Antimicrobial prescribing patterns for respiratory diseases including tuberculosis in Russia: a possible role in drug resistance?

Antibiotic consumption for sore throat and the potential effect of a vaccine against group A Streptococcus: a systematic review and modelling study

BACKGROUND

Antibiotic consumption can lead to antimicrobial resistance and microbiome imbalance. We sought to estimate global antibiotic consumption for sore throat, and the potential reduction in consumption due to effective vaccination against group A Streptococcus (Strep A).

METHODS

We reviewed and analysed articles published between January 2000 and February 2022, identified though Clarivate Analytics' Web of Science search platform, with reference to antibiotic prescribing or consumption, sore throat, pharyngitis, or tonsillitis. We then used those analyses, combined with assumptions for the effectiveness, duration of protection, and coverage of a vaccine, to calculate the estimated reduction in antibiotic prescribing due to the introduction of Strep A vaccines.

FINDINGS

We identified 101 studies covering 38 countries. The mean prescribing rate for sore throat was approximately 5 courses per 100 population per year, accounting for approximately 5% of all antibiotic consumption. Based on 2020 population estimates for countries with empiric prescribing rates, antibiotic consumption for sore throat was estimated to exceed 37 million courses annually, of which half could be attributable to treatment for Strep A. A vaccine that reduces rates of Strep A infection by 80%, with 80% coverage and 10 year's duration of protection, could avert 2.8 million courses of antibiotics prescribed for sore throat treatment among 5-14 year-olds in countries with observed prescribing rates, increasing to an estimated 7.5 million averted if an effective vaccination program also reduced precautionary prescribing.

INTERPRETATION

A vaccine that prevents Strep A throat infections in children may reduce antibiotic prescribing for sore throat by 32-87% depending on changes to prescribing and consumption behaviours.

FUNDING

The Wellcome Trust, grant agreement number 215490/Z/19/Z.

A Qualitative Analysis of the Culture of Antibiotic Use for Upper Respiratory Tract Infections Among Patients in Northwest Russia

Introduction: Due to the globally persistent threat of Antimicrobial Resistance (AMR), the purpose of this study was to gain an in-depth understanding of the antibiotic (AB) practices, knowledge and attitudes among patients residing in five regions in the northwest part of Russia. Given the high prevalence, this study focused on ABs for Upper Respiratory Tract Infections (URTI).

Methods: The qualitative, semi-structured interviews followed a guide organized by major themes such as common symptoms, consultations with doctors and external influences in decision-making. Patient participants were recruited via convenience sampling. Fifty-five interviews were conducted among patients using ABs for URTIs purchased with or without prescription. Data was analyzed using a direct content analysis and validation rounds were conducted between interviewers and data analyzers.

Results: Self-medication with ABs seemed a common practice across all five Russian regions; in some cases, patients tried to persuade pharmacists into selling them ABs without prescription. Factors, such as time spent going to the doctor, need of a sick leave or self-persuasion, influenced the decisions of whether or not to seek the doctor for symptoms of URTIs. Knowledge of ABs and AMR was generally low; however, some patients with seemingly good knowledge practiced self-medication from time to time. Family members and friends were often involved in decisions about how to handle symptoms of URTIs, especially among those patients using ABs without prescription. Few patients had noticed ABs awareness campaigns, and very few reported having learned something important from them.

Conclusion: Despite enforced regulation of AB use in Russia, self-medication still exists. Knowledge is not always linked to appropriate use of AB, and the few campaigns conducted were not always noticed.

Compensatory evolution drives multidrug-resistant tuberculosis in Central Asia

Bacterial factors favoring the unprecedented multidrug-resistant tuberculosis (MDR-TB) epidemic in the former Soviet Union remain unclear. We utilized whole genome sequencing and Bayesian statistics to analyze the evolutionary history, temporal emergence of resistance and transmission networks of MDR Mycobacterium tuberculosis complex isolates from Karakalpakstan, Uzbekistan (2001-2006). One clade (termed Central Asian outbreak, CAO) dating back to 1974 (95% HPD 1969-1982) subsequently acquired resistance mediating mutations to eight anti-TB drugs. Introduction of standardized WHO-endorsed directly observed treatment, short-course in Karakalpakstan in 1998 likely selected for CAO-strains, comprising 75% of sampled MDR-TB isolates in 2005/2006. CAO-isolates were also identified in a published cohort from Russia (2008-2010). Similarly, the presence of mutations supposed to compensate bacterial fitness deficits was associated with transmission success and higher drug resistance rates. The genetic make-up of these MDR-strains threatens the success of both empirical and standardized MDR-TB therapies, including the newly WHO-endorsed short MDR-TB regimen in Uzbekistan.

Antibiotic use practices of pharmacy staff: a cross-sectional study in Saint Petersburg, the Russian Federation

BACKGROUND

Non-prescription access to antimicrobials is common, and self-prescribing is increasingly popular in Russian society. The aim of this study was to assess the attitudes of community pharmacists regarding antibiotic use and self-medication.

METHODS

We conducted a cross-sectional study from September-December 2015 of community pharmacists in the Saint-Petersburg and Leningrad region, Russia. A self-administered questionnaire was used to assess antibiotic use and self-medication practices. The data were analysed using logistic regression and Pearson chi-squared tests.

RESULTS

Of the 316 pharmacists (77.07%) who completed the questionnaire, 230 (72.8%) self-medicated with antibiotics. Antibiotics were mostly used to self-treat upper (53.3%) and lower respiratory tract infections (19.3%), relying on their own knowledge (81.5%), previous treatment experience (49%) and patients' prescriptions (17%). The most commonly used antibiotics were macrolides (33.2%). Characteristics such as age, education and experience were related to antibiotic use and self-medication.

CONCLUSIONS

The study confirmed that self-prescription of antibiotics is a common practice amongst pharmacists in Saint Petersburg and also identified personal and professional characteristics of pharmacists strongly associated with self-medication.

The Impact of Restricting Over-the-Counter Sales of Antimicrobial Drugs: Preliminary Analysis of National Data

To describe the nationwide impact of a restrictive law on over-the-counter sales of antimicrobial drugs, implemented in Brazil in November 2010. Approximately 75% of the population receives healthcare from the public health system and receives free-of-charge medication if prescribed. Total sales in private pharmacies as compared with other channels of sales of oral antibiotics were evaluated in this observational study before and after the law (2008-2012). Defined daily dose per 1000 inhabitants per day (DDD/TID) was used as standard unit. In private pharmacies the effect of the restrictive law was statistically significant (P < 0.001) with an estimated decrease in DDD/TID of 1.87 (s.e. =  0.18). In addition, the trend of DDD/TID before the restrictive law was greater than after the intervention (P < 0.001). Before November 2010, the slope for the trend line was estimated as 0.08 (s.e. = 0.01) whereas after the law, the estimated slope was 0.03 (s.e. = 0.01). As for the nonprivate channels, no difference in sales was observed (P = 0.643). The impact in the South and Southeast (more developed) regions was higher than in the North, Northeast, and Mid-West. The state capitals had a 19% decrease, compared with 0.8% increase in the rest of the states. Before the law, the sales of antimicrobial drugs were steadily increasing. From November 2010, with the restrictive law, there was an abrupt drop in sales followed by an increase albeit at a significantly lower rate. The impact was higher in regions with better socio-economic status.

Rapid diagnostics of tuberculosis and drug resistance in the industrialized world: clinical and public health benefits and barriers to implementation

In this article, we give an overview of new technologies for the diagnosis of tuberculosis (TB) and drug resistance, consider their advantages over existing methodologies, broad issues of cost, cost-effectiveness and programmatic implementation, and their clinical as well as public health impact, focusing on the industrialized world. Molecular nucleic-acid amplification diagnostic systems have high specificity for TB diagnosis (and rifampicin resistance) but sensitivity for TB detection is more variable. Nevertheless, it is possible to diagnose TB and rifampicin resistance within a day and commercial automated systems make this possible with minimal training. Although studies are limited, these systems appear to be cost-effective. Most of these tools are of value clinically and for public health use. For example, whole genome sequencing of Mycobacterium tuberculosis offers a powerful new approach to the identification of drug resistance and to map transmission at a community and population level.

Enabling factors for antibiotic prescribing for upper respiratory tract infections: perspectives of Lithuanian and Russian general practitioners

INTRODUCTION

General practitioners (GPs) write about 80% of all antibiotic prescriptions, the greatest number of them for patients with respiratory tract infections. However, there is a lack of research targeting the influence of external factors on antibiotic prescribing by physicians. This study aimed to explore experiences of GPs in Lithuania and the Russian Federation with regard to antibiotic prescription for upper respiratory tract infections. By such means it might be possible to reveal external enabling factors that influence antibiotic prescribing in these countries.

METHOD

Five focus groups were performed with 22 GPs from Lithuania and 29 GPs from the Kaliningrad Region of the Russian Federation; then, thematic analysis of data was performed.

RESULTS

Six thematic categories were identified that are related to external forces enabling antibiotic prescription: the necessity for political leadership to encourage clinically grounded antibiotic use; over-the-counter sale of antibiotics; designation of antibiotics as reimbursable medications; supervision by external oversight institutions; lack of guidelines for the treatment of upper respiratory tract infections; and pharmaceutical company activities.

CONCLUSIONS

Comprehensive efforts to reduce the burden of non-clinically grounded antibiotic prescription should go beyond addressing factors at the physician-patient level and take into account important factors in the enabling environment as well.

Antimicrobial prescribing practice in UK equine veterinary practice

REASONS FOR PERFORMING STUDY

Antimicrobial use is known to select for the emergence of resistant strains of bacteria; therefore prudent use in both human and veterinary medicine is essential to preserve their efficacy.

OBJECTIVES

To characterise antimicrobial prescribing patterns in UK equine practice and evaluate factors associated with prescribing.

METHODS

A postal questionnaire including 4 clinical scenarios was sent to 740 veterinary surgeons that treat horses. Data were collected on the clinician, their practice and sources of information regarding antimicrobials and their use. Multivariable logistic regression analysis was used to ascertain factors associated with 5 outcomes; prescribing off-licence drugs; prescribing at incorrect doses; prescribing 3rd or 4th generation cephalosporins; prescribing fluoroquinolones and prescribing potentiated sulphonamides.

RESULTS

Questionnaires were completed by 38% of veterinary surgeons who were sent questionnaires. Less than 1% of practices had antimicrobial use guidelines. Trimethoprim-sulphonamides were most commonly prescribed in each clinical scenario. Eleven percent of prescriptions were for antimicrobial drugs not licensed for use in horses in the UK. Five percent of prescriptions for licensed antimicrobials were under the recommended dose rate and 56% over the recommended dose rate. Fluoroquinolones and 3rd and 4th generation cephalosporins accounted for 1 and 3% of prescriptions, respectively. Veterinary surgeons working at referral practices were more likely to prescribe 3rd and 4th generation cephalosporins and fluoroquinolones and off-licence antimicrobials whereas those working in first-opinion practices were more likely to prescribe potentiated sulphonamides. Sources of information regarding antimicrobials also had an effect on prescribing.

CONCLUSIONS AND POTENTIAL RELEVANCE

Prescription of antimicrobials at inappropriate doses was common even when provided with the weight of the animal. It is uncommon for UK equine veterinary practices to have guidelines for antimicrobial use. The introduction of such guidelines could lead to more prudent use of antimicrobials.

Resistance surveillance studies: a multifaceted problem--the fluoroquinolone example

INTRODUCTION

This review summarizes data on the fluoroquinolone resistance epidemiology published in the previous 5 years.

MATERIALS AND METHODS

The data reviewed are stratified according to the different prescription patterns by either primary- or tertiary-care givers and by indication. Global surveillance studies demonstrate that fluoroquinolone- resistance rates increased in the past several years in almost all bacterial species except Staphylococcus pneumoniae and Haemophilus influenzae causing community-acquired respiratory tract infections (CARTIs), as well as Enterobacteriaceae causing community-acquired urinary tract infections. Geographically and quantitatively varying fluoroquinolone resistance rates were recorded among Gram-positive and Gram-negative pathogens causing healthcare-associated respiratory tract infections. One- to two-thirds of Enterobacteriaceae producing extended-spectrum β-lactamases (ESBLs) were fluoroquinolone resistant too, thus, limiting the fluoroquinolone use in the treatment of community- as well as healthcare-acquired urinary tract and intra-abdominal infections. The remaining ESBL-producing or plasmid-mediated quinolone resistance mechanisms harboring Enterobacteriaceae were low-level quinolone resistant. Furthermore, 10-30 % of H. influenzae and S. pneumoniae causing CARTIs harbored first-step quinolone resistance determining region (QRDR) mutations. These mutants pass susceptibility testing unnoticed and are primed to acquire high-level fluoroquinolone resistance rapidly, thus, putting the patient at risk. The continued increase in fluoroquinolone resistance affects patient management and necessitates changes in some current guidelines for the treatment of intra-abdominal infections or even precludes the use of fluoroquinolones in certain indications like gonorrhea and pelvic inflammatory diseases in those geographic areas in which fluoroquinolone resistance rates and/or ESBL production is high. Fluoroquinolone resistance has been selected among the commensal flora colonizing the gut, nose, oropharynx, and skin, so that horizontal gene transfer between the commensal flora and the offending pathogen as well as inter- and intraspecies recombinations contribute to the emergence and spread of fluoroquinolone resistance among pathogenic streptococci. Although interspecies recombinations are not yet the major cause for the emergence of fluoroquinolone resistance, its existence indicates that a large reservoir of fluoroquinolone resistance exists. Thus, a scenario resembling that of a worldwide spread of β-lactam resistance in pneumococci is conceivable. However, many resistance surveillance studies suffer from inaccuracies like the sampling of a selected patient population, restricted geographical sampling, and undefined requirements of the user, so that the results are biased. The number of national centers is most often limited with one to two participating laboratories, so that such studies are point prevalence but not surveillance studies. Selected samples are analyzed predominantly as either hospitalized patients or patients at risk or those in whom therapy failed are sampled; however, fluoroquinolones are most frequently prescribed by the general practitioner. Selected sampling results in a significant over-estimation of fluoroquinolone resistance in outpatients. Furthermore, the requirements of the users are often not met; the prescribing physician, the microbiologist, the infection control specialist, public health and regulatory authorities, and the pharmaceutical industry have diverse interests, which, however, are not addressed by different designs of a surveillance study. Tools should be developed to provide customer-specific datasets.

CONCLUSION

Consequently, most surveillance studies suffer from well recognized but uncorrected biases or inaccuracies. Nevertheless, they provide important information that allows the identification of trends in pathogen incidence and antimicrobial resistance.

Cross-sectional survey of antimicrobial prescribing patterns in UK small animal veterinary practice

The increase in the prevalence of antimicrobial resistance has resulted in both human and veterinary antimicrobial use coming under increased scrutiny. The aim of this study was to characterise antimicrobial prescribing patterns in small-animal veterinary practices in the UK. A cross-sectional survey of UK small animal veterinarians was undertaken. A postal questionnaire to evaluate antimicrobial prescribing habits was sent to 900 clinicians. Data were collected on the clinicians, their practices and their sources of information regarding antimicrobials and their use. Respondents were asked if they would prescribe antimicrobials to animals described in four clinical scenarios, and, if so, to provide details of the prescription(s). Questionnaires were completed by 51% of the veterinarians. Only 3.5% of clinicians reported that their practice had an antimicrobial use policy. Penicillins were most commonly prescribed in three clinical scenarios, and 1st generation cephalosporins were most commonly prescribed in a scenario about canine pyoderma. In one scenario, fluoroquinolones and 3rd generation cephalosporins accounted for 10% and 13% of prescriptions respectively. Five percent of all prescriptions were under the recommended dose and 20% were over the recommended dose. Overall, 2.3% of prescriptions were not licensed for use in dogs or cats in the UK. Associations between the use of various antimicrobial drugs and independent variables were analysed using multivariable logistic regression models. Off-license prescriptions and inaccurate dosing of antimicrobials by small-animal clinicians in the UK appears to occur. Antimicrobial use guidelines are rare in small animal practice. The introduction of such guidelines has been shown to lead to more appropriate use of antimicrobials and is therefore recommended.

Knowledge of tuberculosis-treatment prescription of health workers: a systematic review

Treating tuberculosis (TB) patients with inappropriate treatment regimens can lead to treatment failure and, thus, patients who have not been cured and/or to the development of (multi)-drug resistance. A systematic review was performed to assess the knowledge of appropriate TB drug regimens among all categories of healthcare workers (HCWs).

In January 2011, MEDLINE, EMBASE and other databases were searched for relevant articles. Observational studies published as of the year 2000 that assessed HCW knowledge of TB treatment were selected. A treatment regimen, drug dosage or treatment duration was considered inappropriate if it was not recommended by national guidelines or by the World Health Organization (WHO).

Of 1,896 studies, 31 were included from 14 different countries. No study was performed in Europe. In all studies, HCWs with inappropriate knowledge of treatment regimens (8–100%) or treatment duration (5–99%) were observed. The few studies providing detailed data showed that HCWs mainly reported giving treatment regimens with too many drugs and for too long. Knowledge of appropriate doses was also insufficient in most studies.

The available studies show that there is a lack of knowledge of national or international TB treatment guidelines and recommendations. Generalisation of the findings to other settings and countries should be done with caution.

Non-prescription antimicrobial use worldwide: a systematic review

In much of the world antimicrobial drugs are sold without prescription or oversight by health-care professionals. The scale and effect of this practice is unknown. We systematically reviewed published works about non-prescription antimicrobials from 1970-2009, identifying 117 relevant articles. 35 community surveys from five continents showed that non-prescription use occurred worldwide and accounted for 19-100% of antimicrobial use outside of northern Europe and North America. Safety issues associated with non-prescription use included adverse drug reactions and masking of underlying infectious processes. Non-prescription use was common for non-bacterial disease, and antituberculosis drugs were available in many areas. Antimicrobial-resistant bacteria are common in communities with frequent non-prescription use. In a few settings, control efforts that included regulation decreased antimicrobial use and resistance. Non-prescription antimicrobial and antituberculosis use is common outside of North America and northern Europe and must be accounted for in public health efforts to reduce antimicrobial resistance.

Survival of civilian and prisoner drug-sensitive, multi- and extensive drug- resistant tuberculosis cohorts prospectively followed in Russia

Objective and Methods

A long-term observational study was conducted in Samara, Russia to assess the survival and risk factors for death of a cohort of non-multidrug resistant tuberculosis (non-MDRTB) and multidrug resistant tuberculosis (MDRTB) civilian and prison patients and a civilian extensive drug-resistant tuberculosis (XDRTB) cohort.

Results

MDRTB and XDRTB rates of 54.8% and 11.1% were identified in the region. Half (50%) of MDRTB patients and the majority of non-MDRTB patients (71%) were still alive at 5 years. Over half (58%) of the patients died within two years of establishing a diagnosis of XDRTB. In the multivariate analysis, retreatment (HR = 1.61, 95%CI 1.04, 2.49) and MDRTB (HR = 1.67, 95%CI 1.17, 2.39) were significantly associated with death within the non-MDR/MDRTB cohort. The effect of age on survival was relatively small (HR = 1.01, 95%CI 1.00, 1.02). No specific factor affected survival of XDRTB patients although median survival time for HIV-infected versus HIV-negative patients from this group was shorter (185 versus 496 days). The majority of MDRTB and XDRTB strains (84% and 92% respectively) strains belonged to the Beijing family. Mutations in the rpoB (codon 531 in 81/92; 88.8%), katG (mutation S315T in 91/92, 98.9%) and inhA genes accounted for most rifampin and isoniazid resistance respectively, mutations in the QRDR region of gyrA for most fluroquinolone resistance (68/92; 73.5%).

Conclusions

Alarmingly high rates of XDRTB exist. Previous TB treatment cycles and MDR were significant risk factors for mortality. XDRTB patients' survival is short especially for HIV-infected patients. Beijing family strains comprise the majority of drug-resistant strains.

Fluoroquinolones are associated with delayed treatment and resistance in tuberculosis: a systematic review and meta-analysis

BACKGROUND

Current guidelines for treating community-acquired pneumonia recommend the use of fluoroquinolones for high-risk patients. Previous studies have reported controversial results as to whether fluoroquinolones are associated with delayed diagnosis and treatment of pulmonary tuberculosis (TB) and the development of fluoroquinolone-resistant Mycobacterium tuberculosis. We performed a systematic review and meta-analysis to clarify these issues.

METHODS

The following databases were searched through September 30, 2010: PubMed, EMBASE, CINAHL, Cochrane Library, Web of Science, BIOSIS Previews, and the ACP Journal Club. We considered studies that addressed the issues of delay in diagnosis and treatment of TB and the development of resistance.

RESULTS

Nine eligible studies (four for delays and five for resistance issues) were included in the meta-analysis from the 770 articles originally identified in the database search. The mean duration of delayed diagnosis and treatment of pulmonary TB in the fluoroquinolone prescription group was 19.03 days, significantly longer than that in the non-fluoroquinolone group (95% confidence interval (CI) 10.87 to 27.18, p<0.001). The pooled odds ratio of developing a fluoroquinolone-resistant M. tuberculosis strain was 2.70 (95% CI 1.30 to 5.60, p=0.008). No significant heterogeneity was found among studies in the meta-analysis.

CONCLUSIONS

Empirical fluoroquinolone prescriptions for pneumonia are associated with longer delays in diagnosis and treatment of pulmonary TB and a higher risk of developing fluoroquinolone-resistant M. tuberculosis.

Heightened vulnerability to MDR-TB epidemics after controlling drug-susceptible TB

BACKGROUND

Prior infection with one strain TB has been linked with diminished likelihood of re-infection by a new strain. This paper attempts to determine the role of declining prevalence of drug-susceptible TB in enabling future epidemics of MDR-TB.

METHODS

A computer simulation of MDR-TB epidemics was developed using an agent-based model platform programmed in NetLogo (See http://mdr.tbtools.org/). Eighty-one scenarios were created, varying levels of treatment quality, diagnostic accuracy, microbial fitness cost, and the degree of immunogenicity elicited by drug-susceptible TB. Outcome measures were the number of independent MDR-TB cases per trial and the proportion of trials resulting in MDR-TB epidemics for a 500 year period after drug therapy for TB is introduced.

RESULTS

MDR-TB epidemics propagated more extensively after TB prevalence had fallen. At a case detection rate of 75%, improving therapeutic compliance from 50% to 75% can reduce the probability of an epidemic from 45% to 15%. Paradoxically, improving the case-detection rate from 50% to 75% when compliance with DOT is constant at 75% increases the probability of MDR-TB epidemics from 3% to 45%.

CONCLUSIONS

The ability of MDR-TB to spread depends on the prevalence of drug-susceptible TB. Immunologic protection conferred by exposure to drug-susceptible TB can be a crucial factor that prevents MDR-TB epidemics when TB treatment is poor. Any single population that successfully reduces its burden of drug-susceptible TB will have reduced herd immunity to externally or internally introduced strains of MDR-TB and can experience heightened vulnerability to an epidemic. Since countries with good TB control may be more vulnerable, their self interest dictates greater promotion of case detection and DOTS implementation in countries with poor control to control their risk of MDR-TB.

Prescribing in maternity care in Russia: The legacy of Soviet medicine

Remarkably, there has been very little detailed research on clinical practice in Russia and its neighbours in what was the USSR, even though it is known that the USSR was isolated from many international developments, in particular evidence-based medicine. In this study we examine obstetric practice, an area of practice where there is an extensive body of evidence on the appropriateness of many interventions. The study is undertaken in Tula, a region 200 km south of Moscow. Building on earlier detailed analyses of data from the facilities in the region, it reports a series of structured interviews with 52 obstetricians from all 19 facilities in the region, designed to identify patterns of prescribing, supplemented by 36 more detailed re-interviews to explore reasons for the differing practices. The study demonstrates a widespread divergence from internationally accepted practice. Maternity care is extremely medicalised but many non-evidence based medicines are used. Some are heavily marketed by large pharmaceutical companies, some were widely used during the Soviet period but never evaluated, and a few are not known to be used anywhere else in the world. For several conditions, the most widely used drugs are clearly inferior to alternative products and some are used for indications quite different from those in other countries. This study contributes to the growing evidence that much of the care provided in Russian maternity units is ineffective or potentially dangerous but also begins to offer some explanations for why this is, including a lack of access to information and a lack of awareness of the concept of evidence-based practice.

The Directly Observed Therapy Short-Course (DOTS) strategy in Samara Oblast, Russian Federation

BACKGROUND

The World Health Organisation (WHO) defines Russia as one of the 22 highest-burden countries for tuberculosis (TB). The WHO Directly Observed Treatment Short Course (DOTS) strategy employing a standardised treatment for 6 months produces the highest cure rates for drug sensitive TB. The Russian TB service traditionally employed individualised treatment. The purpose of this study was to implement a DOTS programme in the civilian and prison sectors of Samara Region of Russia, describe the clinical features and outcomes of recruited patients, determine the proportion of individuals in the cohorts who were infected with drug resistant TB, the degree to which resistance was attributed to the Beijing TB strain family and establish risk factors for drug resistance.

METHODS

Prospective study.

RESULTS

2,099 patients were recruited overall. Treatment outcomes were analysed for patients recruited up to the third quarter of 2003 (n = 920). 75.3% of patients were successfully treated. Unsuccessful outcomes occurred in 7.3% of cases; 3.6% of patients died during treatment, with a significantly higher proportion of smear-positive cases dying compared to smear-negative cases. 14.0% were lost and transferred out. A high proportion of new cases (948 sequential culture-proven TB cases) had tuberculosis that was resistant to first-line drugs; (24.9% isoniazid resistant; 20.3% rifampicin resistant; 17.3% multidrug resistant tuberculosis). Molecular epidemiological analysis demonstrated that half of all isolated strains (50.7%; 375/740) belonged to the Beijing family. Drug resistance including MDR TB was strongly associated with infection with the Beijing strain (for MDR TB, 35.2% in Beijing strains versus 9.5% in non-Beijing strains, OR-5.2. Risk factors for multidrug resistant tuberculosis were: being a prisoner (OR 4.4), having a relapse of tuberculosis (OR 3.5), being infected with a Beijing family TB strain (OR 6.5) and having an unsuccessful outcome from treatment (OR 5.0).

CONCLUSION

The implementation of DOTS in Samara, Russia, was feasible and successful. Drug resistant tuberculosis rates in new cases were high and challenge successful outcomes from a conventional DOTS programme alone.