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Extensively Drug Resistant Tuberculosis(XDR-TB)
| Content Provider | Semantic Scholar |
|---|---|
| Author | Narang, Sanjeev |
| Copyright Year | 2009 |
| Abstract | Introduction Extensively drug-resistant tuberculosis (XDR-TB) was first described in March 2006 following a joint survey of laboratories by the WHO, IUATLD, and CDC. The original definition of XDR-TB was revised at the WHO Global Task Force on XDR-TB, October 2006 (1). WHO in February, 2008, showed that the number of cases has reached the highest level ever recorded (2). What is XDR-TB? In 2000, the Stop TB Partnership's Green Light Committee was created to increase access to second line drugs worldwide while ensuring their proper use to prevent increased drug resistance. While assisting MDR TB treatment programs worldwide, and ensuring the proper use of second line drugs in resource limited countries the committee encountered reports of multiple cases of TB with resistance to virtually all second line drugs (3). This led to the emergence of a new terminology in relation to the drug resistant tuberculosis, known as extensively drug resistant tuberculosis (XDR-TB). XDRTB was defined by US CDC and WHO as tuberculosis caused by M. tuberculosis that was resistant not only to isoniazid and rifampicin (MDR-TB) but also to at least three of the six classes of second-line anti-TB drugs (aminoglycosides, polypeptides, fluoroquinolones, thioamides, cycloserine and para-aminosalycilic acid) (4). WHO XDR-TB Task Force Committee gave a muchaccepted definition of XDR-TB which defines it as "resistance to at least rifampicin and isoniazid among the first line-anti tubercular drugs in addition to resistance to any fluroquinolones i.e. ofloxacin, ciprofloxacin and levofloxacin, and at least one of three injectable second line anti tubercular drugs i.e. amikacin, kanamycin and capreomycin (1). Magnitude of the Problem Prevalence of XDR-tuberculosis cases is notably high in eastern Europe, sub-Saharan Africa and Asia (5). In one study the prevalence of XDR-TB among all MDRTB patients was 6.6% overall worldwide,6.5% in industrialized countries, 13.6% in Russia and Eastern Europe, 1.5% in Asia, 0.6% in Africa and Middle East, 15.4% in Republic of Korea. As of June 2008, a total of 49 countries worldwide reported to the World Health Organization (WHO) at least one case of extensively drug-resistant tuberculosis (6). Mechanism of resistance in XDR-TB (7) The basis of tuberculosis drug resistance is the selection of bacterial mutants with innate resistance to chemotherapy.Acquired and amplified drug resistance is the primary means by which tuberculosis drug-resistant strains have been generated.However, the key determinant that has led to the exponential rise in XDRtuberculosis cases is likely to have been transmitted resistance. |
| Starting Page | 102 |
| Ending Page | 103 |
| Page Count | 2 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://www.jkscience.org/archive/vol112/16Horizons-Extensively%20drug%20resistant%20tuberculosis.pdf |
| Volume Number | 11 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
