‘World’s most deadly infection’ can be transmitted simply by breathing, scientists warn – as cases rise

AS tuberculosis makes a comeback in England, a new study has revealed that catching the disease might be easier than we once thought.

Dutch scientists now believe that even people who show no signs of the disease can pass on the killer bug.

GettyPeople can pick up the infection just by breathing near someone who has the bug[/caption]

Until now, healthcare experts thought TB germs were transmitted via coughing, laughing or speaking, singing or sneezing.

But a new study has found that four in five people testing positive for the killer bug don’t suffer from a cough – previously thought to be a key symptom of TB.

However, even those who don’t have a cough carry the infectious disease in their spit, which can be spewed into the air when someone talks or breathes, they found.

This means people can pick up the infection just by breathing near someone who has the bug but isn’t showing any obvious signs, they said

“A persistent cough is often the entry point for a diagnosis,” study author Professor Frank Cobelens of Global Health at Amsterdam University Medical Center said.

“But if 80 per cent of those with TB don’t have one, then it means that a diagnosis will happen later, possibly after the infection has already been transmitted to many others, or not at all,” he added.

The latest research, published in The Lancet Infectious Diseases, analysed data on more than 600,000 people in 12 countries across Africa and Asia, some of whom had TB.

They found that 82.8 per cent of those with the disease had no persistent cough and 62.5 per cent had no cough at all.

A quarter of those without cough have high loads of dangerous bacteria in their spit and are probably highly infectious.  

Professor Frank is now calling for medics to consider new ways of diagnosing the disease so cases are not missed.

“When we take all of these factors into account, it becomes clear that we need to really rethink large aspects of how we identify people with TB,” he said.

“It’s clear that current practice, especially in the most resource-poor settings, will miss large numbers of patients with TB.”

Cases on the rise

Cases of the Victorian disease increased by over 10 per cent last year, according to the UK Health Security Agency – up from 4,380 in 2022 to 4,850 in 2023.

Health chiefs are scrambling to “investigate the reasons” behind this sudden infection rise.

Anyone with a persistent cough and fever, particularly those in groups at a higher risk of catching TB, is being urged not to dismiss their symptoms as a cold.

Globally, 7.5million people were diagnosed with TB in 2022 – the highest number ever recorded.

The World Health Organisation (WHO) previously said this was because many people were unable to get a diagnosis or receive treatment during Covid lockdowns.

A separate report found cases of drug-resistant TB had increased by three per cent between 2020 and 2021.

What is TB?

TB remains one of the world’s most deadly diseases, and the second leading infectious killer after Covid-19.

The bacterial infection spreads in the air when people carrying the bug cough, sneeze or spit.

Symptoms include a cough for more than three weeks, feeling exhausted, a high temperature, weight loss and loss of appetite.

It can be life-threatening, but most cases can be successfully treated with antibiotics.

The infection can spread to your brain, heart, abdomen, glands, bones and nervous system.

People are at higher risk of the disease if they are in close contact with a person known to have the disease, travel to countries with high rates of TB, are homeless, are addicted to drugs, have a weakened immune system or are in prison.

There’s a jab that protects against the bug, but vaccination programmes have been scrapped in several countries over the last 20 years.