THURSDAY, Aug. 30 (HealthDay News) -- There are alarmingly high levels of extensively drug-resistant tuberculosis in many areas of the world, a new study finds.
Researchers found high rates of resistance to at least one second-line drug (nearly 44 percent) among multidrug-resistant TB patients in eight countries in Africa, Asia, Europe and Latin America. They also found higher-than-expected overall levels of extensively drug-resistant TB.
Multidrug-resistant TB can withstand to at least two first-line drugs: soniazid and rifampicin. Extensively drug-resistant TB is resistant to isoniazid, rifampicin, a fluoroquinolone and a second-line injectable drug.
Fluoroquinolones are a class of antibiotics that include ciprofloxacin, levofloxacin and gatifloxacin.
For the study, samples collected from nearly 1,300 adults with multidrug-resistant TB in Estonia, Latvia, Peru, the Philippines, Russia, South Africa, South Korea and Thailand were tested for resistance to 11 first-line and second-line anti-TB drugs. Overall, in nearly 44 percent of patients, resistance to any second-line drug was detected. Rates ranged from 33 percent in Thailand to 62 percent in Latvia.
Overall, one-fifth of patients had resistance to at least one second-line injectable drug, ranging from 2 percent in the Philippines to 47 percent in Latvia. The overall rate of resistance to a fluoroquinolone was nearly 13 percent, ranging from 7 percent in the Philippines to 32 percent in South Korea.
Extensively drug-resistant TB was found in 6.7 percent of patients overall, with prevalence in South Korea (15 percent) and Russia (11 percent) more than twice the current World Health Organization estimate for the same time period (5.4 percent).
The researchers also found that the risk of extensively drug-resistant TB was more than four times higher in patients previously treated for TB, and that previous treatment with second-line drugs was the s
All rights reserved