Coronavirus disease (COVID-19): Tuberculosis

11 May 2020 | Q&A

WHO is continuously monitoring and responding to tuberculosis (TB) prevention and care during the COVID-19 pandemic. Health services need to be actively engaged for an effective and rapid response to COVID-19 while ensuring that TB and other essential health services are maintained.

While experience on COVID-19 infection in tuberculosis (TB) patients remains limited, it is anticipated that people ill with both TB and COVID-19 may have poorer treatment outcomes, especially if TB treatment is interrupted.

Older age, diabetes and chronic obstructive pulmonary disease (COPD) are linked with more severe COVID-19 and are also risk factors for poor outcomes in TB.

TB patients should take precautions as advised by health authorities to be protected from COVID-19 and continue their TB treatment as prescribed.

People ill with COVID-19 and TB show similar symptoms such as cough, fever and difficulty breathing. Both diseases attack primarily the lungs and although both biological agents transmit mainly via close contact, the incubation period from exposure to disease in TB is longer, often with a slow onset.

While both tuberculosis (TB) and COVID-19 spread by close contact between people the exact mode of transmission differs, explaining some differences in infection control measures to mitigate the two conditions.

TB bacilli remain suspended in the air in droplet nuclei for several hours after a TB patient coughs, sneezes, shouts, or sings, and people who inhale them can get infected. The size of these droplet nuclei is a key factor determining their infectiousness. Their concentration decreases with ventilation and exposure to direct sunlight.

COVID-19 transmission has primarily been attributed to the direct breathing of droplets expelled by someone with COVID-19 (people may be infectious before clinical features become apparent). Droplets produced by coughing, sneezing, exhaling and speaking may land on objects and surfaces, and contacts can get infected with COVID-19 by touching them and then touching their eyes, nose or mouth . Handwashing, in addition to respiratory precautions, are thus important in the control of COVID-19. 

 

Modelling work suggests that if the COVID-19 pandemic led to a global reduction of 25% in expected TB detection for 3 months – a realistic possibility given the levels of disruption in TB services being observed in multiple countries – then we could expect a 13% increase in TB deaths, bringing us back to the levels of TB mortality that we had 5 years ago. This may even be a conservative estimate as it does not factor in other possible impacts of the pandemic on TB transmission, treatment interruptions and poorer outcomes in people with TB and COVID-19 infection (Predicted impact of the COVID-19 pandemic on global tuberculosis deaths in 2020, P. Glaziou). Between 2020 and 2025 an additional 1.4 million TB deaths could be registered as a direct consequence of the COVID-19 pandemic (Stop TB Partnership analysis).

All measures should be taken to ensure continuity of services for people who need preventive and curative treatment for tuberculosis (TB). 

People-centred delivery of tuberculosis (TB) prevention, diagnosis, treatment and care services should be ensured in tandem with the COVID-19 response.

Prevention: Measures must be implemented to limit transmission of TB and COVID-19 in congregate settings and health care facilities. Administrative, environmental and personal protection measures apply to both (e.g. basic infection prevention and control, cough etiquette, patient triage).

Provision of TB preventive treatment should be maintained as much as possible.

Diagnosis: Tests for TB and COVID-9 are different and both should be made available for individuals with respiratory symptoms, which may be similar for the two diseases.

Treatment and care: People-centred outpatient and community-based care should be strongly preferred over hospital treatment for TB patients (unless serious conditions require hospitalization) to reduce opportunities for transmission.

Anti-TB treatment, in line with the latest WHO guidelines, must be provided for all TB patients, including those in quarantine and those with confirmed COVID-19 disease. Adequate stocks of TB medicines should be provided to all patients to reduce trips to collect medicines.

Use of digital health technologies for patients and programmes should be intensified. In line with WHO recommendations, technologies like electronic medication monitors and video-supported therapy can help patients complete their TB treatment.

 

Appropriate planning and monitoring are essential to ensure that procurement and supply of tuberculosis (TB) medicines and diagnostics are not interrupted.

WHO is monitoring medicine supply at the global level, while The Global Fund, the Stop TB Partnership Global Drug Facility (GDF), USAID, Unitaid and other donors play an essential role in supporting countries to secure adequate and sustainable supplies of TB medicines, drugs and diagnostics. 

Countries are advised to place their orders for 2020 delivery as soon as possible given anticipated delays in transport and delivery mechanisms.

The response to COVID-19 can benefit from the capacity building efforts developed for tuberculosis (TB) over many years of investment by national authorities and donors. These include infection prevention and control, contact tracing, household and community-based care, and surveillance and monitoring systems.

Although modes of transmission of the two diseases are slightly different, administrative, environmental and personal protection measures apply to both (e.g. basic infection prevention and control, cough etiquette, patient triage).

TB laboratory networks have been established in countries with the support of WHO and international partners. These networks as well as specimen transportation mechanisms could also be used for COVID-19 diagnosis and surveillance.

Respiratory physicians, pulmonology staff of all grades, TB specialists and health workers at the primary health care level may be points of reference for patients with pulmonary complications of COVID-19. They should familiarize themselves with the most current WHO recommendations for the supportive treatment and containment of COVID-19.

TB programme staff with their experience and capacity, including in active case finding and contact tracing, are well placed to support the COVID-19 response.

Various digital technologies used in TB programmes can support the COVID-19 response, including adherence support, electronic medical records and eLearning.

 

 

Health care facilities, including those that diagnose and care for tuberculosis (TB) and lung diseases, are bound to receive patients with COVID-19, many of whom may be undiagnosed. Additional measures may be needed to avoid that staff in these centres are exposed to COVID-19 infection.

The Information Note includes additional, temporary measures that should be considered. These include alternative arrangements to reduce visits for TB follow-up, precautions for sputum collection, transportation and testing. The note also includes a description of ethical obligations in this setting.

Existing WHO recommendations for infection prevention and control for TB and for COVID-19 should be strictly implemented, including personal protection equipment.

Lessons learnt over many years of TB infection prevention and control, contact tracing, investigation and management can benefit efforts to stop the spread of COVID-19.


 

In a context of widespread restriction of movement of the population in response to the pandemic and isolation of COVID-19 patients, communication with the healthcare services should be maintained so that people with tuberculosis (TB), especially those most vulnerable, get essential services. This includes management of adverse drug reactions and co-morbidities, nutritional and mental health support, and restocking of the supplies of medicines.

Enough TB medicines will need to be dispensed to the patient or caregiver to last until the next visit. This will limit interruption or unnecessary visits to the clinic. Mechanisms to deliver medicines at home and even to collect specimens for follow-up testing may become expedient. Home-based TB treatment is bound to become more common. Alternative arrangements to reduce clinic visits may involve limiting appointments to specific times to avoid exposure to other clinic attendees; using digital technologies to maintain treatment support. Community health workers become more critical as treatment is more decentralized.

More TB patients will probably start their treatment at home and therefore limiting the risk of household transmission of TB during the first few weeks is important.

Vulnerable populations who have poor access to healthcare should not get further marginalized during the pandemic.

 

The diagnostic methods for tuberculosis (TB) and COVID-19 are quite distinct and commonly require different specimens.  

Sputum, as well as many other biological specimens, can be used to diagnose TB using culture or molecular techniques.

Tests for COVID-19 are done most commonly by nasopharyngeal or oropharyngeal swab or wash in ambulatory patients, but sputum or endotracheal aspirate or bronchoalveolar lavage may be used in patients with severe respiratory disease.  Molecular testing is the currently recommended method for the identification of infectious COVID-19 and just as for TB, serological assays are not recommended for the routine diagnosis of COVID-19.

The pipeline for COVID-19 diagnostics has flourished impressively within a few months. Amongst these is the Xpert® Xpress SARS-CoV-2 cartridge for use on GeneXpert machines, which are machines used in TB diagnosis. WHO is currently evaluating this cartridge as well as other tests. Additional resources to roll out COVID-19 testing should be mobilized rather than relying only on existing resources that are used for TB, to ensure that the diagnostic coverage for TB is maintained as necessary.

 

 

Testing of the same patient for both tuberculosis (TB) and COVID-19 would generally be indicated for three main reasons, subject to the specific setting in each country:

  1. clinical features that are common to both diseases; or 
  2. simultaneous exposure to both diseases; or
  3. presence of a risk factor

As the pandemic advances, more people of all ages, including TB patients, will be exposed to COVID-19. The Information Note contains further considerations for simultaneous testing for the two diseases.


 

In most cases tuberculosis (TB) treatment is not different in people with or without COVID-19 infection.

Experience on joint management of both COVID-19 infection and TB remains limited. However, suspension of TB treatment in COVID-19 patients should be exceptional. TB preventive treatment, treatment for drug-susceptible or drug-resistant TB disease should continue uninterrupted to safeguard the patient’s health, reduce transmission and prevent the development of drug-resistance.

While treatment trials are ongoing, no medication is currently recommended for COVID-19 and therefore no cautions on drug-drug interactions are indicated at present. TB patients on treatment should nonetheless be asked if they are taking any medicines, including traditional cures, that may interact with their medication.

Effective treatments to prevent TB and to treat active TB have been scaled up and are in use worldwide. The risk of death in TB patients approaches 50% if left untreated and may be higher in the elderly or in the presence of comorbidity. It is critical that TB services are not disrupted during the COVID-19 response.

Gathering evidence as this pandemic unfolds will be very important, while upholding the norms of professional conduct and patient confidentiality when handling clinical details.

There is no evidence at this point that the Bacille Calmette-Guérin vaccine (BCG) protects people against infection with COVID-19 virus. Clinical trials addressing this question are underway, and WHO will evaluate the evidence when it is available. In the absence of evidence, WHO does not recommend BCG vaccination for the prevention of COVID-19. WHO continues to recommend reserving BCG for neonatal vaccination in settings with a high risk of tuberculosis.