Abstract
The interruption of centuries of decline in case rates of Tuberculosis (TB) occurred, in most cases, in the late 1980s and involved industrialized countries due to increased poverty in urban settings and the immigration from TB high-burden countries. Thus, no sustainable control of TB epidemics can be reached in any setting without properly addressing the global epidemic.
A considerable rate of deaths from TB has been attributed to co-infection with Mycobacterium tuberculosis and Human Immunodeficiency Virus (TB-HIV). Immune deficient patients with HIV are at increased risk of latent M. tuberculosis infections (LTBI) progressing to active disease and being transmitted to others represents a considerable reservoir of bacilli. In addition, more than a half of the new TB cases are potentially MDR-TB “super strains” in the hot zones, such as the “BRICS” countries (Brazil, the Russian Federation, India, China and South Africa). MDR-TB strains, an airborne bacterium that is spread just as easily as drug-sensitive TB, are resistant to at least three of the four main drugs used to treat TB. Likewise, it has been reported the emergence of extensively drug-resistant (XDR) TB cases, defined as cases in persons with TB whose isolates are resistant to isoniazid and rifampicin (MDR-TB) as well as resistant to any one of the fluoroquinolone drugs and to at least one of the three injectable second-line drugs, Amikacin, Kanamycin or Capreomycin. XDR-TB is widespread raising the prospect of virtually incurable TB worldwide, such as the novel Total Drug-Resistant (TDR) TB strains found in India, Italy and Iran. The factors that most influence the emergence of drug-resistant strains include inappropriate treatment regimens, and patient noncompliance in completing the prescribed courses of therapy due to the lengthy standard “short-course” treatment or when the side effects become unbearable.
Citation
Antas PRZ. The Brazilian Experience on BCG Immunization and the Development of New Vaccines against Tuberculosis. SM Vaccine Vaccin. 2015;1(1):1002.