Browsing by Author "Mulder, C."

Now showing 1 - 5 of 5

Accuracy of giant African pouched rats for diagnosing tuberculosis: comparison with culture and Xpert W MTB/RIF
(Researchgate, 2017) Mulder, C.; Mgode, G. F.; Ellis, H.; Valverde, E.; Beyene, N.; Cox, C.; Reid, S. E.; Van’t Hoog, A. H.; Edwards, T. L.
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
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.
Pediatric tuberculosis detection using trained African giant pouched rats
(2018 International Pediatric Research Foundation, Inc., 2018) Mgode, G. F.; Cox, C. L.; Mwimanzi, S.; Mulder, C.
BACKGROUND: Tuberculosis (TB) diagnosis in children is a challenge with up to 94% of children with TB treated empirically in TB high-burden countries. Therefore, new diagnostic tests are needed for TB diagnosis. We determined the performance of trained rats in the diagnosis of pediatric TB and whether they can improve detection rate compared to the standard of care. METHODS: Presumptive TB patients in 24 TB clinics in Tanzania were tested. Samples indicated as TB-positive by rats underwent confirmation by concentrated smear microscopy. TB yield of bacteriologically confirmed pediatric TB patients (≤5 years) was compared with yield of standard of care. RESULTS: Sputum samples from 55,148 presumptive TB patients were tested. Nine hundred eighty-two (1.8%) were the children between 1 and 5 years. Clinics detected 34 bacteriologically positive children, whereas rats detected additional 23 children yielding 57 bacteriologically TB- positive children. Rats increased pediatric TB detection by 67.6%. Among 1–14-year-old children, clinics detected 331 bacteriologically positive TB whereas rats found the additional 208 children with TB that were missed by clinics. Relative increase in TB case detection by rats decreased with the increase in age (Po0.0001). CONCLUSION: Trained rats increase pediatric TB detection significantly and could help address the pediatric TB diagnosis challenges. Further determination of accuracy of rats involving other sample types is still needed.
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.
Tuberculosis diagnostic technology: an African solution ... think rats
(AOSIS, 2017-03-31) Mulder, C.; Mgode, G.; Reid, S. E.
Introduction Tuberculosis has now gained ranking alongside HIV as one of the two leading causes of death from infectious diseases worldwide. 1 In 2014, it was estimated that 1.5 million people died as a result of and 9.6 million fell ill with tuberculosis. 1 Despite these alarming figures, efforts to reduce the annual tuberculosis incidence rate over the last decade have resulted in only a meagre 1.5% decline. 1 In order to reach the ambitious targets of the Sustainable Development Goals by 2030 of reducing tuberculosis deaths by 90%, reducing the tuberculosis incidence rate by 90%, and ensuring that no tuberculosis-affected family is facing catastrophic costs due to tuberculosis, a paradigm shift is urgently needed. 1 Recently, a series of papers was published in The Lancet on how to eliminate tuberculosis, suggesting repacking current interventions into a comprehensive control strategy. 2 The World Health Organization End TB Strategy supports this and also emphasises the need for better adoption and rapid uptake of new tools to diagnose tuberculosis earlier, the systematic screening of high-risk populations, and the effective and rapid roll-out of these strategies in highly-affected countries. 3 However, the practicality of achieving these components remains challenging because of the lack of a rapid, simple, accurate and affordable point-of-care diagnostic and screening algorithm that can be scaled-up to screen large numbers of individuals. Nevertheless, achievement of these goals is necessary and must catalyse the development of new interventions in Africa, for Africa, the continent with the highest tuberculosis mortality and morbidity rates.