Pathophysiology: Totally drug-resistant tuberculosis (TDR-TB) is a generic term for tuberculosis strains that are resistant to a wider range of drugs than strains classified as Extensively drug-resistant tuberculosis. TDR-TB has been identified in three countries; India, Iran, and Italy. TDR-TB has resulted from further mutations within the bacterial genome to confer resistance, beyond those seen in XDR- and MDR-TB. Development of resistance is associated with poor management of cases.
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. 3,231 deaths in Mexico 2000 (Regional Core Health Data Initiative, Pan American Health Organisation, 2003)
Treatment: Treatment of tuberculosis starts with prevention. In countries where tuberculosis is common, vaccination with the BCG vaccine is often recommended. The BCG vaccine is not commonly used in the U.S. Preventing the spread of tuberculosis and other contagious diseases also includes covering the mouth and nose with an elbow or a tissue when sneezing or coughing. Treatment of tuberculosis also includes ensuring good nutrition and extra rest.
Major Research: Recent observational studies of the ef fectiveness of short treatment regimens for MDR-TB in Niger and Cameroon found that a 12-month regimen was ef fective and well-tolerated in patients not previously exposed to second-line drugs. At least 16 countries in Africa and Asia have introduced shorter regimens as part of trials or observational studies under operational research conditions, and WHO will reassess current guidance on their use in 2016.