The incremental value of tuberculosis detecting African giant pouched rats over Smear microscopy and Xpert MTB/RIF for Tanzanian TB detection

• DOI: 10.1371/journal.pone.0321866
• Publication Date: 2025-04-29T17:29:52Z
• Authors: Tefera B. Agizew; Joseph Soka; Stephen Mwimanzi; Cynthia D. Fast; Gilbert Mwesiga; Nashon Edward; Marygiven Stephen; Rehema Kondo; Christophe Cox; Negussie Beyene
• Keywords: Ziehl–Neelsen stain

Background Prior studies that used Anti-Persoonsmijnen Ontmijnende Product Ontwikkeling (APOPO)-trained African giant pouched rats reported an annual average of 40% increase in sputum-smear-positive tuberculosis (TB) detection. Sputum-smear microscopy (smear) is being replaced by Xpert MTB/RIF (Xpert)-based diagnostic algorithms many countries. We evaluated the incremental values rat-based case detection over smear and Xpert. Methods From January to December 2023, sputum samples were collected from presumptive TB patients at 69 health facilities use or smear-based algorithms. An five APOPO re-evaluate second sample Xpert-negative smear-negative sample. Concentrated smears Ziehl-Neelsen staining confirm rat-positive (samples indicated positive ≥ 1 rat). analyzed (incremental yield) compared rise against Mycobacterium bacillary load using Chi-square test. Results A total 43,153 34,565 re-evaluated rats. There 6,717 bacteriologically confirmed cases; 4,541 (68%) these cases detected (3,239 1,302 sites); remaining 2,176 (32%) found trained rats, representing 48% (2,176/4,541) overall value. Of which, 65% (1,409/2,176) 35% (767/2,176) among patients, respectively. The Incremental yield was 44% (1,409/3,239), while it 59% (767/1,302) facilities, Odds Ratio, OR = 0.74, 95% confidence interval, CI:0.66–0.82. 47% more likely identify Acid Fast Bacilli + scanty than [91% (1,276/1,409) versus 87% (665/767), 1.47, CI:1.12–1.94]. difference between children adults, however, not substantial, [69% (68/98) 67% (1,138/1,701), 1.12, CI:0.72–1.74]. Conclusions Our finding reasonably added benefit DOT findings. According our data, switching sites lowered value a quarter, even though with lower loads.