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. 2024 Jan;12(1):e45-e54.
doi: 10.1016/S2214-109X(23)00469-2.

Oral swabs with a rapid molecular diagnostic test for pulmonary tuberculosis in adults and children: a systematic review

E Chandler Church  1 , Karen R Steingart  2 , Gerard A Cangelosi  3 , Morten Ruhwald  4 , Mikashmi Kohli  4 , Adrienne E Shapiro  5
Affiliations

Oral swabs with a rapid molecular diagnostic test for pulmonary tuberculosis in adults and children: a systematic review

E Chandler Church et al. Lancet Glob Health. 2024 Jan.

Abstract

Background: Tuberculosis is a leading cause of infectious disease mortality worldwide, but diagnosis of pulmonary tuberculosis remains challenging. Oral swabs are a promising non-sputum alternative sample type for the diagnosis of pulmonary tuberculosis. We aimed to assess the diagnostic accuracy of oral swabs to detect pulmonary tuberculosis in adults and children and suggest research implications.

Methods: In this systematic review, we searched published and preprint studies from Jan 1, 2000, to July 5, 2022, from eight databases (MEDLINE, Embase, Scopus, Science Citation Index, medRxiv, bioRxiv, Global Index Medicus, and Google Scholar). We included diagnostic accuracy studies including cross-sectional, cohort, and case-control studies in adults and children from which we could extract or derive sensitivity and specificity of oral swabs as a sample type for the diagnosis of pulmonary tuberculosis against a sputum microbiological (nucleic acid amplification test [NAAT] on sputum or culture) or composite reference standard.

Findings: Of 550 reports identified by the search, we included 16 eligible reports (including 20 studies and 3083 participants) that reported diagnostic accuracy estimates on oral swabs for pulmonary tuberculosis. Sensitivity on oral swabs ranged from 36% (95% CI 26-48) to 91% (80-98) in adults and 5% (1-14) to 42% (23-63) in children. Across all studies, specificity ranged from 66% (95% CI 52-78) to 100% (97-100), with most studies reporting specificity of more than 90%. Meta-analysis was not performed because of sampling and testing heterogeneity.

Interpretation: Sensitivity varies in both adults and children when diverse methods are used. Variability in sampling location, swab type, and type of NAAT used in accuracy studies limits comparison. Although data are suggestive that high accuracy is achievable using oral swabs with molecular testing, more research is needed to define optimal methods for using oral swabs as a specimen for tuberculosis detection. The current data suggest that tongue swabs and swab types that collect increased biomass might have increased sensitivity. We would recommend that future studies use these established methods to continue to refine sample processing to maximise sensitivity.

Funding: Bill and Melinda Gates foundation (INV-045721) and FIND (Netherlands Enterprise Agency on behalf of the Minister for Foreign Trade and Development Cooperation [NL-GRNT05] and KfW Development Bank, German Federal Ministry of Education and Research [KFW-TBBU01/02]).

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Conflict of interest statement

Declaration of interests This study received funding from FIND. ECC reports institution payments from FIND. MK and MR are employed by FIND. AES is supported in part by a National Institutes of Health (NIH) K23 AI40918 award. GAC is funded by the NIH and Bill and Melinda Gates foundation and reports receiving donations of research supplies (FLOQswabs) from Copan Italia. KS has received financial support from Cochrane Infectious Diseases, McGill University, Baylor College of Medicine, Maastricht University, TB Proof, and WHO Global Tuberculosis Programme; consultancy fees from FIND, the global alliance for diagnostics; consulting fees from Stellenbosch University, and travel support to attend WHO guideline development group meetings.

Figures

Figure 1
Figure 1
Potential sources of variability in sensitivity and specificity for oral swabs LAMP=loop-mediated isothermal amplification. Mfr=manufacturer. NAAT=nucleic acid amplification test.
Figure 2
Figure 2
Study selection mWRD=molecular WHO-recommended rapid diagnostic.
Figure 3
Figure 3
Forest plot (A) and SROC plot (B) of oral swabs in adults using a microbiological reference standard by location of oral cavity swabbed OSA=oral swab analysis. SROC=summary receiver operating characteristic.
Figure 4
Figure 4
Forest plot of oral swabs in children using a composite (A) and microbiological (B) reference standard
See this image and copyright information in PMC

Comment in

References

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