Preventive therapy for contacts of multidrug-resistant tuberculosis : a Delphi survey

Several outbreaks of multidrug resistant tuberculosis (MDR-TB) have recently occurred in which healthcare workers and others have become infected. Given the lack of clinical data to guide preventive therapy for such contacts, a Delphi survey of a panel of 31 TB therapy experts was undertaken to identify a consensus regimen. An initial questionnaire presented three scenarios describing persons with significant exposure to MDR-TB and with new tuberculin skin test reactions > 15 mm (except one anergic patient) without evidence of disease. Panelists were asked to suggest possible preventive therapy regimens. During a second round survey, the panel members were asked to review the suggested regimens provided for each scenario and to rank them from one to nine as extremely inappropriate to extremely appropriate. Results of this second survey were tabulated and shared with the members of the panel who were then asked to rerank each regimen in light of the previous cumulative panel responses. No specific regimen achieved initial positive consensus by predefined criteria. In two of the three scenarios the no treatment option, however, was deemed clearly inappropriate. The data were also analyzed by what percentage of respondents who ranked a regimen as at all appropriate (ie, six or more on the nine point scale). For scenarios involving a nurse, an HIV-positive tuberculin reactor, and a patient who was anergic HIV-positive, treatment with pyrazinamide 1,500 mg daily with ciprofloxacin 750 mg twice a day for 4 months received a somewhat appropriate rating from more than 50 percent of respondents. The management of persons exposed to and infected by patients with MDR-TB has become a serious problem in the context of MDR-TB outbreaks. This panel of experts agreed that some form of preventive therapy was warranted; however, they were not able to reach defined consensus on what regimen should be used, although a regimen of pyrazinamide 1,500 mg daily with ciprofloxacin 750 mg twice a day for 4 months was considered somewhat appropriate. Clinical data on the efficacy of alternative preventive therapy regimens for such contacts are urgently needed.