Last reviewed/revised: July 28, 2023

What is Tuberculosis (TB)?

Tuberculosis (TB) is caused by the ‘germ’ Mycobacterium tuberculosis. TB is a bacterial infection that can affect the lungs or other parts of the body.

How is Tuberculosis (TB) spread?

TB is spread from person to person through the air. This could be when a person with Active TB coughs, sneezes, or spits TB germs into the air.  These germs can be inhaled by the people they live, work or spend a lot of time with. TB cannot be spread through a short interaction or passing, as it takes a fairly long time for it to spread.

Who is at the highest risk of getting Tuberculosis (TB)?

Risk means the chance of getting the disease. People of all ages are at risk of getting a TB infection. However, there are some individuals that are at a higher risk of getting TB.

Those at a higher risk of TB include:

  • people who have had close contact with a TB infected person;
  • people who have immigrated from areas in the world with high rates of TB (e.g., India, China, Indonesia, the Philippines, Pakistan, Nigeria, Bangladesh and South Africa);
  • those working or living in areas with higher exposure to TB (e.g., homeless shelters, hospitals, correctional facilities);
  • individuals with weak immune systems (e.g., people living with HIV/AIDs, diabetes, malnutrition);
  • seniors;
  • people who use tobacco.

What is Active Tuberculosis (TB)?

Active TB occurs when the body’s immune system cannot stop the TB germs from growing. This might happen if the immune system cannot fight the germs (primary tuberculosis). It can also happen when the body has already fought off a TB infection but, these germs ‘wake up’ and become active again (reactivation tuberculosis).

Active Tuberculosis (TB) Signs and Symptoms

Active TB disease can affect people differently. This depends on where in the body the TB germs are growing. Pulmonary TB is the most common and happens when the TB germs grow in the lungs.

Symptoms of Pulmonary Active Tuberculosis (TB) include:

  • bad cough (lasting 3+ weeks)
  • chest pain
  • coughing up blood or sputum (phlegm)

Other Symptoms of Active Tuberculosis (TB) include:

  • fatigue and weakness
  • weight loss (unintentional)
  • loss of appetite
  • chills
  • fever
  • night sweats

Is Active Tuberculosis (TB) contagious?

Individual's with Active TB can be contagious. This means that the germs can be given to another person.  Active TB is contagious when it is in the lungs (known as pulmonary TB). TB in other parts of the body usually cannot spread to others.

Do you need to treat Active Tuberculosis (TB)?

Yes, you will need to take medications to treat the disease.

See the Treatment and Medication Section below.

What is Latent Tuberculosis (LTBI)?

Latent tuberculosis (LTBI) is also known as Latent Tuberculosis Infection or inactive tuberculosis. With LTBI, the TB germs are found in the body, but are considered inactive or dormant. Inactive or dormant means that although the TB germs are in the body, the germs are ‘sleeping’.  Generally, people who have latent TB do not have any symptoms or feel sick.

How is Latent Tuberculosis (LTBI) spread?

If you have latent TB, it cannot be spread to others. However, if the germs ‘wake-up’, it can become active TB.

Are those with Latent Tuberculosis (LTBI) contagious?

No, people with latent TB cannot pass the TB germs to others and are not contagious.

Do you need to treat Latent Tuberculosis (LTBI)?

Your health care provider will do a risk vs. benefit assessment. This will help to decide if you should take latent TB treatment medication. Medication for latent TB is used to stop the TB from becoming active and making you sick. Without treatment, 5-10% of latent TB individuals will develop Active TB over their life time. This is most likely to happen in the first two years after a TB infection. This risk is higher in those who have weak immune systems. If the health care provider decides the risk of developing active TB is low, an individual may not be prescribed latent TB medication.

Table 1: Differences between Latent TB and Active TB.


Active TB

(Has active TB bacteria in the body)

Latent (Inactive) TB

(Has inactive TB bacteria in the body)

Will my TB skin test be positive? Yes Yes
Will my chest x-ray be normal? No Usually
Will I feel sick? Yes No
Am I Contagious? Yes, only if the infection is in your lungs (Pulmonary TB) No
Do I need Treatment? Yes Possibly (Preventative)

Where can you get tested?

For those with a family doctor, testing for TB can be done in the doctor's office. For those without a family doctor, testing may be done at a walk-in clinic. For Trent University and Fleming College students, the campus health center can provide testing.

PLEASE NOTE: Peterborough Public Health only provides TB skin testing for individuals who have been identified as close contacts to an individual with active tuberculosis.

What do my test results mean?

A negative test result means that an active or latent TB infection is unlikely. If your test is positive, it means that you have likely been infected with the TB germs and that further testing (See Types of Tests section) needs to be done.

Types of Tests:

Mantoux Skin Test:

A Mantoux tuberculin skin test involves a small injection under the surface of your skin. This will form a small bubble or ‘bleb’ which may disappear the same day. Your TB skin test is read 48-72 hours after the injection. The nurse will focus on the size of any raised, hard, or swollen area at the injection site. Most people only need one test. Some people need it done twice because of work, school, or other reasons. The second test is called a ‘two-step’ TB test.

IGRA Blood Draw:

A TB blood test is known as an interferon-gamma release assay (IGRA) and is done by a health care provider by collecting a sample of blood, and sending it to the lab for testing. This is preferred when the person cannot return for the skin test reading, or for those who have had TB vaccination.

*Peterborough Public Health does not offer IGRA testing at this time

Chest X-Ray:

A chest x-ray is used to see if there are any signs of TB in the lungs. An X-ray is done when a person has a positive TB skin or blood test but has no symptoms. An X-ray is not used to diagnose TB, but is used to see if there is evidence of TB in the lungs.

Sputum Sample:

A sputum sample is collected and tested for TB. Sputum comes from deep in the lungs and is thick and cloudy phlegm. It is not the same as saliva or spit. Providing three sputum samples is best for most accurate results. The doctor ordering the sputum sample will provide containers to collect the sputum in, as well as instructions on how to do so.

Peterborough Public Health’s role in Tuberculosis (TB) management

Peterborough Public Health plays an important role in protecting individual and community health through the facilitation of testing, treatment, and surveillance of TB cases in Peterborough and the surrounding areas. Peterborough Public Health plays this role to keep people safe from undetected TB cases.

Tuberculosis medical surveillance (TBMS) is a medical check-up for a person who has newly arrived in Canada.  This helps to check-on the presence or status of TB. For example, TBMS can help to determine if you have TB, or can help to check if inactive TB has become active TB. This is a requirement of Immigration, Refugee and Citizenship Canada (IRCC).

What is the Tuberculosis Medical Surveillance (TBMS) process?

  1. Your documents are sent to IRCC during immigration
  2. IRCC notifies public health for follow up
  3. Public health will contact you and give you a medical surveillance form for your health care provider to complete
  4. Attend your medical surveillance appointment and give the form to your health care provider.
  5. Your completed form is sent to public health
  6. Public health ensures all documents are completed and follows up with IRCC

For more information, please visit: Medical Surveillance from the Government of Canada.

Does Tuberculosis Medical Surveillance (TBMS) cost?

If you are an international student, contact your health insurance company to verify if TBMS is covered. The cost of TBMS in Ontario may be covered by the Ontario Health Insurance Plan (OHIP). To find out if you are eligible, please call the Service Ontario INFOline at 1-800-268-1154 or visit Ministry of Health’s Apply for OHIP and Get a Health Card.

What is the treatment for Tuberculosis (TB)?

TB is treated with antibiotics (medications).

If you have active TB, you will take medications to treat the disease. If you have latent TB, your health care provider may have you take medications to stop latent TB from becoming active TB.  You may be on TB medication for a long time. This is because TB germs take a long time to die.

What happens if you do not take the treatment medications correctly?

Taking medication exactly as prescribed is important. Even if you start to feel better, you must continue to take the medication for as long as your health care provider said. If you stop taking the medications, the TB germs can become resistant, which could mean the TB germs may not die, and it may become active TB. If this happens, you will likely have to take different medications for a longer length of time.

How long is treatment?

Medication for active TB disease is given in 2 phases: the intensive phase and continuation phase. The intensive phase will rapidly kill TB germs and prevent drug-resistant organisms and usually lasts around 2 months.  The continuation phase prevents TB disease reoccurrence. This can vary in duration, but typically will continue for several months after the intensive phase.

Lengths of treatment can differ based on the types of medications used (Table 1).

Table 1: Common medications and treatment regimens for TB

  Duration Frequency Common Adverse Effects
First-Line Regimens
Rifapentine and isoniazid (3HP) 3 months
(12 doses)
Once weekly Flu-like reactions, drug interactions
Rifampin (4 R) 4 months
(120 doses)
Daily Rash, drug interactions
Second-Line Regimens
Isoniazid (9H) 9 months
(270 doses)
Daily Hepatoxicity, peripheral neuropathy
Alternative Regimens
Isoniazid (6H) 6 months
(180 doses)

Hepatoxicity, peripheral neuropathy

Intermittent isoniazid for 9 months

9 months
(78 doses)

Twice Weekly

Hepatoxicity, peripheral neuropathy

Isoniazid and rifampin (3HR)

3 months
(90 doses)

Daily Hepatoxicity, peripheral neuropathy, drug interactions

Information from Canadian Tuberculosis Standards (8th edition).

What are possible side effects to the medications?

It is important to review all other medications that you are taking to ensure they are safe to take with TB medications.

When taking medications for the treatment of TB, many individuals will experience some side effects.  Please call your health care provider immediately if you experience any side effects.

Some of the side effects that may occur from TB medications include:

  • Flu-like symptoms
  • Hepatoxicity
    • Rash
    • Nausea
    • Vomiting
    • Stomach pain
    • Fever
    • Tiredness/Fatigue
    • Dark colored urine or light-colored stool
    • Jaundice (yellowing of skin and eyes)
    • Lack of appetite
    • Tingling sensation in hands and feet
    • Tingling or numbness around the mouth

If you are taking rifampin (RIF) or rifapentine (RPT) you may notice an orange discoloration of urine and possibly other body fluids. This is normal.

Isolation Guidance for Tuberculosis (TB) Cases

To help protect your family and friends, stay at home if you have been instructed to isolate. Isolation means staying away from other people in your house, not going into public places (for example work, school, places of worship, community centers, grocery stores), and not taking public transportation (for example buses, trains, airplanes, boats). A public health nurse will tell you when you can end your isolation but plan for this to be around two weeks. To end isolation, you must not be able to spread the TB disease to other people.

Guidance for Tuberculosis (TB) Contacts

If you have been exposed to someone with active TB, Peterborough Public Health will contact you.  You may be recommended to get a TB skin test or TB blood test. These tests can determine if you have TB germs in your body. You will not be told who exposed you as this is protected health information.