scholarly journals Anti-tuberculosis drug resistance and associated risk factors in a tertiary level TB center in Iran: a retrospective analysis

2011 ◽  
Vol 5 (07) ◽  
pp. 511-519 ◽  
Author(s):  
Muayad Aghali Merza ◽  
Parissa Farnia ◽  
Payam Tabarsi ◽  
Mehdi Khazampour ◽  
Mohammad Reza Masjedi ◽  
...  
Keyword(s):  
Risk Factors ◽  
Drug Resistance ◽  
Retrospective Analysis ◽  
Drug Susceptibility Testing ◽  
Control Programme ◽  
High Rate ◽  
Factors Associated ◽  
Mdr Tb ◽  
Previously Treated ◽  
Resistant Strains

Introduction: This study aimed to determine first-line anti-tuberculosis drug resistance rates in new and previously treated cases and to identify risk factors associated with multidrug resistant tuberculosis (MDR-TB) at the National Reference Tuberculosis Laboratory of Iran. Methodology:  This was a retrospective analysis of all confirmed TB patients from December 2000 to June 2005. Drug susceptibility testing to isoniazid, rifampicin, streptomycin, ethambutol and pyrazinamide was performed on Löwenstein-Jensen (LJ) medium according to the proportion method. Results: Mycobacterium tuberculosis strains were isolated from 1,742 patients with TB, of whom 935 (53.7%) were male. The mean age of patients was 44.2 ± 17.4 years (SD). A total of 1,074 patients were native Iranians while 668 (38.3%) were immigrant patients. Out of 1,139 (65.4%) new cases, 340 (29.9%) had at least one drug resistance. Of 603 (34.6%) previously treated cases, 416 (69.0%) had resistant strains. There were 263 patients (15.1%) with MDR-TB, 72 of whom were new (6.3% of all new cases) and 191 were previously treated (31.7% of all previously treated cases). Factors associated with MDR-TB included age under 45 years, male sex, previous TB treatment, immigration, poor living conditions, and unemployment. Conclusions: The high rate of initial resistance in MDR-TB cases and the high rate of MDR-TB in a young age group were indicators of recent transmission. Therefore, closer monitoring of transmission trends of drug resistant strains should be considered as priority, to ensure a successful TB control programme.

scholarly journals The fourth national anti-tuberculosis drug resistance survey in Peru

2020 ◽  
Vol 24 (2) ◽  
pp. 207-213
Author(s):  
N. Quispe ◽  
L. Asencios ◽  
C. Obregon ◽  
G. E. Velásquez ◽  
C. D. Mitnick ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Contact Tracing ◽  
Sputum Smear ◽  
Reference Laboratory ◽  
First Line ◽  
Mdr Tb ◽  
Previously Treated Patients ◽  
Previously Treated

BACKGROUND: Peru has one of the highest burdens of multidrug-resistant tuberculosis (MDR-TB), but universal drug susceptibility testing (DST) has not yet been achieved.OBJECTIVE: To estimate the proportion of drug resistance among smear-positive TB patients in Peru.DESIGN: From September 2014 to March 2015, we performed a national drug resistance survey of patients aged ≥15 years; TB was diagnosed based on sputum smear positivity. We performed DST at the National Reference Laboratory of the Peruvian National Institute of Health, Lima, Peru, using the proportion method in Middlebrook 7H10 agar for four first-line drugs and six second-line drugs, and the Wayne method for pyrazinamide.RESULTS: Of the 1908 new and 272 previously treated patients included in the analysis, 638 (29.3%) patients had resistance to at least one first-line drug. MDR-TB was diagnosed in 7.3% of new and 16.2% of previously treated patients (P < 0.001). There were five (0.2%) patients with extensively drug-resistant TB.CONCLUSION: MDR-TB has increased to 7.3% in new patients from 5.3% in the previous survey, indicating that resistance to anti-tuberculosis drugs is increasing in Peru. Ongoing community transmission of resistant strains highlights an urgent need for early diagnosis, optimised treatment and effective contact tracing of MDR-TB patients.

scholarly journals Diagnostic Value of GeneChip for Detection of Resistant Mycobacterium tuberculosis in Patients with Differing Treatment Histories

2014 ◽  
Vol 53 (1) ◽  
pp. 131-135 ◽  
Author(s):  
Limei Zhu ◽  
Qiao Liu ◽  
Leonardo Martinez ◽  
Jinyan Shi ◽  
Cheng Chen ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Diagnostic Value ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Drug Susceptibility Testing ◽  
Standard Drug ◽  
Related Data ◽  
Resistant Tuberculosis ◽  
Mdr Tb ◽  
Previously Treated

The increasing burden of drug-resistant tuberculosis (TB) poses an escalating threat to national TB control programs. To assist appropriate treatment for TB patients, accurate and rapid detection of drug resistance is critical. The GeneChip test is a novel molecular tool for the diagnosis of TB drug resistance. Performance-related data on GeneChip are limited, and evaluation in new and previously treated TB cases has never been performed. We evaluated the diagnostic performance of GeneChip in detecting resistance to rifampin (RMP) and isoniazid (INH) and in detecting multidrug-resistant tuberculosis (MDR-TB) in comparison with standard drug susceptibility testing (DST) and compared the results in a group of previously treated and newly detected TB patients in an urban area in southeastern China. One thousand one hundred seventy-three (83.8%) new cases and 227 (16.2%) previously treated cases were collected between January 2011 and September 2013. The GeneChip showed a specificity of 97.8% and a sensitivity of 94.8% for detection of RMP resistance and 97.3% and 70.9%, respectively, for INH resistance in new cases. For previously treated cases, the overall sensitivity, specificity, and agreement rate are 94.6%, 91.3%, and 92.1%, respectively, for detection of RMP resistance and 69.7%, 95.4%, and 86.8%, respectively, for INH resistance. The sensitivity and specificity of MDR-TB were 81.8% and 99.0% in new cases and 77.8% and 93.4% in previously treated cases, respectively. The GeneChip system provides a simple, rapid, reliable, and accurate clinical assay for the detection of TB drug resistance, and it is a potentially important diagnostic tool in a high-prevalence area.

scholarly journals Risk Factors and Treatment Outcome Analysis Associated with Second-Line Drug-Resistant Tuberculosis

2021 ◽  
Vol 2 (1) ◽  
pp. 1-12
Author(s):  
Muralidhar Aaina ◽  
Kaliyaperumal Venkatesh ◽  
Brammacharry Usharani ◽  
Muthukumar Anbazhagi ◽  
Gerard Rakesh ◽  
...  
Keyword(s):  
Risk Factors ◽  
Drug Resistance ◽  
Drug Resistant ◽  
First Line ◽  
Drug Resistant Tuberculosis ◽  
Factors Associated ◽  
Resistant Tuberculosis ◽  
Increased Risk ◽  
Mdr Tb ◽  
Line Drug

The present study aimed at analyzing the treatment outcomes and risk factors associated with fluoroquinolone drug resistance having mutations in the gyrA and gyrB genes. A total of 258 pulmonary tuberculosis samples with first-line drug-resistant (H, R, or HR) were subjected to GenoType MTBDRsl assay for the molecular detection of mutations. Among the 258 samples, 251 were drug-resistant tuberculosis and seven were sensitive to all first-line TB drugs. Out of 251 DR-TB cases, 42 cases were MDR TB, 200 were INH mono-resistant and nine cases were RIF mono-resistant tuberculosis. Out of 251 DR-TB cases performed with a MTBDRsl assay, 14 had Pre-XDR-FQ, one patient had pre-XDR-SLID, one had extensively drug-resistant tuberculosis (XDR-TB) and 235 cases were sensitive to both FQ and SLID drugs. The study group had a mean average of 42.7 ± 16.4 years. The overall successful treatment outcomes among the MDR, INH mono-resistant, and pre-XRD patients were 70.6%, 82.0%, and 51%, respectively. The percentage of risk for the unfavorable outcomes in the pre-XDR, INH -mono-resistant, and XDR cases were 113.84% increased risk with RR 2.14; 95% CI 0.7821–5.8468. The independent risk factor associated with the unfavorable outcomes to failure was 77.78% increased risk with RR 1.78; 95% CI 0.3375–9.3655. Logistic regression analysis revealed that the percentage relative risk among MDR-TB patients for gender, male (RR: 1.85), age ≥ 61 years (RR: 1.96), and diabetics (RR: 1.05) were 84.62%, 95.83%, and 4.76%, respectively. The independent risk factors associated with INH mono-resistant cases of age 16–60 (RR: 1.86), ≥61 year (RR: 1.18), and treated cases (RR: 5.06). This study presaged the significant risk of INH mono-resistant, pre-XDR, and MDR among males, young adults, diabetics, and patients with previous treatment failure. Timely identification of high-risk patients will give pronounced advantages to control drug resistance tuberculosis diseases.

scholarly journals Analysis of drug resistance and mutation profiles in Mycobacterium tuberculosis isolates in a surveillance site in Beijing, China

2021 ◽  
Vol 49 (1) ◽  
pp. 030006052098493
Author(s):  
Jie Zhang ◽  
Yixuan Ren ◽  
Liping Pan ◽  
Junli Yi ◽  
Tong Guan ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Drug Testing ◽  
Multidrug Resistant ◽  
High Rate ◽  
Drug Resistant ◽  
Surveillance Site ◽  
Mdr Tb ◽  
Previously Treated Patients ◽  
Beijing China

Objective This study analyzed drug resistance and mutations profiles in Mycobacterium tuberculosis isolates in a surveillance site in Huairou District, Beijing, China. Methods The proportion method was used to assess drug resistance profiles for four first-line and seven second-line anti-tuberculosis (TB) drugs. Molecular line probe assays were used for the rapid detection of resistance to rifampicin (RIF) and isoniazid (INH). Results Among 235 strains of M. tuberculosis, 79 (33.6%) isolates were resistant to one or more drugs. The isolates included 18 monoresistant (7.7%), 19 polyresistant (8.1%), 28 RIF-resistant (11.9%), 24 multidrug-resistant (MDR) (10.2%), 7 pre-extensively drug-resistant (XDR, 3.0%), and 2 XDR strains (0.9%). A higher rate of MDR-TB was detected among previously treated patients than among patients with newly diagnosed TB (34.5% vs. 6.8%). The majority (62.5%) of RIF-resistant isolates exhibited a mutation at S531L in the DNA-dependent RNA polymerase gene. Meanwhile, 62.9% of INH-resistant isolates carried a mutation at S315T1 in the katG gene. Conclusion Our results confirmed the high rate of drug-resistant TB, especially MDR-TB, in Huairou District, Beijing, China. Therefore, detailed drug testing is crucial in the evaluation of MDR-TB treatment.

scholarly journals Constraints of Drug Resistance in Mycobacterium tuberculosis - Prospects for Pharmacological Reversion of Susceptibility to Antibiotics

2017 ◽  
Vol 8 (1) ◽  
pp. 33-43 ◽  
Author(s):  
Aleksandr I. Ilin ◽  
Murat E. Kulmanov ◽  
Ilya S. Korotetskiy ◽  
Marina V. Lankina ◽  
Gulshara K. Akhmetova ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Genetic Heterogeneity ◽  
Multidrug Resistant ◽  
Resistance Mutations ◽  
General Increase ◽  
Drug Induced ◽  
Mdr Tb ◽  
Resistant Strains

Emergence of multidrug resistant strains ofMycobacterium tuberculosis(MDR-TB) threatens humanity. This problem was complicated by the crisis in development of new anti-tuberculosis antibiotics. Induced reversion of drug resistance seems promising to overcome the problem. Successful clinical trial of a new anti-tuberculosis nanomolecular complex FS-1 has demonstrated prospectively of this approach in combating MDR-TB. Several clinical MDR-TB cultures were isolated from sputum samples prior and in the process of the clinical trial. Every isolate was tested for susceptibility to antibiotics and then they were sequenced for comparative genomics. It was found that the treatment with FS-1 caused an increase in the number of antibiotic susceptible strains among Mtb isolates that was associated with a general increase of genetic heterogeneity of the isolates. Observed impairing of phthiocerol dimycocerosate biosynthesis by disruptive mutations inppsACDsubunits indicated a possible virulence remission for the sake of persistence. It was hypothesized that the FS-1 treatment eradicated the most drug resistant Mtb variants from the population by aggravating the fitness cost of drug resistance mutations. Analysis of distribution of these mutations in the global Mtb population revealed that many of them were incompatible with each other and dependent on allelic states of many other polymorphic loci. The latter discovery may explain the negative correlation between the genetic heterogeneity of the population and the level of drug tolerance. To the best of our knowledge, this work was the first experimental confirmation of the drug induced antibiotic resistance reversion by the induced synergy mechanism that previously was predicted theoretically.

Risk factors associated with reoperation in posterior cervical fusions: A large-scale retrospective analysis

2020 ◽  
Vol 195 ◽  
pp. 105828
Author(s):  
Royce W. Woodroffe ◽  
Logan C. Helland ◽  
Andrew J. Grossbach ◽  
Kirill V. Nourski ◽  
Patrick W. Hitchon
Keyword(s):  
Risk Factors ◽  
Retrospective Analysis ◽  
Large Scale ◽  
Factors Associated

scholarly journals Analysis of loss to follow-up in 4099 multidrug-resistant pulmonary tuberculosis patients

2019 ◽  
Vol 54 (1) ◽  
pp. 1800353 ◽  
Author(s):  
Ian F. Walker ◽  
Oumin Shi ◽  
Joseph P. Hicks ◽  
Helen Elsey ◽  
Xiaolin Wei ◽  
...  
Keyword(s):  
Risk Factors ◽  
Adverse Event ◽  
Treatment Success ◽  
Multidrug Resistant ◽  
Cox Proportional Hazards Model ◽  
Serious Adverse Event ◽  
Loss To Follow Up ◽  
Factors Associated ◽  
Mdr Tb

Loss to follow-up (LFU) of ≥2 consecutive months contributes to the poor levels of treatment success in multidrug-resistant tuberculosis (MDR-TB) reported by TB programmes. We explored the timing of when LFU occurs by month of MDR-TB treatment and identified patient-level risk factors associated with LFU.We analysed a dataset of individual MDR-TB patient data (4099 patients from 22 countries). We used Kaplan–Meier survival curves to plot time to LFU and a Cox proportional hazards model to explore the association of potential risk factors with LFU.Around one-sixth (n=702) of patients were recorded as LFU. Median (interquartile range) time to LFU was 7 (3–11) months. The majority of LFU occurred in the initial phase of treatment (75% in the first 11 months). Major risk factors associated with LFU were: age 36–50 years (HR 1.3, 95% CI 1.0–1.6; p=0.04) compared with age 0–25 years, being HIV positive (HR 1.8, 95% CI 1.2–2.7; p<0.01) compared with HIV negative, on an individualised treatment regimen (HR 0.7, 95% CI 0.6–1.0; p=0.03) compared with a standardised regimen and a recorded serious adverse event (HR 0.5, 95% CI 0.4–0.6; p<0.01) compared with no serious adverse event.Both patient- and regimen-related factors were associated with LFU, which may guide interventions to improve treatment adherence, particularly in the first 11 months.

scholarly journals Low Occurrence of Tuberculosis Drug Resistance among Pulmonary Tuberculosis Patients from an Urban Setting, with a Long-Running DOTS Program in Zambia

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Chanda Mulenga ◽  
Allan Chonde ◽  
Innocent C. Bwalya ◽  
Nathan Kapata ◽  
Mathilda Kakungu-Simpungwe ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Urban Setting ◽  
Second Line ◽  
Community Based ◽  
Proportion Method ◽  
Previously Treated Patients ◽  
Previously Treated ◽  
Low Levels

We set out to determine the levels ofMycobacterium tuberculosisresistance to first- and second-line TB drugs in an urban population in Zambia. Sputum samples were collected consecutively from all smear-positive, new and previously treated patients, from four diagnostic centres in Ndola between January and July 2006. Drug susceptibility testing was performed using the proportion method against four first- and two second-line TB drugs.Results. Among 156 new cases, any resistance was observed to be 7.7%, monoresistance to isoniazid and rifampicin was 4.5% and 1.3%, respectively. Of 31 retreatment cases, any resistance was observed to be 16.1%, monoresistance to isoniazid and rifampicin was 3.3% for each drug, and one case of resistance to both isoniazid and rifampicin (multidrug resistance) was detected. No resistance to kanamycin or ofloxacin was detected.Conclusion. Although not representative of the country, these results show low levels of drug resistance in a community with a long-standing DOTS experience. Resource constrained countries may reduce TB drug resistance by implementing community-based strategies that enhance treatment completion.

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