Isoniazid-monoresistant tuberculosis in France: risk factors, treatment outcomes and adverse events.

Abstract Objectives Isoniazid-monoresistant tuberculosis (HR-TB) is the most prevalent form of drug-resistant TB worldwide and in France and is associated with poorer treatment outcomes compared to drug-susceptible TB (DS-TB). The objective of this study was to determine the characteristics of HR-TB patients in France and to compare outcomes and safety of treatment for HR-TB and DS-TB. Methods A case-control multicentre study was performed to identify risk factors associated with HR-TB and to compare treatment outcomes and safety among HR-TB patients and DS-TB patients. Results Characteristics of 99 HR-TB diagnosed and treated in university hospitals of Paris, Lille, Caen and Strasbourg were compared to 99 DS-TB’s. Female sex (OR = 2.2; 1.0-4.7), birth in the West-Pacific WHO region (OR = 4.6; 1.1-18.7) and resistance to streptomycin (OR = 77.5; 10.1-594.4) were found to be independently associated with HR-TB. Rates of treatment success did not differ significantly between HR-TB and DS-TB. Conclusions Factors associated with HR-TB are not relevant enough to efficiently screen TB patients at risk of HR-TB. The systematic implementation of rapid molecular testing on clinical samples remains the only effective way to make the early diagnosis of HR-TB and adapt the treatment.