FAQ: Tuberculosis (TB)
What is TB? +
Tuberculosis (TB) is an infection caused by a bacterium, Mycobacterium tuberculosis. TB can affect almost any organ in the body, e.g. lymph nodes, kidneys, brain, and bone. But the most common, Pulmonary TB (in the lungs or throat), is the only form of the illness that is infectious.
How Does It Spread? +
TB bacteria are released into the air when someone with infectious TB coughs or sneezes. It may then enter the lungs of someone nearby.
A person with untreated infectious TB passes the illness on to 10-15 other people, on average, each year without knowing.
TB cannot be spread through touch, sharing cutlery, bedding or clothes.
Who Is At Risk? +
Anyone can be affected by TB, though certain factors do increase risk. Living where TB is common, homelessness, or living in poorly ventilated or overcrowded accommodation etc.
Immune system pressures such as poor nutrition, poverty, poor housing and substance abuse can all weaken the immune system. Other illnesses can also make someone more vulnerable to TB. People living with HIV are at a particular risk from TB. In some clinics, more than half the TB patients also have HIV.
How is TB diagnosed? +
If the doctor thinks you may be ill with TB in the lungs or throat they will ask you to give a sputum (phlegm) sample, which they will test for TB bacteria. If the doctor thinks you may have TB in another part of your body, they may do the same test using a sample of cells, fluid or tissue. You may also be offered a skin test, blood test or x-ray.
A chest x-ray can show damage in your lungs, but you might need further tests to prove you have TB, such as sputum and culture tests or scans.
A lab will use a microscope to look at any sputum (phlegm) that you cough up. If there are TB germs in your sputum, you have tuberculosis of the lungs or throat (pulmonary TB). This test also helps doctors to understand how infectious you may be.
A culture test uses your sputum or tissue sample to grow any TB bacteria that may be there. It tells doctors how infectious you are and also whether your TB is resistant to any antibiotics. This helps ensure they put you on a combination of drugs that will cure you. As TB culture grows slowly, it may take up to eight weeks to get some of the results.
If it is thought that you have TB, but not in your lungs or throat, the doctor may take a biopsy to test for TB. This is a small sample of tissue or fluid taken from the area where the TB is thought to be.
What are the most common symptoms of TB? +
Symptoms of TB will depend on which part of the body is affected. For example, a cough is a common symptom of TB in the lungs. Someone with TB in the lymph nodes may have a swollen throat. Aches and pains in the joints could be TB in the bones. TB meningitis often gives a person severe headaches.
- a cough for three weeks or longer
- weight loss
- loss of appetite
- high temperature or fever
- night sweats
- extreme tiredness or lack of energy.
How is TB treated? +
TB treatment is effective. Worldwide, nearly 90% of cases of TB and 48% of cases of drug-resistant TB are cured.
You will need to have TB treatment for at least six months, to make sure all the TB bacteria are killed. If you have TB of the lungs or throat, after two weeks of treatment you should no longer be infectious.
Gradually you will start to feel better. This may take weeks, but you will stop feeling sick and tired all the time. Even when you feel better, it’s important to take the full course of your treatment, or you could become ill again.
Treating drug-resistant TB +
Drug-resistant TB can occur when TB bacteria become resistant to the two most powerful antibiotics normally used to treat the illness. This means the TB is more difficult to treat and treatment will take much longer (usually at least 18 months).
What is latent TB? +
If you have latent TB, you have TB bacteria ‘asleep’ in your body and you are not ill at the moment, but the TB bacteria can 'wake up' and make you ill with TB in the future. The good news is that you can treat latent TB to help stop this happening.
Most people who breathe in TB bacteria do not become unwell. Their immune systems are strong enough to clear TB completely, or hold it in a latent — or sleeping — state. Latent TB can later become active, making someone ill, if their immune system is weakened. A person with latent TB cannot pass TB on to others.
There are many reasons to get tested for latent TB. You may have lived in a country where TB is more common, know someone who has TB, have an illness or take medication that makes you more vulnerable to TB, or work in a healthcare setting.
Many people are offered testing and treatment for latent TB, as this is a good way to help prevent getting active TB in the future.
Latent TB can be treated with antibiotics which kill off the sleeping TB bacteria so they cannot wake up andcause active TB.
How can you prevent TB? +
As with all health conditions, prevention of TB is always better than a cure. Although there is no sure-fire way to completely prevent the spread of TB at this point in time, there are a number of measures that can be put in place to reduce the spread of the illness.
The BCG vaccination
The BCG (Bacille Calmette-Guérin) is a live vaccine against tuberculosis. The vaccine is prepared from a strain of the weakened bovine tuberculosis bacillus, Mycobacterium bovis.
The BCG is currently the only licensed vaccine against TB, and has been in use since 1921. It is one of the most widely used vaccines worldwide, yet we still see around 9 million new cases of TB annually – a testament to the BCG’s limited effectiveness.
The BCG is:
- 80% effective in preventing TB for 15 years
- more effective against complex forms of TB in children
- of limited effectiveness in people over the age of 35
- less effective when given in equatorial regions (due to high levels of naturally occurring environmental mycobacteria).
Early diagnosis and treatment is the most effective way to prevent the spread of tuberculosis.
A person with infectious tuberculosis can infect up to 10–15 other people per year. But once diagnosed with TB, and started on treatment, the majority of patients are no longer infectious after just two weeks of taking the medication.
Limiting the spread of TB depends on successfully finding and treating people with the illness, to prevent them from passing it on to others.
This can be done through raising awareness of TB, so people with TB symptoms know to seek help. Outreach workers and volunteers also work within communities with high rates of TB to find people with symptoms and refer them for testing.
When someone is diagnosed with infectious TB, their close contacts are screened for the illness — this is known as contact tracing.
Managing your environment
As TB is an airborne infection, TB bacteria are released into the air when someone with infectious TB coughs or sneezes. The risk of infection can be reduced by using a few simple precautions:
good ventilation: as TB can remain suspended in the air for several hours with no ventilation natural light: UV light kills off TB bacteria good hygiene: covering the mouth and nose when coughing or sneezing reduces the spread of TB bacteria.In healthcare settings, the spread of TB is reduced through the use of protective masks, ventilation systems, keeping potentially infectious patients separate from other patients, and the regular screening of healthcare workers for TB.
A healthy immune system
Having a healthy immune system is the best form of defence against TB: 60% of adults with a healthy immune system can completely kill TB bacteria.
Prevent the spread of TB if you are infectious
Most important in TB prevention is for people with infectious TB to take their medicine as prescribed. If you are taking medication, you need regular check-ups and possibly additional chest X-rays or sputum tests to show whether the medicine is working, and whether you are still infectious. If the tests show that you still have the bacteria in your sputum even after a few months of treatment, you may need to take some extra drugs, or change the drugs you are taking.
Detection of early cases and prompt treatment are crucial in controlling the spread of TB. The local health department may need to test people who have spent time with you for TB infection.
If you are sick enough to go to hospital, you may be put in a special room with air vents that keep TB bacteria from spreading. People working in these rooms wear face masks to protect themselves from bacteria. You must stay in the room to prevent spreading bacteria.
If you are infectious while at home, protect yourself and others as follows:
- Wash your hands after sneezing, coughing or holding your hands near your mouth or nose.
- Cover your mouth with a tissue when you cough, sneeze or laugh. Discard used tissues in a plastic bag, then seal and throw it away.
- Do not attend work or school.
- Avoid close contact with others.
- Sleep in a room away from other family members.
- Ventilate your room regularly. TB spreads in small closed spaces. Put a fan in your window to blow out air that may contain bacteria.
Social Stigma and Barriers to Access +
It is important that people with TB be visible in their communities, not hidden away.
Neighbours and family members must learn that TB can be cured.
Former TB patients are the best ambassadors for TB control. Those who have suffered from TB and are now cured are living proof of the effectiveness of TB treatment. They are well educated about TB symptoms, treatment and prevention and are therefore extremely valuable in spreading the information throughout their communities.
Why is TB Stigmatised?
TB-HIV awareness raising in ZambiaIn some cultures, TB is associated with witchcraft. TB can be considered a ‘curse’ on a family, as the illness often affects multiple generations – we know that this is simply because TB is an airborne illness, which is more likely to be spread among people living in close proximity.
TB is often associated with factors that can themselves create stigma: HIV, poverty, drug and alcohol misuse, homelessness, a history of prison and refugee status.
People who are discriminated against may be isolated socially, particularly in small communities – even entire families may be shunned. Women are often blamed as the source of TB, and those affected by the illness may be divorced or considered unworthy of marriage.
The impact of stigma
Fear of discrimination can mean people with TB symptoms delay seeking help, making it much more likely that they will become seriously ill and infect others. This then perpetuates the myth that it is the TB treatment itself that causes deaths, as treatment is much less effective if left until the illness is in its advanced stages.
Stigma around TB can also make people reluctant to stick with their course of treatment – over the many months this takes – for fear of being ‘found out’. By taking treatment irregularly, people risk developing drug resistance.
TB is not spread through spitting or sharing crockery or cutlery. You need to be exposed to TB droplets in the air for a long period of time – typically eight hours or more – to be at risk of contracting the illness. This means the idea that TB is easily spread on public transport is also a myth.
Barriers to Access
Of the 9 million people who develop TB each year, around 3 million never reach a qualified doctor. Among those who do, many delay until the illness is more advanced. This has implications for both their own health and the health of others, as someone with untreated infectious TB can pass it on to 10-15 people every year.
People may not seek treatment for a range of reasons including:
- stigma can make them reluctant to seek help for unexplained symptoms, for fear of receiving a diagnosis of TB
- poverty can make it difficult for people, particularly women, to prioritise their health over other demands on resources: the threat of lost income and the costs of travel can stop people seeking appropriate help even where treatment is free
- many people simply do not know about tuberculosis or recognise their symptoms as TB
- people from the marginalised communities that are most often affected by TB may distrust health services, be unaware of their rights to treatment or lead chaotic lifestyles that prevent them from accessing care; others may favour the traditional healers and private practitioners they are familiar with, who may know little about TB.