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Tuberculosis (TB) and COVID-19, a joint battle?

While largely vaccinated countries of the North are abandoning health measures and seem to be "turning the page" on the COVID-19 pandemic, low- and middle-income countries are still struggling to vaccinate their populations. This not only contributes to the emergence of new SARS-CoV-2 variants, but has implications for the control of other infectious diseases, such as tuberculosis (TB). For World TB Day, we are looking at what that means and how researchers from the McGill International TB Centre at the Research Institute of the McGill University Health Centre (RI-MUHC) raise awareness on the current situation and work to put an end to TB.

 “Infectious diseases such as malaria, tuberculosis, and AIDS that are now seen as “Third World diseases” were once serious threats in rich countries, but when the incidence of these diseases began to decline there, the global North moved on and reduced investments in new tools and programs. Now, with COVID-19, the developing world has once again been left to fend for itself against an extremely transmissible virus without the necessary vaccine doses, tests, and treatment tools. Some pandemics never truly end—they just become invisible to people in the global North,” wrote Dr. Madhukar Pai and co-authors in The Atlantic, on March 4, 2022.

Dr. Madhukar Pai
Dr. Madhukar Pai

Internationally renowned for his research and advocacy work towards increased health equity, Dr. Pai is Canada Research Chair in Epidemiology and Global Health at McGill University, as well as Associate Director of the McGill TB Centre and Senior Scientist in the Infectious Diseases and Immunity in Global Health Program at the RI-MUHC. A frequent contributor in Forbes and other important media outlets, he helps sensitize the public to various global health challenges related to TB and COVID-19.

« In 2020, there were roughly 1.5 million tuberculosis deaths worldwide, representing the first year-over-year increase in tuberculosis deaths since 2005,” wrote Dr. Pai with co-authors in an article published in January 2022 in the New England Journal of Medicine, in which they explain that the TB epidemic has been worsening because of COVID-19. The authors report that deaths from TB have increased because of reduced access to care, and that millions of TB cases were undetected in countries that had major COVID-19 outbreaks and healthcare service disruptions. In another article published yesterday in The Lancet Respiratory Medicine - the first of a series- Dr. Pai details the population-level and patient-level effects of COVID-19 on tuberculosis control, and proposes strategies to reverse or mitigate them.

More TB facts from the World Health Organization (WHO):

  • In 2020, TB was the second leading infectious killer after COVID-19.
  • About one quarter of the world's population have TB infection, which means people have been infected by TB bacteria, and the infection is dormant. They are not (yet) ill with the disease and cannot transmit it.
  • People infected with TB bacteria have a 5–10 percent lifetime risk of falling ill with TB. Those with compromised immune systems, such as people living with HIV, malnutrition or diabetes, or people who use tobacco, have a higher risk of falling ill.
  • TB is present in all countries, but in 2020, eight countries accounted for two thirds of new cases of TB disease, with India leading the count, followed by China, Indonesia, the Philippines, Pakistan, Nigeria, Bangladesh and South Africa.
  • Yet, TB is curable and preventable. 

In Canada, TB is particularly prevalent among certain Indigenous populations, including some in remote northern regions. This is true in Quebec, too. According to the Nunavik Regional Board of Health and Social Services (NRBHSS), the rate of TB among Inuit living in Nunavik is more than 100 times higher than that in the rest of Quebec.

RI-MUHC researchers are looking into solutions to change the above realities and progress towards the WHO goal of a world free of TB by 2030.

Reducing outbreaks with an effective screening approach

Dr. Kevin Schwartzman, director of the Division of Respiratory Medicine at the McGill University Health Centre (MUHC) and Senior Scientist in the Translational Research in Respiratory Diseases Program at the RI-MUHC, partnered with Dr. Faiz Ahmad Khan, respirologist at the MUHC and associate director of the McGill International TB Centre, and with the NRBHSS to assess the immediate and potential effects of regular community-wide screening for active and latent tuberculosis in Inuit communities with high TB rates. They found that this screening approach was cost-effective, and recommended it to help reduce outbreaks. Their findings were published in November 2021 in CMAJ.

Dr. Kevin Schwartzman
Dr. Kevin Schwartzman

Using artificial intelligence for TB detection

Dr. Ahmad Khan, who is also a scientist in the Translational Research in Respiratory Diseases Program at the RI-MUHC, has been leading research on using artificial intelligence programs to improve TB detection. Chest X-rays are an important tool to diagnose TB, but in remote areas or resource-limited settings, there isn’t always a radiologist available to read and interpret the images. Dr Ahmad Khan led an international collaboration to evaluate the performance of these programs in four different countries. The findings were published in Clinical Infectious Diseases, and informed new WHO guidance on this novel technology. Drs. Ahmad Khan and Schwartzman also recently led research – published in The Lancet Digital Health and Open Forum Infectious Diseases – that highlight the effectiveness and cost-effectiveness of this technology in Pakistan. Dr. Ahmad Khan has also been supporting efforts led by the NRBHSS and Inuit communities to address TB in Nunavik.

Dr. Ahmad Khan
Dr. Ahmad Khan

Finding shorter, safer and more effective treatments

Dr. Dick Menzies is the director of the McGill International TB Centre and the McGill-WHO Collaborating Centre for TB Research, and holds a Canada Research Chair in TB Research (Tier 1). He is leading the CAB-V (Canada, Australia, Benin and Vietnam) network, an established international research group that participates in the US Centers for Disease Control and Prevention (CDC) Tuberculosis Trials Consortium (TBTC). The group is conducting studies to find shorter, safer and more effective treatments for latent TB infection (TB prevention) and active TB disease. 

Dr. Dick Menzies
Dr. Dick Menzies

Updating the guidelines for front line healthcare workers

Dr. Menzies has also spearheaded new evidence-based guidelines for TB prevention and care in Canada, serving as editor-in-chief of the Canadian Tuberculosis Standards (8th edition) which will be published on-line on March 24, 2022. Many members of the McGill TB Centre have contributed chapters to this new version of the Canadian guide to TB for front line healthcare workers, including RI-MUHC researchers Drs Marcel Behr, Maziar Divangahi, Ahmad Khan, Madhukar Pai, Kevin Schwartzman and Dick Menzies.

Tackling TB and COVID-19 together

Dr. Pai is currently examining disruptions caused by the COVID-19 pandemic on TB services in private healthcare in three countries – India, Indonesia and Nigeria – and leading a project for the validation and integration of rapid testing for COVID-19 and TB. He argues that ending the COVID-19 pandemic quickly is critical for rebuilding tuberculosis services and other essential health services, and that this can only be achieved if rich countries redistribute surplus vaccine doses through the Covid-19 Vaccines Global Access (COVAX) program.