Monday, December 17, 2018

Oral swabs hold promise in TB testing, children to benefit more

  • Nurul Islam Hasib from Guadalajara in Mexico,
    Published: 2017-10-14 00:51:32 BdST


An African study presented at the 48th Union’s world conference on lung health in Mexico shows that oral swabs are “simpler, cleaner, safer, and more uniform” alternatives to sputum as diagnostic samples for tuberculosis.

Angelique Luabeya of the South African Tuberculosis Vaccine Initiative at the University of Cape Town in South Africa reported results of the study on Friday and said that there was a need for alternatives to commonly used sputum for testing TB.

“The capacity to detect the bacterium was very low in sputum samples. There are patients particularly children who cannot produce sputum by coughing enough to test,” she said.

“But swabs can easily be collected from cheek, gum, and tongue and we found that oral swabbing can serve as a convenient and occupationally safe alternative to sputum collection for TB diagnosis,” she said at a press briefing.

The four-day conference which will end on Saturday is presenting new technologies that change the tuberculosis testing, and treatment landscapes.

The Union’s Scientific Director Paula Fujiwara said it is the WHO which will ultimately recommend for countries who to follow, but this new swab testing results will be one additional piece that holds promise to change update the diagnostic guidelines.

Luabeya presenting her study said they pursued a bigger study after a previous study conducted on cheek swabs collected from 20 sputum-GeneXpert confirmed case subjects in South Africa showed the success.

GeneXpert is a technique of testing TB.

In the bigger study, an expanded sample of oral swabs was collected from 46 sputum GeneXpert-confirmed pulmonary TB cases, 11 sputum GeneXpert-negative but culture-positive TB cases, and 26 no TB, but ill cases and 33 healthy people.

Samples were tested by quantitative PCR (qPCR) in a blinded analysis.

First, the method was applied to cheek, gum, and tongue swabs from a subset of GeneXpert-confirmed cases. Tongue swabs yielded 30-fold stronger qPCR signals for MTB DNA than cheek or gum swabs.

She said a study is ongoing involving even more patients.