Extensively drug-resistant tuberculosis

(Redirected from XDR-TB)
Jump to navigation Jump to search

WikiDoc Resources for Extensively drug-resistant tuberculosis

Articles

Most recent articles on Extensively drug-resistant tuberculosis

Most cited articles on Extensively drug-resistant tuberculosis

Review articles on Extensively drug-resistant tuberculosis

Articles on Extensively drug-resistant tuberculosis in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Extensively drug-resistant tuberculosis

Images of Extensively drug-resistant tuberculosis

Photos of Extensively drug-resistant tuberculosis

Podcasts & MP3s on Extensively drug-resistant tuberculosis

Videos on Extensively drug-resistant tuberculosis

Evidence Based Medicine

Cochrane Collaboration on Extensively drug-resistant tuberculosis

Bandolier on Extensively drug-resistant tuberculosis

TRIP on Extensively drug-resistant tuberculosis

Clinical Trials

Ongoing Trials on Extensively drug-resistant tuberculosis at Clinical Trials.gov

Trial results on Extensively drug-resistant tuberculosis

Clinical Trials on Extensively drug-resistant tuberculosis at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Extensively drug-resistant tuberculosis

NICE Guidance on Extensively drug-resistant tuberculosis

NHS PRODIGY Guidance

FDA on Extensively drug-resistant tuberculosis

CDC on Extensively drug-resistant tuberculosis

Books

Books on Extensively drug-resistant tuberculosis

News

Extensively drug-resistant tuberculosis in the news

Be alerted to news on Extensively drug-resistant tuberculosis

News trends on Extensively drug-resistant tuberculosis

Commentary

Blogs on Extensively drug-resistant tuberculosis

Definitions

Definitions of Extensively drug-resistant tuberculosis

Patient Resources / Community

Patient resources on Extensively drug-resistant tuberculosis

Discussion groups on Extensively drug-resistant tuberculosis

Patient Handouts on Extensively drug-resistant tuberculosis

Directions to Hospitals Treating Extensively drug-resistant tuberculosis

Risk calculators and risk factors for Extensively drug-resistant tuberculosis

Healthcare Provider Resources

Symptoms of Extensively drug-resistant tuberculosis

Causes & Risk Factors for Extensively drug-resistant tuberculosis

Diagnostic studies for Extensively drug-resistant tuberculosis

Treatment of Extensively drug-resistant tuberculosis

Continuing Medical Education (CME)

CME Programs on Extensively drug-resistant tuberculosis

International

Extensively drug-resistant tuberculosis en Espanol

Extensively drug-resistant tuberculosis en Francais

Business

Extensively drug-resistant tuberculosis in the Marketplace

Patents on Extensively drug-resistant tuberculosis

Experimental / Informatics

List of terms related to Extensively drug-resistant tuberculosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Extensively drug-resistant tuberculosis (XDR-TB) is defined as tuberculosis that has evolved resistance to rifampicin and isoniazid (resistance to these first line anti-TB drugs defines Multi-drug-resistant tuberculosis, or MDR-TB), as well as to any member of the quinolone family and at least one of the following second-line TB treatments: kanamycin, capreomycin, or amikacin.[1] The old case definition of XDR-TB is MDR-TB that is also resistant to three or more of the six classes of second-line drugs.[2] This definition should no longer be used, but is included here because many older publications refer to it.

The principles of treatment for MDR-TB and for XDR-TB are the same. The main difference is that XDR-TB is associated with a much higher mortality rate than MDR-TB, because of a reduced number of effective treatment options.[2] The epidemiology of XDR-TB is currently not well studied, but it is believed that XDR-TB does not transmit easily in healthy populations, yet is capable of causing epidemics in populations which are already stricken by HIV and therefore more susceptible to TB infection.[3]

Epidemiology of drug-resistant TB

A 1997 survey of 35 countries found mortality rates above 2% in about a third of the countries surveyed. The highest rates were in the former USSR, Argentina, India and China, and was associated with poor or failing national tuberculosis control programs. Likewise, the appearance of high rates of MDR-TB in New York city in the early 1990s was associated with the dismantling of public health programmes.[4][5]

MDR-TB strains appear to be less fit and less transmissible.[6] It has been known for many years that INH-resistant TB is less virulent in guinea pigs, and the epidemiological evidence is that MDR strains of TB do not dominate naturally. A study in Los Angeles found that only 6% of cases of MDR-TB were clustered. MDR-TB has a mortality rate comparable to lung cancer. People who have weakened immune systems (because of diseases such as HIV or because of drugs) are more susceptible to catching TB.

South African epidemic

Since late 2006, there has been an epidemic of XDR-TB in South Africa. The outbreak was first reported as a cluster of 53 patients in a rural hospital in KwaZulu-Natal of whom 52 died.[3] What was particularly worrisome was that the median survival from sputum specimen collection to death was only 16 days and that the majority of patients had never previously received treatment for tuberculosis. This is the epidemic for which the acronym XDR-TB was first used, and although TB strains that fulfill the current definition have been identified retrospectively,[7][8] this was the largest group of linked cases ever found. Since the initial report in September 2006,[9] cases have now been reported in most provinces in South Africa. As of 16 March 2007, there were 314 cases reported, with 215 deaths.[10] It is clear that the spread of this strain of TB is closely associated with a high prevalence of Aids and poor infection control; in other countries where XDR-TB strains have arisen, drug resistance has arisen from mismanagement of cases or poor patient compliance with drug treatment instead of being transmitted from person to person.[11] This strain of TB does not respond to any of the drugs currently available in South Africa for first- or second-line treatment. It is now clear that the problem has been around for much longer than health department officials have suggested, and is far more extensive.[12] By 23 November 2006, 303 cases of XDR-TB had been reported, of which 263 were in KwaZulu-Natal.[13] Serious thought has been put to isolation procedures that may deny some patients their mobility. This has been seen as unconstitutional by the government and patients come and go as they see fit. The few that do get quarantined start riots and stone security guards. Quarantining patients is necessary to prevent further spread of this strain of TB.[14]



See also

References

  1. World Health Organisation. "WHO Global Task Force outlines measures to combat XDR-TB worldwide". Retrieved 2006-10-21.
  2. 2.0 2.1 Center for Disease Control (2006). "Emergence of Mycobacterium tuberculosis with Extensive Resistance to Second-Line Drugs — Worldwide, 2000–2004". MMWR Weekly. 55 (11): 301&ndash, 305.
  3. 3.0 3.1 Sarah McGregor. "New TB strain could fuel South Africa AIDS toll". Reuters. Retrieved 2006-09-17.
  4. Frieden TR, Sterling T, Pablos-Mendez A; et al. (1993). "The emergence of drug-resistant tuberculosis in New York City". N Engl J Med. 328 (8): 521&ndash, 56. PMID 8381207.
  5. Laurie Garrett (2000). Betrayal of trust: the collapse of global public health. New York: Hyperion. pp. 268ff. ISBN 0786884407 Check |isbn= value: checksum (help).
  6. Iseman MD (1994). "Evolution of drug-resistant tuberculosis: a tale of two species". Proc. Natl. Acad. Sci. U.S.A. 91 (7): 2428–9. PMID 8146134. Free Full Text.
  7. Shah NS, Wright A, Drobniewski F; et al. (2005). "Extreme drug resistance in tuberculosis (XDR-TB): global survey of supranational reference laboratories for _Mycobacterium tuberculosis_ with resistance to second-line drugs". Int J Tuberc Lung Dis. 9(Suppl 1): S77.
  8. Centers for Diseases Control (2006). "Emergence of Mycobacterium tuberculosis with extensive resistance to second-line drugs-worldwide, 2000-2004". Morb Mort Wkly Rep. 55: 301&ndash, 5.
  9. Gandhi NR, Moll A, Sturm AW; et al. (2006). "Extensively drug-resistant tuberculosis as a cause of death in patients co-infected with tuberculosis and HIV in a rural area of South Africa". Lancet. 368: 1575&ndash, 80. line feed character in |title= at position 90 (help)
  10. Angela Quintal. "314 XDR-TB cases reported in SA". Cape Times. Retrieved 2007-04-04.
  11. Migliori GB, Ortmann J, Girardi E; et al. (2007). "Extensively drug-resistant tuberculosis, Italy and Germany". 13 (5).
  12. Sidley P. (2006). "South Africa acts to curb spread of lethal strain of TB". Brit Med J. 333: 825.
  13. News24. "300+ cases of killer TB in SA". Retrieved 2006-11-23.
  14. Singh JA, Upshur R, Padayatchi N. (2007). "XDR-TB in South Africa: No Time for Denial or Complacency". PLoS Med. 4 (1): e50. doi:10.1371/journal.pmed.0040050.

External links

Template:Jb1 Template:WH Template:WS