Scientists have said a new blood test could soon be developed that could identify millions of people who unknowingly transmit tuberculosis.
Researchers at the University of Southampton have discovered a group of biological markers that are high among infectious patients, and testing could be an important step in reducing the spread of the disease.
More than one million people die each year from tuberculosis (TB), making it the world's deadliest infectious disease, according to the World Health Organization.
Fortunately, in the UK the numbers remain low. However, TB cases in the UK rose to around 5,000 in 2023, according to the UK Health Security Agency, and are expected to rise further this year.
So how do you get tuberculosis and what else do you need to know about this infectious disease?
What is tuberculosis?
Emma Rubach, head of health advice at the charity Asthma + Lung UK, says TB, or tuberculosis, is a bacterial infection that usually affects the lungs.
“Anyone can get tuberculosis; However, people most at risk are those who have lived outside the UK, where tuberculosis rates are high. Countries where tuberculosis is most common include Bangladesh, China, India, Pakistan and Indonesia.
“Only 5% to 10% of people who breathe in the tuberculosis bacteria develop symptoms and may become ill weeks, months or even years after exposure,” adds Rubach.
“There are two types of tuberculosis. Latent tuberculosis, which is when you have tuberculosis bacteria in your body, but because the body's immune system controls the bacteria and prevents them from growing, you do not experience any symptoms and cannot transmit the infection to other people. “Then there is active tuberculosis, when the body’s immune system cannot control the tuberculosis bacteria and an infection develops.”
How do you catch it?
“Most tuberculosis infections are transmitted through the air. It can be contracted through bacteria shed by another infected person,” says Dr Colin Michie, associate dean of research and knowledge exchange at the University of Central Lancashire.
“There is a less common type of tuberculosis, Mycobacterium bovis, which is found in unpasteurized milk. Therefore, consuming this product may put you at risk of infection, especially if affected cattle are not carefully examined.”
What are the symptoms and is it serious?
Tuberculosis is a serious infection that can be fatal if not treated properly.
“The poet Keats, the composer Chopin and the authors Brontë and Orwell are just some of the people who throughout history have died of tuberculosis,” says Michie.
Rubach says some people may be at higher risk of severe symptoms, such as those with weak immune systems, malnutrition, diabetes, people who smoke, drink or take drugs regularly, as well as children under five years old.
“Active tuberculosis usually affects the lungs, but it can also affect other parts of the body,” says Rubach. “Symptoms include cough lasting more than three weeks, chest pain, weight loss, extreme tiredness, loss of appetite, high temperature, swollen glands, headaches, and body aches and pains.”
Asthma + Lung UK also advises people to call 999 or go to A&E if they have a stiff neck and severe headache, it hurts to look at bright lights, they have had an attack (seizure) or if their behavior changes, for example , you feel confused and if you cannot move certain parts of your body. How do you treat it?Rubach says both latent and active tuberculosis should be treated with antibiotics to help kill the bacteria. “In latent tuberculosis, treatment usually lasts between three and six months, and in active tuberculosis, at least six months,” he adds. “If tuberculosis affects the brain or spinal cord, treatment can last 12 months.”
