Clinical Infectious Diseases最新文献

Background: Rapid, accurate, nonsputum tests are needed to close gaps in tuberculosis (TB) detection. We evaluated the diagnostic performance of molecular testing on saliva and oral swabs.

Methods: We conducted a nested case-control study with 1:1 incidence-density sampling within a prospective cohort of adults and children undergoing evaluation for pulmonary TB at primary care centers in Colombia (July 2023-August 2024). Participants provided a sputum sample for liquid mycobacterial culture and paired saliva and nylon-flocked oral swabs for storage at -80°C. A microbiologist blinded to clinical and culture data performed Xpert MTB/RIF Ultra on thawed saliva and on swab eluate, each mixed 1:1 with sample reagent. We calculated the sensitivity and specificity of saliva and swab against sputum culture and compared them using McNemar's test.

Results: Among 648 enrolled participants, we tested saliva and swabs from all 95 individuals with culture-confirmed TB and 95 matched culture-negative controls (n = 190). Saliva sensitivity was 90.5% (95% confidence interval [CI], 82.8-95.6), and specificity was 95.8% (95% CI, 89.6-98.8). Swab sensitivity was 71.6% (95% CI, 61.4-80.4), and specificity was 99% (95% CI, 94.3-100). Saliva sensitivity exceeded that of swab by an absolute difference of 18.9% (95% CI, +10.0 to +27.9, P < .001), but there was no significant difference in specificity (-3.2%, 95% CI, -7.7 to +1.4, P = .25). Over 95% of participants found saliva and swab collection procedures acceptable.

Conclusions: Both saliva and swabs were highly sensitive and specific for culture-confirmed pulmonary TB. Saliva sensitivity exceeded the World Health Organization's ≥80% target for a low-complexity, nonsputum TB diagnostic test.

Background: Tongue swabs are a promising alternative specimen for tuberculosis (TB) diagnosis. Although test specificity exceeds 98%, sensitivity is lower than sputum-based molecular testing. We investigated whether the use of tongue swabs could increase sample availability, resulting in similar diagnostic yield.

Methods: In this cross-sectional study (July 2024-January 2025), we screened consecutive people with presumptive TB at health centers in the Philippines, Vietnam, Uganda, and Zambia. Participants were asked to provide tongue swabs and referred for routine sputum collection. Tongue swabs were tested in research laboratories using the MiniDock MTB Test (Guangzhou Pluslife Biotech Co., Ltd., China); sputum was tested using WHO-recommended molecular testing per national guidelines. We compared diagnostic yield, defined as proportion of positive test results among all participants, between tongue swab- and sputum-based molecular testing with a prespecified 3.0% non-inferiority margin.

Results: Of 1639 participants, 851 (51.9%) were female, 415 (25.3%) were living with HIV, and 132 (8.1%) were children <5 years. All provided tongue swabs, but only 1389 (84.7%) produced sputum. Diagnostic yield was 3.8% (63/1639) for tongue swabs and 4.1% (68/1639) for sputum-based (68/1639, 4.1%) molecular testing. The difference (0.3%, 95% CI -0.6 to +1.2) was within the prespecified non-inferiority margin. Results were consistent across countries and key subgroups (age, sex, and HIV status).

Conclusions: Tongue swab-based molecular testing with MiniDock MTB achieved non-inferior diagnostic yield compared with sputum-based molecular testing. These findings support scale-up of swab-based platforms as a cost-efficient alternative, particularly where sputum collection is challenging or smear microscopy remains the primary diagnostic method.