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

Extensively drug resistant tuberculosis in Mali: a case report

Abstract Background Drug resistant tuberculosis presents a major public health challenge. Case presentation We present here the first two patients diagnosed with extensively drug resistant tuberculosis in Bamako, Mali. Genotypic findings suggest possible nosocomial transmission from the first patient to the second one, resulting in superinfection of the second patient. After being diagnosed with extensively drug resistant tuberculosis in August 2016, the patients only started receiving appropriate treatment 10 months later. Conclusion The identification of these patients highlights the need for improved diagnostic and treatment algorithms for better surveillance and management of drug resistance in Mali. In the interest of these as well as future patients suffering from resistant tuberculosis, all steps recommended for programmatic management of drug resistant tuberculosis must be urgently prioritized in order to strengthen the multidrug resistant tuberculosis program

<i>Mycobacterial species</i> isolated, demographic characteristics, symptoms and treatment assigned to each patient.

@<p><i>Mycobacterium species</i> most closely related;</p>*<p>Patients were naïve to TB treatment before they were enrolled in the study and received the TB standard regimen for their disease.</p>$<p>Based on National treatment guidelines for TB, the Standard regimen comprises 2 months of rifampin, isoniazid, pyrazinamide and ethambutol and 4 months of isoniazid and rifampin (2RHZE/4RH). Patients with sputum smears positive at month-5 of standard regimen, receive 1 month of rifampin, isoniazid, pyrazinamide, ethambutol and streptomycin followed by 2 months of rifampin, isoniazid, pyrazinamide, ethambutol and 5 months of rifampin, isoniazid and ethambutol (2RHZES/1RHZE/5RHE called re-treatment regimen). The second line treatment for chronic cases (patients with sputum smears positive after re-treatment regimen) comprises kanamycin, ofloxacin, ethionamide and pyrazinamide (3KOEtZ/18OetZ) for MDR disease. <i>M.af: Mycobacterium africanum</i>; <i>M.tb: Mycobacterium tuberculosis</i>; <i>Neg: negative</i>; <i>Pos: positive</i>; <i>AFB: acid-fast bacilli.</i></p

Impact of NTM on TB sputum smears or cultures.

<p><i>NTM: Nontuberculous mycobacteria</i>; <i>MTBC: Mycobacterium tuberculosis</i> complex;</p>*<p><i>Pos: positive in at least two occasions</i>;</p>#<p><i>Neg: negative in three occasions</i>.</p

Distribution of patients in the naïve and chronic treatment groups based on culture and susceptibility results.

*<p><i>M. tuberculosis</i> complex,</p>#<p>Resistant to isoniazid and rifampin,</p>@<p>Nontuberculous Mycobacteria.</p

The most frequent Mycobacterium tuberculosis complex families in mali (2006–2016) based on spoligotyping

Background: To identify strains of Mycobacterium tuberculosis complex (MTBc) circulating in Bamako region during the past 10 years. Methods: From 2006 to 2016, we conducted a cross-sectional study to identify with spoligotyping, clinical isolates from tuberculosis (TB)-infected patients at different stages of their treatments in Bamako, Mali. Results: Among the 904 suspected TB patients included in the study and thereafter tested in our BSL-3 laboratory, 492 (54.4%) had MTBc and therefore underwent spoligotyping. Overall, three subspecies, i.e., MTB T1 (31.9%) and MTB LAM10 (15.3%) from lineage 4 and M. africanum 2 (16.8%) from lineage 6 were the leading causes of TB in Bamako region during the past 10 years. Other spoligotypes such as MTB T3, MTB Haarlem 2, MTB EAI3, and MTB family 33 were also commonly seen from 2010 to 2016. Conclusion: This study showed a high genetic diversity of strains isolated in Bamako region and highlights that M. tuberculosis T1 strain was the most prevalent. Furthermore, the data indicate an increasing proportion of primary drug resistance overtime in Bamako

Clinical risk factors associated with multidrug-resistant tuberculosis (MDR-TB) in Mali

Background: MDR-TB is a major threat to global TB control. In 2015, 580,000 were treated for MDR-TB worldwide. The worldwide roll-out of GeneXpert MTB/RIF® has improved diagnosis of MDR-TB; however, in many countries laboratories are unable to assess drug resistance and clinical predictors of MDR-TB could help target suspected patients. In this study, we aimed to determine the clinical factors associated with MDR-TB in Bamako, Mali. Methods: We performed a cross-sectional study of 214 patients with presumed MDR-TB admitted to University of Bamako Teaching Hospital, Point-G between 2007 and 2016. We calculated crude and adjusted odds ratios for MDR-TB disease diagnosis using SPSS. Results: We found that age ≤40 years (OR = 2.56. 95% CI: 1.44–4.55), two courses of prior TB treatment (OR = 3.25, 95% CI: 1.44–7.30), TB treatment failure (OR = 3.82, 95% CI 1.82–7.79), sputum microscopy with 3+ bacilli load (OR = 1.98, 95% CI: 1.13–3.48) and a history of contact with a TB patient (OR = 2.48, 95% CI: 1.11–5.50) were significantly associated with confirmation of MDR-TB disease. HIV was not a risk factor for MDR-TB (aOR = 0.88, 95% CI: 0.34–1.94). Conclusion: We identified several risk factors that could be used to identify MDR-TB suspects and prioritize them for laboratory confirmation. Prospective studies are needed to understand factors associated with TB incidence and clinical outcomes of TB treatment and disease. Keywords: Multi-Drug Resistant Tuberculosis, Risk factors, Mal