Preferences for Tongue Swab versus Sputum Collection for Tuberculosis Testing: A Multi-Country Survey

Sputum collection for tuberculosis (TB) diagnosis poses challenges for children, people living with HIV, and those who struggle with sputum production. Tongue swab-based molecular testing offers a promising non-invasive alternative, but person-centered research on acceptability is limited.

We conducted a pragmatic survey across eight countries (Vietnam, Philippines, South Africa, Nigeria, Zambia, India, Uganda, Peru) among people with presumptive TB attending primary care facilities. Participants provided both tongue swab and sputum samples, then completed a 5-10 minute survey about their collection preferences.

From October 2023 to July 2024, 1,297 participants were enrolled (median age 43 years, 45% female, 13% HIV-positive). Overall, 61% (95% CI: 58-64%) preferred tongue swab collection compared to 22% (95% CI: 20-25%) who preferred sputum collection and 17% (95% CI: 15-19%) with no preference. Preference for tongue swab was consistent across demographic and clinical subgroups, with country-level variation ranging from 47% in South Africa to 74% in Zambia and Nigeria.

Strong preference for tongue swab over sputum collection among individuals with presumptive TB supports this diagnostic innovation's potential to overcome barriers to timely TB testing, particularly for populations struggling with sputum production.