Extensively drug resistant tuberculosis (XDR-TB): An overview.

ABSTRACT

Tuberculosis or TB is a common and often deadly infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis in humans. Tuberculosis usually attacks the lungs but can also affect other parts of the body. It is spread through the air, when people who have the disease cough, sneeze, or spit. Most infections in humans result in anasymptomatic, latent infection, and about one in ten latent infections eventually progresses to active disease, which, if left untreated, kills more than 50% of its victims. Extensively drugresistant tuberculosis (XDR TB) is a relatively rare type of multi drug-resistant tuberculosis (MDR TB). It is resistant to almost all drugs used to treat TB, including the two best first-line drugs isoniazid and rifampin. XDR TB is also resistant to the best second-line medications fluoroquinolones and at least one of three injectable drugs (i.e., amikacin, kanamycin, or capreomycin). One in three people in the world is infected with dormant TB germs (i.e. 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 person’s immunity, such as HIV, advancing age, or some medical conditions. TB can usually be treated with a course of four standard, or first-line, anti- TB drugs. If these drugs are misused or mismanaged, multidrug-resistant TB (MDRTB) can develop. MDR-TB takes longer to treat with second-line drugs, which are more expensive and have more side-effects. XDR-TB can develop when these second-line drugs are also misused or mismanaged and therefore also become ineffective. Because XDR-TB is resistant to first- and second-line drugs, treatment options are seriously limited. It is therefore vital that TB control is managed properly. This article presents a brief review of extensively drug-resistant tuberculosis with an emphasis on its various aspects associated i.e. introduction, symptoms, transmission, diagnosis, treatment, vaccines as well as prevention; the article reveals the different approaches in the management of Multi-drug resistant tuberculosis and correlation between XDR-TB as well as HIV/AIDS.