Multidrug-Resistant TB

Pathophysiology: The bacteria that cause TB can develop resistance to the antimicrobial drugs used to cure the disease. Multidrug-resistant TB (MDR-TB) is TB that does not respond to at least isoniazid and rifampicin, the two most powerful anti-TB drugs. it is becoming increasingly difficult to treat MDR-TB. Treatment options are limited and expensive, recommended medicines are not always available, and patients experience many adverse effects from the drugs.

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 Israel the incidence of Tuberculosis reported from 2001-2005 is 6 cases, and from 2006-2015 is also reported as 6 cases.

Treatment: The treatment and prognosis of MDR-TB are much more akin to those for cancer than to those for infection. Treatment of MDR-TB must be done on the basis of sensitivity testing: it is impossible to treat such patients without this information. When treating a patient with suspected MDR-TB, pending the result of laboratory sensitivity testing, the patient should be started on SHREZ (Streptomycin+isonicotinyl Hydrazine+Rifampicin+Ethambutol+pyraZinamide)+moxifloxacin+cycloserine.

Major Research: Several new TB treatment regimens for drug-susceptible and/or drug-resistant TB are being tested in Phase II or Phase III trials; at least two more trials are scheduled to start towards the end of 2015 or in early 2016. " WHO has issued interim guidance on the use of bedaquiline (in 2013) and delamanid (in 2014).