Breathing may be a bigger cause for the spread of tuberculosis than coughing, according to a new study, forcing the scientific community to rethink centuries of containment strategies.
The findings were presented by a team of South African researchers at a scientific conference on Tuesday, 19 October, according to The New York Times.
The researchers measured the disease-causing Mycobacterium tuberculosis (Mtb) in 39 people with TB.
They looked at aerosols released during regular breathing, deep breathing and coughing and found that after five minutes all three produced particles containing the dangerous bacteria.
The study found that as much as 90 percent of TB bacteria released may be carried via tiny droplets, called aerosols, by simply exhaling, according to AFP.
What is tuberculosis?
TB is caused by bacteria called 'Mycobacterium tuberculosis', which was discovered in 1882. It is the world’s deadliest infectious disease after COVID-19.
It's spread when people who are ill expel the bacteria into the air. It usually attacks the lungs.
According to the World Health Organization (WHO), the deaths from TB have risen during the COVID-19 pandemic – and for the first time in a decade, 1.5 million people have died from TB in 2021, of which 214,000 were HIV positive.
Whom does tuberculosis affect?
According to WHO, one in four people in the world is infected with the bacteria, meaning a higher risk of developing disease. But not everyone who gets it becomes ill.
In about 90 percent cases, it occurs in adults - and those with compromised immune systems, such as people with HIV, diabetes, or malnutrition, have a higher risk of becoming ill.
According to the WHO, the burden of HIV-associated TB is highest in Africa, where 85 percent of TB patients in 2020 had a documented HIV test result.
What are the symptoms?
Symptoms can be similar to COVID-19 and include coughing (sometimes with blood), fever, night sweats, or weight loss.
How are the new findings useful?
Earlier, researchers believed that most of the TB transmission occurred when an infected person coughed. While some bacteria were thought to be released through breathing, it was much less than by coughing.
The findings do not change the earlier understanding that a single cough can expel more bacteria than a single breath. But because an infected person breathes all day long, simply exhaling may result in emission of more bacteria.
The findings, like Covid, show why closed spaces are breeding grounds for TB, similar to Covid. The research suggests that like in Covid, masks, ventilation, are important in curtailing the spread, NYT reported.
The findings also suggest that the current approach of testing and treating might not work. Doctors should not wait for an infected person to come to the clinic with telltale symptoms.
“We just need to screen the entire population, just like you would do if you’re looking for a lot of Covid,” Dr. Horsburgh was quoted as saying by NYT.
What is India's burden of tuberculosis?
According to the WHO, India has topped the world in missing tuberculosis cases last year due to the COVID1-19 pandemic.
The countries that contributed most to the global reduction in tuberculosis notifications between 2019 and 2020 were India (41 percent), Indonesia (14 percent), the Philippines (12 percent) and China (8 percent).
(With inputs from The New York Times & AFP.)
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