Sample Transport Optimization: Mali Pilot Study.

In Mali, qualified laboratories for testing of dangerous pathogens are centralized in Bamako. Creating a specimen transport system respecting timeline, specimen quality, biosafety, and biosecurity standards is a challenge. The current ad hoc system that relies on untrained public transport companies carries risks of spoilage, accidental release of pathogens, and delays, which compromise specimen quality. This pilot study aimed to evaluate the effectiveness (ie, timeline, quality of specimen, and cost) of using the trained postal service for sample transportation from district to central level, compared with the current system. The postal service intervention ran from mid-2016 to mid-2017 and covered 3 districts. Data were collected in the same districts during the same period of the preceding year for comparison. In all, 41 specimens were shipped using public transportation and 51 were shipped using the postal service. These included suspected meningitis, measles, yellow fever, and polio samples. Only 46% of samples sent by public transportation were received in Bamako within 72 hours of collection, compared to 71% of samples shipped via the postal service (p < .05). Further, 93% of samples shipped by public transportation arrived in good condition at the receiving laboratory, compared to 98% by postal service. Although cost comparisons were difficult (flat fee vs per-specimen fare), the average cost per specimen was 8 times higher with the postal service. Shipment of specimens from districts to central level using the postal service was feasible and appeared to be faster than public transportation, thus allowing specimen quality to be preserved. Further analysis regarding the most efficient costing mechanism is needed.

Stool microbiome reveals diverse bacterial ureases as confounders of oral urea breath testing for Helicobacter pylori and Mycobacterium tuberculosis in Bamako, Mali.

Detection of bacterial urease activity has been utilized successfully to diagnose Helicobacter pylori (H. pylori). While Mycobacterium tuberculosis (M. tuberculosis) also possesses an active urease, it is unknown whether detection of mycobacterial urease activity by oral urease breath test (UBT) can be exploited as a rapid point of care biomarker for tuberculosis (TB) in humans. We enrolled 34 individuals newly diagnosed with pulmonary TB and 46 healthy subjects in Bamako, Mali and performed oral UBT, mycobacterial sputum culture and H. pylori testing. Oral UBT had a sensitivity and specificity (95% CI) of 70% (46-88%) and 11% (3-26%), respectively, to diagnose culture-confirmed M. tuberculosis disease among patients without H. pylori, and 100% sensitivity (69-100%) and 11% specificity (3-26%) to diagnose H. pylori among patients without pulmonary TB. Stool microbiome analysis of controls without TB or H. pylori but with positive oral UBT detected high levels of non-H. pylori urease producing organisms, which likely explains the low specificity of oral UBT in this setting and in other reports of oral UBT studies in Africa.

Molecular identification of Mycobacterium bovis from cattle and human host in Mali: expanded genetic diversity.

BACKGROUND: Bovine tuberculosis (BTB) is a contagious, debilitating human and animal disease caused by Mycobacterium bovis, a member of the Mycobacterium tuberculosis complex. The study objective were to estimate the frequency of BTB, examine genetic diversity of the M. bovis population in cattle from five regions in Mali and to determine whether M. bovis is involved in active tuberculosis (TB) in humans. Samples from suspected lesions on cattle at the slaughterhouses were collected. Mycobacterial smear, culture confirmation, and spoligotyping were used for diagnosis and species identification. Mycobacterium DNA from TB patients was spoligotyped to identify M. bovis. RESULTS: In total, 675 cattle have been examined for lesions in the five regions of Mali. Out of 675 cattle, 79 specimens presented lesions and then examined for the presence of M. bovis. Thus, 19 (24.1 %) were identified as M. bovis; eight (10.1 %) were non-tuberculous Mycobacterium (NTM). Nineteen spoligotype patterns were identified among 79 samples with five novel patterns. One case of M. bovis (spoligotype pattern SB0300) was identified among 67 TB patients. CONCLUSION: This study estimates a relatively true proportion of BTB in the regions of Mali and reveals new spoligotype patterns.

Failure to recognize nontuberculous mycobacteria leads to misdiagnosis of chronic pulmonary tuberculosis.

BACKGROUND: Nontuberculous mycobacterial (NTM) infections cause morbidity worldwide. They are difficult to diagnose in resource-limited regions, and most patients receive empiric treatment for tuberculosis (TB). Our objective here is to evaluate the potential impact of NTM diseases among patients treated presumptively for tuberculosis in Mali. METHODS: We re-evaluated sputum specimens among patients newly diagnosed with TB (naïve) and those previously treated for TB disease (chronic cases). Sputum microscopy, culture and Mycobacterium tuberculosis drug susceptibility testing were performed. Identification of strains was performed using molecular probes or sequencing of secA1 and/or 16S rRNA genes. RESULTS: Of 142 patients enrolled, 61 (43%) were clinically classified as chronic cases and 17 (12%) were infected with NTM. Eleven of the 142 (8%) patients had NTM disease alone (8 M. avium, 2 M. simiae and 1 M. palustre). All these 11 were from the chronic TB group, comprising 11/61 (18%) of that group and all were identified as candidates for second line treatment. The remaining 6/17 (35.30%) NTM infected patients had coinfection with M. tuberculosis and all 6 were from the TB treatment naïve group. These 6 were candidates for the standard first line treatment regimen of TB. M. avium was identified in 11 of the 142 (8%) patients, only 3/11 (27.27%) of whom were HIV positive. CONCLUSIONS: NTM infections should be considered a cause of morbidity in TB endemic environments especially when managing chronic TB cases to limit morbidity and provide appropriate treatment.