Heart failure with preserved ejection fraction (HFpEF) is increasingly recognised and diagnosed in clinical practice, a trend driven by an ageing population and a rise in contributing comorbidities, such as obesity and diabetes. Representing at least half of all heart failure cases, HFpEF is recognised as a complex clinical syndrome. Its diagnosis and management are challenging due to its diverse pathophysiology, varied epidemiological patterns, and evolving diagnostic and treatment approaches. This Seminar synthesises the latest insights on HFpEF, integrating findings from recent clinical trials, epidemiological research, and the latest guideline recommendations. We delve into the definition, pathogenesis, epidemiology, diagnostic criteria, and management strategies (non-pharmacological and pharmacological) for HFpEF. We highlight ongoing clinical trials and future developments in the field. Specifically, this Seminar offers practical guidance tailored for primary care practitioners, generalists, and cardiologists who do not specialise in heart failure, simplifying the complexities in the diagnosis and management of HFpEF. We provide practical, evidence-based recommendations, emphasising the importance of addressing comorbidities and integrating the latest pharmacological treatments, such as SGLT2 inhibitors.

Infants and young children born prematurely are at high risk of severe acute lower respiratory infection (ALRI) caused by respiratory syncytial virus (RSV). In this study, we aimed to assess the global disease burden of and risk factors for RSV-associated ALRI in infants and young children born before 37 weeks of gestation.

Since the discovery of norovirus in 1972 as a cause of what was contemporarily known as acute infectious non-bacterial gastroenteritis, scientific understanding of the viral gastroenteritides has continued to evolve. It is now recognised that a small number of viruses are the predominant cause of acute gastroenteritis worldwide, in both high-income and low-income settings. Although treatment is still largely restricted to the replacement of fluid and electrolytes, improved diagnostics have allowed attribution of illness, enabling both targeted treatment of individual patients and prioritisation of interventions for populations worldwide. Questions remain regarding specific genetic and immunological factors underlying host susceptibility, and the optimal clinical management of patients who are susceptible to severe or prolonged manifestations of disease. Meanwhile, the worldwide implementation of rotavirus vaccines has led to substantial reductions in morbidity and mortality, and spurred interest in vaccine development to diminish the impact of the most prevalent viruses that are implicated in this syndrome.

Dengue, caused by four closely related viruses, is a growing global public health concern, with outbreaks capable of overwhelming health-care systems and disrupting economies. Dengue is endemic in more than 100 countries across tropical and subtropical regions worldwide, and the expanding range of the mosquito vector, affected in part by climate change, increases risk in new areas such as Spain, Portugal, and the southern USA, while emerging evidence points to silent epidemics in Africa. Substantial advances in our understanding of the virus, immune responses, and disease progression have been made within the past decade. Novel interventions have emerged, including partially effective vaccines and innovative mosquito control strategies, although a reliable immune correlate of protection remains a challenge for the assessment of vaccines. These developments mark the beginning of a new era in dengue prevention and control, offering promise in addressing this pressing global health issue.

Thyrotoxicosis causes a variety of symptoms and adverse health outcomes. Hyperthyroidism refers to increased thyroid hormone synthesis and secretion, most commonly from Graves' disease or toxic nodular goitre, whereas thyroiditis (typically autoimmune, viral, or drug induced) causes thyrotoxicosis without hyperthyroidism. The diagnosis is based on suppressed serum concentrations of thyroid-stimulating hormone (TSH), accompanied by free thyroxine and total or free tri-iodothyronine concentrations, which are raised (overt hyperthyroidism) or within range (subclinical hyperthyroidism). The underlying cause is determined by clinical assessment, detection of TSH-receptor antibodies and, if necessary, radionuclide thyroid scintigraphy. Treatment options for hyperthyroidism include antithyroid drugs, radioactive iodine, and thyroidectomy, whereas thyroiditis is managed symptomatically or with glucocorticoid therapy. In Graves' disease, first-line treatment is a 12-18-month course of antithyroid drugs, whereas for goitre, radioactive iodine or surgery are preferred for toxic nodules or goitres. Evidence also supports long-term treatment with antithyroid drugs as an option for patients with Graves' disease and toxic nodular goitre.

Although dopamine replacement therapy remains a core component of Parkinson's disease treatment, the onset of motor fluctuations and dyskinetic movements might require a range of medical and surgical approaches from a multidisciplinary team, and important new approaches in the delivery of dopamine replacement are becoming available. The more challenging, wide range of non-motor symptoms can also have a major impact on the quality of life of a patient with Parkinson's disease, and requires careful multidisciplinary management using evidence-based knowledge, as well as appropriately tailored strategies according to the individual patient's needs. Disease-modifying therapies are urgently needed to prevent the development of the most disabling refractory symptoms, including gait and balance difficulties, cognitive impairment and dementia, and speech and swallowing impairments. In the third paper in this Series, we present the latest evidence supporting the optimal treatment of Parkinson's disease, and describe an expert approach to many aspects of treatment choice where an evidence base is insufficient.

Parkinson's disease is a progressive neurodegenerative condition associated with the deposition of aggregated α-synuclein. Insights into the pathogenesis of Parkinson's disease have been derived from genetics and molecular pathology. Biochemical studies, investigation of transplanted neurons in patients with Parkinson's disease, and cell and animal model studies suggest that abnormal aggregation of α-synuclein and spreading of pathology between the gut, brainstem, and higher brain regions probably underlie the development and progression of Parkinson's disease. At a cellular level, abnormal mitochondrial, lysosomal, and endosomal function can be identified in both monogenic and sporadic Parkinson's disease, suggesting multiple potential treatment approaches. Recent work has also highlighted maladaptive immune and inflammatory responses, possibly triggered in the gut, that accelerate the pathogenesis of Parkinson's disease. Although there are currently no disease-modifying treatments for Parkinson's disease, we now have a solid basis for the development of rational neuroprotective therapies that we hope will halt the progression of this disabling neurological condition.

The epidemiology of Parkinson's disease shows marked variations in time, geography, ethnicity, age, and sex. Internationally, prevalence has increased over and above demographic changes. There are several potential reasons for this increase, including the decline in other competing causes of death. Whether incidence is increasing, especially in women or in many low-income and middle-income countries where there is a shortage of high-quality data, is less certain. Parkinson's disease is more common in older people and men, and a variety of environmental factors have been suggested to explain why, including exposure to neurotoxic agents. Within countries, there appear to be ethnic differences in disease risk, although these differences might reflect differential access to health care. The cause of Parkinson's disease is multifactorial, and involves genetic and environmental factors. Both risk factors (eg, pesticides) and protective factors (eg, physical activity and tendency to smoke) have been postulated to have a role in Parkinson's disease, although elucidating causality is complicated by the long prodromal period. Following the establishment of public health strategies to prevent cardiovascular diseases and some cancers, chronic neurodegenerative diseases such as Parkinson's disease and dementia are gaining a deserved higher priority. Multipronged prevention strategies are required that tackle population-based primary prevention, high-risk targeted secondary prevention, and Parkinson's disease-modifying therapies for tertiary prevention. Future international collaborations will be required to triangulate evidence from basic, applied, and epidemiological research, thereby enhancing the understanding and prevention of Parkinson's disease at a global level.

The COVID-19 pandemic profoundly affected all mass gatherings for sporting and religious events, causing cancellation, postponement, or downsizing. On March 24, 2020, the Japanese Government, the Tokyo Organising Committee of the Olympic and Paralympic Games, and the International Olympic Committee decided to postpone the Tokyo 2020 Olympic and Paralympic Games until the summer of 2021. With the emergence of SARS-CoV-2, the potential creation of a superspreading event that would overwhelm the Tokyo health system was perceived as a risk. Even with a delayed start date, an extensive scale of resources, planning, risk assessment, communication, and SARS-CoV-2 testing were required for the Games to be held during the COVID-19 pandemic. The effectiveness of various mitigation and control measures, including the availability of vaccines and the expansion of effective testing options, allowed event organisers and the Japanese Government to successfully host the rescheduled 2020 Tokyo Olympic Games from July 23 to Aug 8, 2021 with robust safety plans in place. In February and March, 2022, Beijing hosted the 2022 Winter Olympic Games as scheduled, built on the lessons learnt from the Tokyo Games, and developed specific COVID-19 countermeasure plans in the context of China's national framework for the plan called Zero COVID. Results from the testing programmes at both the Tokyo and Beijing Games show that the measures put in place were effective at preventing the spread of COVID-19 within the Games, and ensured that neither event became a COVID-19-spreading event. The extensive experience from the Tokyo and Beijing Olympic Games highlights that it is possible to organise mass gatherings during a pandemic, provided that appropriate risk assessment, risk mitigation, and risk communication arrangements are in place, leaving legacies for future mass gatherings, public health, epidemic preparedness, and wider pandemic response.

Rheumatoid arthritis is a chronic, systemic, autoimmune inflammatory disease that mainly affects the joints and periarticular soft tissues. In this Seminar, we provide an overview of the main aspects of rheumatoid arthritis. Epidemiology and advances in the understanding of rheumatoid arthritis pathogenesis will be reviewed. We will discuss the clinical manifestations of rheumatoid arthritis, classification criteria, and the value of imaging in the diagnosis of the disease. The advent of new medications and the accumulated scientific evidence demand continuous updating regarding the diagnosis and management, including therapy, of rheumatoid arthritis. An increasing number of patients are now able to reach disease remission. This major improvement in the outcome of patients with rheumatoid arthritis has been determined by a combination of different factors (eg, early diagnosis, window of opportunity, treat-to-target strategy, advent of targeted disease-modifying antirheumatic drugs, and combination therapy). We will discuss the updated recommendations of the two most influential societies for rheumatology worldwide (ie, the American College of Rheumatology and European Alliance of Associations for Rheumatology) for the management of rheumatoid arthritis. Furthermore, controversies (ie, the role of glucocorticoids in the management of rheumatoid arthritis and safety profile of Janus kinase inhibitors) and outstanding research questions, including precision medicine approach, prevention, and cure of rheumatoid arthritis will be highlighted.

Chagas disease persists as a global public health problem due to the high morbidity and mortality burden. Despite the possibility of a cure and advances in transmission control, epidemiological transformations, such as urbanisation and globalisation, and the emerging importance of oral and vertical transmission mean that Chagas disease should be considered an emerging disease, with new cases occurring worldwide. Important barriers to diagnosis, treatment, and care remain, resulting in repressed numbers of reported cases, which in turn leads to inadequate public policies. The validation of new diagnostic tools and treatment options is needed, as existing tools pose serious limitations to access to health care. Integrated models of surveillance, with community and intersectional participation, embedded in the concept of One Health, are essential for control. In addition, mitigation strategies for the main social determinants of health, including difficulties imposed by migration, are important to improve access to comprehensive health care in a globalised scenario.

The global HIV response has made tremendous progress but is entering a new phase with additional challenges. Scientific innovations have led to multiple safe, effective, and durable options for treatment and prevention, and long-acting formulations for 2-monthly and 6-monthly dosing are becoming available with even longer dosing intervals possible on the horizon. The scientific agenda for HIV cure and remission strategies is moving forward but faces uncertain thresholds for success and acceptability. Nonetheless, innovations in prevention and treatment have often failed to reach large segments of the global population (eg, key and marginalised populations), and these major disparities in access and uptake at multiple levels have caused progress to fall short of their potential to affect public health. Moving forward, sharper epidemiologic tools based on longitudinal, person-centred data are needed to more accurately characterise remaining gaps and guide continued progress against the HIV epidemic. We should also increase prioritisation of strategies that address socio-behavioural challenges and can lead to effective and equitable implementation of existing interventions with high levels of quality that better match individual needs. We review HIV epidemiologic trends; advances in HIV prevention, treatment, and care delivery; and discuss emerging challenges for ending the HIV epidemic over the next decade that are relevant for general practitioners and others involved in HIV care.

Gene therapy has become a clinical reality as market-approved advanced therapy medicinal products for the treatment of distinct monogenetic diseases and B-cell malignancies. This Therapeutic Review aims to explain how progress in genome editing technologies offers the possibility to expand both therapeutic options and the types of diseases that will become treatable. To frame these impressive advances in the context of modern medicine, we incorporate examples from human clinical trials into our discussion on how genome editing will complement currently available strategies in gene therapy, which still mainly rely on gene addition strategies. Furthermore, safety considerations and ethical implications, including the issue of accessibility, are addressed as these crucial parameters will define the impact that gene therapy in general and genome editing in particular will have on how we treat patients in the near future.

The increasing prevalence of type 2 diabetes in working-age people imposes a substantial societal burden. Although physical activity is crucial for diabetes management, limited evidence exists to inform optimal strategies for promoting physical activity in this population. We aimed to determine and compare the effectiveness of interventions for increasing physical activity level in working-age people with diabetes.

Poor diet is a major public health concern. In 2021, 63·8% of adults and 22·2% of reception-age children were either overweight or obese in England. Fiscal interventions have become a popular policy measure to reduce obesity and encourage healthy eating. Such measures are highly controversial, leading to media debate promoting pro-tax and anti-tax arguments. To better understand food tax debates and the use of media analysis in public health research, we conducted a scoping review of media analyses using food taxes as a case study.

Type 2 diabetes is a public health priority for the UK. A growing body of evidence has indicated ethnic and socioeconomic disparities in rates of diabetes prevalence and complications. Attendance at diabetes follow-up checks is key to ensuring complications are identified and managed at an early stage. The aim of this rapid review was to identify and summarise evidence of ways to improve diabetes management in ethnic minority groups.

The prevalence of autoimmune conditions is two-fold higher in women than in men, especially during the reproductive years. Autoimmune conditions have been associated with a greater risk of adverse pregnancy outcomes, and some conditions have been studied more than others with inconsistent findings. The objective of this umbrella review was to identify, appraise, synthesise, and consolidate findings from published systematic reviews of autoimmune conditions and adverse pregnancy outcomes.