Low incidence of rifampicin-resistant tubercle bacilli.

In a six-year survey 10(0.15%) of 6849 patients with European names and 31 (1.0%) of 3079 patients with non-European names yielded cultures of Mycobacterium tuberculosis that were resistant to rifampicin. Only two of each group had organisms resistant to rifampicin alone. Resistance to one or more other antituberculous drugs was found in eight of the European and 29 of the non-European group. Two patients in each group were known to have received treatment for the first time in the United Kingdom; 17 of the non-Europeans were known to have been treated abroad; precise information was not available for the other 12. The overall six-year incidence of patients with rifampicin-resistant M tuberculosis was only 0.41%. The very low incidence among Europeans is probably the result of stricter regimens than are possible in some other areas.