The Lancet Global Health

Objective/BackgroundTransmission-dynamic models are commonly used to study infectious disease epidemiology. Calibration involves identifying model parameter values that align model outputs with observed data or other evidence. Inaccurate calibration and inconsistent reporting produce inference errors and limit reproducibility, compromising confidence in modeled results. No standardized framework exists for reporting on calibration of infectious disease models, and an understanding of current cal...

Individual-based models (IBMs) informing public health policy should be calibrated to data and provide estimates of uncertainty. Two main components of model-calibration methods are the parameter-search strategy and the goodness-of-fit (GOF) measure; many options exist for each of these. This review provides an overview of calibration methods used in IBMs modelling infectious disease spread. We identified articles on PubMed employing simulation-based methods to calibrate IBMs informing public h...

Monitoring healthcare quality at a subnational resolution is key to identify and resolve geographic inequities and ensure that no sub-population is left behind. Yet, health facility surveys are typically not powered to report reliable estimates at a subnational scale. In this study, we present a framework to fill this gap and jointly analyse publicly available facility survey data, allowing exploration of temporal trends and subnational disparities in healthcare quality metrics. Specifically, o...

ObjectiveCOVID-19 transmission and the public health lock-down response are now established in sub-Saharan Africa, including Uganda. Population structure and prior morbidities differ markedly between these countries from those where outbreaks were previously established. We predicted the relative impact of COVID-19 and the response in Uganda to understand whether the benefits could be outweighed by the costs. Design and settingAge-based COVID-19 mortality data from China were applied to the po...

ObjectivesWe aimed to quantify transmission trends in South Africa during the first four waves of the COVID-19 pandemic using estimates of the time-varying reproduction number (R) and to compare the robustness of R estimates based on three different data sources and using data from public and private sector service providers. MethodsWe estimated R from March 2020 through April 2022, nationally and by province, based on time series of rt-PCR-confirmed cases, hospitalizations, and hospital-associ...

IntroductionChildren experience elevated risks of developing and dying from tuberculosis (TB). We estimated the additional pediatric TB cases and deaths that could occur over 2025-2034 if programmes supported by United States bilateral health aid and the Global Fund to Fight AIDS, Tuberculosis, and Malaria (Global Fund) are discontinued. MethodsWe collated data on funding sources for TB and HIV programs in low- and middle-income countries and constructed scenarios representing reductions in hea...

BackgroundGlobal investments to combat HIV, tuberculosis, and malaria (HTM) have delivered substantial health gains, and may have reduced the burden placed by these diseases on the routine health system. We estimated the reduction in primary health care (PHC) utilization resulting from the scale-up of HTM services over 2000-2023 in 108 low- and middle-income countries. MethodsFor each disease, we applied established mathematical models to quantify PHC utilization (outpatient visits and inpatien...

BackgroundTuberculosis remains a major public health problem in South Africa, with an estimated 300,000 cases and 55,000 deaths in 2021. New tuberculosis vaccines could play an important role in reducing this burden. Phase IIb trials have suggested efficacy of the M72/AS01E vaccine candidate and BCG-revaccination. The potential population impact of these vaccines is unknown. MethodsWe used an age-stratified transmission model of tuberculosis, calibrated to epidemiological data from South Africa...

BackgroundDelays in identifying and treating individuals with infectious tuberculosis (TB) contribute to poor health outcomes and allow ongoing community transmission of M. tuberculosis (Mtb). Current recommendations for screening for tuberculosis specify community characteristics (e.g., areas with high local tuberculosis prevalence) that can be used to target screening within the general population. However, areas of higher tuberculosis burden are not necessarily areas with higher rates of tran...

Global health initiatives have expanded access to treatment for infectious diseases - especially HIV, tuberculosis, and malaria (HTM) - in low- and middle-income countries. However, these "vertically"-funded programs often operate within fragile health systems, where workforce shortages and supply chain failures constrain their effectiveness and sustainability 1,2. Meanwhile, evaluating the health impact and value-for- money of "horizontal" investments in systems, such as supply chain strengthen...

ObjectivesAs of August 24th 2020, there have been 1,084,904 confirmed cases of SARS-CoV-2 and 24,683 deaths across the African continent. Despite relatively lower numbers of cases initially, many African countries are now experiencing an exponential increase in case numbers. Estimates of the progression of disease and potential impact of different interventions are needed to inform policy making decisions. Herein, we model the possible trajectory of SARS-CoV-2 in 52 African countries under diffe...

In response to the COVID-19 pandemic, the South African government employed various nonpharmaceutical interventions (NPIs) in order to reduce the spread of SARS-CoV-2. In addition to mitigating transmission of SARS-CoV-2, these public health measures have also functioned in slowing the spread of other endemic respiratory pathogens. Surveillance data from South Africa indicates low circulation of respiratory syncytial virus (RSV) throughout the 2020-2021 Southern Hemisphere winter seasons. Here w...

ObjectiveHuge investments in HIV, TB, and malaria (HTM) control in Malawi have greatly reduced disease burden. However, the joint impact of these services across multiple health domains and the health system resources required to deliver them are not fully understood. MethodsAn integrated epidemiological and health system model was used to assess the impact of HTM programmes in Malawi from 2010 to 2019, incorporating interacting disease dynamics, intervention effects, and health system usage. F...

BackgroundMpox, caused by the Mpox virus, is a zoonotic disease historically endemic in Central and West Africa. The Democratic Republic of Congo (DRC) bears the highest burden, with evolving epidemiology and significant public health challenges. Understanding severity and mortality trends is critical for global control efforts. MethodsThis systematic review and meta-analysis followed PRISMA guidelines to synthesize evidence on Mpox severity and mortality in the DRC from 1970 to 2024. We search...

Background and objectivesInfectious disease modelling plays a critical role in guiding policy during outbreaks. However, ongoing debates over the utility of these models highlight the need for a deeper understanding of their role in policymaking. In this scoping review we sought to assess how infectious disease modelling informs policy, focusing on challenges and facilitators of translating modelling insights into actionable policies. MethodsWe searched the Ovid database to identify modelling s...

Development assistance for health (DAH) to Malawi will likely decrease as a fraction of GDP in the next few decades. Given the countrys significant reliance on DAH for the delivery of its healthcare services, estimating the impact that this could have on health projections for the country is particularly urgent. We use the Malawi-specific, individual-based "all diseases - whole health-system" Thanzi La Onse model to estimate the impact this could have on health system capacities, proxied by the ...

BackgroundIn March 2020 the South African COVID-19 Modelling Consortium was formed to support government planning for COVID-19 cases and related healthcare. Models were developed jointly by local disease modelling groups to estimate cases, resource needs and deaths due to COVID-19. MethodsThe National COVID-19 Epi Model (NCEM) while initially developed as a deterministic compartmental model of SARS-Cov-2 transmission in the nine provinces of South Africa, was adapted several times over the cour...

1Malawi is facing a dual burden of disease, with an increase in non-communicable diseases coinciding with still-high infectious disease burdens. What this will look like in the future, and how it will impact demand for healthcare, is unknown. In this study, we use the Thanzi La Onse (TLO) model - an individual-based "all diseases - whole health-system" model calibrated to Malawis demographic, epidemiological, and healthcare data - to project population, disease burdens, and healthcare demand fro...

Background Acute malnutrition remains a major public health challenge among children under five in Malawi due to undetected and untreated cases. While several policies and programmes are in place, they face significant resource input and implementation constraints. In this study, we evaluate the potential health impact and cost-effectiveness of three interventions designed to address constraints along the care pathway in childhood acute malnutrition management. These include improving early reco...

BackgroundCurrent tuberculosis (TB) prevention and care strategies have failed to reduce disease burden at the pace required to meet global targets. Community screening may enable more rapid declines in TB burden, but evidence is limited. We used mathematical modelling to evaluate trade-offs in diagnostic algorithm, population coverage, and duration of screening. Methods and FindingsWe used a TB model, which recognised symptomatic and asymptomatic infectious TB (defined by whether an individual...