Multidrug-resistant Tuberculosis Treatment Regimen Research Articles

Resistance patterns, prevalence, and predictors of fluoroquinolones resistance in multidrug resistant tuberculosis patients

BackgroundFluoroquinolones are the backbone of multidrug resistant tuberculosis treatment regimens. Despite the high burden of multidrug resistant tuberculosis in the country, little is known about drug resistance patterns, prevalence, and predictors of fluoroquinolones resistance among multidrug resistant tuberculosis patients from Pakistan. ObjectiveTo evaluate drug resistance patterns, prevalence, and predictors of fluoroquinolones resistance in multidrug resistant tuberculosis patients. MethodsThis was a cross-sectional study conducted at a programmatic management unit of drug resistant tuberculosis, Lady Reading Hospital Peshawar, Pakistan. Two hundred and forty-three newly diagnosed multidrug resistant tuberculosis patients consecutively enrolled for treatment at study site from January 1, 2012 to July 28, 2013 were included in the study. A standardized data collection form was used to collect patients’ socio-demographic, microbiological, and clinical data. SPSS 16 was used for data analysis. ResultsHigh degree of drug resistance (median 5 drugs, range 2–8) was observed. High proportion of patients was resistant to all five first-line anti-tuberculosis drugs (62.6%), and more than half were resistant to second line drugs (55.1%). The majority of the patients were ofloxacin resistant (52.7%). Upon multivariate analysis previous tuberculosis treatment at private (OR=1.953, p=0.034) and public private mix (OR=2.824, p=0.046) sectors were predictors of ofloxacin resistance. ConclusionThe high degree of drug resistance observed, particularly to fluoroquinolones, is alarming. We recommend the adoption of more restrictive policies to control non-prescription sale of fluoroquinolones, its rational use by physicians, and training doctors in both private and public–private mix sectors to prevent further increase in fluoroquinolones resistant Mycobacterium tuberculosis strains.

Pharmacokinetics and Safety of Ofloxacin in Children with Drug-Resistant Tuberculosis.

Ofloxacin is widely used for the treatment of multidrug-resistant tuberculosis (MDR-TB). Data on its pharmacokinetics and safety in children are limited. It is not known whether the current internationally recommended pediatric dosage of 15 to 20 mg/kg of body weight achieves exposures reached in adults with tuberculosis after a standard 800-mg dose (adult median area under the concentration-time curve from 0 to 24 h [AUC0-24], 103 μg · h/ml). We assessed the pharmacokinetics and safety of ofloxacin in children <15 years old routinely receiving ofloxacin for MDR-TB treatment or preventive therapy. Plasma samples were collected predose and at 1, 2, 4, 8, and either 6 or 11 h after a 20-mg/kg dose. Pharmacokinetic parameters were calculated using noncompartmental analysis. Children with MDR-TB disease underwent long-term safety monitoring. Of 85 children (median age, 3.4 years), 11 (13%) were HIV infected, and of 79 children with evaluable data, 14 (18%) were underweight. The ofloxacin mean (range) maximum concentration (Cmax), AUC0-8, and half-life were 8.97 μg/ml (2.47 to 14.4), 44.2 μg · h/ml (12.1 to 75.8), and 3.49 h (1.89 to 6.95), respectively. The mean AUC0-24, estimated in 72 participants, was 66.7 μg · h/ml (range, 18.8 to 120.7). In multivariable analysis, AUC0-24 was increased by 1.46 μg · h/ml for each 1-kg increase in body weight (95% confidence interval [CI], 0.44 to 2.47; P = 0.006); no other assessed variable contributed to the model. No grade 3 or 4 events at least possibly attributed to ofloxacin were observed. Ofloxacin was safe and well tolerated in children with MDR-TB, but exposures were well below reported adult values, suggesting that dosage modification may be required to optimize MDR-TB treatment regimens in children.

Bedaquiline for the treatment of multidrug-resistant tuberculosis: great promise or disappointment?

Acquired drug resistance by Mycobacterium tuberculosis (MTB) may result in treatment failure and death. Bedaquiline was recently approved for the treatment of multidrug-resistant tuberculosis (MDR-TB). This report examines the available data on this novel drug for the treatment of MDR-TB. PubMed searches, last updated 18 February 2015, using the terms bedaquiline, TMC 207 and R207910 identified pertinent English citations. Citation reference lists were reviewed to identify other relevant reports. Pertinent MDR-TB treatment reports on the US Food and Drug Administration, Centers for Disease Control and Prevention (CDC), World Health Organization (WHO) and Cochrane websites were also evaluated. Bedaquiline is an adenosine triphosphate (ATP) synthase inhibitor specific for MTB and some nontuberculous mycobacteria. The early bactericidal activity (EBA) of bedaquiline is delayed until ATP stores are depleted but subsequently it is similar to the EBA of isoniazid and rifampin. Bedaquiline demonstrated excellent minimum inhibitory concentrations (MICs) against both drug-sensitive and MDR-TB. Adding it to the WHO-recommended MDR-TB regimen reduced the time for sputum culture conversion in pulmonary MDR-TB. Rifampin, other cytochrome oxidase 3A4 inducers or inhibitors alter its metabolism. Adverse effects are common with MDR-TB treatment regimens with or without bedaquiline. Nausea is more common with bedaquiline and it increases the QTcF interval. It is not recommended for children, pregnant or lactating women. More patients died in the bedaquiline-treatment arms despite better microbiological outcomes in two recent trials. The WHO and CDC published interim guidelines that recommend restricting its use to patients with MDR-TB or more complex drug resistance who cannot otherwise be treated with a minimum of three effective drugs. It should never be added to a regimen as a single drug nor should it be added to a failing regimen to prevent the emergence of bedaquiline-resistant strains.

Successful MDR-TB treatment regimens including amikacin are associated with high rates of hearing loss.

BackgroundAminoglycosides are a critical component of multidrug-resistant tuberculosis (MDR-TB) treatment but data on their efficacy and adverse effects in Botswana is scarce. We determined the effect of amikacin on treatment outcomes and development of hearing loss in MDR-TB patients.MethodsPatients started on MDR-TB treatment between 2006 and 2012 were included. Multivariate analysis was used to determine the effect of amikacin on treatment outcomes and development of hearing loss.Results437 MDR-TB patients were included, 288 (66%) of whom were HIV co-infected. 270 (62%) developed hearing loss, of whom 147 (54%) had audiometry. Of the 313 (72%) patients who completed treatment, 228 (73%) had a good outcome (cure or treatment completion). Good outcome was associated with longer amikacin treatment (adjusted OR [aOR] 1.13, 95% CI 1.06 - 1.21) and higher dosage (aOR 1.90, 95% CI 1.12 – 2.99). Longer amikacin duration (aOR 1.98, 95% CI 1.86 – 2.12) and higher dosage per weight per month (aOR 1.15, 95% CI 1.04 – 1.28) were associated with development of hearing loss. Amikacin treatment duration modified the effect of the dosage on the risk of hearing loss, increasing this risk as the duration increased.ConclusionsAmikacin was effective for MDR-TB treatment, but was associated with a high incidence of hearing loss especially in our study population. Total treatment duration and average monthly amikacin dose were associated with improved outcomes; however these were also associated with development of hearing loss.

Time to culture conversion and regimen composition in multidrug-resistant tuberculosis treatment.

Sputum cultures are an important tool in monitoring the response to tuberculosis treatment, especially in multidrug-resistant tuberculosis. There has, however, been little study of the effect of treatment regimen composition on culture conversion. Well-designed clinical trials of new anti-tuberculosis drugs require this information to establish optimized background regimens for comparison. We conducted a retrospective cohort study to assess whether the use of an aggressive multidrug-resistant tuberculosis regimen was associated with more rapid sputum culture conversion. We conducted Cox proportional-hazards analyses to examine the relationship between receipt of an aggressive regimen for the 14 prior consecutive days and sputum culture conversion. Sputum culture conversion was achieved in 519 (87.7%) of the 592 patients studied. Among patients who had sputum culture conversion, the median time to conversion was 59 days (IQR: 31–92). In 480 patients (92.5% of those with conversion), conversion occurred within the first six months of treatment. Exposure to an aggressive regimen was independently associated with sputum culture conversion during the first six months of treatment (HR: 1.36; 95% CI: 1.10, 1.69). Infection with human immunodeficiency virus (HR 3.36; 95% CI: 1.47, 7.72) and receiving less exposure to tuberculosis treatment prior to the individualized multidrug-resistant tuberculosis regimen (HR: 1.58; 95% CI: 1.28, 1.95) were also independently positively associated with conversion. Tachycardia (HR: 0.77; 95% CI: 0.61, 0.98) and respiratory difficulty (HR: 0.78; 95% CI: 0.62, 0.97) were independently associated with a lower rate of conversion. This study is the first demonstrating that the composition of the multidrug-resistant tuberculosis treatment regimen influences the time to culture conversion. These results support the use of an aggressive regimen as the optimized background regimen in trials of new anti-TB drugs.

Intensive-Phase Treatment Outcomes among Hospitalized Multidrug-Resistant Tuberculosis Patients: Results from a Nationwide Cohort in Nigeria

BackgroundNigeria is faced with a high burden of Human Immunodeficiency Virus (HIV) infection and multidrug-resistant tuberculosis (MDR-TB). Treatment outcomes among MDR-TB patients registered across the globe have been poor, partly due to high loss-to-follow-up. To address this challenge, MDR-TB patients in Nigeria are hospitalized during the intensive-phase(IP) of treatment (first 6–8 months) and are provided with a package of care including standardized MDR-TB treatment regimen, antiretroviral therapy (ART) and cotrimoxazole prophylaxis (CPT) for HIV-infected patients, nutritional and psychosocial support. In this study, we report the end-IP treatment outcomes among them.MethodsIn this retrospective cohort study, we reviewed the patient records of all bacteriologically-confirmed MDR-TB patients admitted for treatment between July 2010 and October 2012.ResultsOf 162 patients, 105(65%) were male, median age was 34 years and 28(17%) were HIV-infected; all 28 received ART and CPT. Overall, 138(85%) were alive and culture negative at the end of IP, 24(15%) died and there was no loss-to-follow-up. Mortality was related to low CD4-counts at baseline among HIV-positive patients. The median increase in body mass index among those documented to be underweight was 2.6 kg/m2 (p<0.01) and CD4-counts improved by a median of 52 cells/microL among the HIV-infected patients (p<0.01).ConclusionsEnd-IP treatment outcomes were exceptional compared to previously published data from international cohorts, thus confirming the usefulness of a hospitalized model of care. However, less than five percent of all estimated 3600 MDR-TB patients in Nigeria were initiated on treatment during the study period. Given the expected scale-up of MDR-TB care, the hospitalized model is challenging to sustain and the national TB programme is contemplating to move to ambulatory care. Hence, we recommend using both ambulatory and hospitalized approaches, with the latter being reserved for selected high-risk groups.

Market size and sales pattern of tuberculosis drugs in the Philippines.

To identify the availability, types and quantity of anti-tuberculosis drugs in the public and private sectors from 2007 to 2011 in the Philippines. Analysis of the procurement of and sales data on anti-tuberculosis drugs from both the public and private sectors from 2007 to 2011. Publicly procured anti-tuberculosis drugs were sufficient to treat all reported new tuberculosis (TB) cases from 2007 to 2011 in the Philippines. Nevertheless, the volume of anti-tuberculosis drugs in the private sector would have sufficed for the intensive phase of treatment for an additional 250 000 TB patients annually, assuming compliance with national treatment guidelines. Fixed-dose combination drugs comprised the main bulk (81%) of private market sales, while sales of loose drugs decreased over the years. Combining public and private sales in 2011, 484 725 new TB patients, i.e., 2.4 times the number of notified cases, could have been placed on treatment and treated for at least the intensive phase. Key second-line drugs are not available in the private market, making it impossible to design an adequate treatment regimen for multidrug-resistant TB (MDR-TB) in the private sector. An enormous quantity of anti-tuberculosis drugs was channelled through the private market outside the purview of the Philippine National Tuberculosis Control Program, suggesting significant out-of-pocket expenditure, severe underreporting of TB cases and/or misuse of drugs due to overdiagnosis and overtreatment.

High Rate of Hypothyroidism in Multidrug-Resistant Tuberculosis Patients Co-Infected with HIV in Mumbai, India

BackgroundAdverse events (AEs) among HIV-infected patients with multidrug-resistant tuberculosis (MDR-TB) receiving anti-TB and antiretroviral treatments (ART) are under-researched and underreported. Hypothyroidism is a common AE associated with ethionamide, p-aminosalicylic acid (PAS), and stavudine. The aim of this study was to determine the frequency of and risk factors associated with hypothyroidism in HIV/MDR-TB co-infected patients.MethodsThis was a prospective, observational cohort study, using routine laboratory data in a Médecins Sans Frontières (MSF) clinic in collaboration with Sewri TB Hospital, Mumbai, India. Hypothyroidism was defined as a thyroid stimulating hormone (TSH) result >10 mIU/L at least once during treatment. Patients having a baseline result and one additional result after 3 months were eligible for enrolment.ResultsBetween October 2006 and March 2013, 116 patients were enrolled, 69 of whom were included. The median (IQR) age was 38 years (34-43) and 61% were male. By March 2013, 37/69 (54%) had hypothyroidism after at least 90 days of treatment. Age, gender, CD4 counts and stavudine-based ART were not associated with the occurrence of hypothyroidism in multivariate models. The co-administration of PAS and ethionamide was found to double the risk of hypothyroidism (RR: 1.93, 95% CI: 1.06-3.54).DiscussionHigh rate of hypothyroidism was recorded in a Mumbai cohort of MDR-TB/HIV co-infected patients on treatment. This is a treatable and reversible AE, however, it may go undiagnosed in the absence of regular monitoring. Care providers should not wait for clinical symptoms, as this risks compromising treatment adherence. Simple, affordable and reliable point-of-care tools for measuring TSH are needed, especially in high MDR-TB burden countries. Our findings suggest the need for TSH screening at baseline, three months, six months, and every six months thereafter for HIV-infected patients on MDR-TB treatment regimens containing PAS and/or ethionamide, until newer, safer and more efficacious MDR-TB regimens become available.

Safety of cycloserine and terizidone for the treatment of drug-resistant tuberculosis: a meta-analysis [Review article

Although cycloserine (CS) is recommended by the World Health Organization as a second-line agent for the treatment of multidrug-resistant tuberculosis (MDR-TB), safety concerns have impeded its uptake by several national TB programmes. Terizidone (TRD), a structural analogue of cycloserine, may be better tolerated. To assess the safety of CS and TRD for TB treatment, a systematic review and meta-analysis were conducted. From articles published up to December 2011, 27 studies with 2164 patients were included in our review of CS use. The pooled estimate for the frequencies of any adverse drug reaction (ADR) from CS was 9.1% (95%CI 6.4-11.7); it was 5.7% (95%CI 3.7-7.6) for psychiatric ADRs, and 1.1% (95%CI 0.2-2.1) for central nervous system (CNS) related ADRs. TRD showed no better to moderately better safety than CS in a systematic review of the available literature. The published evidence suggests that CS is associated with a higher frequency of psychiatric and CNS-related ADRs than other second-line drugs. While data were limited, treatment discontinuation rates appeared to be manageable. There were no significant differences in tolerability by region, study period or combination. As countries review and revise their treatment programmes, CS, and potentially TRD, should be included in MDR-TB treatment regimens. Adequate information on possible ADRs should be provided to patients, their families and attending health care workers. Greater attention to MDR-TB patients' mental health and a significant increase in resources devoted to pharmacovigilance and treatment of MDR-TB are essential.

Systematic review of clofazimine for the treatment of drug-resistant tuberculosis.

The increased incidence of drug-resistant tuberculosis has created an urgent necessity for the development of new and effective anti-tuberculosis drugs and for alternative therapeutic regimens. Clofazimine (CFZ) is a fat-soluble riminophenazine dye used in the treatment of leprosy worldwide. CFZ has also been used as a Group 5 drug in the treatment of tuberculosis (TB). A large cohort study from Bangladesh published in 2010 described a treatment regimen for multidrug-resistant tuberculosis (MDR-TB) including CFZ as being highly effective against MDR-TB. We searched multiple databases for studies published through February 2012 that reported use of CFZ in MDR- and extensively drug-resistant TB (XDR-TB) treatment regimens. We identified nine observational studies (6 MDR-TB and 3 XDR-TB) including patients with drug-resistant TB treated with CFZ. Overall, 65% (95% confidence interval [95%CI] 54-76) of the patients experienced favorable outcomes, defined as either cure or treatment completion. Using random effects meta-analysis, 65% (95%CI 52-79) of those with MDR-TB and 66% (95%CI 42-89) of those with XDR-TB experienced favorable treatment outcomes. High-quality prospective cohort studies and clinical trials examining the effect of CFZ as part of drug-resistant TB treatment regimens are needed.

Aggressive Regimens for Multidrug-Resistant Tuberculosis Decrease All-Cause Mortality

RationaleA better understanding of the composition of optimal treatment regimens for multidrug-resistant tuberculosis (MDR-TB) is essential for expanding universal access to effective treatment and for developing new therapies for MDR-TB. Analysis of observational data may inform the definition of an optimized regimen.ObjectivesThis study assessed the impact of an aggressive regimen–one containing at least five likely effective drugs, including a fluoroquinolone and injectable–on treatment outcomes in a large MDR-TB patient cohort.MethodsThis was a retrospective cohort study of patients treated in a national outpatient program in Peru between 1999 and 2002. We examined the association between receiving an aggressive regimen and the rate of death.Measurements and Main ResultsIn total, 669 patients were treated with individualized regimens for laboratory-confirmed MDR-TB. Isolates were resistant to a mean of 5.4 (SD 1.7) drugs. Cure or completion was achieved in 66.1% (442) of patients; death occurred in 20.8% (139). Patients who received an aggressive regimen were less likely to die (crude hazard ratio [HR]: 0.62; 95% CI: 0.44,0.89), compared to those who did not receive such a regimen. This association held in analyses adjusted for comorbidities and indicators of severity (adjusted HR: 0.63; 95% CI: 0.43,0.93).ConclusionsThe aggressive regimen is a robust predictor of MDR-TB treatment outcome. TB policy makers and program directors should consider this standard as they design and implement regimens for patients with drug-resistant disease. Furthermore, the aggressive regimen should be considered the standard background regimen when designing randomized trials of treatment for drug-resistant TB.

Multidrug-resistant tuberculosis

Despite the efforts made worldwide to reduce the number of cases of drug-susceptible tuberculosis, multidrug-resistant tuberculosis (MDR-TB) constitutes an important public health issue. Around 440,000 new cases of MDR-TB are estimated annually, although in 2008 only 7% of these (29,423 cases) were notified. The laboratory tests for diagnosing resistance may be phenotypic (based on culture growth in the presence of drugs) or genotypic (i.e. identification of the presence of mutations that confer resistance). The urgent need for a rapid means of detecting resistance to anti-TB drugs has resulted in the development of many genotypic methods over recent years. The treatment of MDR-TB is expensive, complex, prolonged (18–24 months) and associated with a higher incidence of adverse reactions. Some basic principles must be observed when prescribing an adequate treatment regimen for MDR-TB: (a) the association of at least four drugs (three of which should not have been used previously); (b) use of a fluoroquinolone; and (c) use of an injectable anti-TB drug. In Brazil, the therapeutic regimen for MDR-TB has been standardized and consists of five drugs: terizidone, levofloxacin, pyrazinamide, ethambutol and an aminoglycoside (streptomycin or amikacin). Pulmonary resection is an important tool in the coadjuvant treatment of MDR-TB. While a recent meta-analysis revealed an average cure rate of MDR-TB of 69%, clinical studies are currently being conducted with new drugs and with drugs already available on the market but with a new indication for TB, with encouraging results that will enable more effective treatment regimens to be planned in the future.

WHO guidelines for the programmatic management of drug-resistant tuberculosis: 2011 update

The production of guidelines for the management of drug-resistant tuberculosis (TB) fits the mandate of the World Health Organization (WHO) to support countries in the reinforcement of patient care. WHO commissioned external reviews to summarise evidence on priority questions regarding case-finding, treatment regimens for multidrug-resistant TB (MDR-TB), monitoring the response to MDR-TB treatment, and models of care. A multidisciplinary expert panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to develop recommendations. The recommendations support the wider use of rapid drug susceptibility testing for isoniazid and rifampicin or rifampicin alone using molecular techniques. Monitoring by sputum culture is important for early detection of failure during treatment. Regimens lasting ≥ 20 months and containing pyrazinamide, a fluoroquinolone, a second-line injectable drug, ethionamide (or prothionamide), and either cycloserine or p-aminosalicylic acid are recommended. The guidelines promote the early use of antiretroviral agents for TB patients with HIV on second-line drug regimens. Systems that primarily employ ambulatory models of care are recommended over others based mainly on hospitalisation. Scientific and medical associations should promote the recommendations among practitioners and public health decision makers involved in MDR-TB care. Controlled trials are needed to improve the quality of existing evidence, particularly on the optimal composition and duration of MDR-TB treatment regimens.

Treatment Outcomes for HIV‐Uninfected Patients with Multidrug‐Resistant and Extensively Drug‐Resistant Tuberculosis

Multidrug-resistant (MDR) tuberculosis (TB) is more difficult to treat than is drug-susceptible TB. To elucidate the optimal therapy for MDR TB, we assessed the treatment outcomes and prognostic factors for patients with MDR TB. This study included patients who received an individualized treatment regimen for MDR TB at Samsung Medical Center, a tertiary referral hospital in Seoul, Korea, from January 1995 through December 2004. To identify the prognostic factors related to favorable treatment outcomes, univariate comparison and multiple logistic regression were performed. Of 155 patients, 18 (12%) had newly diagnosed MDR TB, 81 (52%) had previously received treatment with first-line drugs, and 56 (36%) had received treatment with second-line drugs. The isolated strains were resistant to a median of 5 drugs. Twenty-seven patients (17%) had extensively drug-resistant (XDR) TB at the start of treatment. Outcome assessment revealed that 102 patients (66%) were cured or completed therapy. The treatment success rates did not differ significantly between patients with non-XDR MDR TB and those with XDR TB (66% vs. 67%). Surgical resection was performed more frequently for patients with XDR TB than for those with non-XDR MDR TB (48% vs. 17%). Combined surgical resection, body mass index >/=18.5 (calculated as the weight in kilograms divided by the square of the height in meters), use of >4 effective drugs, and a negative sputum smear result were independent predictors of a favorable outcome. Early aggressive treatment comprising at least 4 effective drugs and surgical resection, when indicated, may improve the outcome for patients with MDR TB or XDR TB.

Community-Based Therapy for Children With Multidrug-Resistant Tuberculosis

The goals were to describe the management of multidrug-resistant tuberculosis among children, to examine the tolerability of second-line antituberculosis agents among children, and to report the outcomes of children treated for multidrug-resistant tuberculosis in poor urban communities in Lima, Peru, a city with high tuberculosis prevalence. A retrospective analysis of data for 38 children <15 years of age with multidrug-resistant tuberculosis, either documented with drug sensitivity testing of the child's tuberculosis isolate or suspected on the basis of the presence of clinical symptoms for a child with a household contact with documented multidrug-resistant tuberculosis, was performed. All 38 children initiated a supervised individualized treatment regimen for multidrug-resistant tuberculosis between July 1999 and July 2003. Each child received 18 to 24 months of therapy with > or =5 first- or second-line drugs to which their Mycobacterium tuberculosis strain was presumed to be sensitive. Forty-five percent of the children had malnutrition or anemia at the time of diagnosis, 29% had severe radiographic findings (defined as bilateral or cavitary disease), and 13% had extrapulmonary disease. Forty-five percent of the children were hospitalized initially because of the severity of illness. Adverse events were observed for 42% of the children, but no events required suspension of therapy for >5 days. Ninety-five percent of the children (36 of 38 children) achieved cures or probable cures, 1 child (2.5%) died, and 1 child (2.5%) defaulted from therapy. Multidrug-resistant tuberculosis disease among children can be treated successfully in resource-poor settings. Treatment is well tolerated by children, and severe adverse events with second-line agents are rare.

Clinical outcome of individualised treatment of multidrug-resistant tuberculosis in Latvia: a retrospective cohort study

Background Latvia has one of the highest rates of multidrug-resistant tuberculosis (MDRTB). Our aim was to assess treatment outcomes for the first full cohort of MDRTB patients treated under Latvia's DOTS-Plus strategy following WHO guidelines. Methods We retrospectively reviewed all civilian patients who began treatment with individualised treatment regimens for pulmonary MDRTB in Latvia between Jan 1, and Dec 31, 2000. We applied treatment outcome definitions for MDRTB, developed by an international expert consensus group, and assessed treatment effectiveness and risk factors associated with poor outcome. Findings Of the 204 patients assessed, 55 (27%) had been newly diagnosed with MDRTB, and 149 (73%) had earlier been treated with first-line or second-line drugs for this disease. Assessment of treatment outcomes showed that 135 (66%) patients were cured or completed therapy, 14 (7%) died, 26 (13%) defaulted, and treatment failed in 29 (14%). Of the 178 adherent patients, 135 (76%) achieved cure or treatment completion. In a multivariate Cox proportional-hazards model of these patients, independent predictors of poor outcome (death and treatment failure) included having previously received treatment for MDRTB (hazard ratio 5·7, 95% CI 1·9–16·6), the use of five or fewer drugs for 3 months or more (3·2, 1·1–9·6), resistance to ofloxacin (2·6, 1·2–5·4), and body-mass index less than 18·5 at start of treatment (2·3, 1·1–4·9). Interpretation The DOTS-Plus strategy of identifying and treating patients with MDRTB can be effectively implemented on a nationwide scale in a setting of limited resources. Latvia has one of the highest rates of multidrug-resistant tuberculosis (MDRTB). Our aim was to assess treatment outcomes for the first full cohort of MDRTB patients treated under Latvia's DOTS-Plus strategy following WHO guidelines. We retrospectively reviewed all civilian patients who began treatment with individualised treatment regimens for pulmonary MDRTB in Latvia between Jan 1, and Dec 31, 2000. We applied treatment outcome definitions for MDRTB, developed by an international expert consensus group, and assessed treatment effectiveness and risk factors associated with poor outcome. Of the 204 patients assessed, 55 (27%) had been newly diagnosed with MDRTB, and 149 (73%) had earlier been treated with first-line or second-line drugs for this disease. Assessment of treatment outcomes showed that 135 (66%) patients were cured or completed therapy, 14 (7%) died, 26 (13%) defaulted, and treatment failed in 29 (14%). Of the 178 adherent patients, 135 (76%) achieved cure or treatment completion. In a multivariate Cox proportional-hazards model of these patients, independent predictors of poor outcome (death and treatment failure) included having previously received treatment for MDRTB (hazard ratio 5·7, 95% CI 1·9–16·6), the use of five or fewer drugs for 3 months or more (3·2, 1·1–9·6), resistance to ofloxacin (2·6, 1·2–5·4), and body-mass index less than 18·5 at start of treatment (2·3, 1·1–4·9). The DOTS-Plus strategy of identifying and treating patients with MDRTB can be effectively implemented on a nationwide scale in a setting of limited resources.

Clinical outcome of individualised treatment of multidrug-resistant tuberculosis in Latvia: a retrospective cohort study

Latvia has one of the highest rates of multidrug-resistant tuberculosis (MDRTB). Our aim was to assess treatment outcomes for the first full cohort of MDRTB patients treated under Latvia's DOTS-Plus strategy following WHO guidelines. We retrospectively reviewed all civilian patients who began treatment with individualised treatment regimens for pulmonary MDRTB in Latvia between Jan 1, and Dec 31, 2000. We applied treatment outcome definitions for MDRTB, developed by an international expert consensus group, and assessed treatment effectiveness and risk factors associated with poor outcome. Of the 204 patients assessed, 55 (27%) had been newly diagnosed with MDRTB, and 149 (73%) had earlier been treated with first-line or second-line drugs for this disease. Assessment of treatment outcomes showed that 135 (66%) patients were cured or completed therapy, 14 (7%) died, 26 (13%) defaulted, and treatment failed in 29 (14%). Of the 178 adherent patients, 135 (76%) achieved cure or treatment completion. In a multivariate Cox proportional-hazards model of these patients, independent predictors of poor outcome (death and treatment failure) included having previously received treatment for MDRTB (hazard ratio 5.7, 95% CI 1.9-16.6), the use of five or fewer drugs for 3 months or more (3.2, 1.1-9.6), resistance to ofloxacin (2.6, 1.2-5.4), and body-mass index less than 18.5 at start of treatment (2.3, 1.1-4.9). The DOTS-Plus strategy of identifying and treating patients with MDRTB can be effectively implemented on a nationwide scale in a setting of limited resources.

Treatment of multidrug-resistant tuberculosis

Recent outbreaks of multi-drug-resistant tuberculosis (MDR-TB) have resulted in significant morbidity and mortality in patients with AIDS. The poor outcomes are attributable to delayed diagnoses, slow reporting of antimycobacterial susceptibility results, inadequate treatment regimens and profound immunosuppression. There are no prospective clinical trials which have evaluated the optimal treatment of MDR-TB. A retrospective study has shown that in immunocompetent patients with secondary MDR-TB, only 56% responded to prolonged courses of multiple drug regimens, and 22% died of TB. In patients with AIDS, even fewer patients respond, with median survivals of 2–4 months. In general, better responses have been associated with in vitro susceptibility of patients' isolates. If possible, patients with MDR-TB should receive at least three drugs to which their isolates are susceptible for at least 24 months; these regimens are likely to include ethambutol, pyrazinamide, a quinolone, and an aminoglycoside. Selected patients benefit from surgical intervention combined with aggressive chemotherapy. MDR-TB is best prevented by directly observed therapy of patients with susceptible organisms and rigorous infection control practices in areas of high incidence of MDR-TB. Effective treatment regimens for MDR-TB await the development of novel compounds which have better in vitro activity against MDR-TB than currently available drugs.