COVID-19 and TB

TB took 1.4 million lives in 2019, but COVID-19 – another airborne contagion that is spreading at a scale and speed unparalleled in recent history – could exacerbate TB incidence and mortality rates, derailing hard-earned gains.

While TB is important to end in its own right, as TB advocates and affected communities have stressed, the global TB response can provide important insights for the response to COVID-19. Strategies, innovations and lessons learned can be leveraged from decades of TB elimination efforts. Additionally, understanding how COVD-19 interacts with TB is essential to designing a complementary response that curtails the spread of both.

The rapid spread of COVID-19 should be a wake-up call for policy makers around the world to invest in strengthened health systems that can better address epidemics of today and be ready for the inevitable epidemics of tomorrow.

Similarities between TB and COVID-19

The TB community sees a familiar foe as the world faces COVID-19. Both diseases are airborne respiratory infections that impede host immunity, attack the lungs and cause a wide spectrum of symptoms. Both TB and COVID-19 are spread primarily through contact with respiratory droplets (in the air or on surfaces) produced during breathing, talking, coughing and sneezing. The period between exposure to the pathogen and onset of symptoms or infectivity, known as the incubation period, is much faster for COVID-19 than for TB. Individuals infected with COVID-19 typically develop symptoms of disease or become infectious within one to two weeks after exposure. In contrast, around half of people that develop TB do so within two years of infection.

Both diseases tend to disproportionately impact vulnerable populations, such as the elderly, people living with HIV who are not on treatment, the immunocompromised and people with existing respiratory illnesses. The risk for developing adverse health outcomes from both is exacerbated by underlying social, economic, racial and geographic disparities, in addition to other health conditions. TB survivors have contended with stigma and discrimination for many years in ways that are similar to what those who test positive for COVID-19 face today.

Risks to Current Progress in Global and Domestic TB Response

COVID-19 has ground economies to a halt, disrupted entire health systems and had far-reaching impacts on vertical and primary healthcare programs all over the world. A modeling analysis commissioned by the Stop TB Partnership concluded that a three-month lockdown for COVID-19 could cause an excess of 1.4 million TB deaths and 6.3 million cases in the next five years. According to the results of a recent Global Fund survey, programs across 106 countries show widespread disruptions to HIV, TB and malaria service delivery as a result of the COVID-19 pandemic, impacting approximately three-quarters of HIV, TB and malaria programs.

Supply chain disruptions have resulted in shortages and misallocation of personal protective equipment (PPE) as well as an inadequate supply and unsuitable allocation of diagnostic cartridges for both diseases. National lockdowns and stay-at-home orders are preventing the continued identification of people in need of TB prevention or treatment interventions, and disrupting treatment and support services for people with TB. In most countries, TB program staff have been detailed to the COVID-19 response. The delivery of vaccines has been put on hold in some countries, further exacerbating inadequate levels of protection against TB.

Domestic TB programs in the U.S. face similar impacts, with preliminary data from a National TB Controllers Association survey illustrating a significant shift in resources for state/local TB programs to COVID-19. Respondents reported that more than 90 percent of state and local health programs have deployed TB program personnel to their jurisdiction’s COVID-19 response. Jurisdictions are also having to devote physical resources such as supplies and space to the COVID-19 response. For example, an entire TB in-patient setting in Los Angeles, Olive View, was re-purposed for COVID-19, resulting in the premature discharge of TB patients.

The consequences of disrupting TB services are dire, especially as TB patients with lung damage may have a higher likelihood of developing life-threatening complications from COVID-19.

Countries have worked to adapt TB services to regain momentum in the fight against TB, with the backing of the Global Fund and USAID. For instance, South Africa has done community-based screenings for both TB and COVID-19. Indonesia, the Philippines and others are providing patients with several weeks’ worth of medication so they do not have to travel to a clinic, and then maintaining contact with patients via mobile phone.

Lessons Drawn from TB

TB controllers, public health practitioners and community health workers bring a wealth of expertise in airborne infection response. They know how to manage outbreaks while ensuring treatment access and socioeconomic support for patients. The TB field pioneered the comprehensive community-based strategy of “search, treat and prevent” which led to dramatic reductions of TB in the developed world. The active contact tracing strategy for testing is particularly crucial to disrupt transmission from asymptomatic carriers, and has been piloted across the world to curb the spread of COVID-19. The TB field also helped pioneer protocols for quarantine and isolation measures that have become commonplace during this pandemic.

Networks of TB diagnostic platforms across countries are well-positioned to support the response to COVID-19. For example, the GeneXpert diagnostic machine – developed through U.S. taxpayer funding to the Department of Defense, NIH and PEPFAR – was originally utilized and brought to scale for TB diagnostics. It has now been approved for rapid COVID-19 testing. There are over 23,000 GeneXpert devices worldwide that can facilitate testing, especially in low and middle-income countries. The Global Fund seeks to train more personnel to use the machines for both TB and COVID-19.

In addition, as governments around the globe partner with researchers and private companies in the race for a COVID-19 vaccine, current vaccine platforms developed for TB are being looked at in new light for possible efficacy against COVID-19. This includes the Bacillus Calmette-Guérin (BCG) vaccine, currently used to prevent childhood TB, which preliminary observational research indicates may confer some protection against COVID-19.

The experiences of the TB community can be a valuable part of the global response to COVID-19, but must not divert funds and other resources away from tuberculosis to COVID-19. The only way to defeat both of these deadly infectious diseases is to grow the total resources for both.