In November 2023 the WHO shared the Global Tuberculosis Report 2023, a “comprehensive and up-to-date assessment” on the epidemic and progress in preventing, diagnosing, and treating the disease at all levels. The report uses data from national ministries of health, with 192 countries and areas providing insights into more than 99% of the global population and cases. WHO reflects that the report “underscores a significant worldwide recovery” from 2022, an “encouraging trend” in response to the “detrimental effects of COVID-19 disruptions” on tuberculosis measures.
The ‘what’ and ‘why’
The report begins with an introduction to this “preventable and usually curable disease”: tuberculosis (TB). It is caused by the bacillus Mycobacterium tuberculosis, spread through bacteria expelled into the air by infected patients. Despite the progress that has been made in prevention and control, WHO reports that, in 2022, TB was the “world’s second leading cause of death from a single infectious agent”, following COVID-19. It caused “almost twice as many deaths as HIV/AIDS”.
“More than 10 million people continue to fall ill with TB every year.”
Roughly quarter of the global population is believed to have been infected with TB, and the risk of developing TB disease is highest in the first 2 years after infection. However, some may clear the infection. Although the disease “typically affects the lungs”, it can affect other areas as well. If a patient cannot access treatment, the risk of death is high, but for those who receive the recommended 4–6-month course of anti-TB drugs, there is an 85% chance of curing it.
“Universal health coverage (UHC) is necessary to ensure that all people who need treatment for TB disease or infection can access these treatments.”
The report also states that the number of people who become infected and develop disease, and consequently the number of TB-related deaths, can be reduced through “multisectoral action” to address determinants such as “poverty, undernourishment, HIV infection, smoking, and diabetes”. Despite these management strategies, WHO calls for “research breakthroughs” such as a new vaccine to “rapidly reduce” TB incidence.
In September 2023, a high-level meeting on TB resulted in a political declaration that “reaffirms” global targets. This report, just over a month later, comprises 3 components. The main report presents “key findings and messages”, which we explore below. To access the report yourself, click here.
Main findings and messages
The report offers an optimistic indication that we have seen “major global recovery” in the number of diagnoses and patients treated after 2 years of “COVID-related disruptions”. Although this has “started to reverse or moderate” the effects of the pandemic on the number of people dying or experiencing illness with TB, the disease was still second to COVID-19 as the cause of death from a single infectious agent. While there is a positive trend, global targets set in 2018 “have been missed” and others remain “off track”.
Case notifications
The “most obvious and immediate” consequence of COVID-19 on TB was a “large global fall” in the number of people who were “newly diagnosed with TB and reported”. Between 2019 and 2020 there was a reduction of 18%, from 7.1 million to 5.8 million, with a “partial recovery” to 6.4 million in 2021. In 2022, 7.5 million people were newly diagnosed and officially notified as a TB case, a “rebound” to above the pre-COVID-19 level that “probably” reflects the diagnosis of a “sizeable backlog of people” as well as an increase in cases.
Deaths caused
The report infers from the reduction in reported cases that “the number of people with undiagnosed and untreated TB had grown”. This means that there was an increase in deaths from TB and more community transmission of infection, which later results in increased numbers of people developing TB. In 2022 the total number of deaths caused by TB was 1.30 million, which is down from “best estimates of 1.4 million in 2020 and 2021”. COVID-related disruptions are estimated to have resulted in “almost half a million excess deaths from TB” between 2020 and 2022, compared to the number if pre-pandemic trends had continued.
Number of people developing TB
In 2022 an estimated 10.6 million people became ill with TB, an increase from 10.3 million in 2021 and 10.0 million in 2020. The TB incidence rate (new cases per 100,000 population per year) is believed to have increased by 3.9% between 2020 and 2022. This comes after an average decline of about 2% a year from 2010 to 2020. The subsequent “reversal of progress” reflects the estimated effect of disruptions to essential services during the pandemic/
Milestones
This finding contrasts “some success stories” at regional level with a “mostly off track” warning. The first End TB Strategy milestones for reductions in TB disease burden were a 35% reduction in total deaths and a 20% reduction in TB incidence rate by 2020, in comparison with 2015. The second milestones were set for 2025: a 75% reduction in deaths and a 50% reduction in incidence.
“The first milestones set for 2020 have not yet been reached either globally or in most WHO regions and countries, and the second milestones are far away in most parts of the world.”
Beyond 2022
The report refers to 26 country-specific models for the period of 2020-2022, which also allow projections for subsequent years. It is hoped that if the recoveries in 2022 are sustained, the global number of deaths should “continue to decline”. The upward trend in TB incidence may be reversed in 2023 or 2024.
Global targets can only be achieved if diagnostic, treatment, and prevention services are offered “within the context of progress towards UHC” with “multisectoral action to address the broader determinants”. When countries adopt the Sustainable Development Goals (SDGs), they commit to achieving UHC by 2030.
The need for a vaccine
The End TB Strategy targets will not be met without “intensified research and innovation”. The priorities identified in the report include a “vaccine to reduce the risk of infection” and a vaccine or drug to “cut the risk of TB disease in people already infected”. In 2020 Member States adopted WHO’s strategy for research and innovation, which seeks to encourage “accelerated” research and innovation and “improve equitable access” to the results of this research.
Despite some progress, research is “constrained by the overall level of investment”. Although WHO recognises “modest increases”, recent data show that only “half of the global target” from the first high-level meeting on TB has been secured.
Dr Tedros Adhanom Ghebreyesus, WHO Director-General, commented that humanity has the “opportunity that no generation in the history of humanity has had: the opportunity to write the final chapter in the story of TB”.
Have you read the report yet? Let us know your thoughts in the comments. For more on TB vaccine development at the World Vaccine Congress West Coast this month get your tickets here. If you can’t join us, don’t forget to subscribe for more insights.
