What Are the Differences Between Tuberculosis and COVID-19?

Tuberculosis (TB) and COVID-19 (coronavirus disease 2019) are both infectious respiratory illnesses. Although tuberculosis and COVID-19 are different diseases with varying symptoms, they share some of the same symptoms such as cough, fever, shortness of breath, fatigue, and loss of appetite.
Tuberculosis (TB) and COVID-19 (coronavirus disease 2019) are both infectious respiratory illnesses. Although tuberculosis and COVID-19 are different diseases with varying symptoms, they share some of the same symptoms such as cough, fever, shortness of breath, fatigue, and loss of appetite.

Tuberculosis (TB) and COVID-19 (coronavirus disease 2019) both cause respiratory illness, but they are different diseases. 

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis that usually affects the lungs. It is not very common in the U.S., but it remains a leading cause of death in other parts of the world.

COVID-19 (coronavirus disease 2019) is a novel (new) coronavirus, one not previously identified in humans, responsible for an outbreak of respiratory illness that became a global pandemic in 2020. COVID-19 is different from other coronaviruses that cause mild illness, such as the common cold.

Symptoms of both tuberculosis and COVID-19 that are similar include:

Symptoms of active tuberculosis disease that are different from COVID-19 include:

Symptoms of COVID-19 that are different from symptoms of tuberculosis include:

In addition to several different symptoms, other differences between tuberculosis and COVID-19 include: 

  • Cause: The diseases are caused by different types of germs
    • Tuberculosis is caused by a bacterium called Mycobacterium tuberculosis
    • COVID-19 is caused by a virus called the novel coronavirus (or SARS-Cov-2)
  • Transmission: Both tuberculosis and COVID-19 are spread through respiratory droplets propelled into the air when a person infected with either illness coughs or sneezes
    • People only need to inhale a few tuberculosis bacteria to become infected; asymptomatic people who have latent TB infection cannot spread the disease
    • COVID-19 can be transmitted through the air with close contact, but asymptomatic patients can also spread the disease
  • Incubation period
    • A person may test positive on a tuberculin tests between 2 to 12 weeks following exposure, but the bacteria is usually dormant and the incubation period for active disease is between one to two years
    • The incubation period for COVID-19 is between 2 to 14 days, with an average of 5 days
  • Diagnosis
    • Tuberculosis is diagnosed with a skin tuberculin test and a chest X-ray
    • COVID-19 is diagnosed with a PCR test or an antigen test

What Causes Tuberculosis and COVID-19?

Tuberculosis is caused by a bacterium called Mycobacterium tuberculosis. The bacteria are spread through respiratory droplets propelled into the air when a person sick with tuberculosis coughs or sneezes.

Rarely, tuberculosis may be spread by eating or drinking something infected with tuberculosis, such as unpasteurized milk from an animal with TB. 

Risk factors for developing tuberculosis include: 

  • Being a health care or laboratory worker in contact with patients with active TB disease
  • Known exposure to someone with active TB
  • Birth or extended stay in a part of the world where TB is common
  • Medications that weaken the immune system, such as steroids or medications for rheumatoid arthritis
  • HIV infection

COVID-19 (coronavirus disease 2019) is caused by a novel strain of coronavirus that is transmitted from person-to-person through respiratory droplets that are propelled into the air when an infected person sneezes or coughs. 

Less commonly, COVID-19 may be transmitted when a person touches a surface or object that has the virus on it, and then touches their mouth, nose, or eyes.

How Are Tuberculosis and COVID-19 Diagnosed?

Tuberculosis is diagnosed with a medical history and physical exam and the following tests:

  • Tuberculin skin test (sometimes also called a purified protein derivative test [PPD])
  • Blood test (interferon-gamma release assays [IGRAs])
  • Imaging such as a chest X-ray to make sure the TB is not active and causing disease

COVID-19 (coronavirus disease 2019) is diagnosed with a medical history (including any recent known exposure to COVID-19) and physical exam, looking for symptoms of COVID-19. Tests used to diagnose COVID-19 include:

  • PCR tests (genetic or molecular test) 
  • Antigen test

An antibody test may be used to determine if there is a past COVID-19 infection. Antibody tests are not used to diagnose current infections because it takes up to three weeks following infection for the body to produce antibodies to the virus. 

What Is the Treatment for Tuberculosis and COVID-19?

Tuberculosis can be cured; however, it is important for patients to take all medicines for the duration they are prescribed, exactly as prescribed. Drug-resistant TB is harder and more expensive to treat. Untreated tuberculosis can be deadly. 

Treatment for latent tuberculosis infection usually lasts three months or longer and includes: 

  • There are several different drug regimens 
    • Rifampin daily for four months
    • Isoniazid plus rifampin daily for three months
    • Isoniazid plus rifapentine weekly for three months (usually given weekly by a trained health care worker)
    • For people who cannot take rifampin or rifapentine, an alternative is isoniazid daily for six or nine months
  • Avoiding alcohol and acetaminophen (Tylenol), both of which can make the liver work harder, potentially increasing the risk of liver injury from TB medications
  • People treated for latent TB infection are usually monitored once monthly by a doctor to check for medication toxicity, such as liver damage 

Treatment for active tuberculosis disease usually lasts six to nine months and includes: 

  • First-line anti-TB agents that form the core of treatment regimens are:
  • Regimens for treating TB disease have an intensive phase of two months, followed by a continuation phase of either four or seven months (total of six to nine months for treatment)

There is no current cure for COVID-19 (coronavirus disease 2019) and treatment is aimed at relieving symptoms in mild to moderate cases. 

Patients with mild to moderate illness are advised to remain home and self-isolate for up to 14 days to avoid spreading the virus. Treatments for mild to moderate COVID-19 symptoms include:

  • Over-the-counter (OTC) pain relievers 
  • Cough suppressants
  • Rest
  • Drinking plenty of fluids 

Two medications called bamlanivimab and REGN-COV2, which are monoclonal antibodies, have received Emergency Use Authorization (EUA) from the Food and Drug Administration (FDA) to treat mild-to-moderate COVID-19 in patients at high risk for progressing to severe COVID-19 and/or hospitalization. Bamlanivimab and REGN-COV2 are not indicated for use in severe cases.

For more severe COVID-19 cases, patients may require hospitalization. Treatments may include:

  • Antiviral therapy with remdesivir 
  • Corticosteroids 
  • Immunotherapy 
    • Convalescent plasma
    • Immunoglobulin products
    • Interleukin inhibitors
    • Interferons
    • Kinase inhibitors
  • Antithrombotic therapy: anticoagulants and antiplatelet therapy 
  • High-flow nasal cannula (HFNC) oxygen 
  • Ventilation 

Studies on hydroxychloroquine have shown it to be ineffective with a high risk of fatal heart arrhythmias, and it is not recommended to treat COVID-19. 

How Do You Prevent Tuberculosis and COVID-19?

There is a tuberculosis vaccine called Bacillus Calmette-Guérin (BCG) that is given in many countries to prevent infection with TB, however, BCG is not routinely used to prevent TB in the U.S.

If you have been diagnosed with latent tuberculosis infection and you are in a high-risk group for developing active TB disease, medication should be taken to prevent development of TB disease.

Tuberculosis is much more common in other parts of the world than it is in the U.S. Travelers to parts of the world where TB is endemic are advised to avoid close contact or prolonged time with known TB patients in crowded, enclosed environments such as clinics, hospitals, prisons, or homeless shelters.

There are several vaccines available to prevent COVID-19. The U.S. Food and Drug Administration (FDA) has issued emergency use authorizations (EUAs) for several vaccines to prevent coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in individuals 16 years of age and older. Other vaccines for COVID-19 are in clinical trials. 

To protect yourself from getting COVID-19 (coronavirus disease 2019): 

  • Wash hands frequently with soap and water for at least 20 seconds. 
  • If soap and water are not available, use hand sanitizer with at least 60% alcohol and use a sufficient amount to rub in for 20 seconds.
  • Do not touch your mouth, nose, or eyes with unwashed hands.
  • Avoid close contact with anyone who has been diagnosed with COVID-19. 
  • If there is an outbreak in your community, stay at home and limit close contact with others. 
  • Maintain a distance of at least 6 feet from other people. 
  • Wear a face mask when out in public. 

To protect others:

  • Stay home if you’re sick, unless you need medical care. 
  • Wear a face mask around other people if you are sick. 
  • Cover your mouth and nose with a tissue or the inside of your elbow when you cough or sneeze. Discard used tissues. Immediately wash hands with soap and water for at least 20 seconds or use a hand sanitizer with at least 60% alcohol if soap and water is not available. 
  • Clean and disinfect frequently touched surfaces daily. This includes countertops, doorknobs, handles, tables, light switches, phones, keyboards, toilets, faucets, and sinks. Use EPA-registered household disinfectants.
References
https://www.cdc.gov/coronavirus/2019-ncov/index.html

https://www.covid19treatmentguidelines.nih.gov/

https://www.uptodate.com/contents/coronavirus-disease-2019-covid-19-clinical-features?search=covid19&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1#H2222473005

https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-fda-authorizes-monoclonal-antibody-treatment-covid-19

https://www.uptodate.com/contents/tuberculosis-beyond-the-basics?search=tuberculosis&source=search_result&selectedTitle=2~150&usage_type=default&display_rank=2

https://www.cdc.gov/tb/default.htm

https://news.cgtn.com/news/2020-03-24/World-Tuberculosis-Day-How-to-distinguish-TB-from-COVID-19-P74oOyLIwE/index.html