Browsing by Author "Poling, A."

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Active tuberculosis detection by pouched rats in 2014: more than 2,000 new patients found in two countries
(2016 Society for the Experimental Analysis of Behavior, 2016) Poling, A.; Beyene, N.; Valverde, E.; Mulder, C.; Cox, C.; Mgode, G.; Edwards, T. L.
Tuberculosis (TB) is a major problem in poor countries because sensitive diagnostic tools are unavail- able. In 2014, our pouched rats evaluated sputum from 21,600 Tanzanians and 9,048 Mozambicans whose sputum had previously been evaluated by microscopy, the standard diagnostic for TB. Evalua- tion by the rats revealed 1,412 new patients with active TB in Tanzania and 645 new patients in Mozambique, increases of 39% and 53%, respectively, when compared to detections by microscopy alone. These results provide further support for the applied use of scent-detecting rats.
Pouched rats’ detection of tuberculosis in human sputum: Comparison to culturing and polymerase chain reaction
(Tuberculosis Research and Treatment, 2012) Mahoney, A.; Weetjens, B. J.; Cox, C.; Beyene, N.; Reither, K.; Makingi, G.; Jubitana, M.; Kazwala, R. R.; Mfinanga, G. S.; Kahwa, A.; Durgin, A.; Poling, A.
Setting. Tanzania. Objective. To compare microscopy as conducted in direct observation of treatment, short course centers to pouched rats as detectors of Mycobacterium tuberculosis. Design. Ten pouched rats were trained to detect tuberculosis in sputum using operant conditioning techniques. The rats evaluated 910 samples previously evaluated by smear microscopy. All samples were also evaluated through culturing and multiplex polymerase chain reaction was performed on culture growths to classify the bacteria. Results. The patientwise sensitivity of microscopy was 58.0%, and the patient-wise specificity was 97.3%. Used as a group of 10 with a cutoff (defined as the number of rat indications to classify a sample as positive for Mycobacterium tuberculosis) of 1, the rats increased new case detection by 46.8% relative to microscopy alone. The average samplewise sensitivity of the individual rats was 68.4% (range 61.1–73.8%), and the mean specificity was 87.3% (range 84.7–90.3%). Conclusion. These results suggest that pouched rats are a valuable adjunct to, and may be a viable substitute for, sputum smear microscopy as a tuberculosis diagnostic in resource-poor countries.
Tuberculosis detection by pouched rats: Opportunities for reinforcement under low-prevalence conditions
(2017 Elsevier B.V, 2017) Edwards, T. L.; Ellis, H.; Watkins, E. E.; Mulder, C.; Mgode, G.; Cox, C.; Poling, A.
Giant African pouched rats (Cricetomys ansorgei) have been employed successfully in two operational tuberculosis-detection projects in which they sniff sputum samples from symptomatic individuals who have visited tuberculosis clinics. The prevalence of pulmonary tuberculosis in this population is high, approximately 20% in the regions where the rats have been used. If the rats are to be used to screen individuals from lower- prevalence populations, their performance under such conditions must first be evaluated. In this study, the prevalence of tuberculosis-positive samples presented to eight pouched rats was reduced to approximately 5%, and the percentage of known-positive samples included as opportunities for reinforcement was varied in sequence from 10 to 8, 6, 4, 2, 4, and 2. Liquid food reinforcers were delivered for identification responses to known-positive samples and at no other time. The rats’ accuracy was clinically and statistically significantly lower at 2% than at the other values. These results indicate that the rats can perform well in low-prevalence scenarios but, if they are used under the conditions of the present study, at least 4% of the samples presented to them must be opportunities for reinforcement.
Using giant african pouched rats to detect human tuberculosis: A review
(Pan African Medical Journal, 2015-08-31) Poling, A.; Mahoney, A.; Beyene, N.; Mgode, G.; Weetjens, B.; Cox, C.; Durgin, A.
Despite its characteristically low sensitivity, sputum smear microscopy remains the standard for diagnosing tuberculosis (TB) in resource-poor countries. In an attempt to develop an alternative or adjunct to microscopy, researchers have recently examined the ability of pouched rats to detect TB-positive human sputum samples and the microbiological variables that affect their detection. Ten published studies, reviewed herein, suggest that the rats are able to detect the specific odor of Mycobacterium tuberculosis , which causes TB, and can substantially increase new-case detections when used for second-line TB screening following microscopy. Further research is needed to ascertain the rats' ability to detect TB in children and in HIV-positive patients, to detect TB when used for first-line screening, and to be useful in broad-scale applications where cost- effectiveness is a major consideration.