The intersecting pandemics of tuberculosis and COVID-19: population-level and patient-level impact, clinical presentation, and corrective interventions

Abstract

The global tuberculosis burden remains substantial, with more than 10 million people newly ill per year. Nevertheless, tuberculosis incidence has slowly declined over the past decade, and mortality has decreased by almost a third in tandem. This positive trend was abruptly reversed by the COVID-19 pandemic, which in many parts of the world has resulted in a substantial reduction in tuberculosis testing and case notifications, with an associated increase in mortality, taking global tuberculosis control back by roughly 10 years. Here, we consider points of intersection between the tuberculosis and COVID-19 pandemics, identifying wide-ranging approaches that could be taken to reverse the devastating effects of COVID-19 on tuberculosis control. We review the impact of COVID-19 at the population level on tuberculosis case detection, morbidity and mortality, and the patient-level impact, including susceptibility to disease, clinical presentation, diagnosis, management, and prognosis. We propose strategies to reverse or mitigate the deleterious effects of COVID-19 and restore tuberculosis services. Finally, we highlight research priorities and major challenges and controversies that need to be addressed to restore and advance the global response to tuberculosis.

Figure 1

Impact of the COVID-19 pandemic on global, regional, and national tuberculosis detection and mortality There has been a substantial decline in tuberculosis case detection globally of about 18% in newly ill people reported with tuberculosis at the global (A), regional (B), and national (C) levels, across key regions. Modelling has predicted that this acute drop will probably be followed by a rebound increase in tuberculosis incidence (C); data from three exemplar countries are shown relative to baseline trajectories before COVID-19. The decline in case detection is also estimated to have resulted in an acute increase in mortality in 2020 and is anticipated to take the next few years to reach prepandemic baselines (D); data from three exemplar countries are shown relative to baseline trajectories before COVID-19. Images reproduced by permission of WHO.

Figure 2

Tuberculosis cascade of care and the potential effects of the COVID-19 pandemic A detailed look at the potential effects of the COVID-19 pandemic at each step of the typical tuberculosis care cascade: exposure and susceptibility to Mycobacterium tuberculosis; access to preventive services; testing, diagnosis, and treatment initiation; and completion. The effects of COVID-19 at each step of the tuberculosis care cascade (blue) are detailed in the adjacent boxes, with an increase in the burden of tuberculosis denoted by red text or a decrease denoted by green text. ACF=active case finding. BCG=Bacillus Calmette-Guérin. HCW=health-care worker. IPC=infection prevention and control. PTLF=pretreatment loss to follow-up.

Figure 3

Catastrophic effects of the COVID-19 pandemic on global tuberculosis response and the global economy An overview of how the COVID-19 pandemic has affected the resources available for tuberculosis control efforts and its effect on individual households leading to a cycle of increased susceptibility, death, and poverty. Poverty is driven by tuberculosis-related and COVID-19-related deterioration in macroeconomic conditions, leading to catastrophic costs at the patient level, and is a proxy for increased mortality and burden of tuberculosis. GDP=gross domestic product. LMICs=low-income and middle-income countries. PPE=personal protective equipment.

Figure 4

Co-prevalence of COVID-19, tuberculosis, HIV, and non-communicable diseases (A) Euler diagram of the estimated prevalence of HIV, current tuberculosis, and non-communicable comorbid conditions in patients admitted to hospital with SARS-CoV-2 infection by age group. (B) Forest plot of the effect of HIV and active tuberculosis on the risk of mortality associated with COVID-19. Multivariable analysis of factors associated with COVID-19 in-hospital mortality from published South African data is shown., The model adjusted for age, sex, race, other comorbid conditions, health sector, province, and month of admission. Adjusted odds ratios and 95% CIs are shown for HIV only, current tuberculosis only, and HIV and tuberculosis co-infection. Values that overlap between comorbidities are noted in the appendix (p 13).