Tuesday, March 23, 2010

World TB Day

March 24 is World TB Day. Tomorrow marks the 128th anniversary of the discovery of Mycobacterium tuberculosis, the bacterium that causes tuberculosis, by the German physician and microbiologist Robert Koch.
Tuberculosis has largely faded from public consciousness in the United States. Annually there are now fewer than 13,000 cases of TB and fewer than 1,000 deaths in the U.S., less than half of the TB burden 30 years ago. But in developing nations, TB is more dangerous than ever, where multidrug-resistant (MDR) strains drain medical and economic resources and kill millions of people.

Last week, the World Health Organization (WHO) published a new report on multidrug- and extensively drug-resistant TB, reporting 440,000 cases of MDR-TB worldwide in 2008. In total, there were 9.4 million new TB cases and 1.8 million TB deaths in 2008.

MDR-TB is defined as a strain of tuberculosis that is resistant to at least isoniazid and rifampicin, two first-line TB drugs. It can develop in an individual patient when drugs are misused – as is common with TB treatments because they require months of administration – or when a resistant strain is passed between people. MDR-TB takes longer to treat than drug-susceptible infections, and it also costs a lot more to treat: up to $5,000 per case, compared to $20 for susceptible TB. The WHO reports that in some regions MDR-TB makes up more than a quarter of new TB diagnoses, and almost half of all cases come from China and India. Mistreatment of MDR-TB can lead to an even more dangerous and costly condition, extensively drug-resistant (XDR) tuberculosis, which is resistant to both first- and second-line treatments.

With resistant TB strains persisting and representing a growing share of new diagnoses, development of new treatments is essential. Last week, the Global Alliance for TB Drug Development, the Critical Path Institute and the Bill & Melinda Gates Foundation announced a new initiative that aims to make these treatments available sooner. The Critical Path to TB Drug Regimens will test combinations of early development TB drugs from a range of pharmaceutical companies, including Johnson & Johnson, Pfizer and GlaxoSmithKline in an attempt to identify the best possible treatment regimens coming out of the pipeline (read the press release here). This could drastically reduce the time to market for these drug regimens, but in order for new drugs to remain effective they must be used in a way that prevents the development of resistance. The U.S. battle with TB may be winding down, but it is only intensifying worldwide.

See the CDC website for information on World TB Day activities as well as e-Cards to spread TB awareness.

Image courtesy of www.cdc.gov

No comments:

Post a Comment