Epidemics Of Multidrug-resistant Tuberculosis Research Articles

Challenge of the Rising Multidrug-Resistant Tuberculosis in China: A Predictive Study Using Markov Modeling

Background: Multidrug-resistant tuberculosis (MDR-TB) is emerging in China. We used a dynamic Markov model to predict the longitudinal trends of MDR-TB in China by 2050, and assess the effects of alternative control measures. Methods Eight states of TB transmission were set up in the Markov model using a hypothetical cohort of 100,000 people. Prevalence of MDR-TB and bacteriological confirmed drug-susceptible TB (DS-TB+) were simulated. MDR-TB was stratified into being treated with the recommended regimen or not. Findings: Under the current China’s TB control conditions, by 2050, prevalence of DS-TB+ could be estimated to decrease to 39 per 100,000 people, a 37·1% reduction from 2019 , whereas MDR-TB would increase by three times to 58/100,000. Furthermore, by the year of 2050, 86·2% of the MDR-TB cases would be left untreated. If the detection rate of MDR-TB could reach 50% or 70% at 5% per year, the decline of MDR-TB prevalence would be 25·9% and 36·2% respectively. If treatment coverage was improved to 70% or 100% by 5% yearly , MDR-TB prevalence in 2050 would gain a reduction of 13·8% and 24·1%, respectively. If both detection rate and treatment coverage could reach 70%, the prevalence of MDR-TB would be reduced to 28/100, 000, a 51·7% reduction by 2050. Interpretation: MDR-TB, especially untreated MDR-TB, would rise rapidly under current MDR-TB control strategies in China. Interventions on promoting effective detection and treatment of MDR-TB are imperative in the fights against MDR-TB epidemics. Funding Statement: The Sweden-China (VR-NSFC) joint project (PI, Biao Xu, 81361138019 and Sven Hoffner, 540-2013-8797). Declaration of Interests: The authors stated: None declared. Ethics Approval Statement: Not required.

Projecting the impact of variable MDR-TB transmission efficiency on long-term epidemic trends in South Africa and Vietnam

Whether multidrug-resistant tuberculosis (MDR-TB) is less transmissible than drug-susceptible (DS-)TB on a population level is uncertain. Even in the absence of a genetic fitness cost, the transmission potential of individuals with MDR-TB may vary by infectiousness, frequency of contact, or duration of disease. We used a compartmental model to project the progression of MDR-TB epidemics in South Africa and Vietnam under alternative assumptions about the relative transmission efficiency of MDR-TB. Specifically, we considered three scenarios: consistently lower transmission efficiency for MDR-TB than for DS-TB; equal transmission efficiency; and an initial deficit in the transmission efficiency of MDR-TB that closes over time. We calibrated these scenarios with data from drug resistance surveys and projected epidemic trends to 2040. The incidence of MDR-TB was projected to expand in most scenarios, but the degree of expansion depended greatly on the future transmission efficiency of MDR-TB. For example, by 2040, we projected absolute MDR-TB incidence to account for 5% (IQR: 4–9%) of incident TB in South Africa and 14% (IQR: 9–26%) in Vietnam assuming consistently lower MDR-TB transmission efficiency, versus 15% (IQR: 8–27%)and 41% (IQR: 23–62%), respectively, assuming shrinking transmission efficiency deficits. Given future uncertainty, specific responses to halt MDR-TB transmission should be prioritized.

On the spread and control of MDR-TB epidemics: an examination of trends in anti-tuberculosis drug resistance surveillance data.

Multidrug resistant tuberculosis (MDR-TB) poses serious challenges for tuberculosis control in many settings, but trends of MDR-TB have been difficult to measure. We analyzed surveillance and population-representative survey data collected worldwide by the World Health Organization between 1993 and 2012. We examined setting-specific patterns associated with linear trends in the estimated per capita rate of MDR-TB among new notified TB cases to generate hypotheses about factors associated with trends in the transmission of highly drug resistant tuberculosis. 59 countries and 39 sub-national settings had at least three years of data, but less than 10% of the population in the WHO-designated 27-high MDR-TB burden settings were in areas with sufficient data to track trends. Among settings in which the majority of MDR-TB was autochthonous, we found 10 settings with statistically significant linear trends in per capita rates of MDR-TB among new notified TB cases. Five of these settings had declining trends (Estonia, Latvia, Macao, Hong Kong, and Portugal) ranging from decreases of 3% to 14% annually, while five had increasing trends (four individual oblasts of the Russian Federation and Botswana) ranging from 14% to 20% annually. In unadjusted analysis, better surveillance indicators and higher GDP per capita were associated with declining MDR-TB, while a higher existing absolute burden of MDR-TB was associated with an increasing trend. Only a small fraction of countries in which the burden of MDR-TB is concentrated currently have sufficient surveillance data to estimate trends in drug-resistant TB. Where trend analysis was possible, smaller absolute burdens of MDR-TB and more robust surveillance systems were associated with declining per capita rates of MDR-TB among new notified cases.

Multidrug-resistant tuberculosis in Belarus: the size of the problem and associated risk factors

To assess the problem of multidrug-resistant tuberculosis (MDR-TB) throughout Belarus and investigate the associated risk factors. In a nationwide survey in 2010-2011, 1420 tuberculosis (TB) patients were screened and 934 new and 410 previously treated cases of TB were found to meet the inclusion criteria. Isolates of Mycobacterium tuberculosis from each eligible patient were tested for susceptibility to anti-TB drugs. Sociobehavioural information was gathered in interviews based on a structured questionnaire. MDR-TB was found in 32.3% and 75.6% of the new and previously treated patients, respectively, and, 11.9% of the 612 patients found to have MDR-TB had extensively drug-resistant TB (XDR-TB). A history of previous treatment for TB was the strongest independent risk factor for MDR-TB (odds ratio, OR: 6.1; 95% confidence interval, CI: 4.8-7.7). The other independent risk factors were human immunodeficiency virus (HIV) infection (OR: 2.2; 95% CI: 1.4-3.5), age < 35 years (OR: 1.4; 95% CI: 1.0-1.8), history of imprisonment (OR: 1.5; 95% CI: 1.1-2.0), disability sufficient to prevent work (OR: 1.9; 95% CI: 1.2-3.0), alcohol abuse (OR: 1.3; 95% CI: 1.0-1.8) and smoking (OR: 1.5; 95% CI: 1.1-2.0). MDR-TB is very common among TB patients throughout Belarus. The numerous risk factors identified for MDR-TB and the convergence of the epidemics of MDR-TB and HIV infection call not only for stronger collaboration between TB and HIV control programmes, but also for the implementation of innovative measures to accelerate the detection of TB resistance and improve treatment adherence.

Impact of joined-up HIV harm reduction and multidrug resistant tuberculosis control programmes in Estonia: System dynamics simulation model

In Eastern Europe and Central Asia (ECA) the control of tuberculosis, multidrug resistant tuberculosis (MDRTB) and human immunodeficiency virus (HIV) poses important public health challenges. We used system dynamics simulation to determine impact on cumulative HIV/AIDS, tuberculosis and HIV-associated-tuberculosis deaths, over 20 years, of harm-reduction programmes to reduce needle-sharing and injection-frequency amongst injecting drug users (IDUs) and multidrug resistant tuberculosis (MDRTB) control in a population with an explosive HIV epidemic in IDUs and high MDRTB prevalence. We estimate that the number of HIV-associated-deaths will decline by 30% with effective harm-reduction programmes but double if these are ineffective. In our model, effective MDRTB and HIV control reduces cumulative tuberculosis deaths by 54%, cumulative MDRTB deaths 15-fold and cumulative HIV-associated-tuberculosis-deaths 2-fold. Effective MDRTB control, without effective harm-reduction programmes, only reduce tuberculosis deaths by 22%. However, effective harm-reduction programme with a poor MDRTB control reduce cumulative tuberculosis deaths by 34%, MDRTB by 14% and HIV-associated-tuberculosis by 56%. Even with good control programmes for drug sensitive TB, neglecting harm reduction and MDRTB control will result in 50% more tuberculosis-related deaths than if both are effectively addressed. Effective harm-reduction programmes reduces cumulative deaths from tuberculosis more substantively than effective MDRTB control. Our finding have important policy implications for communicable disease policies in post-Soviet countries, which need to substantially change if they are to effectively address the emerging HIV and MDRTB epidemics.

Twin Epidemics of Multidrug-Resistant Tuberculosis: Russia and New York City

The epidemics of multidrug-resistant tuberculosis in Russia and New York City demonstrate that vigilance must be maintained even when an infectious disease appears to be easily treated or virtually eradicated. Virtual Mentor is a monthly bioethics journal published by the American Medical Association.