Diagnostic predictive values of the Hain genotype MTBDRsl assay in mycobacterial strains isolated from Sudan.

INTRODUCTION: hain GenoType MTBDRsl is nucleic acid amplification assay based on reverse hybridization with specific oligonucleotide probes on nitrocellulose strips. MTBDRsl identifies M. tuberculosis complex and detects resistance to fluoroquinolone, second line injectable drugs and ethambutol evident as mutations of gyrA, rrs and embB genes respectively. This study aimed to evaluate the diagnostic performance of the Hain GenoType MTBDRsl Assay using 1% proportion method on LJ medium as gold standard. METHODS: a total of 52 rifampicin resistant (RR) isolates were tested for second line drug sensitivity by 1% proportion method and by MTBDRsl assay. RESULTS: two strains were identified as mycobacteria other than tuberculosis MOTT and the rest were Mycobacterium tuberculosis complex MTBC. Five of the MTBC isolates (5/50; 10%) showed resistance to at least one second line drug and one isolate (1/50; 2%) was XDR. XDR strain was concordantly detected by the two methods. One of two Kanamycin-resistant isolates showed discordant results. Ofloxacin showed one false positive and one false negative result. Most discrepancies were detected with Ethambutol. The sensitivity, specificity, positive and negative predictive values were respectively as follows: Ethambutol (63.3.4%, 85.7%, 94.4% and 62%), for Kanamycin (67%, 100%, 100% and 97.9%), for Amikacin and Capreomycin (100%, 100%, 100% and 100%), for Ofloxacin (75%, 97.5%, 75% and 97.8%). For XDR isolate the values were 100%, 100%, 100% and 100% respectively. CONCLUSION: MTBDRsl showed high specificity and negative predictive values making it acceptable and time-saving for early presumptive detection of resistance to second-line drugs in Sudan.

Assessment of multidrug-resistant tuberculosis (MDR-TB) treatment outcomes in Sudan; findings and implications.

Background: Multidrug-resistant tuberculosis (MDR-TB) has a socioeconomic impact and threatens global public health. We assessed treatment outcomes of MDR-TB and predictors of poor treatment outcomes in Sudan given current high prevalence rates.Methods: Combined retrospective and prospective cohort study at Abu-Anga hospital (TB specialized hospital in Sudan). All patients with MDR-TB between 2013 and 2017 were targeted.Results: A total of 156 patients were recruited as having good records, 117 (75%) were male, and 152 (97.4%) had pulmonary TB. Patients were followed for a median of 18 months and a total of 2108 person-months. The overall success rate was 63.5% and the mortality rate was 14.1%. Rural residency (P < 0.05) and relapsing on previous treatments (P < 0.05) were determinants of time to poor MDR-TB treatment outcomes.Conclusion: Overall, more attention needs to be given to special MDR-TB groups that are highly susceptible to poor outcomes, i.e. rural patients. As a result, it is highly recommended to maintain total coverage of medicines for all MDR-TB patients for the entire period of treatment in Sudan. It is also recommended to instigate more treatment centers in rural areas in Sudan together with programs to enhance adherence to treatments including patient counseling to improve future outcomes.

Assessment of the risk factors associated with multidrug-resistant tuberculosis in Sudan: a case-control study.

OBJECTIVES: The emergence of multidrug-resistant tuberculosis (MDR-TB) is a major challenge for the global control of tuberculosis (TB). The aim of this study was to determine the risk factors associated with MDR-TB in Sudan. METHODS: This case-control study was conducted from May 2017 to February 2019. Patients newly diagnosed with MDR-TB were selected as cases, and controls were selected from TB patients who responded to first-line anti-TB drugs. A questionnaire was designed and used to collect data from study participants. Logistic regression was used to evaluate associations between risk factors and MDR-TB infection. The best multivariate model was selected based on the likelihood ratio test. RESULTS: A total of 430 cases and 860 controls were selected for this study. A history of previous TB treatment (adjusted odds ratio [aOR], 54.85; 95% confidence interval [CI], 30.48 to 98.69) was strongly associated with MDR-TB infection. We identified interruption of TB treatment (aOR, 7.62; 95% CI, 3.16 to 18.34), contact with MDR-TB patients (aOR, 5.40; 95% CI, 2.69 to 10.74), lower body weight (aOR, 0.89; 95% CI, 0.87 to 0.91), and water pipe smoking (aOR, 3.23; 95% CI, 1.73 to 6.04) as factors associated with MDR-TB infection. CONCLUSIONS: Previous TB treatment and interruption of TB treatment were found to be the main predictors of MDR-TB. Additionally, this study found that contact with MDR-TB patients and water pipe smoking were associated with MDR-TB infection in Sudan. More efforts are required to decrease the rate of treatment interruption, to strengthen patients' adherence to treatment, and to reduce contact with MDR-TB patients.

Initial second-line drug resistance of Mycobacterium tuberculosis isolates from Sudanese retreatment-patients.

SETTING: Multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) are a major public health threat. OBJECTIVE: This study aimed to determine resistance patterns to second line anti-TB drugs (SLDs), and to determine the frequency of extensively drug resistant Mycobacterium tuberculosis (XDR-TB). DESIGN: During the period from July 2009 to July 2010; sputum specimens were collected from TB retreatment patients; isolates were tested for sensitivity to first line anti-TB drugs by the 1% proportion method; MDR strains were tested for second line anti-TB drugs sensitivity by 1% proportion method and by version 1. Hain GenoType MTBDRsl Assay. RESULTS: One hundred and forty three mycobacterial isolates were successfully recovered from a total of 239 specimens (143/239; 59.8%). Fifty six strains were rifampicin resistant (RR); of these 54 were multi-drug resistant (MDR); two were RIF/INH-resistant mycobacterium other than tuberculosis (MOTT). Five of MDR (5/50; 10%) showed resistance to at least one second line drug and one isolate (1/50; 2%) was XDR. The XDR strain was concordantly detected by the two methods. CONCLUSION: Initial resistance to second line anti-TB drugs among MDR-TB patients is at 10% levels and XDR-TB is prevalent at low levels (2%). Nevertheless; without great efforts from national tuberculosis control program (NTP) this figure can fuel the TB epidemics in Sudan.