Tuberculosis

Tuberculosis is often considered a disease of the past, but it’s still kicking around today, so what exactly is it?

What is TB?

Mycobacterium tuberculosis, along with its close relatives, is a bacterium most commonly known for infecting the lungs and sometimes other parts of the body, spread through droplets coughed or sneezed by a person with active pulmonary TB. The majority of people exposed to TB will not go on to develop disease as their immune system will either fight it off or can contain it in a latent state – however, some will develop active TB and are then infections and require treatment. Untreated, TB will be fatal but following a long course of antibiotics can be cured.

TB is currently one of the top diseases on WHO’s hit list, with the aim to reduce deaths by 95% and incidence by 90% before 2035.

TB Species Number Diagnosed Percentage of diagnoses
M. tuberculosis 3,063 97.1
M. bovis 35 1.1
M. africanum 47 1.5
M. microti 3 0.1
Mycobacterium tuberculosis complex 5 0.2

How common is TB?

In 2017 there were 5,102 cases of TB reported in the UK, 234 of these being in the south west. The rate of infection is twice a high in those people with social risk factors, including alcohol or drug misuse, homelessness or being in prison, while those in areas of increased social deprivation are seven times as high.

Antibiotic resistance

Antibiotic resistance can be a real problem when it comes to treating TB. The current gold standard involved a minimum of 2 months treatment with four antibiotics and a further 4 months of two antibiotics – however, this depends on the sensitivity of the bacterium to the medications.

First-line drug resistance – “resistance to at least one of the first line drugs
(isoniazid, rifampicin, ethambutol, pyrazinamide)”

Multi-drug resistant TB – “resistance to at least isoniazid and rifampicin, with or without resistance to other drugs”

Extensively drug resistant TB – “resistance to isoniazid and rifampicin (MDR-TB), at least one injectable agent (capreomycin, kanamycin or amikacin) and at least one
fluoroquinolone (moxifloxacin, ofloxacin, ciprofloxacin)”

For some patients where their form of TB is resistant to certain drugs, they often have to use other antibiotics and have much longer courses – up to 24 months. Once a patient has been on their antibiotics for two weeks, they will no longer be infectious to others.

Whole genome sequencing

Whole genome sequencing is a new use of technology to diagnose TB. This involves reading the DNA of an organism in one chunk – utilising this as part of TB diagnosis enables more accurate diagnoses and treatment of the TB strain. It can also allow for samples to be compared to see if they’re similar and detect patterns of spread.

So what?

In the UK, incidence of TB is still really low and is decreasing every year, and chances are most nurses will never look after someone with the disease. However, nurses should at least have a basic understanding of TB and the importance of the medication regimes just in case. One of the main concerns patients with TB have is the length of their antibiotic treatment – part of the nursing role is to support these patients, reassuring them that it is curable and reiterating the importance of taking the full course.

References

Public Health England (2018) Tuberculosis in England: 2018. Available at: http://www.facebook.com/PublicHealthEngland (Accessed: 7 December 2018).

WHO (2015) The End TB Strategy. Available at: https://www.who.int/tb/End_TB_brochure.pdf?ua=1 (Accessed: 15 December 2018).

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