You may have heard of tuberculosis, but what exactly is it? Tuberculosis (TB) is an infectious disease caused by a bacteria called Mycobacterium tuberculosis. It most often affects the lungs but can also impact other parts of the body, like the brain, spine, and kidneys.
TB is the 13th leading cause of death worldwide and the second leading infectious killer after COVID-19 (above HIV/AIDS). The World Health Organization reported an estimated 10 million new cases in 2019 alone. What is a TB? How do you get TB? For answers to these questions and more, keep reading to find out more.
What is TB?
Tuberculosis, more commonly known as TB, is a bacterial infection caused by the Mycobacterium tuberculosis bacterium. It has been around for centuries, and it is believed to have killed 1 in 4 humans during its peak in the 19th century when we lacked the treatment and means to contain the bacterial spread. Although the bacteria can affect any part of the human body, it primarily targets the lungs, rendering them increasingly vulnerable to other serious illnesses. It is believed that one-third of the world’s population carries this bacterium without displaying any symptoms.
How is TB spread?
Tuberculosis is a highly contagious infection that spreads through the air from infected persons to those in close contact. When an infected person talks, coughs or sneezes, microscopic droplets are released into the air and can be inhaled by anyone nearby. TB is most likely to spread when spending much time with an infected person in enclosed places, such as homes, offices or other small spaces like elevators. Although TB can survive longer in larger areas, it usually needs prolonged and close contact with a sick individual to get infected.
Most people who breathe in TB germs do not get sick because the body’s immune system can fight off the TB bacteria. However, some people cannot fight the TB germs because of certain health problems or weakened immune systems. These people will develop active TB disease.
What are the symptoms of TB disease?
The symptoms of tuberculosis disease depend on where in the body the infection is located. Symptoms of TB disease in the lungs (pulmonary TB) may include:
- A bad cough that lasts more than 3 weeks
- Chest pain
- Coughing up blood or sputum (phlegm from deep inside the lungs)
- Weakness or fatigue
- Weight loss
- No appetite
- Sweating at night
Suppose the infection has spread to other parts of your body, such as the kidney, bone, joint, gastrointestinal tract, lymph nodes, meninges (the membrane around the brain and spinal cord), eye, heart, or endocrine glands. In that case, additional symptoms occur depending on which organs are affected. You may experience additional symptoms such as:
- Nausea and vomiting
- Yellowing of the skin and eyes (jaundice)
- Swelling in your abdomen
Different types of tuberculosis infection
A person can be infected with TB in two ways: active TB or latent TB infection.
Active TB symptoms can include a persistent cough, fatigue, shortness of breath, night sweats, fever, loss of appetite and unintentional weight loss. In comparison, people with latent TB infection may not have any symptoms connected to the infection and, therefore, may not even realise they have it. The main difference between active and latent TB infections is treatment. While both require antibiotics to eradicate the bacteria completely, those with active infections need multiple drugs over a long period to prevent complications. Those with latent infections are likely on a single drug for a much shorter duration.
How is TB disease diagnosed?
Your doctor will ask about your symptoms and medical history. They will also perform a physical exam. To confirm the diagnosis, your doctor may order one or more of the following tests:
- A chest X-ray – This can show changes in your lungs that are characteristic of TB disease
- A skin test – This is also known as the Mantoux tuberculin skin test. A positive skin test means you have been infected with TB bacteria at some point. A negative skin test means you probably do not have a TB infection, or you have recently been infected, and your body has not had time to develop a positive reaction to the skin test
- A blood test can show if you have antibodies to the TB bacteria in your blood. These tests, also called interferon-gamma release assays (IGRAs), measure the response when TB proteins are mixed with a small amount of your blood
- A sputum sample – A sputum sample is a sample of mucus that you cough up from your lungs. The sample is examined under a microscope for evidence of TB bacteria. It can also be cultured for TB bacteria
- A biopsy – In some cases, a small tissue sample (biopsy) from your lung may be removed and examined under a microscope for evidence of TB bacteria.
If you have a latent TB infection and no symptoms of TB disease, you may not need any tests. Your doctor may want to check on you occasionally to ensure the latent infection does not develop into an active disease.
How is TB Disease Treated?
Treatment for Active Tuberculosis Disease
Active TB disease occurs when someone who has never had tuberculosis or whose previous illness was cured becomes sick with active tuberculosis because their body cannot stop the multiplication of Mycobacterium tuberculosis in their lungs or other organs.
Active tuberculosis is an infectious disease that typically affects the lungs but may spread to other body areas. If left untreated, a person with active tuberculosis can spread it to other people.
Treatment for Active Tuberculosis requires at least 6 months of medication to kill the bacteria that cause the infection. The usual treatment is:
- 2 antibiotics (isoniazid and rifampicin) for 6 months
- 2 additional antibiotics (pyrazinamide and ethambutol) for the first 2 months of the 6-month treatment period
Drugs must be taken regularly as prescribed by your doctor or health care provider. Patients should follow directions carefully and take all required medications until their doctor tells them they have completed their treatment. Sticking to this schedule of treatment increases success rates significantly.
Treatment for Latent TB Infection
Latent TB Infection is a non-threatening form of TB in which no symptoms are present, and neither can it be spread to others. However, if left untreated, it can lead to active TB, which presents more serious health complications. Treatment for latent TB generally involves:
- Either taking a combination of rifampin and isoniazid for 3 months
- Or isoniazid on its own for 6 months
Other methods involve taking Vitamin D supplements to boost the body’s immune system or using Bacille Calmette-Guerin (BCG) vaccination to prevent reoccurrence and even reverse LTBI. Regardless of the chosen treatment option, recipients will require regular follow-ups and tests to ensure their bodies clear the infection completely.
Patients must take all their medications exactly as their doctors prescribe so drug-resistant strains do not develop during therapy.
Drug-resistant tuberculosis can occur when TB bacteria become resistant to standard drugs used to treat the disease. An inadequate or incomplete course of TB treatment causes it. When people fail to take their medication as prescribed and complete their full course of treatment, bacteria may survive and become resistant to the drugs used in conventional treatment. Drug-resistant TB can have serious consequences ranging from longer and more complex treatments, with considerable inconvenience to patients, to greatly reduced cure rates. Suspected cases of drug-resistant TB must be tested immediately for accurate diagnosis and appropriate treatment.
Side effects of treatment
During treatment, people usually feel better within 2 to 3 weeks after starting therapy. Common side effects include nausea, vomiting, loss of appetite, stomachache, diarrhoea/constipation, headache, fatigue/weakness, itching/rash, joint pain/swelling, hair loss, fever/chills and night sweats. Most side effects go away gradually after therapy, although some effects, such as hearing loss associated with ethambutol use, could be permanent.
Who is at high risk of catching TB?
People at high risk of catching TB are those with weakened immune systems, such as:
- Young children
- Pregnant women
- Individuals with HIV/AIDS
- Individuals with chronic diseases such as kidney disease or diabetes
Additionally, certain jobs or occupations present a higher risk than others. Healthcare workers may be more exposed than the general population due to high patient contact rates. Furthermore, TB is often passed from person to person within the same family. Therefore, close family members of an individual affected by TB can potentially be at risk of TB themselves.
Unfortunately, due to overcrowded living spaces and lack of adequate nutrition and healthcare facilities in many parts of the world, rates of TB are still quite high around the world. As such, it is important to be aware of risk factors associated with TB so that preventative measures can be taken more proactively.
Prevention of TB
While the BCG vaccine offers some protection against TB, it does not provide complete immunity and is not recommended for everyone in certain settings. A key way to help prevent the spread of TB is to practice good hygiene habits, such as washing hands regularly, particularly after coughing or sneezing and covering your nose and mouth when sneezing or coughing important to avoid exposing others. Additionally, ensuring proper ventilation in living and work spaces can help prevent the spread of airborne droplets that may contain TB bacteria. In general, taking steps to protect yourself and those around you from respiratory illnesses can help reduce the risk of contracting and spreading the infection.
The BCG vaccine is not given as part of the standard NHS vaccination schedule but plays a vital role in helping to prevent TB. However, it’s recommended only for those considered at higher risk of contracting this illness and must be administered just once within an individual’s lifetime. If you think you may have come into contact with tuberculosis or are concerned about your current level of protection against this infection, speak with a healthcare professional today.
Is TB curable?
Yes, TB is curable. If you have tuberculosis and you’re treated, your outlook is good if you’ve followed directions and taken your medications for as long as you should and in the way you were told.
TB is a serious infection, but it is treatable and curable. If you think you might have symptoms of TB disease, it’s important that you see a doctor right away so you can start treatment. You can get rid of the infection and live a healthy life with proper treatment.
Now Patient is the UK’s first regulated digital health service that uses predictive analytics and artificial intelligence to provide you with personalised care and resources that can help improve your health outcomes, FREE of charge.
Prescriptions, healthcare resources & live video consultations all in one place for FREE