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Beyond sputum: Why WHO’s new tongue swab test is a ‘major advance’ in fight against TB

Experts suggest that this near-point-of-care molecular test can be implemented at the primary care level and at a lower cost.

4 min readPuneUpdated: Mar 6, 2026 05:21 PM IST

Experts suggest that this near-point-of-care molecular test can be implemented at the primary care level and at a lower cost.

A new policy from the World Health Organization (WHO) marks a significant advancement in tuberculosis (TB) testing. Experts suggest that this near-point-of-care molecular test can be implemented at the primary care level and at a lower cost.

Professor Madhukar Pai, Inaugural Chair, Department of Global and Public Health, McGill School of Population and Global Health McGill University, emphasized the importance of the new WHO policy for TB.

“For the first time, they have approved a near-point-of-care molecular test that can be used at the primary care level and also with a tongue swab, since many people are unable to produce sputum, and is a major advance in TB testing. Near-point-of-care molecular tests can now reach the level of primary care and are far more affordable than any existing molecular test. In addition, tongue swabs come in very handy when people are not able to spontaneously produce sputum samples,” Prof Pai told The Indian Express.

Former TB officers with the Central TB Division, Government of India, said that these tests would be very helpful and come at a lesser cost. “It may take a few years, but there is a huge potential for scaling up of the tests,” the officer said.

According to a statement by WHO, the recommendations mark a major step in making TB testing faster and more accessible.

Dr. Tereza Kasaeva, Director of WHO’s Department of HIV, TB, Hepatitis, and STIs, stated that WHO encourages countries and partners to collaborate in implementing these guidelines to address ongoing diagnostic gaps and ensure that everyone with TB can be diagnosed early and start life-saving treatment without delay.

WHO has recommended a new class of near-point-of-care nucleic acid amplification tests (NPOC-NAATs) for the initial detection of TB without rifampicin resistance. These tests can be administered at peripheral levels of the health system, such as in peripheral laboratories, primary healthcare centers, and communities, at lower costs than existing molecular tests.

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Additionally, the WHO endorses the use of tongue swabs as easy-to-collect specimens for NPOC-NAATs and low-complexity automated NAATs for the initial detection of TB, including cases with and without rifampicin resistance among adults and adolescents who cannot produce sputum.

The new test is available through the Global Drug Facility at $3.50 per test, making it far more affordable than any previous molecular test. Several countries plan to roll this out through a special Global Fund programme, according to experts.

Dr. Zarir Udwadia, a consultant pulmonologist at Hinduja Hospital in Mumbai, criticized existing sputum smear microscopy as a test with very poor sensitivity and accuracy.

“It should have been phased out a decade ago. The new generation of PCR-based tests is the gold standard, which should be universal first-line tests for all TB suspects. There is not enough data to routinely recommend tongue swabs apart from a few small studies, but they could be considered in patients unable to produce sputum (infants and children),” he said

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Sriram Natarajan, Executive Director and CEO of Molbio Diagnostics, said that these are early stages based on limited evidence, and the use cases still need to be more clearly defined. “This will need a few years of pilot introductions for scale-up, depending on the outcome. This category also cannot do drug resistance as of now, which is another limiting factor,” he said.

Anuradha Mascarenhas

Anuradha Mascarenhas is a Senior Editor at The Indian Express, based in Pune. With a career spanning three decades, she is one of the most respected voices in Indian journalism regarding healthcare, science and environment and research developments. She also takes a keen interest in covering women's issues . Professional Background Education: A gold medalist in Communication and Journalism from Savitribai Phule Pune University and a Master’s degree in Literature. Author: She authored the biography At The Wheel Of Research, which chronicles the life and work of Dr. Soumya Swaminathan, the former Chief Scientist at the WHO. Key Focus: She combines scientific accuracy with storytelling, translating complex medical research into compelling public and human-interest narratives. Awards and Recognition Anuradha has won several awards including the Press Council of India's national award for excellence in journalism under the gender based reporting category in 2019 and the Laadli Media award (gender sensitivity -2024). A recipient of the Lokmat journalism award (gender category-2022), she was also shortlisted for the RedInk awards for excellence in journalism-2021. Her debut book At The Wheel Of Research, an exclusive biography of Dr Soumya Swaminathan the inaugural chief scientist of World Health Organisation was also nominated in the Popular Choice Category of JK Paper AUTHER awards. She has also secured competitive fellowships including the Laadli Media Fellowship (2022), the Survivors Against TB – New Research in TB Media Fellowship (2023) and is part of the prestigious 2025 India Cohort of the WomenLift Health Leadership Journey.” Recent Notable Articles (Late 2025) 1. Cancer & Specialized Medical Care "Tata Memorial finds way to kill drug-resistant cancer cells" (Nov 26, 2025): Reporting on a breakthrough for triple-negative breast cancer, one of the most aggressive forms of the disease. Discipline, diet and purpose; How a 97-year-old professor defies ageing'' (Nov 15, 2025) Report about Prof Gururaj Mutalik, the first Head of Department at Pune's B J Government Medical College who at 97 credits his longevity to healthy habits and a strong sense of purpose. 2. Environmental Health (The "Breathless Pune" Series) Long-term exposure even to 'moderate' air leads to chronic heart, lung, kidney issues" (Nov 26, 2025): Part of an investigative series highlighting that even "safe" pollution levels are damaging to vital organs. "For every 10 µg/m3 increase in PM2.5 level, there was 6-8% jump in medicine sales" (Nov 23, 2025): Using commercial data to prove the direct link between air quality and respiratory illnesses in Pune. 3. Lifestyle & Wellness News "They didn't let cancer, diabetes and heart disease stop them from travelling" (Dec 22, 2025): A collaborative piece featuring survivors who share practical tips for traveling with chronic conditions. At 17, his BP shot up to 200/120 mmHG; Lancet study flags why child and teen hypertension doubled between 2000 and 2020'' (Nov 12,2025)--A report that focusses on 17-year-old-boy's hypertensive crisis and reflects the rising global trend of high blood pressure among children and adolescents. 4. Scientific Recognition & Infrastructure For promoting sci-comm, gender diversity: IUCAA woman prof highlighted in Nature" (Nov 25, 2025): Covering the global recognition of Indian women scientists in gender studies and physics. Pune researchers find a spiral galaxy like the Milky Way from early universe'' (December 3, 2025)- A report on how Indian researchers discovered a massive galaxy that existed when the universe was just 1.5 billion years old , one of the earliest to have been observed so far. Signature Beat: Health, Science & Women in Leadership Anuradha is known for her COVID-19 reportage, where she was one of the first journalists to provide detailed insights into the Covishield and Covaxin trials. She has a dedicated interest in gender diversity in health and science, often profiling women researchers who are breaking the "leaky pipeline" in STEM fields. Her writing style is scrupulous, often featuring interviews with top-tier scientists and health experts from various institutions. ... Read More

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