Multidrug-Resistant TB

Pathophysiology: TB is the world's leading cause of death from a single infectious organism, killing 2 million people each year. The TB crisis has intensified because multidrug-resistant (MDR) microbes have emerged. An incurable form of the disease may develop from infections caused by these organisms. WHO estimates more than 50 million people worldwide may be infected with MDR strains of TB.

Statistics: Incidence of tuberculosis is the estimated number of new and relapse tuberculosis cases arising in a given year, expressed as the rate per 100,000 population. All forms of TB are included, including cases in people living with HIV. In Japan the incidence of Tuberculosis reported from 2001-2005 is 20 cases, and from 2006-2015 is also reported as 19 cases.

Treatment: Multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis are generally thought to have high mortality rates. However, many cases can be treated with the right combination and rational use of available antituberculosis drugs. Drugs are chosen with a stepwise selection process through five groups on the basis of efficacy, safety, and cost. Drugs in group five should be used in the following order: clofazimine, amoxicillin with clavulanate, linezolid, carbapenems, thioacetazone, then clarithromycin.

Major Research: The characteristics of M. tuberculosis strains analysed showed that MDR strains accumulate additional antibiotic resistances with about 50% of them carrying pyrazinamide resistances. New drugs are under identification using phenotypic screening of chemical libraries and genomic approaches. Drugs used in clinic and new leads provided by partners of the EC NAREB project will be associated to nanocarriers with the aim to increase efficacy and lower side effects.