Two in 10, of the one million children with
tuberculosis (TB) globally, die each year.
Speaking from the Union World Conference on
Lung Health that took place in Mexico earlier this month, Dr Jeffery Starke said
a staggering 96% of these deaths are in children who never received anti-TB
drugs because the disease is very difficult to diagnose in kids.
A much-needed solution
An international paediatric TB expert, based
at the Texas Children’s Hospital in the United States, he said the largely
preventable and treatable disease causes so many deaths in children because it
is often misdiagnosed as
pneumonia or meningitis.
But new research coming out of the
University of Cape Town (UCT), presented at the conference, may provide a much-needed solution.
TB is usually diagnosed using sputum
samples: mucous coughed up from the lungs. But children often don’t have the
force to cough such samples up and may be subjected to very “invasive”
diagnostic methods, if at all, said Dr Paula Fujiwara, scientific director for
the Union Against Tuberculosis and Lung Disease.
These can include a technique called
gastric lavage where a tube is inserted through the nose and fed down to the
stomach of the child to extract the contents, which are then sent to a lab to
test for TB.
Tissue from the tongue
Three consecutive samples are ideally
needed for a correct diagnosis, requiring three repeat trips to a health
facility or for the patient to be admitted – which is labour intensive and
costly to both patients and their families as well as the health system.
But for the first time, scientists are investigating
whether tissue from the oral cavity, including from the cheeks tongue and gums
can be used to successfully diagnose TB.
Researchers from UCT and the Tuberculosis
Vaccine Initiative found that tissue from the tongue was the most sensitive.
They are currently involved in phase two of a trial which aims to enrol 275
patients in the Western Cape to test if these samples can successfully be used
to diagnose TB – especially for patients who can’t or find it difficult to
So far they have “promising” results for 49
samples from TB patients, 45 of which have tested positive in the laboratory
using the oral swab method, translating into a sensitivity rate of 92%.
Rapid point-of-care tool
The implications for the success of this
study are significant, particularly for children, according to Dr Angelique
Luabeya, one of the trial’s lead researchers.
“It would be so easy to take a sample. My
daughter could do it,” she said. “Patients themselves could even take a sample
– it would be as simple as brushing your teeth and nobody does that for you.”
A small brush is used to scrape the inside
of the mouth, after which the brush is sealed in a small container and sent to
the laboratory for testing. In contrast,
sputum testing requires a patient to cough up mucus, a process that, if not
done under the right circumstances, can even aid transmission of the air-borne
The “long-term” vision is to translate this
diagnostic method into a rapid point-of-care tool that can be used by lay
health workers without the need for laboratory testing.
Said Luabeya: “The beauty of it is it's so
simple that we wonder why no-one's done it before.” – Health-e News.
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