 9.7 in Texas (Laredo) to 53.1 in California. The overall observed prevalence estimate was similar to estimates calculated using Bayesian hierarchical and random effects models. ASD was 3.4 times as prevalent among boys (49.2) than girls (14.3). Overall, ASD prevalence was lower among non-Hispanic White (White) children (27.7) than among Asian or Pacific Islander (A/PI) (38.2), American Indian or Alaska Native (AI/AN) (37.5), non-Hispanic Black or African American (Black) (36.6), Hispanic or Latino (Hispanic) (33.0), and multiracial children (31.9). No association was observed between ASD prevalence and neighborhood median household income (MHI) at 11 sites; higher ASD prevalence was associated with lower neighborhood MHI at five sites.Record abstraction was completed for 15 of the 16 sites for 8,613 children aged 8 years who met the ASD case definition. Of these 8,613 children, 68.4% had a documented diagnostic statement of ASD, 67.3% had a documented autism special education eligibility, and 68.9% had a documented ASD ICD-9 or ICD-10 code. All three elements of the ASD case definition were present for 34.6% of children aged 8 years with ASD.Among 5,292 (61.4% of 8,613) children aged 8 years with ASD with information on cognitive ability, 39.6% were classified as having an intellectual disability. Intellectual disability was present among 52.8% of Black, 50.0% of AI/AN, 43.9% of A/PI, 38.8% of Hispanic, 32.7% of White, and 31.2% of multiracial children with ASD. The median age of earliest known ASD diagnosis was 47 months and ranged from 36 months in California to 69.5 months in Texas (Laredo).Cumulative incidence of ASD diagnosis or eligibility by age 48 months was higher among children born in 2018 (aged 4 years in 2022) than children born in 2014 (aged 8 years in 2022) at 13 of the 15 sites that were able to abstract records. Overall cumulative incidence of ASD diagnosis or eligibility by age 48 months was 1.7 times as high among those born in 2018 compared with those born in 2014 and ranged from 1.4 times as high in Arizona and Georgia to 3.1 times as high in Puerto Rico. Among children aged 4 years, for every 10 children meeting the case definition of ASD, one child met the definition of suspected ASD.Children with ASD who were born in 2018 had more evaluations and identification during ages 0-4 years than children with ASD who were born in 2014 during the 0-4 years age window, with an interruption in the pattern in early 2020 coinciding with onset of the COVID-19 pandemic.Overall, 66.5% of children aged 8 years with ASD had a documented autism test. Use of autism tests varied widely across sites: 24.7% (New Jersey) to 93.5% (Puerto Rico) of children aged 8 years with ASD had a documented autism test in their records. The most common tests documented for children aged 8 years were the Autism Diagnostic Observation Schedule, Autism Spectrum Rating Scales, Childhood Autism Rating Scale, Gilliam Autism Rating Scale, and Social Responsiveness Scale. INTERPRETATION: Prevalence of ASD among children aged 8 years was higher in 2022 than previous years. ASD prevalence was higher among A/PI, Black, and Hispanic children aged 8 years than White children aged 8 years, continuing a pattern first observed in 2020. A/PI, Black, and Hispanic children aged 8 years with ASD were also more likely than White or multiracial children with ASD to have a co-occurring intellectual disability. Identification by age 48 months was higher among children born in 2018 compared with children born in 2014, suggesting increased early identification consistent with historical patterns. PUBLIC HEALTH ACTION: Increased identification of autism, particularly among very young children and previously underidentified groups, underscores the increased demand and ongoing need for enhanced planning to provide equitable diagnostic, treatment, and support services for all children with ASD. The substantial variability in ASD identification across sites suggests opportunities to identify and implement successful strategies and practices in communities to ensure all children with ASD reach their potential.

BACKGROUND: Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infection in children less than 5 years of age worldwide. In the United States, RSV commonly causes hospitalization in young children and is the leading cause of hospitalizations in infants. As new RSV immunizations become available, burden estimates are critical to guide the implementation of recommendations and quantify impact. METHODS: We estimated RSV-associated hospitalization rates at a large US pediatric medical center during an 8-year period using five approaches, namely, estimation directly from active and passive surveillance systems, both a crude and stratified capture-recapture analysis of data from both systems, and estimation based on discharge diagnosis codes. The stratified analysis was performed to ensure adherence with the capture-recapture methodology assumption that samples are independent and participants have an equal probability of being observed within each system. RESULTS: Overall, estimated RSV-associated hospitalization rates per 1000 children were 4.0 (2.5, 6.1) based on adjusted estimates from active surveillance, 1.7 (2.1, 4.4) from passive surveillance, 7.9 (5.7, 13.0) from crude capture-recapture analysis, 5.0 (3.8, 7.2) from the stratified capture-recapture, and 4.4 (4.0, 4.9) from discharge diagnosis codes. CONCLUSIONS: Each method has limitations and inherent biases that may impact the estimation of the burden of RSV. Capture-recapture analysis may be a useful tool to estimate the burden of RSV, but needs to be adjusted to account for possible violation of the assumptions of independence and equal probability of capture to ensure accurate approximation of disease burden and avoid over estimation.

We conducted formative interviews and design workshops to tailor evidence-based tools addressing informational needs around pre-exposure prophylaxis (PrEP) use among men who have sex with men (MSM) of color. Clients (n = 18) and providers (n = 19) were interviewed to explore needs and preferences for PrEP-related decision-making tools. Next, we developed an analysis matrix to design personas to tailor materials to real-world contexts. Existing PrEP educational materials were then revised using participant feedback elicited through the personas. We presented personas, findings, and revised materials to clients (n = 9) and providers (n = 9) in iterative design workshops and solicited further feedback. Revisions to materials for providers included tips for destigmatizing PrEP counseling and routine care, sexual practices, and structural barriers that YMSM of color often navigate. Our evidence-based approach has the potential to enhance shared decision-making and destigmatize HIV prevention counseling in our larger trial, thus promoting both PrEP uptake and persistence among YMSM of color. © 2025 National Communication Association.

Nirsevimab is a long-acting monoclonal antibody that protects infants and young children against severe respiratory syncytial virus (RSV) disease. Children are eligible for one 50 mg dose, one 100 mg dose, or two 100 mg doses of nirsevimab based on age, weight, time of year, maternal vaccination, and risk of severe disease. In winter 2023/2024, we developed a model to project the number of nirsevimab doses needed to immunize all eligible U.S. children during the 2024/2025 season. We grouped all births from March 2023 through March 2025 into weekly cohorts, partitioned those cohorts based on eligibility criteria, and computed eligibility for each partition. In the absence of maternal RSV vaccination, we estimated U.S. children would be eligible to receive 4.3 million nirsevimab doses in 2024/2025, of which 48% would be 100 mg doses. Projections of total eligibility can be used to inform production goals and avoid shortages of nirsevimab.

Inflammation and infections such as malaria affect concentrations of many micronutrient biomarkers, and hence estimates of nutritional status. We aimed to assess the relationship between malaria infection and micronutrient biomarker concentrations in pre-school children (PSC), school-age children (SAC) and women of reproductive age (WRA) in Malawi, and to examine the potential role of malaria immunity on the relationship between malaria and micronutrient biomarkers. Data from the 2015/2016 Malawi micronutrient survey were used. The associations between current or recent malaria infection, detected by rapid diagnostic test, and concentration of serum ferritin, soluble transferrin receptor (sTfR), zinc, serum folate, red blood cell (RBC) folate and vitamin B12, were estimated using multivariable linear regression. Factors related to malaria immunity including age, altitude and presence of hemoglobinopathies were examined as effect modifiers. Serum ferritin, sTfR and zinc were adjusted for inflammation using the BRINDA method. Malaria infection was associated with 68% (95% CI 51, 86), 28% (18,40) and 34% (13,45) greater inflammation-adjusted ferritin in PSC, SAC and WRA respectively (p<0.001 for each). In PSC, the positive association was stronger in younger children, in high altitude, and in children who were not carriers of the sickle cell trait. In PSC and SAC, sTfR was elevated (+ 25% (16, 29) and + 15% (9,22) respectively, p<0.001). Serum folate and RBC folate were elevated in WRA with malaria (+ 18% (3,35) and + 11% (1,23), p=0.01 and p=0.003 respectively). Malaria affects the interpretation of micronutrient biomarker concentrations and examining factors related to malaria immunity may be informative.

BACKGROUND: Since 2013, national trends in behavioral factors that increase STI risk among adolescent and young adult (A/YA) females have been mixed (e.g., fewer sex partners, lower condom use). We used data from a national sample of A/YA females to examine racial disparities in CT prevalence considering these trends. METHODS: Using 2011-March 2020 National Health and Nutrition Examination Survey data, we estimated the prevalence, unadjusted and adjusted prevalence ratios (APRs) of a positive CT urine test among sexually experienced non-Hispanic Black (Black), Hispanic, non-Hispanic Other race (NHO), and non-Hispanic White (White) A/YA females. Percentages were categorized by race/ethnicity, and each compared to the average of the other race/ethnic groups (e.g., Black vs. Hispanic, NHO and White). Covariates included age group, health insurance coverage, number of sex partners and condom use (both past year). RESULTS: Overall, the prevalence of CT infection among A/YA females was 5.8% (95% CI: 4.5%-7.3%). CT prevalence was higher among Black females (vs. Hispanic, NHO, and White) (11.7%; 95%CI: 8.7%-15.2%) and lower among White females (vs. Black, Hispanic, and NHO) (3.2%; 95%CI: 1.7%-5.5%). Compared with the average CT prevalence for Hispanic, NHO, and White females, Black females had a higher adjusted CT prevalence (APR: 2.48, 95%CI: 1.63-3.75). CONCLUSIONS: Nationally, CT prevalence was 2.5 times as high among Black A/YA females than the average prevalence for Hispanic, NHO, and White females. Inclusion of behavioral STI risk factors did not attenuate this association. Research incorporating sexual network-level factors associated with CT transmission may provide additional insights.

BACKGROUND: Child survival rates have improved globally, but neonatal mortality due to infections, such as group B Streptococcus (GBS), remains a significant concern. The global burden of GBS-related morbidity and mortality is substantial. However, data from low and middle-income countries are lacking. Vaccination during pregnancy could be a feasible strategy to address GBS-related disease burden. METHODS: We assessed maternal rectovaginal GBS colonization and neonatal disease rates in a prospective cohort of 6062 women-infant pairs. Surveillance for invasive infant disease occurred in parallel at 2 Kampala hospital sites. In a nested case-control study, we identified infants <90 days of age with invasive GBS disease (iGBS) (n = 24) and healthy infants born to mothers colonized with GBS (n = 72). We measured serotype-specific anticapsular immunoglobulin G (IgG) in cord blood/infant sera using a validated multiplex Luminex assay. RESULTS: We found a high incidence of iGBS (1.0 per 1000 live births) within the first 90 days of life across the surveillance sites, associated with a high case fatality rate (18.2%). Maternal GBS colonization prevalence was consistent with other studies in the region (14.7% [95% confidence interval, 13.7%-15.6%]). IgG geometric mean concentrations were lower in cases than controls for serotypes Ia (0.005 vs 0.12 µg/mL; P = .05) and III (0.011 vs 0.036 µg/mL; P = .07) and in an aggregate analysis of all serotypes (0.014 vs 0.05 µg/mL; P = .02). CONCLUSIONS: We found that GBS is an important cause of neonatal and young infant disease in Uganda and confirmed that maternally derived antibodies were lower in early-onset GBS cases than in healthy exposed controls.

Non-disclosure of known HIV-positive status is a barrier to ending HIV as a global health threat as it leads to biased measurements of HIV-treatment coverage indicators and inaccurate estimates of epidemic progress, resulting in wasted resources. Identifying and understanding factors driving non-disclosure among people living with HIV is necessary for encouraging engagement with HIV services and improving treatment coverage, resource allocation, and monitoring of HIV programs in high HIV-burden areas. This analysis assessed factors associated with non-disclosure among survey respondents who had antiretrovirals (ARVs) detected in blood specimens. HIV-positive blood specimens (n = 2,038) from the 2021 Mozambique Population-based HIV Impact Assessment were tested for the presence of ARVs. Weighted prevalence estimates of non-disclosure and select covariates are reported and factors associated with non-disclosure modeled via multivariate logistic regression. Among 1,358 respondents with ARVs detected, 14.1% did not self-report their HIV-positive status during the interview. Adjusting for socio-demographic and clinical factors, non-disclosure was more likely among younger participants aged 15-24 years (adjusted odds ratio [aOR]: 2.15, 95% Confidence Interval [CI] 1.16-4.01) and among those without knowledge of their recent sexual partner's HIV-status (aOR: 2.67, 95%CI: 1.38-5.15). Participants with an unsuppressed viral load were over six times (aOR: 6.27, 95%CI: 2.76-14.23) more likely to not disclose. Improving disclosure rates is vital to obtaining accurate HIV-treatment estimates and assessing epidemic progress. Initiatives prioritizing pre- and post-test counseling, stressing treatment literacy, emphasizing undetectable = untransmittable (U = U) campaigns, and encouraging programs that promote social support may encourage disclosure among individuals living with HIV.

Human metapneumovirus (hMPV) is an important cause of respiratory illness. However, information about hMPV incidence, patient characteristics, and symptoms outside hospital settings is limited. During June 2022-March 2024, participants aged 6 months-49 years who were enrolled in the CASCADIA community-based cohort study submitted weekly illness surveys and nasal swabs, and completed follow-up illness surveys. Swabs collected 0-3 days before reporting new or worsening symptoms were tested for hMPV and other respiratory viruses by multiplex polymerase chain reaction. Incidence was analyzed using an exponential survival model. Among 3,549 participants, 306 had symptomatic hMPV infection, representing an average of 7.5 cases per 100 persons per year (95% CI = 6.7-8.4). Incidence was highest during January-March (adjusted hazard ratio [aHR] = 4.3; 95% CI = 3.0-6.0) compared with October-December, and among those aged 2-4 years (aHR = 5.8; 95% CI = 3.8-9.0) compared with those aged ≥40 years. The most frequently reported symptoms were cough (80.4%) and nasal congestion (71.9%). Among 252 (82.4%) participants who completed a post-illness follow-up survey, 68 (27.0%) missed work, school, or child care facility attendance. Together, these findings indicate that hMPV is a common cause of respiratory illness during late winter to spring, particularly among young children, and frequently disrupts daily activities. Understanding hMPV epidemiology can guide surveillance definitions, clinical testing, and prioritization of prevention strategies.

BACKGROUND: Chlamydia and gonorrhea are among the most commonly reported sexually transmitted infections (STIs) in the U.S. Testing for chlamydia and gonorrhea infection can be conducted by anatomic site (site-specific). Monitoring testing volume and positivity by anatomic site is important. METHODS: Using a large national laboratory dataset, we assessed chlamydia and gonorrhea test volume and positivity by anatomical site in patients aged 15-60 years. RESULTS: The data contained 45 million tests each for chlamydia and gonorrhea for 2019-2023. Of chlamydia tests, 71.6% were for women. Among women, 0.4%, 1.5%, and 98.1% were performed on rectal, pharyngeal, and urogenital specimens; chlamydia positivity was 7.3%, 2.0%, and 4.3%, respectively. Among men, 10.5%, 13.7%, and 75.8% were performed on rectal, pharyngeal, and urogenital specimens; chlamydia positivity was 8.0%, 1.4%, and 6.3%, respectively. Among people aged 15-24 years, chlamydia positivity was 12.8% for rectal, 3.4% for pharyngeal, and 8.7% for urogenital among women, and 11.6%, 2.4%, and 12.2% among men, respectively. Gonorrhea testing volume overall and by age and sex was similar to that of chlamydia. Gonorrhea rectal, pharyngeal, and urogenital positivity was 3.2%, 2.4%, and 1.0% among women; 6.8%, 5.2%, and 3.3% among men; and 4.3%, 3.0%, and 1.6% among women aged 15-24 years, and 10.5%, 7.2%, and 4.6% among men aged 15-24 years, respectively. CONCLUSION: Although men accounted for <30% of overall chlamydia and gonorrhea testing, they accounted for a majority of extragenital testing. High rates of chlamydia and gonorrhea positivity by specimen type among many demographic groups, especially for extragenital specimens from men and young people, highlight the importance of STI prevention in the U.S.

BACKGROUND: The first dose of measles-rubella (MR) vaccine is routinely administered to infants aged 9 months as part of a standard two-dose schedule. However, during large measles outbreaks and in other settings of increased circulation or increased risk, WHO recommends administering a supplementary dose at age 6 months to protect young infants. We aimed to assess the immunogenicity and safety of a first dose of MR vaccine administered to infants aged 6 months and its effect on the immune response to the routine MR vaccine at age 9 months. METHODS: This open-label, randomised trial enrolled healthy infants aged 6 months in Matlab, Bangladesh, who had never received an MR vaccine dose and had no history of measles or rubella. Using a computer-generated block randomisation scheme, infants were randomly assigned (1:1) to receive either two doses of the MR vaccine, one at age 6 months and the second at age 9 months (two-dose group), or one dose at age 9 months (one-dose group). Baseline characteristics were recorded for all enrolled participants at age 6 months. Blood samples were drawn for antibody assays before each vaccination and at final follow up when infants were aged 11 months. The primary outcome was immunogenicity of a first MR vaccine in infants aged 6 months or 9 months and the immunogenicity of a second MR vaccine in infants aged 9 months who received their first MR vaccine at 6 months. Immunogenicity was measured as the proportion of infants who seroconverted in the 12 weeks after vaccination at age 6 months or the 8 weeks after vaccination at age 9 months. Seroconversion was defined as a 4-times increase in IgG concentrations relative to the pre-vaccination concentrations or achieving seroprotective antibody concentrations between study timepoints. The modified intention-to-treat analysis included all infants who received MR vaccines per group assignment and had antibody results at baseline, 9 months, and 11 months. All enrolled infants were included in the safety analysis of the immediate reactions (observed by study staff at the fixed-site clinic in the first 30 min after vaccination), adverse events within 48 h of vaccination among infants in the two-dose group receiving their first MR vaccine at age 6 months, and adverse events observed by study staff or parents at any time during the study. The trial is registered on ClinicalTrials.gov, NCT03071575, and is closed to enrolment. FINDINGS: Between March 9, 2017, and March 18, 2018, 620 infants were enrolled and randomly assigned to the two study groups (312 in the two-dose group and 308 in the one-dose group). Of the 301 infants vaccinated at 6 months, 282 seroconverted for measles (94%, 95% CI 90-96), and 283 seroconverted for rubella (94%, 91-96). By 11 months, after receiving a second dose at age 9 months, 297 (cumulative 99%, 95% CI 97-100) infants seroconverted for measles and 297 infants seroconverted for rubella (cumulative 99%, 96-100). Of the 292 infants vaccinated at 9 months only, 291 seroconverted for both antigens by age 11 months (100%, 95% CI 98-100). 123 adverse events were observed; 72 in the two-dose group and 51 in the one-dose group, with no differences in severity (p=0·78) or outcomes (p=0·71) by study group. 12 (17%) events in the two-dose group and seven (14%) in the one-dose group were severe; most events were mild, resolved without sequelae, and were unrelated to the MR vaccine. One death occurred in the one-dose group before the infant received the 9-month dose of the vaccine, and therefore was deemed to be unrelated to the MR vaccine. INTERPRETATION: The data presented support use of MR vaccine at 6 months to protect young infants during measles outbreaks and in settings with increased risk or high transmission. We recommend additional studies to evaluate longer-term immunity based on age at vaccination. FUNDING: US Centers for Disease Control and Prevention. TRANSLATIONS: For the French and Spanish translations of the abstract see Supplementary Materials section.

BACKGROUND: Adverse birth outcomes (ABOs) cause significant infant morbidity and mortality in resource-limited settings. Many of the maternal risk factors associated with ABOs can be prevented. We present the prevalence, trends, and risk factors of selected ABOs from a hospital-based birth defects surveillance program in Kampala, Uganda. METHODS: We analyzed data for all mothers with singleton deliveries collected from four urban hospitals between 2015 and 2022. Prevalence of preterm birth [PTB], low birth weight [LBW], small for gestational age [SGA], and stillbirth [SB] and maternal HIV seroprevalence were calculated among 222,427 births. SB was defined as infant born without life ≥ 28 weeks of gestation, LBW as term live birth weighing < 2500 g and PTB as live birth born < 37 weeks of gestation. Time trends of ABOs by maternal HIV status and age were computed using quasi-Poisson regression model and presented graphically. Risk factor associations were estimated using robust Poisson models adjusting for infant sex, hospital of delivery, and birth year. RESULTS: Prevalence of PTB, LBW, SGA, and SB were 14.8%, 4.3%, 17.8%, and 3.1%, respectively. Maternal HIV seroprevalence was 7.7%. Compared to mothers aged 25-34 years, young adolescents 10-18 years was associated with PTB (adjusted risk ratio [aRR]: 1.44, 95% confidence interval (CI): 1.38-1.50); LBW (1.65,1.51-1.81); and SGA (1.18; 1.12-1.24). HIV seropositivity was associated with PTB (1.18; 1.14-1.22), LBW (1.54; 1.43-1.65), and SGA (1.28; 1.23-1.33). Compared to starting ANC in the first trimester, no antenatal care (ANC) was associated with PTB (2.44; 2.33-2.56), LBW (1.80; 1.55-2.09), SGA (1.37; 1.27-1.49), and SB (3.73; 3.32-4.15) and late attendance with LBW (1.09; 1.02-1.16), SGA (1.26; 1.22-1.30), and SB (1.09; 1.02-1.17). Our findings also indicate a rising trend in PTB among adolescent and young women aged 10-24 years, and a declining trend in LBW and SGA over time (ptrend < 0.05 for all). CONCLUSIONS: Young maternal age, maternal HIV, and late or no ANC attendance were associated with ABO. Childbearing in the ages 25-34, preventing HIV in women, and supporting early and frequent ANC attendance are important in improving birth outcomes.