Tuberculosis (TB) in humans is caused by a type of bacterium called Mycobacterium. There are different species of Mycobacterium, but the one which causes most cases of TB in humans is called Mycobacterium tuberculosis.
TB is often thought of as an ‘old’ infectious disease that no longer affects people in the UK. Overall, there has been a downward trend in cases in the UK, but the rate of decline is slowing. 4,425 cases were reported in England in 2021. See the UKHSA TB incidence and epidemiology in England, 2021 for more information.
Groups most at risk are people, and the families of people, from countries where there are high rates of TB (more than 40 cases of TB per year, for every 100,000 people), and people with social risk factors, such as homelessness, alcohol misuse or being in prison.
If TB is not treated it can be fatal, even in people with no other health issues. Around 350 people a year in the UK die from TB-related causes. The most severe forms of the disease are more likely to affect children.
TB usually affects the lungs, but it can affect almost any part of the body including bones and the nervous system. It can be treated by a long course of antibiotics, but TB which is resistant to the first line antibiotics is becoming more common, and some strains are resistant to almost all TB drugs (known as XDR strains).