The fourth national anti-tuberculosis drug resistance survey in Peru

BACKGROUND: Peru has one of the highest burdens of multidrug-resistant tuberculosis (MDR-TB), but universal drug susceptibility testing (DST) has not yet been achieved. OBJECTIVE: To estimate the proportion of drug resistance among smear-positive TB patients in Peru. DESIGN: From September 2014 to March 2015, we performed a national drug resistance survey of patients aged >= 15 years; TB was diagnosed based on sputum smear positivity. We performed DST at the National Reference Laboratory of the Peruvian National Institute of Health, Lima, Peru, using the proportion method in Middlebrook 7H10 agar for four first-line drugs and six second-line drugs, and the Wayne method for pyrazinamide. RESULTS: Of the 1908 new and 272 previously treated patients included in the analysis, 638 (29.3%) patients had resistance to at least one first-line drug. MDR-TB was diagnosed in 7.3% of new and 16.2% of previously treated patients (P < 0.001). There were five (0.2%) patients with extensively drug-resistant TB. CONCLUSION: MDR-TB has increased to 7.3% in new patients from 5.3% in the previous survey, indicating that resistance to anti-tuberculosis drugs is increasing in Peru. Ongoing community transmission of resistant strains highlights an urgent need for early diagnosis, optimised treatment and effective contact tracing of MDR-TB patients.