Tuberculosis (TB) is an infection that is spread through coughing, sneezing or spitting. You can have a latent form of TB for many years before developing symptoms.
Key points about tuberculosis (TB)
- About a third of the world's population is likely to be infected with the TB bacteria, Mycobacterium tuberculosis. Most don't know they have been infected and have no symptoms. This is called latent (sleeping) TB.
- About 1 in 10 people with latent TB develop active TB at some time in their lives.
- While TB usually infects your lungs, other organs and parts of your body can also be affected.
- TB can be a very serious disease, particularly for young children under 5 years of age as well as older people.
- TB is treated by taking a combination of antibiotics for at least 6 months.
- If you have spent time with someone with active TB, see your doctor.
How is TB spread?
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. Read more about latent TB.
Who is most at risk of getting TB?
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.
What are the symptoms of TB?
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|
How is TB diagnosed?
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.
How is TB treated?
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.
How can I care for myself with TB?
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 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.
How do you prevent TB?
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.
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 Immunisation Advisory Centre, NZ
- Guidelines for tuberculosis control in New Zealand Ministry of Health, NZ, 2019
- Antituberculosis drugs New Zealand Formulary
- Temporary cessation of BCG vaccination until further notice Ministry of Health, NZ, 2016
|Dr Helen Kenealy is a geriatrician and general physician working at Counties Manukau DHB. She has a broad range of interests and has worked in a variety of settings including inpatient rehabilitation, orthgeriatrics and community geriatrics.|