Key points about tuberculosis

  • Tuberculosis (TB) is an infection spread through coughing, sneezing or spitting. You can have a latent form of TB for many years before developing symptoms.
  • About a third of the world's population is likely to be infected with the TB bacteria and most don't know they've been infected and have no symptoms (latent or sleeping TB).
  • About 1 in 10 people with latent TB develop active TB at some point..
  • While TB usually infects your lungs, other parts of your body can also be affected.
  • TB can be a very serious disease, particularly for young children and older people.
  • TB is treated by taking a combination of antibiotics for at least 6 months. If you've spent time with someone with active TB, see your doctor. 
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Video: How the body reacts to tuberculosis

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(Médecins Sans Frontières/Doctors Without Borders, UK, 2014) 

Most people who are infected with the TB bacteria don't have symptoms of infection, because the bacteria are not active. This is called latent (or sleeping) TB.

One in 10 people who have latent TB may develop active TB at some time in their lives. The risk of developing active disease is greatest in the first year after infection, but active disease often doesn't occur until many years later.

Can I catch TB off someone with latent TB?

A person with latent TB infection can't spread the bacteria to other people. You don't need to be tested if you have spent time with someone with latent TB infection. However, if you have spent time with someone with TB disease or someone with symptoms of TB, you should be tested.

How is latent TB diagnosed?

A Mantoux skin test is used to identify people with latent TB – people who may be infected with TB bacteria but don't have active disease. You will be asked to have a Mantoux skin test if you are at increased risk of exposure to TB. Read more about the Mantoux skin test.

How is latent TB treated?

Not all people with latent TB are treated. Only people at high risk of developing active TB disease are treated, such as people who have recently been exposed to TB disease, people with certain ongoing medical conditions or people taking certain medications that weaken their immune system.

Treatment for latent TB is antibiotics taken for 3–12 months. Treatment is effective in reducing your future risk of developing TB disease.

TB is spread through coughing, sneezing or spitting. The bacteria are carried into the air and people nearby can breathe them in through their mouths and noses. 

TB can stay inactive your body for many years before it develops. This is called latent tuberculosis infection. Even though you feel well and healthy, if you have latent TB your doctor may still advise treatment to make sure you don't develop TB disease. 

The following people are at greatest risk of getting TB:

  • People in close contact with someone who is a known case of TB. Most children get TB from an infectious adult in their immediate or extended family/whānau.
  • People living in institutions, including refugee camps and immigration centres, prisons, rest homes and mental health facilities.
  • People regularly coming into contact with cows, deer, possums and certain animal products are at risk of getting bovine TB. This is very rare in Aotearoa New Zealand. The most likely source of exposure to bovine TB is drinking unpasteurised milk from an infected cow or handling an infected animal carcass.

You cannot get TB from clothes, drinking glasses, eating utensils, toilets or other surfaces where a person with TB has been, or from shaking hands with them. 

Symptoms of TB depend on which part of your body is affected. Tuberculosis of your lungs is by far the most common type. 

Symptoms of TB in your lungs
  • ongoing cough (lasting 3 weeks or longer)
  • coughing up blood in your spit 
  • chest pain when you cough 
  • weight loss
  • loss of appetite (not feeling like eating)
  • fever
  • sweating at night
  • feeling weak and tired
  • feeling unwell
  • swollen glands (usually in your neck)

If you have been around someone who has TB, you should go to your doctor for tests. To start with, you will usually have a chest x-ray, followed by phlegm (sputum) tests. A chest x-ray usually shows any active lung TB.

If the chest x-ray suggests that TB is possible, the next test is to look for TB bacteria from your lung. This is done by sending samples of sputum to the laboratory. 

TB is curable. However, the bugs that cause TB are strong and it can take a long time for them to die.

Active TB (when there are symptoms) is treated with a combination of antibiotics for at least 6 months. A combination is used to prevent the bacteria becoming resistant. Examples of antibiotics used to treat TB include isoniazid, rifampicin, ethambutol and pyrazinamide.

  • It is very important if you have TB to take your medicine regularly and finish the course of medicine. 
  • If you stop taking the antibiotics too soon, you can become sick again.
  • If you don't take the antibiotics correctly, the bacteria that are still alive may become resistant to those antibiotics.
  • TB that is resistant to antibiotics is harder and more expensive to treat.
  • In some situations, healthcare providers meet with people who have TB to watch them take their medicines. This is called directly observed therapy (DOT).
  • DOT helps you complete the treatment in the least amount of time.

If you have TB, here are a few things you can do to take care of yourself and protect your family/whānau and friends.

Take your medicine

Taking your medicine and finishing all of it is the best way to protect yourself and others from TB. When you stop treatment early or miss doses, TB bacteria have a chance to develop mutations (changes) that allow them to survive despite you taking TB medicine. These drug-resistant strains are much more difficult to treat.

Healthy eating and exercise 

As well as taking your medicine, you can help your body fight the infection by eating healthy foods, getting enough sleep and exercise. Many people lose weight because of the infection. If you are losing too much weight, eat balanced meals with enough protein and calories to help you keep weight on.

Mental health and wellbeing

People often feel embarrassed about having TB and worry that other people will find out about it. It's also easy to feel isolated and alone because you can't go to work, school or public places until you can no longer infect other people. If you are feeling depressed or have a low mood, tell your doctor or call or text 1737(external link) to talk to a counsellor for free any time day or night.

Reduce the spread

It usually takes a few weeks of treatment before you're not infectious (able to spread TB to other people). In the first 3–4 weeks, you can reduce the spread of infection by:

  • staying home and not going to work or school
  • avoiding sharing a room with others
  • wearing a surgical mask when you are around others
  • covering your mouth when you sneeze, cough or laugh
  • airing or ventilating your room, because TB spreads more easily in closed spaces. 

If you have latent TB (no symptoms), your doctor may advise you to take medicine to reduce your chance of getting active TB. By preventing latent TB from becoming active, you also won't spread TB to anyone else.

BCG vaccine

The BCG (Bacillus Calmette-Guérin) vaccine helps protect against severe forms of TB by helping your immune system fight against it. In New Zealand, the BCG vaccine is not recommended for the general population because the rates of TB are quite low in many parts of the country.

BCG vaccination is recommended for babies or children under 5 years of age if they have a higher risk of getting TB. Read more about the BCG vaccine.  

Tuberculosis (TB) HealthEd, NZ English(external link)Russian(external link), Ukraine(external link)
Tuberculosis(external link) Immunisation Advisory Centre, NZ
Tuberculosis disease(external link) Health New Zealand | Te Whatu Ora
Tuberculosis (TB)(external link) National Public Health Service – Northern Region
Tuberculosis(external link) NHS, UK


Resources from other organisations that give you more information on tuberculosis, including in other languages.
Tuberculosis factsheet – Information about TB, including symptoms and treatmentHealth Ed, NZ, 2022 English(external link), Russian(external link), Ukraine(external link)
BCG vaccine – information for parents(external link) HealthEd, NZ, 2023 English(external link), te reo Māori(external link), Tongan(external link), Amharic(external link), Arabic(external link), Burmese(external link), Cambodian-Khmer(external link), Chinese (simplified)(external link), Chinese (traditional)(external link), Fijian(external link), Hindi(external link), Japanese(external link), Persian (Farsi)(external link), Pushto(external link), Somali(external link), more languages(external link)
BCG vaccine – aftercare for parents(external link) Health Ed, NZ, 2009 English(external link), Te reo Māori(external link), Tongan(external link), Amharic(external link), Arabic(external link), Burmese(external link), Chinese traditional(external link), Chinese simplified(external link), Fijian(external link), Japanese(external link), Hindi(external link), Khmer (Cambodian)(external link), Persian (Farsi)(external link), Pushto(external link), Somali(external link), Vietnamese(external link), more languages(external link)

Note: These resources are from overseas so some details may be different in New Zealand, eg, phone 111 for emergencies or, if it’s not an emergency, freephone Healthline 0800 611 116.
Tuberculosis factsheet(external link) NSW Multicultural Health Communication Service, Australia, 2005 English(external link), Samoan(external link), Tongan(external link), Chinese (traditional)(external link), Farsi(external link), Thai(external link), Vietnamese(external link)
Tuberculin skin test(external link) NSW Multicultural Health Communication Service, Australia, 2005 English(external link), Samoan(external link), Tongan(external link), Chinese (traditional)(external link), Farsi(external link), Thai(external link), Vietnamese(external link)
What you should know about tuberculosis (TB)(external link)Association of Asian Pacific Community Health Organizations, 1995 English(external link), Chinese(external link), Ilocano(external link), Korean(external link), Tagalog(external link), Thai(external link), Vietnamese(external link) 


  1. Tuberculosis(external link) Immunisation Advisory Centre, NZ
  2. Guidelines for tuberculosis control in NZ(external link) Health New Zealand | Te Whatu Ora
  3. Antituberculosis drugs(external link) NZ Formulary
  4. BCG vaccine and vaccinator endorsement Health New Zealand | Te Whatu Ora

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Credits: Healthify editorial team. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Dr Helen Kenealy, Geriatrician and General Physician, Counties Manukau DHB

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