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  • Journal article
    Johnson LF, Kubjane M, Imai-Eaton JW, Brown LR, Jamieson L, Naidoo P, Tanna G, Meyer-Rath Get al., 2026,

    Towards ending tuberculosis in South Africa: an uncertainty analysis of the programmes and factors most critical to future declines.

    , Glob Health Action, Vol: 19

    BACKGROUND: The WHO End Tuberculosis (TB) strategy targets 80% and 90% reductions in TB incidence and mortality, respectively, between 2015 and 2030. OBJECTIVE: To assess which policy-changeable and external factors are most critical to reducing future TB in South Africa. METHODS: We adapted an existing mathematical model of TB and HIV in South Africa. Prior distributions were specified to represent uncertainty ranges for 27 model parameters that are highly uncertain and potentially important in driving future TB dynamics. Latin Hypercube Sampling was used to sample 1000 parameter combinations from these distributions, and the model was projected to 2040 for each. Partial rank correlation coefficients (PRCCs) were calculated to assess correlation between each parameter and average adult TB incidence and mortality rates over 2025-2040. RESULTS: Adult TB incidence and mortality rates in South Africa were projected to decline by 46% (95% uncertainty interval [UI]: 17-69%) and 54% (95% UI: 21-84%) respectively by 2030, relative to 2015. The parameters most strongly associated with future TB incidence were the increase in microbiological testing in symptomatic individuals due to near-point-of-care/tongue swab (NPOC/TS) testing (PRCC = -0.67), reductions in social contact rates post-COVID (PRCC = -0.61), the probability of sputum testing in symptomatic individuals in the absence of NPOC/TS testing (PRCC = -0.39), and the efficacy of TB preventive therapy (PRCC = -0.35). TB mortality predictors were similar. CONCLUSIONS: Increasing testing among people with TB symptoms, including through new NPOC/TS technologies, is likely to have the largest impact on progress towards End TB goals in South Africa, though attainment by 2030 is unlikely.
  • Journal article
    Cidade JP, Taccone FS, Reyes LF, Merson L, Lefevre B, Citarella BW, fatoni AZ, Póvoa P, Zucman D, Zoufaly A, Zayyad H, Zaynah N, Zawadka K, Zanella A, Zambrano M, Zambon M, Zaidan NZB, Zahid M, Zabbe M, Zaaqoq A, Yuliarto S, Yousif O, Yonis H, Yiaye T, Yeoh CH, Yelnik C, Abdelaal AYM, Hing NYL, Yazdanpanah Y, Yarad E, Yamazaki M, Yakop SRBM, Xynogalas I, Xian LS, Wong C, Wong TF, Wong YS, Wong XC, Wittman J, Witt K, Wils EJ, Williams B, Williams PJ, Williams V, Wijaya SO, Wiedemann A, White N, Whelan B, Wham M, Wesselius S, Wen TP, Webb S, Walsh L, Wainstein M, Wahid NA, Wahab NH, Wahab SA, Vuotto F, Vongsouvath M, Villoldo A, Villar J, Vijayan D, Vieira C, Verbon A, Ventura S, Veislinger A, Veeran S, Vauchy C, Vasudayan SR, Varrone M, Vanel N, van Willigen H, van Twillert G, van Someren Gréve F, van Netten C, van Hattem J, van Gulik L, van Gorp E, Van Der Werf S, Van der Voort P, van der Feltz M, van den Berge M, Val-Flores L, Vajdovics C, Uyeki TM, Usman A, Uribe A, Ullrich R, Udy A, Udayanga PGI, Uchiyama M, Twardowski P, Tveita A, Turtle LCW, Turgeon AF, Tuite H, Tubiana S, Tual C, Truong J, Trontzas Iet al., 2026,

    Immune dysregulation through longitudinal lymphocyte trajectories and their clinical determinants in hospitalized COVID-19 patients

    , Intensive Care Medicine Experimental, Vol: 14

    Objective: Immune dysregulation plays a pivotal role in the pathophysiology of sepsis and COVID-19, with lymphopenia emerging as a consistent marker of severity and poor prognosis. However, most existing studies have assessed lymphocyte counts at isolated time points, limiting insights into their temporal behavior and prognostic value. The dynamics of lymphocyte recovery or persistence of lymphopenia remain largely unexplored in large populations, as well as the impact of adjunctive therapies such as corticosteroids. We hypothesized that the persistence or recovery of lymphopenia may be key to understanding disease progression and predicting outcomes. Using the multinational ISARIC cohort, we investigated longitudinal lymphocyte trajectories in hospitalized patients and the clinical determinants associated with their evolution over time. Methods: We conducted a multinational prospective observational cohort study using data from the ISARIC-WHO Clinical Characterization Protocol. Patients with confirmed SARS-CoV-2 infection and at least four lymphocyte measurements during the first 28 days of hospitalization were included. We analyzed lymphocyte trajectories, Cox regression survival analyses and multivariable linear regression modelling. We also applied multistate models and joint modeling to assess the association between lymphocyte trajectories and 28-day mortality, incorporating corticosteroid use as a time-varying covariate. Results: Of 945,317 screened patients, 231,933 hospitalized adults with confirmed COVID-19 and sufficient lymphocyte data were included, with 56.6% classified as lymphopenic. Lymphopenia was independently associated with higher rates of ICU admission, organ support, and in-hospital mortality (OR = 1.52, 95% CI 1.48–1.55), and lower absolute lymphocyte counts were strongly linked to worse survival in adjusted Cox models (HR = 1.33 per 1 × 10⁹ cells/L decrease, 95% CI 1.28–1.38). Multistate modeling revealed that lymphope
  • Journal article
    Ahmed S, Mangal TD, Hallett TB, Turner Het al., 2026,

    When is elimination of an infectious disease cost- effective? An analytical framework to guide elimination priorities

    , Cost Effectiveness and Resource Allocation, Vol: 24, ISSN: 1478-7547

    BackgroundElimination targets for infectious diseases are increasingly common in global health, yet the economic rationale for pursuing elimination is often assumed rather than rigorously assessed. Existing evaluations frequently emphasise future cost savings or broader economic benefits while overlooking health opportunity costs—the health that could have been gained had resources been allocated elsewhere. This study aimed to develop an analytical framework to investigate when disease elimination generates positive net health benefit (NHB) and to illustrate how key factors interact to shape this assessment.MethodsWe constructed a generalisable analytical framework incorporating ten factors related to intervention and disease costs, intrinsic disease/intervention characteristics, and stakeholder viewpoints and evaluation parameters. The framework was applied to create an exemplar model that showed how these factors jointly influence the NHB of achieving elimination. This was evaluated across wide parameter ranges informed by the literature, using different cost-effectiveness thresholds, discount rates, and time horizons. ResultsThe framework revealed distinct regions of parameter space in which elimination yield positive NHB. The cost effectiveness threshold, discount rates, disease burden, and intervention impact were strong determinants of NHB. In particular, lower thresholds, higher discount rates, and shorter time horizons reduced the likelihood that elimination would generate positive NHB. The framework also showed that elimination may be cost effective in some settings but not in others, even for the same disease, due to differences in costs, burden, and opportunity costs.ConclusionsDisease elimination is not always a good investment; its value depends on the interplay between disease characteristics, programme costs, and the health opportunity costs of resource use. The proposed framework provides a transparent, health opportunity cost-based structure f
  • Journal article
    Ngwili N, Kachepa U, Korir M, Chavula M, Wood C, Chiphwanya J, Kafanikhale H, Glazer C, Juziwelo L, Munkhondia-Phiri P, Musaya J, Thomas LF, Dixon-Zegeye Met al., 2026,

    Spatial and temporal risk mapping of human and porcine Taenia solium infections in Malawi: a systematic review and geostatistical approach

    , One Health Outlook, Vol: 8, ISSN: 2524-4655

    Background Taenia solium, colloquially called the pork tapeworm, is a zoonotic parasite with a human definitive host and a porcine intermediate host. Humans can become an aberrant intermediate host due to accidental ingestion of parasite eggs from the environment or through autoinfection, resulting in human cysticercosis (HCC), neurocysticercosis (NCC) if the central nervous system is infected. Pigs become infected with the larval stage, porcine cysticercosis (PCC), through the ingestion of parasite eggs shed by humans through defecation. Malawi has been classified as endemic for T. solium by the WHO based on the presence of key risk factors; however, the subnational distribution is not known. To ensure the appropriate resources are mobilized to support targeted future T. solium control measures in Malawi, there is a need to understand the variation in T. solium endemicity status across the country.Methods The current study uses a systematic literature review (SLR) using a pre-registered protocol; (PROSPERO CRD42023411044) to collate all available evidence on T. solium in Malawi. A geospatial risk mapping approach was conducted based on data from Malawi demographic health surveys (MDHS), and pig density data from the Food and Agriculture Organization (FAO) database to create geospatial risk maps of endemic subnational areas for 2000, 2004, 2010, and 2016. To create a single composite risk factor map for the four years from the MDHS, each parameter was plotted as a binary variable with the high or low risk categories and overlaid into a single composite risk factor classification. Additional data from hospital records on NCC and meat inspection records across several Agricultural Development Divisions (ADDs) were also collected.
  • Journal article
    McCain K, Topazian HM, Challenger JD, Okell L, Winskill P, Ghani ACet al., 2026,

    Public health impact of catch-up vaccination or additional booster doses with pre-erythrocytic malaria vaccine R21/Matrix-M: a modelling study

    , BMC Medicine, Vol: 24, ISSN: 1741-7015

    Background The malaria vaccine R21/Matrix-M is recommended for young children in malaria-endemic regions. However, the small vaccine-eligible population and waning vaccine efficacy mean that routine vaccination is unlikely to prevent severe cases in older children who experience significant malaria burden. As R21/Matrix-M vaccination expands, targeting older age groups may be warranted, depending on funding. Methods Using a stochastic, individual-based P. falciparum malaria transmission model, we estimate the impact of 1) one-off catch-up campaigns with R21/Matrix-M to previously unvaccinated age groups between age 6 months and 14 years, and/or 2) extra boosters at 2, 5 and/or 10 years after the primary series in low, moderate, and high transmission settings. We assume that vaccine immunogenicity in older children is equivalent to that of the standard target age group, though clinical trials have shown lower immunogenicity in older children.ResultsCatch-up campaigns in moderate-to-high transmission settings targeting younger children averted the most uncomplicated cases per 1000 additional doses (358 (95% Credible Interval (CI) 113-570) in children aged 6 months-2 years at 45% PfPR2-10), compared with targeting older children. In low transmission settings, the impact was similar across age groups, with a slightly higher impact when targeting school-aged children (373 (95% CrI 240-518) in children aged 5-9 years at 5% PfPR2-10). Across extra booster strategies, an extra booster 10 years post-primary series averted the most severe cases per 1000 additional doses at low transmission (12 (95% CrI 6-18) at 5% PfPR2-10), but the least at high transmission (-4 (95% CrI -11-3) at 45% PfPR2-10). Expanding the vaccine-eligible population in areas of moderate-to-high transmission often had higher incremental efficiency than routine age-based vaccination at low transmission. Sensitivity analyses assuming lower immunogenicity in older children modestly reduced the per-dose impac
  • Journal article
    Fraser K, Cibrelus L, Horton J, Kodama C, Staples E, Gaythorpe Ket al., 2026,

    Yellow fever outbreak potential in Djibouti, Somalia and Yemen: a mathematical modelling study

    , BMC Global and Public Health, Vol: 4, ISSN: 2731-913X

    BackgroundThe importation of arbovirus diseases into new countries is a global concern. This risk is exacerbated by human movement and climate change effects. In the World Health Organization (WHO) Eastern Mediterranean regional office, three countries - Djibouti, Somalia, and Yemen - are currently classified as potential or moderate risk for yellow fever (YF) outbreaks.MethodsHere we present a quantitative assessment of the risk of introduction and propagation of yellow fever virus (YFV) transmission in Djibouti, Somalia and Yemen. This modelling has two components: i) projecting the risk of importation of infectious individuals into the countries of interest using a radiation model of human movement and ii) estimating the risk of onward transmission given importation using a dynamic compartmental model of yellow fever virus transmission. Both components are multiplicatively combined to give an overall relative outbreak risk combining both risk of importation and risk of an outbreak given importation.ResultsWe show that areas such as the western coast of Yemen, regions of Somalia bordering Ethiopia and Kenya, and Djibouti City have potential for YF outbreaks (where the estimated probability of an outbreak given an imported infectious case is over 50%). This is due to environmental suitability for transmission based on factors such as temperature and projected human mobility between endemic and at-risk regions.ConclusionsCountries bordering existing YF endemic regions are potentially vulnerable to both introduction of YF cases and subsequent outbreak spread. This promotes the awareness of YF importation potential when conducting clinical surveillance in at-risk countries.
  • Journal article
    Ghafari M, Watson OJ, Dascalu S, Mon SHH, Abeler-Dörner L, Rezaee-Zavareh MS, Pley C, Kordasti S, Abbas K, Madani K, Panovska-Griffiths Jet al., 2026,

    Global vaccine readiness: equity-by-design in pandemic preparedness and response.

    , Expert Rev Vaccines, Vol: 25

    INTRODUCTION: COVID-19 showed that rapid vaccine development and roll-out, while lifesaving, can still yield large, avoidable harms when equity is not considered from the outset. Disparities in vaccine timing and coverage, especially in low-resource settings, amplified health and economic burdens, highlighting the need for preparedness frameworks that combine speed with fairness. AREAS COVERED: We synthesize evidence from literature and policy reports regarding global vaccine roll-out, focusing on avertable mortality under alternative sharing scenarios, procurement design, pooled mechanisms such as COVAX, and the role of distributed manufacturing and delivery capacity. We also examine how transparent data-sharing, effective public communication, genomic surveillance, adaptive trial designs, and modeling hubs can support more responsive and equitable vaccine deployment. Across six reflection points, we translate these lessons into practical priorities for future pandemic readiness, including strengthening healthcare infrastructure, equitable procurement, data transparency, and safeguarding public health decision-making from political and commercial distortion. EXPERT OPINION: We argue that equity-by-design is essential if vaccine innovation is to deliver equitable public health impact. This requires geographically distributed manufacturing, transparency, equity-conditioned advance purchase agreements, and pre-agreed, epidemiology-triggered allocation of vaccines. We recommend institutionalizing disaggregated reporting, standardized data-sharing, greater pathogen genomic sequencing capacity, and communication strategies that support public health protection while countering misinformation.
  • Journal article
    Topazian HM, Morgan CE, Goel V, 2026,

    Spatial and temporal associations between animal ownership and malaria prevalence in Africa using cross-sectional national Demographic and Health Surveys.

    , One Health, Vol: 23, ISSN: 2352-7714

    Use of zooprophylaxis as a malaria control strategy has been recommended historically, but a complex relationship exists between animal ownership and malaria infection, with mixed associations described in the literature. We sought to characterize this relationship spatially and temporally in malaria-endemic regions of Africa. We used data from 392,843 individuals from 66 Demographic and Health surveys from countries within Africa to investigate the association between household animal ownership and Plasmodium infection. We used Bayesian models with Integrated Nested Laplace Approximation to incorporate spatially varying coefficient processes, allowing the association of interest to vary over space, time, and within strata of vector species occurrence, land cover, and number of animals owned by households. Spatially varying intercept models showed that ownership of cattle, chickens/poultry, goats, horses/donkeys/mules, pigs, and sheep was broadly associated with malaria infection, with odds ratios ranging from 1.55 to 1.67. However, spatially varying slope models revealed considerable heterogeneity, with odds ratio estimates for all animal types demonstrating both protective and harmful effects varying from 0.33 to 3.33 both subnationally and across time. We found no evidence that modification by vector species, number of animals owned, and land cover fully explained the variation in estimates. Unobserved localized cultural, behavioral, or ecological factors likely modify the association between animal ownership and malaria prevalence. Further exploring the nature of this relationship over space and time will be important to understanding how context-specific One Health dynamics between humans, animals and the environment affect malaria prevention and control efforts.
  • Journal article
    Fehlmann CA, Meuleman B, Robert-Ebadi H, Righini M, Perrier A, de Kraker ME, Abbas Met al., 2026,

    Machine learning models for suspected pulmonary embolism in emergency department patients: a multicentre diagnostic study.

    , Thromb Haemost

    Background Pulmonary embolism (PE) is frequently suspected in emergency departments (EDs). Safely ruling out PE without additional testing could reduce imaging use and ED crowding. Machine learning (ML) may improve accuracy and efficiency. Objectives To evaluate ML models for ruling out PE without additional testing in ED patients with suspected PE, while maintaining a failure rate <2%. Methods We retrospectively analysed pooled data from four prospective European studies of ED patients with suspected PE (2000-2013). A total of 5038 patients were randomly split into training (n=2400) and validation (n=2638) datasets. ML models classified patients into low, intermediate, and high pre-test probability groups. In intermediate-risk patients, post-test probability was refined using either a fixed D-dimer threshold or a second ML model. The primary outcome was the failure rate assessed in the validation cohort and defined as the proportion of missed PE diagnoses. Results The best-performing algorithm combined weighted ridge regression (pre-test) with weighted random forest (post-test), achieving a failure rate of 1.44% (95% CI 1.04-1.99) and a Matthews correlation coefficient of 0.470 (95%CI 0.440-0.500). This model ruled out PE without any testing in 9.7% of patients, with an estimated imaging proportion of 54.1%, comparable to 4PEPS (52.9%) and lower than PERC (66.8%). Conclusion A two-step ML algorithm performed comparably to the best existing clinical decision rules, with a failure rate whose confidence interval remained below the prespecified 2% criterion and an estimated imaging proportion similar to 4PEPS. Prospective external validation is warranted.
  • Journal article
    Berhe N, Desalegn H, Mengistu H, Birhane D, Kebede B, Maru M, Girma F, Bekele D, Gure T, Yaid H, Abdi S, Shimakawa Y, Johannessen A, Nayagam S, Ndow G, DAllessandro U, Dibba B, Bojang L, Toure-Kane C, Lo G, Diouf A, Faye A, Ba A, Hallett T, Lemoine M, Ward Jet al., 2026,

    Effectiveness of timely hepatitis B birth dose vaccination to prevent mother-to-child transmission in Ethiopia

    , Clinical Infectious Diseases, ISSN: 1058-4838

    <jats:title>Abstract</jats:title> <jats:sec> <jats:title>Background</jats:title> <jats:p>Mother-to-child transmission (MTCT) is an important route of new hepatitis B virus (HBV) infections. In Africa, limited and conflicting data on the effectiveness of hepatitis B birth dose vaccination (HepB-BD) have contributed to fragmented adoption and sub-optimal implementation. We aimed to assess the effectiveness of timely HepB-BD in preventing HBV MTCT in Ethiopia.</jats:p> </jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>We conducted a multi-centre cross-sectional observational study in Ethiopia from May 2022 to June 2024. We identified mothers who had tested positive for hepatitis B surface antigen (HBsAg) during pregnancy and assessed mother-infant pairs at 6-12 months post-partum for HBV MTCT. We stratified effectiveness of HepB-BD by maternal risk profile (HBV DNA level, hepatitis B e-antigen (HBeAg) status).</jats:p> </jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>The analysis included 387 children born to HBV-positive, HIV-negative mothers who had completed routine HBV vaccination (HepB3). The median age of infant testing was 10 months (IQR 7.0-11). Overall MTCT risk was 5.2% (95% CI 3.4,7.8). MTCT was significantly lower among infants receiving HepB-BD alone (0/39, 0% [95% CI 0-9.0]) compared to those without immunoprophylaxis at birth (20/131, 15.3% [95% CI 10.1-22.4]) (p = 0.009). No transmission occurred with HepB-BD plus HBIg (0/217, 0% [95% CI 0-1.7]). Maternal viral load &amp;gt;200,000 IU/ml (AOR 16.6, 95% CI 4.82,57.19) and HBeAg positivity (AOR 4.21, 95% CI 1.08,16.44) were associated with increased MTCT risk amongst infa

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