With over 2 million deaths a year worldwide, and around 8,000 new cases diagnosed annually in the UK alone, Tuberculosis, commonly abbreviated to TB, is still very much an active problem. Though the concentration of cases in Great Britain is low compared to some parts of the world, global travel has seen a rise in the numbers since the 1980s, including from areas such as sub-Saharan Africa and South Asia, where the incidence is much higher.
TB is caused by the bacteria Mycobacterium Tuberculosis (M. Tuberculosis), and is spread by droplet infection; hence transmission is from the respiratory secretions of individuals with active disease.
In otherwise healthy individuals, close contact with a person with active TB results in two outcomes, either complete eradication, or latent tuberculosis infection (LTBI), where the infection is contained by the body’s defence systems, often without symptoms, and is not of risk to either the individual or those around them. However, if this person then becomes ill, latent TB can become active, and if present in the lungs, coughing can transmit M. tuberculosis to other persons with whom they have regular association.
The classical symptoms of active TB include cough, productive sputum which can sometimes be blood-stained, night sweats, and weight loss. However, as TB has the ability to invade any organ in the body, it can present in a multitude of ways. Therefore it is up to the healthcare professionals involved to consider it in the differential for any presentation where the patient is at high risk of TB. This includes immigrants from regions where the disease is common, those with weakened immune systems, and anyone who has come into contact with an individual with active TB.
A high index of suspicion is of great importance. It is estimated that a person with active TB will infect around ten close contacts if not identified and treated. In addition, untreated TB is a major cause of morbidity and mortality. Yet despite this, when diagnosed and given the appropriate antibiotics, a person with active tuberculous infection will no longer be of risk to those around them within as little as two weeks.
As mentioned, those infected are often from groups with little assistance, and a lower understanding of the importance of treatment. While the acute management and that of any acutely ill person is in hospital, the bulk of management is in the community. A prolonged course of multiple antibiotic drugs is the basis of most regimens, supported by community TB specialist nurses. There is even support for those with poor compliance, with thrice weekly medication directly supervised by a health care worker.
Previously all school age children were immunised, however vaccination is now more selective and targets those at presumed higher risk. Healthcare workers are naturally among this group. A sign of already being immunised is the BCG ‘scar’, typically found on the upper outer arm. Vaccination generally provides excellent immunity against disease, without the need for booster doses.
Control of this disease relies on healthcare professionals considering TB in the diagnosis where the symptoms are suggestive, or in atypical presentations where the individual is at high risk of tuberculosis.
“It is estimated that a person with active TB will infect around ten close contacts if not identified and treated”