Tuberculosis

What is tuberculosis?

Tuberculosis (TB) is a bacterial infection caused by a type of bacterium called Mycobacterium tuberculosis. It mainly affects the lungs, but it can affect any part of the body, including the abdomen glands, bones and nervous system.

Globally the disease is extremely common with millions of new infections and many deaths occurring yearly. The rate of disease varies widely from country to country, with the highest rates and most deaths occurring in developing countries for example Sub-Saharan Africa and South East Asia.

Tuberculosis is a serious condition, but it can be cured with antibiotic treatment. Vaccination is also available for prevention.1

The following is a summary about the disease. For further details speak to your local pharmacist or GP.

How is tuberculosis spread?

Tuberculosis is most commonly spread from person to person through the air by coughing and sneezing.  The bacteria are carried in the air in tiny water droplets. They then begin to multiply in the lungs and the infection may progress into:

  1. Minor infection with no symptoms (most cases)
  2. Active TB (some cases)
  3. Secondary TB – reactivated infection causing active disease2

Which countries at risk from tuberculosis?

TB occurs in every part of the world. Regions with higher rates of TB include:

  • Africa
  • Western Pacific
  • South-East Asia3

A map showing the rate TB (per 100 000 population) can be found here4. Vaccination is recommended for some travellers to countries with incidence rates at or above 40 cases per 100 000 population

What are the signs and symptoms of tuberculosis?

Most TB infections are mild and asymptomatic. If the infection develops into active TB, symptoms may include:

  • Cough – lasting more than 3 weeks. It can continue for months and get worse. During that time the cough produces a lot of phlegm, which may be blood-stained.
  • High temperature
  • Night sweats
  • Feeling unwell
  • Weight loss
  • Loss of appetite5

What are the complications of tuberculosis?

Untreated TB infection can spread to various parts of the body – this is called miliary TB, and can affect many organs, including lungs, bones, liver, eyes and skin. Symptoms vary depending on which part of the body is affected:

  • Lymph glands: swollen gland(s) can form anywhere in the body. If the swollen glands are in the neck, armpit or groin is more noticeable.
  • Gut or abdomen: may cause stomach pain or swelling, or poor digestion of food with diarrhoea and weight loss
  • Bones and joints: leading to pain and swelling
  • Heart: may cause inflammation around the heart, with chest pain or shortness of breath
  • Kidneys and bladder: may cause pain in the side (loin), or pain when passing urine.
  • Brain – can cause meningitis, with symptoms such as headache, nausea and vomiting, fits, drowsiness
  • Skin – can lead to severe rashes and ulcers2

Latent TB infection may reactivate in later life; particularly if an individual’s immune system has become weakened, for example by disease (e.g. HIV), certain medical treatments (e.g. cancer chemotherapy, corticosteroids) or in old age.6

What is the treatment for tuberculosis?

While TB is a serious condition that can be fatal if left untreated, death is rare if the treatment is completed.

The usual treatment is:

  • 2 antibiotics (isoniazid and rifampicin) for 6 months
  • Additional 2 antibiotics (pyrazinamide and ethambutol) for the first 2 months of the 6-month treatment period

After taking antibiotics for two weeks, most people are no longer infectious and feel better. However, it is important to complete the full course of the medications as prescribed otherwise the TB bacteria may become resistant to the antibiotics. This is potentially serious because it can be difficult to treat and will require a longer course of treatment with stronger antibiotics.

What advice is there for travellers?

Travellers should avoid close contact with individuals known to have infectious pulmonary TB. Those at risk during their work (such as healthcare workers) should take appropriate infection control precautions that may include isolation and barrier nursing procedures.5

Country specific information can be found here.7

When to consider vaccination

In the UK, vaccination against TB (BCG vaccine) forms part of the national immunisation programme and is targeted to high-risk individuals, including some travellers.

TB vaccine is recommended when travelling for longer than 3 months to areas which are high risk for TB or where there is a resistance to TB medication. This includes:

  • Unvaccinated children under 16 years travelling to stay with friends/family or local people.
  • Unvaccinated individuals working in settings that are of high risk of exposure to patients diagnosed with TB

TB vaccine should be offered to those in the following occupational groups, with direct patient contact or contact with infectious materials:

  • Healthcare or laboratory workers (who have direct contact with TB patients or infectious clinical materials)
  • Veterinary staff (who handle animals or animal materials which could be infected with TB)
  • Staff working with people at higher risk of acquiring TB (prisoners, homeless persons, persons with drug and alcohol misuse and those working with refugees and asylum seekers.5

Vaccination

BCG vaccine contains a live attenuated strain derived from M. bovis. BCG vaccine does not contain thiomersal or any other preservatives.

BCG is not usually recommended for people aged over 16 years unless the risk of exposure is great (e.g. healthcare or laboratory workers who are at occupational risk).5

Although immunity may wane over time, reinforcing doses are not recommended.5

References

This information is taken from trusted third party websites, NaTHNaC (Travel Health Pro) and EMIS (Patient info) and use of all information has been licenced under the Open Government Licence http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/.

Although the materials are being used/replicated under the provisions of the Open Government Licence this in no way represents endorsement of Traveljab.co.uk by NaTHNaC, Emis, Public Health England, the NHS or the Department of Health and Social Care.

 

Reference:

  1. NHS: Tuberculosis (TB)
  2. Patient.info: Tuberculosis
  3. World Health Organisation (WHO): Tuberculosis
  4. WHO maps: Average incidence of TB
  5. Travel Health Pro (NaTHNaC): Tuberculosis
  6. The Green Book: Chapter 32 – Tuberculosis

Travel Health Pro (NaTHNaC): Country information