Yoav Keynan, MD and NCCID’s Scientific Lead
According to the WHO 2017 report, in 2016 globally, there were 600,000 new cases of tuberculosis with resistance to rifampicin, the most effective first-line drug, of which 490,000 cases had multidrug-resistant TB (MDR-TB), defined as resistance to rifampicin and isoniazid.
Almost half (47%) of these cases were in India, China and the Russian Federation and the outcomes remain significantly worse than non-MDR TB, with a treatment success rate of 54% compared to an estimate of 83% success for non-MDR TB.
Drug resistant TB represents a failure of clinical management of TB, either due to failing to prescribe appropriate therapy or to ensuring administration of treatment. Others are infected with transmitted MDR-TB through exposure to a person with infectious MDR-TB. Additional causes include an interruption in drug supply or poor quality drugs, frequently seen in developing countries.
The acquisition of MDR TB entails a prolonged and complicated course of anti-tuberculous drugs with lower rates of completion and successful therapy1,2. Treatment of isoniazid resistant TB with a standard first line anti-tuberculous regimen is associated with higher rates of failure, relapse and emergence of resistance3. The impact of exposure to MDR-TB on the choice of therapy for latent TB infection (LTBI) among contacts is an important issue; treatment decisions to date are largely based on expert opinion supported by low quality of evidence 4,5.
The most recent summary of tuberculosis in Canada (2015 data) does not include MDR-TB incidence6, however 71% of TB cases were identified among foreign-born individuals. Several studies have documented higher, albeit low risk, of transmission of drug resistant TB from foreign born individuals7,8. The potential for transmitted MDR TB or acquired resistance due to incomplete treatment always poses a concern for the effectiveness of TB therapy, with significant implications for TB control programs9,10.
Summary: MDR TB is posing a challenge on the ability to move towards TB elimination goals as it complicates treatment regimens and decreases treatment success, with a potential effect on the choice of LTBI treatment. Although the risk of transmission in Canada is low, changing immigration patterns and global challenges with MDR TB control require vigilance for the trends of MDR TB. The resources included here provide some of the public health implications of resistant TB as well as guidance from other countries.
List of MDR-TB resources that can inform the Canadian Context:
Infographic and fact sheet
A film which educates viewers on the risks, prevention, and treatment of tuberculosis (TB) and MDR-TB. The Lucky Specials combines animation and live-action storytelling to deeply engage viewers, countering misinformation and stigma of TB and positively impacting health-related decision making. The film was broadcasted throughout the sub-Saharan Africa and screened in partnership with governments, community health workers, NGOs, schools and the private sector. (Available in English only)
Information and user-friendly tools and templates for use by clinicians participating in the management of patients with drug-resistant TB. It covers major topics pertaining to epidemiology, diagnosis, laboratory issues, treatment, medications, pediatrics, co-morbidities and special situations, monitoring and case management, adverse reactions, and treatment of contacts. (Available in English only)
One of the objectives is to increase the American public’s awareness of the threats posed by MDR-TB; serves as a call to action to encourage bilateral and multilateral donors, the private sector, and affected countries to increase investments in this critical area of worldwide concern. (Available in English only)
Training for staff working at DR-TB management centers. A set of training modules developed by the WHO. These modules are designed for health workers who are involved in detecting cases of and managing patients with drug-resistant TB. (Available in English only)
Produced by The Union (International Union Against Tuberculosis and Lung Disease). Fact sheet about TB and MDR-TB, highlighting the challenges in addressing MDR-TB. (Available in English only)
This set of tools is designed to help countries develop or strengthen a multidrug-resistant tuberculosis (MDR-TB) component within their national TB strategy. The toolkit contains key steps for the planning process, including developing objectives for a strong MDR-TB component, identifying and addressing current gaps in service coverage, and determining how to secure resources and monitor progress. The MDR-TB Planning Toolkit is intended for countries, technical partners, international organizations, and donors who want to use WHO standards and policies to improve the diagnosis, treatment, and care of patients with drug-resistant TB. It creates an easy-to-follow process that draws together existing guidance from international organizations, including the World Health Organization (WHO) and the Global Fund to Fight AIDS, Tuberculosis and Malaria (Global Fund). (Available in English only, as pdf, Word Document and with additional materials:
GBCHealth is a global coalition of over 200 private sector companies and top NGOs.
This is an informational brief re: MDR-TB and XDR-TB. Defines MDR-TB, what causes MDR-TB and what can be done. (Available in English only)
A case study about MDR-TB in Peru by two Harvard students. For training purposes (Available in English only)
A document prepared by the WHO. This field guide was created to help health workers to diagnose MDR-TB, initiate second-line anti-TB drugs, and monitor MDR-TB treatment. (Available in English only)
Intended for health professionals and health service organizations. The document is focused mainly on drug-sensitive TB, but it covers MDR-TB. (Available in other language but not in French)
 Provided in chronological order.