The effect of treatment on PCR conversion varied according to geographic region : in Brazil , the odds ratio for PCR conversion was @ ( @ % CI , @ to @ ) at @ years and @ ( @ % CI , @ to @ ) at @ or more years ; in Colombia and El Salvador , the odds ratio was @ ( @ % CI , @ to @ ) at @ years and @ ( @ % CI , @ to @ ) at @ or more years ; and in Argentina and Bolivia , the odds ratio was @ ( @ % CI , @ to @ ) at @ years and @ ( @ % CI , @ to @ ) at @ or more years ( P < @ for interaction ) .