Multidrug-resistant tuberculosis (MDR-TB) is a form of tuberculosis (TB) infection caused by bacteria that are resistant to treatment with at least two of the most powerful first-line anti-TB medications (drugs): isoniazid and rifampin. Some forms of TB are also resistant to second-line medications, and are called extensively drug-resistant TB (XDR-TB).Tuberculosis is caused by infection with the bacterium Mycobacterium tuberculosis. Almost one in four people in the world are infected with TB bacteria. Only when the bacteria become active do people become ill with TB. Bacteria become active as a result of anything that can reduce the persons immunity, such as HIV, advancing age, diabetes or other immunocompromising illnesses. TB can usually be treated with a course of four standard, or first-line, anti-TB drugs (i.e., isoniazid, rifampin, pyrazinamide and ethambutol).However, beginning with the first antibiotic treatment for TB in 1943, some strains of the TB bacteria developed resistance to the standard drugs through genetic changes (see mechanisms.) Currently the majority of multidrug-resistant cases of TB are due to one strain of TB bacteria called the Beijing lineage. This process accelerates if incorrect or inadequate treatments are used, leading to the development and spread of multidrug-resistant TB (MDR-TB). Incorrect or inadequate treatment may be due to use of the wrong medications, use of only one medication (standard treatment is at least two drugs), or not taking medication consistently or for the full treatment period (treatment is required for several months).
have noted that wide-scale interventions have not had their desired effect, especially with regard to the spread of drug-resistant strains of TB. Contributing factors
There are several elements of the Russian prison system that enable the spread of MDR-TB and heighten its severity. Overcrowding in prisons is especially conducive to the spread of tuberculosis; an inmate in a prison hospital has (on average) 3 meters of personal space, and an inmate in a correctional colony has 2 meters. Specialized hospitals and treatment facilities within the prison system, known as TB colonies, are intended to isolate infected prisoners to prevent transmission; however, as Ruddy et al. demonstrate, there are not enough of these colonies to sufficiently protect staff and other inmates. Additionally, many cells lack adequate ventilation, which increases likelihood of transmission. Bobrik et al. have also noted food shortages within prisons, which deprive inmates of the nutrition necessary for healthy functioning.Comorbidity of HIV within prison populations has also been shown to worsen health outcomes. Nachega & Chaisson articulate that while HIV-infected prisoners are not more susceptible MDR-TB infection, they are more likely to progress to serious clinical illness if infected. According to Stern, HIV infection is 75 times more prevalent in Russian prison populations than in the civilian population. Therefore, prison inmates are both more likely to become infected with MDR-TB initially and to experience severe symptoms because of previous exposure to HIV. Shin et al. emphasize another factor in MDR-TB prevalence in Russian prisons: alcohol and substance use. Ruddy et al.