Clinical Infectious Diseases

Background: The U.S. 2024-2025 influenza season was characterized by sustained elevated activity from November 2024 to April 2025, with circulation of both influenza A(H1N1)pdm09 and A(H3N2), the latter of which included some antigenically drifted viruses. Methods: From October 1, 2024, to April 30, 2025, a multistate respiratory virus surveillance network enrolled adults hospitalized with acute respiratory illness in 26 U.S. medical centers. Influenza vaccine effectiveness (VE) against influenza-associated hospitalization and severe in-hospital outcomes was estimated using a test-negative study. The odds of influenza vaccination among influenza-positive case patients and influenza-negative control patients were compared using multivariable logistic regression; VE was calculated as (1-adjusted odds ratio for vaccination) x 100, expressed as a percent. Results: The 2024-2025 seasonal influenza vaccine was effective against influenza-associated hospitalization (VE: 40% [95% confidence interval (CI): 32%-47%]), consistent across age group and influenza A subtypes. Influenza vaccination also reduced the overall risk of all severe in-hospital outcomes evaluated, including standard oxygen therapy (VE: 41% [95% CI: 31%-50%]), non-invasive advanced respiratory support (VE: 38% [95% CI: 19%-52%]), invasive organ support (VE: 58% [95% CI: 44%-69%]), ICU admission (VE: 58% [95% CI: 47%-67%]), and death (VE: 52% [95% CI: 18%-71%]) with effectiveness varying by influenza A subtype and age. Conclusions: Influenza vaccination reduced the risk of influenza-related hospitalization and severe in-hospital outcomes in adults during the severe 2024-2025 influenza season compared to those not vaccinated.

Background: The 2024-25 influenza season was the most severe in the United States (US) since 2017-18, with co-circulation of both influenza A virus subtypes (H1N1 and H3N2). Influenza vaccine effectiveness (VE) has varied by season, setting, and patient characteristics. Methods: Using electronic healthcare encounter data from eight US states, we evaluated influenza vaccine effectiveness (VE) against influenza-associated hospitalizations and emergency department or urgent care (ED/UC) encounters from October 2024-April 2025 among children aged 6 months-17 years and adults aged 18+ years. Using a test-negative, case-control design, we compared the odds of influenza vaccination between acute respiratory illness (ARI) encounters with a positive (cases) versus negative (controls) test for influenza by molecular assay, adjusting for confounders. Results: Analyses included 108,618 encounters (5,764 hospitalizations and 102,854 ED/UC encounters) among children and 309,483 encounters (76,072 hospitalizations and 233,411 ED/UC encounters) among adults. Among children across care settings, 17.0% (6,097/35,765) of cases versus 29.4% (21,449/72,853) of controls were vaccinated. Among adults, 28.2% (21,832/77,477) of cases versus 44.2% (102,560/232,006) of controls were vaccinated. VE was 51% (95% confidence interval [95% CI]: 41-60%) against influenza-associated hospitalizations and 54% (95% CI: 52-55%) against influenza-associated ED/UC encounters among children. VE was 43% (95% CI: 41-46%) against influenza-associated hospitalizations and 49% (95% CI: 47-50%) against influenza-associated ED/UC encounters among adults. Conclusions: Influenza vaccination provided protection against influenza-associated hospitalizations and ED/UC encounters among children and adults in the US during the severe 2024-25 influenza season. These findings support influenza vaccination as an important tool to reduce influenza-associated disease.

Background: Rising antimicrobial resistance in Neisseria gonorrhoeae threatens the effectiveness of existing therapies. Resistance-guided treatment (RGT) may reduce treatment failures, complications, and inappropriate use of last-line agents while slowing resistance emergence. Methods and Findings: We developed an individual-level stochastic simulation model of gonorrhea diagnosis and treatment in the United States, incorporating infection prevalence, symptom status, diagnostic accuracy, resistance profiles, treatment pathways, and partner management (costs in 2025 USD). We evaluated three resistance testing strategies, ciprofloxacin-only, ciprofloxacin+ceftriaxone, and triple-target (including a novel drug A), across a wide range of resistance scenarios. We quantified economic value across three dimensions: (1) per-episode direct medical cost savings, (2) system-level costs attributable to ceftriaxone resistance emergence among MSM, and (3) avoided costs of new antibiotic development, estimating the maximum per-test price at which RGT remains cost-neutral. Per-episode cost-neutrality thresholds ranged from near $0 when ceftriaxone resistance was absent to up to $45/test at 15% ceftriaxone resistance. At 50% ciprofloxacin and 5% ceftriaxone resistance, the population-weighted threshold was $4 (95% UI:$3-$8) for a CIP-only test and $11 (95% UI:$5-$14) for a triple-target test. Among MSM, incorporating system-level resistance emergence costs and avoided antibiotic development costs increased the total per-test value to $35-$145 for a single-target test and $84-$128 for a triple-target test, depending on whether prescribing practices shift when ceftriaxone resistance reaches 5%. Conclusions: Resistance-guided therapy offers economic benefits across multiple dimensions even at relatively high diagnostic prices, supporting investment in gonorrhea resistance testing to improve partner outcomes, delay resistance emergence, and enhance the long-term cost-efficiency of gonorrhea management.

Background: Oseltamivir is an antiviral medication for influenza that can reduce the duration of symptoms and may lower the risk of some complications. Recommendations for use of oseltamivir include in the outpatient setting for individuals at higher risk of developing influenza complications. Objectives: To describe oseltamivir initiation and treatment completion among influenza-positive outpatients and identify factors associated with each. Methods: In a U.S. outpatient household transmission study, index participants with laboratory-confirmed influenza provided up to 12 days of detailed information on medication use. We described oseltamivir initiation among index cases and treatment course completion of [&ge;] 10 doses among cases who initiated oseltamivir. We used unadjusted and adjusted logistic regression to identify factors associated with initiation and course completion. Results: Among 823 enrolled index cases, 324 (39%) initiated oseltamivir treatment. Of 406 persons at higher risk for influenza complications, 172 (42%) initiated treatment. Oseltamivir initiation was lowest among children aged 2 to < 5 years (19%) compared to all other age groups. Among 313 cases who initiated oseltamivir, 42% completed the recommended treatment course of [&ge;] 10 doses. Among 163 individuals at higher risk of influenza complications, 69 (42%) completed the recommended treatment course of [&ge;] 10 doses. Children < 2 years were significantly less likely to complete treatment compared to adults aged 18-50 years (aOR: 0.21, 95% CI: 0.04, 0.78, p= 0.030); reasons for discontinuation could not be determined. Conclusions: These findings reveal differences in oseltamivir treatment in an outpatient setting among groups at higher risk for influenza complications.

Background Five-biomarker-defined hypervirulent Klebsiella pneumoniae (hvKp) causes invasive infections, but its burden in bloodstream infections versus classical K. pneumoniae (cKp) is unclear. Methods This retrospective cohort study at a tertiary hospital in Japan included K. pneumoniae bloodstream infection episodes from January 2022-December 2024. hvKp was defined by the presence of all 5 genotypic biomarkers (rmpA, rmpA2, iucA, iroB, and peg-344). The primary outcome was abscess complications, and secondary outcomes were length of stay and antibiotic duration. Whole-genome sequencing was performed for 164 isolates. Results Among the 207 episodes, 28 (14%) were of hvKp. Abscess complication occurred in 17 (61%) hvKp versus 23 (13%) cKp episodes (adjusted odds ratio 10.7; 95% CI, 4.36-26.2). Median length of stay in hvKp versus cKp was 28 versus 14 days (adjusted ratio 1.60; 95% CI, 1.18-2.16) and median antibiotic duration was 43 versus 14 days (adjusted ratio 2.13; 95% CI, 1.64-2.77). These associations were attenuated after adjusting for abscess-related complications. No significant difference in 30-day mortality was observed, although the study was underpowered. Multidrug resistance was less frequent in hvKp strains than in cKp strains (11% vs. 30%; P = .040). Among the sequenced hvKp episodes, abscess rates varied across lineages, from 9 of 10 in ST23 to 1 of 4 in ST412. Conclusions Five biomarker-defined hvKp strains delineated a bloodstream infection subgroup with frequent abscess complications and prolonged care. hvKp and cKp present distinct clinical challenges; diagnostic tools distinguishing these subgroups may aid abscess evaluation and source control.

Background: Although the hemagglutination inhibition (HAI) titer remains the gold standard correlate of protection against influenza, it does not fully capture the broader antibody responses that contribute to immunity. Methods: We analyzed immune responses in paired pre-infection and convalescent sera from 306 RT-PCR-confirmed A/H3N2 infections from two household studies (2014-18) in Managua, Nicaragua. Antibody responses were measured by HAI and enzyme-linked immunosorbent assays (ELISAs) against full-length hemagglutinin (HA), the HA stalk, and neuraminidase (NA). Participants were classified as HAI responders ([&ge;]4-fold HAI rise), alternate responders (no HAI rise but [&ge;]4-fold boost in [&ge;]1 ELISA), or no-response individuals (no [&ge;]4-fold rise in any assay). We compared demographic, clinical, and pre-infection antibody characteristics across these groups. We also analyzed predictors of an NA response. Results: Overall, 77% of participants had HAI seroconversion or a 4-fold rise. Among the 23% HAI non-responders, 62% had alternate antibody responses. No-response individuals had the highest pre-infection HAI and full-length HA titers (p < 0.0001), the lowest viral loads, and the fewest fever or influenza like illness (ILI) symptoms (p < 0.01). An NA response was more common among symptomatic individuals (p = 0.0483) and those with low or high baseline NA titers. Conclusions: High baseline HAI titers can limit detectable 4-fold rises and are associated with milder illness. Evaluating additional immune responses may capture a more complete picture of the host response to infection, thereby improving surveillance and informing vaccine development. Keywords: Influenza A/H3N2; Hemagglutination inhibition (HAI); Neuraminidase antibodies; symptomatic vs asymptomatic infection; correlates of protection.

Numerous factors may influence the optimal rollout of new gonococcal antibiotics. We compared eight rollout strategies using a gonorrhea transmission model and ranked strategies by the number of gonococcal infections and clinically useful antibiotic lifespan. Rankings were most sensitive to the starting ceftriaxone resistance prevalence and screening frequency.

Background: Binary interpretation of Mycobacterium tuberculosis (Mtb) interferon gamma release assay (IGRA) results discards information about recency of exposure and disease risk. We analysed quantitative IGRA responses to Mtb in a community--based survey to investigate associations with response magnitude and inform understanding of transmission dynamics. Methods: We included QuantiFERON--TB Gold Plus (QFT--Plus) results from 2,895 participants (10--40 years old) in Blantyre, Malawi. Bayesian regression models assessed the probability of a positive response ([&ge;]0.35 IU/mL), response magnitude, and associated factors. We also investigated associations with a TB2-TB1 differential >0.6 IU/mL (proposed to reflect recent transmission), and how hypothetical alternative IGRA positivity thresholds affected inference about age-- and sex--specific transmission. Results: 17.4% (503/2,895) of participants had positive TB1 or TB2 responses at the QFT--Plus positivity threshold (0.35 IU/mL). The distributions of TB1 and TB2 responses, among participants with positive QFT--Plus, were similar across age and sex. A TB2-TB1 differential >0.6 IU/mL occurred in 3.8% (109/2,895) of participants and was not associated with age or sex. However, participants with HIV had reduced odds of TB2-TB1>0.6 IU/mL (adjusted odds ratio 0.37 [0.14--0.93]). At higher hypothetical positivity thresholds, the mean predicted Mtb immunoreactivity prevalence among males exceeded that in females at an earlier age: at 19 years, predicted immunoreactivity prevalence ratios were 0.90 (0.83--0.99) and 1.02 (0.89--1.15) at 0.1 IU/mL and 0.5 IU/mL thresholds, respectively. Conclusions: Quantitative IGRA responses offer information about age-- and sex--specific immunoreactivity and transmission risks that dichotomisation obscures. In high-burden settings, quantitative IGRA responses may clarify Mtb transmission patterns and guide targeted public health strategies.

Background: COVID vaccination with periodically updated compositions remains important as SARS-CoV-2 continues to circulate, cause disease, and evolve. Available COVID-19 vaccines in the 2024-2025 season differed by platform, including mRNA-1273, an mRNA-based vaccine, and NVX-CoV2705, a recombinant protein-based vaccine and antigen composition (KP.2-targeted and JN.1-targeted, respectively). There is limited head-to-head real-world evidence comparing the effectiveness of these different approaches to prevention of severe outcomes with COVID-19. We compared mRNA-1273 with protein-based NVX-CoV2705 in insured US adults vaccinated during the 2024-2025 season. Methods: We conducted a retrospective matched cohort study in a large US claims database. Adults aged 18 years or older who received mRNA-1273 or NVX-CoV2705 between Aug 31, 2024 and Feb 28, 2025 were eligible. Recipients were exactly matched 2:1 on key demographic and clinical factors and then weighted with stabilized inverse probability of treatment weights. Outcomes were medically-attended COVID-19 and hospitalization with COVID-19 from day 7 after vaccination through up to 180 days of follow-up. We calculated comparative vaccine effectiveness (cVE) as 100 x (1-- hazard ratio). Results: Of 858,138 eligible mRNA-1273 recipients and 34,667 eligible NVX-CoV2705 recipients, 69,140 and 34,570, respectively, entered the matched cohort. Median (Q1, Q3) follow-up was 180 (163, 180) days for mRNA-1273 and 180 (162,180) for NVX-CoV2705. Medically attended COVID-19 occurred in 706 (1.02%) mRNA-1273 recipients and 512 (1.48%) NVX-CoV2705 recipients; adjusted cVE (95% CI) was 31.7% (23.4%, 39.1%). Hospitalization with COVID-19 occurred in 61 (0.09%) and 49 (0.14%) recipients, respectively; adjusted cVE (95% CI) was 40.7% (13.5%, 59.4%). In the 47,754 mRNA-1273 recipients matched to 23,877 NVX-CoV2705 recipients aged [&ge;]65, adjusted cVE (95% CI) was 25.7% (15.4%, 34.8%) against medically-attended COVID-19 and 41.7% (14.3%, 60.4%) against hospitalization with COVID-19. Conclusions: In this insured US adult population, mRNA-1273 demonstrated greater effectiveness against medically attended COVID-19 and hospitalization with COVID-19 than the protein-based NVX-CoV2705. These findings highlight the potential public-health importance of considering vaccine platform and variant selection when planning for upcoming seasons.

Background: Tuberculosis recurrence accounts for a substantial proportion of incident tuberculosis in many settings. Distinguishing between its mechanisms can inform public health interventions for prevention. Methods: We conducted a retrospective study of individuals with multiple culture-confirmed TB episodes and available sequential isolates from 2012 to 2023 in Dourados and Campo Grande, Mato Grosso do Sul state, Brazil. Patients were classified as having recurrent TB after treatment completion or retreatment following non-curative outcomes. Whole-genome sequencing was used to assess pairwise genetic distances between isolates, classifying relapse or persistent infection ([&le;]12 single-nucleotide polymorphisms [SNPs]) versus reinfection or retreatment with reinfection (>12 SNPs). Results: Among 9,293 individuals with TB, 772 recurrent or retreatment episodes were identified. Paired isolates from 82 individuals were available for comparisons. Among individuals who completed treatment, reinfection accounted for 74.1% (40/54) of recurrent episodes, while 25.9% (14/54) were classified as relapse. Among individuals with non-curative outcomes, persistent infection (53.6%, 15/28) and retreatment with reinfection (46.4%, 13/28) occurred at similar frequencies. Persistent infection and relapse occurred earlier after the initial episode, whereas reinfection and retreatment with reinfection predominated after two years. Incarceration history was strongly associated with reinfection after treatment completion (92.5%, p=0.012) and after non-curative outcomes (76.9%, p=0.016). Conclusions: In this high-burden setting, reinfection drives TB recurrence among individuals who complete treatment, particularly at longer intervals after initial disease, reflecting sustained exposure risk. Relapse and persistent infection remain clinically important, especially following non-curative outcomes. These findings underscore the need for integrated strategies combining adherence support to prevent treatment-related recurrence with interventions to reduce transmission, particularly in high-risk settings.

Background: Prolonged SARS-CoV-2 infection in immunocompromised individuals may accelerate virus evolution within the host, raising concerns about the virus evading immunity, developing resistance, and forming novel variants of concern. However, the determinants and public health implications of within-host viral evolution in this population remain incompletely understood. Methods: We performed longitudinal analyses of SARS-CoV-2 genomes from 91 patients with COVID-19 who were classified as being severely or moderately immunocompromised. Using serial measurements of viral RNA loads and infectious titers, we modeled the shedding dynamics of the virus and stratified the infected cases by upper respiratory virus shedding duration to assess associations with within-host evolutionary dynamics. Results: Shedding modeling identified two profiles of shedding duration: intermediate and long. The long shedding profile (shedding lasting >21 days) was found in 14.8% of moderately immunocompromised cases and 72.1% of severely immunocompromised cases. Frequent single-nucleotide variants accumulated specifically in severely immunocompromised individuals with the long shedding phenotype, correlating positively with shedding duration. By contrast, mutations remained limited in moderately immunocompromised individuals with the long shedding phenotype and in severely immunocompromised individuals with the intermediate shedding phenotype. We identified mutations in the spike receptor-binding domain associated with monoclonal antibody resistance; however, we found no fitness-enhancing mutations for inter-host transmission, and antiviral drug resistance mutations were rare. Instead, mutations were introduced frequently and randomly across the entire viral genome. Conclusions: Prolonged upper respiratory virus shedding exceeding 21 days combined with severe immunocompromise is a risk factor of the accumulation of within-host SARS-CoV-2 mutations. Although no variants of concern emerged, the introduction of genome-wide random mutations suggests that the risk for novel variant generation cannot be excluded. These findings highlight the need for intensive antiviral strategies to limit shedding duration to less than 21 days in severely immunocompromised patients, and for immunological investigations to elucidate the host factors underlying residual shedding control in those who achieve clearance within this threshold.

Introduction Improved diagnostics are needed for people at risk of tuberculosis, especially adolescents. Tongue swab (TS) molecular testing has emerged as a promising strategy for tuberculosis diagnosis. We evaluated diagnostic accuracy and acceptability of Xpert MTB/RIF Ultra (Xpert) using TS samples for tuberculosis detection among adolescents. Methods We conducted a cross-sectional diagnostic accuracy study with consecutive recruitment in Vietnam. Adolescents aged 10-19 who were recommended to undergo investigation for tuberculosis and had not received tuberculosis treatment in the past years were eligible. Participants provided TS and sputum samples and completed a structured survey regarding sampling experiences. TS was tested on Xpert, with sputum tested on Xpert and liquid culture. We utilised a composite reference standard of a positive result on sputum Xpert or sputum culture to define disease status. Sensitivity, specificity, and diagnostic yield were calculated for TS Xpert. Results From July to December 2025, we enrolled 225 adolescents from Can Tho and An Giang provinces in southern Vietnam. Fewer than half (96/225, 43%) the participants exhibited a tuberculosis -like symptom, and the majority (157/225, 70%) were close contacts of a person recently diagnosed with tuberculosis. TS were collected from all adolescents, while 116 (52%) could provide mucopurulent sputum. Tuberculosis prevalence was relatively low (12/225, 5.3%). TS Xpert sensitivity (90% CI) and specificity (90% CI) were 58.3% (35.6, 78.0) and 99.5% (97.9, 99.9), respectively. Diagnostic yield among all diagnosed was 58.3% (7/12). TS sampling was highly acceptable to adolescents; the short time and simplicity of collecting TS were considered favourably. Conclusions The sensitivity and diagnostic yield of TS Xpert was relatively low among adolescents recommended for tuberculosis investigation, which includes asymptomatic individuals who may not provide high quality sputum. Specificity was excellent, and everyone could provide a TS. TS high acceptability indicates it remains a promising sample for diagnostic algorithms.

Objectives: A pooled testing algorithm for tuberculosis (TB), in which sputum specimens from multiple individuals are tested in pools with individual testing of positive pools, can optimise diagnostic resources. This study evaluated the diagnostic accuracy and cartridge savings of pooled testing with the Xpert MTB/RIF Ultra assay (Xpert Ultra) relative to individual Xpert Ultra testing. Methods: We conducted a cross sectional study among 2,396 adults (aged above 15 years) with presumptive TB enrolled between July 2024 and February 2025, through facility based case finding (FBCF) and community based case finding (CBCF). Participants submitted two sputum specimens. The first underwent individual Xpert Ultra testing; remnant specimens were combined into four specimen pools and tested again with Xpert-Ultra. The second specimen was used to inoculate liquid culture (BACTEC MGIT). Data were used to simulate an up-front pooled testing strategy; sensitivity and specificity of this approach was estimated against culture, and cartridge use was compared with individual Xpert-Ultra testing. Results: Of 2,396 participants, 395 (16.5%) had a positive Xpert Ultra and/or culture, including 360/912 (39.5%) in FBCF and 35/1484 (2.4%) in CBCF. The pooled testing approach had sensitivity of 82.4% (95% confidence interval [CI], 77.9; 86.3) and specificity of 98.5% (97.8; 99.0) compared to culture, with lower sensitivity than individual Xpert-Ultra testing (86.5%, 82.4; 89.9) but high specificity (98.1%, 97.4; 98.7). Sensitivity of pooled testing was lower in CBCF (59.1%, 36.4; 79.3) than in FBCF (84.0%, 79.5;87%), whereas cartridge savings were greater in CBCF (69.1% vs 9.6%). The pooling strategy reduced Xpert-Ultra cartridge use by 46.5%, saving USD 14,447. Conclusions: Pooled Xpert-Ultra testing among adults appears resource-efficient for TB screening in Vietnam. As sensitivity is lower compared to individual Xpert Ultra testing, particularly for paucibacillary disease, these losses should be carefully weighed against gains in affordability and expand access to molecular testing. Careful, context-specific implementation is essential to maximise programmatic benefit while minimising missed persons with TB.

BackgroundThe Toto Bora trial tested whether a course of azithromycin reduced rates of re-hospitalization or death in the 6 months following hospitalization among Kenyan children. We hypothesized that azithromycin would reduce enteric bacteria and increase carriage of macrolide resistance in the subsequent 3 months. MethodsKenyan children (1-59 months) hospitalized and subsequently discharged for non-traumatic conditions provided fecal samples before and 3 months after randomization to a 5-day course of azithromycin or placebo. Quantitative PCR identified enteropathogens and AMR-conferring genes in fecal samples. Generalized estimating equations assessed the impact of the randomization arm on pathogen and resistance gene detection, accounting for baseline presence and site. ResultsAmong 1,393 baseline stools, 12.4% had at least one bacterial enteropathogen, 94.7% had at least one macrolide-resistance gene, and 92.6% had at least one beta-lactamase-resistance gene identified. At month 3, children randomized to azithromycin had a 6.1% higher likelihood of carrying a macrolide resistance gene compared to placebo (adjusted prevalence ratio [aPR], 1.06; 95% CI, 1.04-1.08; P<0.001). Specifically, azithromycin randomization was associated with a higher relative prevalence of erm(B) (aPR, 1.09 [95% CI, 1.04-1.15]; P=0.001), erm(C) (aPR, 1.23 [95% CI, 1.14-1.31]; P<0.001), msr(A) (aPR, 1.14 [95% CI, 1.04-1.25]; P=0.007), and msr(D) (aPR, 1.07 [95% CI, 1.03-1.11]; P=0.001). There was no difference in overall bacterial pathogen prevalence (18.9% vs 17.3%) between randomization arms, but a slightly lower proportion of children had Shigella after randomization in the azithromycin arm (3% vs. 5%, aPR, 0.79 [95% CI, 0.62, 1.01]; P=0.063). InterpretationAzithromycin at hospital discharge was associated with higher carriage of macrolide-resistance-conferring genes in the post-discharge period compared with placebo, without significant declines in enteric pathogen carriage other than modest changes to Shigella. The potential benefits and risks of empiric azithromycin need to be considered, as children are increasingly exposed to this broad-spectrum antibiotic.

BackgroundChlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis are curable sexually transmitted infections (STIs) associated with adverse birth outcomes. Most infections are asymptomatic. Whether antenatal STI screening improves birth outcomes remains uncertain. MethodsIn a randomized three-group trial in South Africa, pregnant women aged 18 years or older were assigned before 27 weeks gestation to: (1) screening and treatment for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis at enrollment, with tests-of-cure (One-Time Screening); (2) screening and treatment at enrollment, repeated at 30 to 34 weeks (Two-Time Screening); or (3) Standard-of-Care (Syndromic management). The primary outcome was a composite of preterm birth (<37 weeks gestation) or low birthweight (<2500 g), analyzed in the modified intention-to-treat population of participants with live births. Components of the composite outcome were evaluated individually as the main secondary outcomes. The study was registered with ClinicalTrials.gov, NCT04446611. FindingsOf 2247 enrolled participants, 1910 had live births. The composite outcome occurred in 22{middle dot}9% of the One-Time Screening group (risk ratio [RR] 0{middle dot}99; 95% confidence interval [CI] 0{middle dot}81-1{middle dot}21), 20{middle dot}6% of the Two-Time Screening group (RR 0{middle dot}89; 95% CI 0{middle dot}72-1{middle dot}09), compared with 23{middle dot}2% of the Standard-of-Care group. Preterm birth occurred in 18{middle dot}9% of the One-Time Screening group (RR 1{middle dot}00; 95% CI 0{middle dot}80-1{middle dot}26), 14{middle dot}5% of the Two-Time Screening group (RR 0{middle dot}77; 95% CI 0{middle dot}60-0{middle dot}99), and 18{middle dot}8% of the Standard-of-Care group. Low birthweight occurred in 14{middle dot}1% of the One-Time Screening group (RR 1{middle dot}10; 95% CI 0{middle dot}83-1{middle dot}46), 12{middle dot}9% of the Two-Time Screening group (RR 1{middle dot}01; 95% CI 0{middle dot}76-1{middle dot}35), and 12{middle dot}8% of the Standard-of-Care group. InterpretationNeither screening strategy for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis reduced the primary composite outcome of preterm birth or low birthweight, or low birthweight alone. The Two-Time antenatal STI screening strategy, however, reduced preterm birth by 23%.

BackgroundWidespread immunity from vaccination and infection has reduced COVID-19 morbidity and mortality, but this immunity varies across the population. Understanding how repeated antigenic exposures influence antibody responses helps to inform future vaccination strategies. MethodsSerum samples collected one and six months after XBB.1.5 vaccination from 25 generally healthy healthcare workers with varying exposure histories were assessed for neutralizing activity against a range of variants, from pre-Omicron variants to latest Omicron JN.1 sublineage variants and divergent BA.3.2 variants, using lentiviral pseudoviruses. Participants were stratified by vaccination and infection history. ResultsXBB.1.5 vaccination elicited broad neutralizing responses, with strong boosting against previously encountered antigens relative to vaccine-matched XBB.1.5 and newer variants. Geometric mean neutralization titers were generally comparable across exposure groups, indicating limited influence of prior Omicron infection or bivalent vaccination, though intra-group heterogeneity was observed. At six months, overall titers declined by 36-62%. Titers remained highest against the pre-Omicron and lowest against JN.1 sublineage variants. N-terminal glycosylation (DelS31, T22N) modestly affected neutralization. ConclusionsXBB.1.5 vaccination elicited broad neutralizing antibody responses against previously encountered and vaccine-matched antigens regardless of exposure history, but titers waned after six months. This waning, compounded by continued emergence of immune-evasive variants and heterogenous population immunity, underscores the need for continually monitoring neutralizing antibody durability and breadth to guide evidence-based COVID-19 vaccine formulation updates.

Background. Targeted Universal Tuberculosis Testing (TUTT) may increase tuberculosis (TB) case detection by including people who are not actively seeking TB care but are at high risk of the disease. Non-invasive tongue swab (TS) testing may facilitate TUTT. We evaluated two TS testing protocols in people with HIV (PWH) tested irrespective of TB symptoms. Methods. Study staff collected Copan FLOQSwab and Medline foam swab specimens, alongside urine and sputa, from PWH, most of whom were presenting for antiretroviral therapy initiation at primary healthcare clinics in KwaZulu-Natal, South Africa. FLOQSwabs were tested by sequence-specific magnetic capture (SSMaC) with qPCR (FLOQSwab-SSMaC). Foam swabs were tested by centrifuge-sedimentation and high-volume qPCR (foam-sedimentation). Urine lipoarabinomannan was detected using LF-LAM. The extended microbiological reference standard (eMRS) comprised any positive result on Xpert Ultra and/or liquid culture of sputum. Results. We enrolled 251 participants (median age 34 years, 56% female, 67% with self-reported TB symptoms). Participants had a median CD4 count of 347 cells/ul, and 16% (40/251) had prior TB. FLOQSwab-SSMaC was 43% sensitive (13/30) and 100% specific (131/131) relative to eMRS. Foam-sedimentation was 47% (9/29) sensitive and 100% (176/176) specific. Sensitivity increased to 52% (FLOQSwab-SSMaC) and 50% (foam-sedimentation) when sputum Xpert Ultra Trace positive results were excluded from eMRS. TS was more sensitive than urine LAM, and both sample types were more sensitive when CD4 counts were below 200. Discussion. TS testing detected about half of PWH with TB and outperformed urine LAM within this population, including among PWH with low CD4 counts.

BackgroundWe explored the efficacy of AS01E-adjuvanted respiratory syncytial virus prefusion F protein-based vaccine (adjuvanted RSVPreF3) in subpopulations of participants with underlying medical conditions in the multi-country, phase 3 AReSVi-006 trial (conducted May/2021-May/2024). MethodsMedically stable [&ge;]60-year-olds were 1:1-randomised to receive one adjuvanted RSVPreF3 or placebo dose pre-RSV season 1. In exploratory post-hoc analyses in subgroups of participants with underlying conditions (including COPD, asthma, diabetes, obesity [BMI[&ge;]30 kg/m2]), we evaluated efficacy of one vaccine dose against RSV-related lower respiratory tract disease (RSV-LRTD), acute respiratory illness (RSV-ARI), and RSV-ARI-related complications (e.g., pneumonia, COPD/asthma exacerbation, cardiovascular events). We also evaluated (post-hoc) RSV-ARI-related systemic corticosteroid and antibiotics use in participants with COPD or asthma. ResultsThe efficacy analyses comprised 12,468 vaccine and 12,498 placebo recipients. Efficacy against RSV-LRTD over three RSV seasons was similar among participants with COPD (75.1%, 95% CI: 40.2-91.4), asthma (65.8%, 31.0-84.7), diabetes (69.8%, 37.5-87.1), and obesity (74.1%, 56.4-85.5) as in the overall study population (62.9%, 97.5% CI: 46.7-74.8). Efficacy was also observed against RSV-ARI in these subgroups. Efficacy against RSV-ARI-related complications was 74.4% (95% CI: 11.2-95.2) in participants with COPD and 60.8% (-9.9-88.7) in those with asthma. Among participants with COPD, 15.4% (1.9-45.4) of RSV-ARI episodes in vaccine vs 22.4% (12.5-35.3) in placebo recipients were treated with systemic corticosteroids, and 46.2% (19.2-74.9) vs 56.9% (43.2-69.8) with antibiotics. ConclusionsPost-hoc analyses of the AReSVi-006 trial suggest that adjuvanted RSVPreF3 may help prevent RSV-ARI, RSV-LRTD, and RSV-related complications in medically stable older adults with underlying medical conditions like COPD and asthma. Trial registrationClinicalTrials.gov: NCT04886596 SummaryPost-hoc analyses of the AReSVi-006 trial suggest that 1 dose of adjuvanted RSVPreF3 may help prevent RSV-related illness and complications over 3 consecutive RSV seasons in subgroups of [&ge;]60-year-olds with chronic medical conditions, e.g., COPD and asthma.

Background: In Rwanda, genomic surveillance identified a dominant multidrug-resistant tuberculosis (MDR-TB) strain, the R3clone, responsible for approximately 70% of rifampicin-resistant TB cases. Its presence beyond Rwanda remains unexplored. Methods: Unique genetic signatures of the R3clone were defined using whole-genome sequencing of MDR-TB isolates from Rwanda. We developed a targeted qPCR assay detecting a clone-specific single-nucleotide polymorphism. With these tools, we screened isolates from neighbouring countries and public genomic repositories. Results: We identified 375 R3clone isolates, including 264 from historical Rwandan collections (1991-2021), 49 from recent Rwandan diagnostic routine (2021-2024), 25 from historical Burundi isolates (2002-2013), and 37 among public repositories from several countries. The R3clone-specific qPCR showed 100% specificity in distinguishing the R3clone from other MTBC (sub-)lineages. Transmission analysis revealed cross-border transmission of the R3clone within the Great Lakes Region. Conclusion: This study comprehensively assesses cross-border transmission of a dominant MDR-TB strain, highlighting the need for coordinated international surveillance.

Patients with myasthenia gravis (MG) may produce autoantibodies neutralizing type I interferons (AAN-I-IFN), which have been shown to underlie severe viral diseases, including critical COVID-19 pneumonia, in patients without MG. We studied an international cohort of 85 unvaccinated SARS-CoV-2-infected MG patients with no antiviral treatment. Hypoxemic pneumonia occurred in 48 of these patients, including 22 (45.8%) with AAN-I-IFN, which neutralized both IFN-2 and IFN-{omega} in 14 (29.2%) patients. Six (16.2%) of the remaining 37 patients had AAN-I-IFN, which neutralized both IFN-2 and IFN-{omega} in three patients. The risk of hypoxemic pneumonia was greater in MG patients with AAN-I-IFN neutralizing 10 ng/mL of both IFN-2 and IFN-{omega} (odds ratio and 95% confidence interval (OR [95% CI]): 12.7 [2.1-78.9], p=0. 0010) or IFN-2 at any dose (4.7 [1.5-15.0], p=0.0054) than in those without such autoantibodies. The risk of AAN-I-IFN production was much higher in MG patients than in the general population (28.9 [10.8-77.7], p=4.9x10-27). Fourteen patients had thymoma, which increased the risk of AAN-I-IFN (64% versus 27%, (OR [95% CI]: 5.6 [1.6-19.4], p=0.0050) and hypoxemic pneumonia (9.2 [1.9-44.2]; p=0.0019). Thymoma is, thus, associated with a higher risk of producing AAN-I-IFN, and these autoantibodies are associated with a higher risk of developing life-threatening COVID-19 pneumonia in patients with MG.