Blood test could identify millions of people unknowingly spreading tuberculosis | UK News

A blood test that could identify millions of people who spread tuberculosis unknowingly is close to being developed, scientists have said.

By comparing proteins found in the blood of people with active TB to those in healthy people and patients with lung infections, researchers from the University of Southampton discovered a group of six biological markers that are found in high levels among infectious patients.

And if successful, a blood test that detects these proteins in the bloodstream could help identify the estimated three million cases of the disease which were missed last year, mostly in developing countries, according to Dr Hannah Schiff, lead author and respiratory expert at Southampton University .

Tuberculosis, or TB, is the world’s deadliest infectious disease and kills more than one million people each year, according to World Health Organization data.

Cases in the UK increased to about 5,000 last year and are expected to continue rising in 2024, according to the UK Health Security Agency.

Pic file: iStock
There were around 5,000 TB cases in the UK last year. Pic file: iStock

Dr Schiff explained that TB spreads through people inhaling tiny droplets from coughs or sneezes of those infected. While it mostly affects the lungs, it can deviate any part of the body.

She said the disease remains a “global catastrophe” because efforts to control the spread are hindered by inadequate testing, meaning a third of people who get infected go undiagnosed and remain infectious.

How do you know if you have TB?

The NHS says that symptoms of tuberculosis usually come on gradually.

The most common includes a cough that lasts more than three weeks. Some individuals may cough up phlegm or mucus with blood in it.

If TB has spread to other parts of the body such as the glands, bones or brain, people may develop other symptoms.

This can include, but is not limited to: swollen glands, body aches and pains, constipation, sickness or feeling confused.

Sometimes, TB doesn’t cause any symptoms, but is still present in the individual’s body. This is called latent TB.

Latent TB can usually be treated with antibiotics for three to six months.

The study, published in the Journal of Clinical Investigation Insight, examined proteins found in the blood of people with active TB in Africa and South America.

Dr Diana Garay-Baquero, co-director of the study, said the findings were a roadmap to developing a TB test that would be as simple as the lateral flows used during the COVID-19 pandemic.

Read more health news:
Vaping causes similar DNA damage to smoking
Mother left with life-long injuries after giving birth breaks ‘silence’

“The new markers we discovered are truly exciting but the important work now is to develop these into tests that can be used for the millions of people who are transmitting TB without knowing it,” she said.

“As the COVID-19 pandemic confirmed, we ignore highly infectious airborne diseases at our disposal.”