THURSDAY, Sept. 20 (HealthDay News) -- Adding the antibiotic moxifloxacin to the standard combination of drugs used to treat highly contagious tuberculosis (TB) could help reduce the time needed to cure patients from six months to four, say American and Brazilian researchers.

Their study of more than 170 people in Rio de Janeiro found that adding moxifloxacin increased by 17 percent the number of patients who cleared active TB infections from their lungs after two months of treatment (raising cure rates to 85 percent from 68 percent), compared to patients taking the standard combination with an older antibiotic called ethambutol.

The findings were to be presented this week at the Interscience Conference on Antimicrobial Agents and Chemotherapy in Chicago.

"This is the most compelling evidence in nearly 25 years that a novel antibiotic drug combination works better than the current gold standard at curing active TB infection," study senior author Dr. Richard E. Chaisson, a professor of medicine, epidemiology and international health at the Johns Hopkins University School of Medicine, said in a prepared statement.

"Beyond the obvious value of healing patients more quickly, a shorter treatment time could also cut down on transmission of the disease to others and make it easier for health care workers worldwide, who are overwhelmed by large numbers of patients, to treat more people and to treat them faster," said Chaisson, the founding director of Hopkins' Center for Tuberculosis Research.

Each year, more than 9 million new TB cases are diagnosed worldwide. and more than 1.5 million people die from the disease.

More information

The American Academy of Family Physicians has more about TB.