Drug-Resistant TB on the Rise

27 March 2000 7:00 pm

Once thought easy prey for antibiotics, tuberculosis fought back in the 1980s and now kills more than 2 million people a year--second only to HIV among infectious diseases. Especially frightening is the appearance of strains resistant to the few drugs that, when taken together, normally cure TB. On 24 March, the World Health Organization (WHO) reported that resistance is rampant, and spreading. "This report confirms our worst fears," WHO Director-General Gro Harlem Brundtland said in a statement.

Normal TB, as well as strains resistant to just one drug, can be cured by a cheap and highly effective 6-month regimen of four drugs--a method that appears to thwart the development of resistance. But to combat multidrug-resistant strains, clinicians rely on second-line drugs that are less effective and more expensive.

WHO and several partners began their first survey of drug-resistant TB in 1994. Now the first indication of trends in multiple-drug resistance (MDR) comes from a follow-up study, released at the Ministerial Conference on TB and Sustainable Development in Amsterdam. Of the 28 regions from a 1997 WHO survey, resistance has increased since 1996 in three: by 50% both in Germany (to 10.3% of cases) and Denmark (to 13.1% of cases) and by more than 100% in New Zealand (to 12%). Officials attribute these rises mainly to immigration; foreign-born TB patients are almost twice as likely as natives to harbor a drug-resistant strain. WHO found 12 hot spots around the world where 5% of TB patients previously treated for TB now have multidrug-resistant strains (the median is 1%). The situation is the worst in Estonia, where 37.8% of these cases are multidrug-resistant.

Drug-resistant TB strains are thought to develop when erratic medication schedules allow mutated bacteria to stage a comeback. But in an alarming trend, the WHO report identifies five regions with a high prevalence (more than 5%) of MDR in first-time TB patients--a sign that resistant strains are spreading. Those hot spots are Henan Province in China, Latvia, the Ivanovo and Tomsk regions in Russia, and Iran. In Estonia, the percentage has climbed from 10.2% in 1994 to 14.1% in 1998.

In other news, on 24 March the Bill and Melinda Gates Foundation announced it was giving $25 million to a new consortium of foundations, international organizations, and pharmaceutical companies called the Global Alliance for TB Drug Development. And more help may be on the way. The same day, U.S. Representatives Sherrod Brown (D-OH) and Connie Morella (R-MD) introduced a measure to boost spending on TB from $35 million to $100 million to establish effective TB programs, especially in nations that suffer most from the disease.

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