The effect of treatment on PCR conversion varied according to geographic region : in Brazil , the odds ratio for PCR conversion was 3.03 ( 95 % CI , 2.12 to 4.34 ) at 2 years and 1.87 ( 95 % CI , 1.33 to 2.63 ) at 5 or more years ; in Colombia and El Salvador , the odds ratio was 1.33 ( 95 % CI , 0.90 to 1.98 ) at 2 years and 0.96 ( 95 % CI , 0.63 to 1.45 ) at 5 or more years ; and in Argentina and Bolivia , the odds ratio was 2.63 ( 95 % CI , 1.89 to 3.66 ) at 2 years and 2.79 ( 95 % CI , 1.99 to 3.92 ) at 5 or more years ( P < 0.001 for interaction ) .