Accuracy of giant African pouched rats for diagnosing tuberculosis: comparison with culture and Xpert W MTB/RIF

Abstract

S E T T I N G : Enhanced tuberculosis (TB) case finding using detection rats in Tanzania. O B J E C T I V E S : To assess the diagnostic accuracy of detection rats compared with culture and Xpert w MTB/ RIF, and to compare enhanced case-finding algorithms using rats in smear-negative presumptive TB patients. D E S I G N : A fully paired diagnostic accuracy study in which sputum of new adult presumptive TB patients in Tanzania was tested using smear microscopy, 11 detection rats, culture and Xpert. R E S U LT S : Of 771 eligible participants, 345 (45%) were culture-positive for Mycobacterium tuberculosis, and 264 (34%) were human immunodeficiency virus (HIV) positive. The sensitivity of the detection rats was up to 75.1% (95%CI 70.1–79.5) when compared with cul- ture, and up to 81.8% (95%CI 76.0–86.5) when compared with Xpert, which was statistically signifi- cantly higher than the sensitivity of smear microscopy. Corresponding specificity was 40.6% (95%CI 35.9– 45.5) compared with culture. The accuracy of rat detection was independent of HIV status. Using rats for triage, followed by Xpert, would result in a statistically higher yield than rats followed by light- emitting diode fluorescence microscopy, whereas the number of false-positives would be significantly lower than when using Xpert alone. C O N C L U S I O N : Although detection rats did not meet the accuracy criteria as standalone diagnostic or triage testing for presumptive TB, they have additive value as a triage test for enhanced case finding among smear- negative TB patients if more advanced diagnostics are not available

Description

The International Journal of Tuberculosis and Lung Disease 21(11):pg. 1127–1133

Keywords

Diagnostic, Olfactory detection, Criceto- mys ansorgei, Sensitivity, Specificity

Citation