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COMMENTARY |
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Year : 2014 | Volume
: 7
| Issue : 1 | Page : 2-4 |
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MDR Tuberculosis: Change in the status quo needed
Debebe Shaweno
Health Systems Research and Application Module team School of Public and Environmental Health, College of Medicine and Health Sciences, Hawassa University, Hawassa, Ethiopia
Date of Web Publication | 10-Dec-2013 |
Correspondence Address: Debebe Shaweno School of Public and Environmental Health, College of Medicine and Health Sciences, Hawassa University, P.O. Box 1560, Hawassa Ethiopia
Source of Support: None, Conflict of Interest: None | Check |
How to cite this article: Shaweno D. MDR Tuberculosis: Change in the status quo needed. Med J DY Patil Univ 2014;7:2-4 |
The recent substantial returns in the prevention and treatment of tuberculosis (TB) [1] are now threatened by the emergence of multidrug-resistant (MDR) strains. [2],[3] Today more than half a century after the introduction of the first anti-TB drugs and also almost a century after introduction of Bacille Calmette-Gue΄rin (BCG vaccine), [4] a third of the world's population is infected with mycobacterium tuberculosis (MTB). [1]
Worst of all, an even more alarming threat, an extensively drug-resistant TB (XDR-TB), which is resistant to virtually all highly effective drugs used in second-line therapy is now reported from 84 countries. [1] As a result, presently, there is a fear that TB is sliding inexorably back to the pre antibiotic era, when it was not amenable to drug treatment. [2]
Though drug resistance of MTB was reported soon after the introduction of anti-TB drugs before half a century, [5] interventions to tackle the resistant strains of MTB were anemic.
The evolution of TB is faster than our interventions. Whereas TB has evolved to drug resistant strains (MDR and XDR), the demanding four first-line regimens currently in use were developed more than half a century ago. [4]
In addition, the very low global coverage of drug-susceptibility testing for rifampicin and isoniazid (that only reached 4% for new cases and 6% for previously treated cases [1] in 2011 clearly attests that MDR TB interventions were pale world-wide.
Drug-resistant strains develop due to non-compliance of patients to treatment under the Directly Observed Treatment Short course DOTS program. [4] Consequently, the prevalence of MDR TB is much higher in previously treated individuals compared with new cases. [3] The fact that MDR TB had been found wherever the diagnostic capacity existed to reveal it, [5] verifies the omission of MDR TB case detection in the DOTS strategy. The low prevalence rate of MDR-TB reported from some poor settings is also related to the lack of appropriate diagnostic capacity.
MDR-TB case detection rate is significantly lower. Overall about 19.7% estimated MDR cases were detected and 18% of the estimated cases of MDR TB were enrolled on second-line treatment in the 30 countries with 90% of the global MDR-TB burden, [2] implying the rest 82% either revolving in the community being a source of infection or wrongly being treated with a first line anti-TB drugs.
Those who have not received appropriate treatment or wrongly put on the first line-drugs continue to fuel a global pandemic by adding new strains resistant to most drugs.
In fear of the catastrophic consequences of spread of drug resistant strains, some argue that it is better to not undergo treatment than to undergo incomplete treatment. [4]
Though, it is well-known that previously treated cases are at the most risk of MDR TB, [3] virtually all previously TB treated patients with the current active TB have been put on the basic first-line regimens that are used in the treatment of drug-susceptible TB without testing drug susceptibility in resource poor countries. This not only wastes resources, but also fuels the MDR pandemic, by amplifying the more dangerous resistant strains. [5]
Such patients are given bullets for 6-8 months duration that nonetheless do not kill or prevent multiplication of the strains of MTB in the concentration of the drug that would normally destroy the mycobacterium. These bullets (drugs) however may facilitate transmission of more dangerous drug resistant strains by creating false impression to the patients that the bacillus is cleared by the drugs they are taking. Such patients may not practice necessary precautions to prevent the spread of the resistant strains.
In conclusion should MDR TB be contained drug susceptibility tests are urgently needed. Although it may be difficult to mount drug susceptibility test in resource poor settings for all with active TB, it is a must to mount routine drug susceptibility test for patients at high risk of resistance before initiation of therapy. Now it is time for the DOTS strategy, which advocates sputum microscopy in resource poor setting to be revised in a way that enables the case detection of drug resistant MTB. It is also time for public health specialists to speak out loudly and boldly to protect and ensure the health of the society from MDR and XDR TB.
References | | |
1. | WHO. Global Tuberculosis Report. Geneva: World Health Organization; 2012. |
2. | Falzon D, Jaramillo E, Wares F, Zignol M, Floyd K, Raviglione MC. Universal access to care for multidrug-resistant tuberculosis: An analysis of surveillance data. Lancet Infect Dis 2013;13:690-7. [PUBMED] |
3. | Shao Y, Yang D, Xu W, Lu W, Song H, Dai Y, et al. Epidemiology of anti-tuberculosis drug resistance in a Chinese population: Current situation and challenges ahead. BMC Public Health 2011;11:110. [PUBMED] |
4. | New tactics in the fight against tuberculosis. Available from: http://www.lankanewspapers.com/news/2009/3/40471_space.html. [Last accessed on 2013 Aug 13]. |
5. | Keshavjee S, Farmer PE. Tuberculosis, drug resistance, and the history of modern medicine. N Engl J Med 2012;367:931-6. [PUBMED] |
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