Stepwise implementation of a new diagnostic algorithm for multidrug-resistant tuberculosis in Haiti

Abstract

SETTING: The uptake of tests endorsed by the World Health Organization to detect and appropriately confirm multidrug-resistant tuberculosis (MDR-TB) in low-income countries remains insufficient. OBJECTIVE: To validate the implementation of line-probe assays (LPA) and liquid culture to develop an algorithm to detect MDR-TB in the challenging setting of Haiti. METHODS: Through an EXPAND-TB (Expanding Access to New Diagnostics for TB) partnership, proficiency testing and validation of 221 acid-fast bacilli positive specimens were performed. Sensitivity, cost and processing time were analysed. RESULTS: Using liquid vs. solid culture shortened the turnaround time from 54 to 19 days, with a sensitivity of 100% vs. 98.6% and a total cost reduction of 13%. LPA detected all TB and MDR-TB cases at a lower cost than culture, in a mean time of 7.5 days. CONCLUSION: The combined use of molecular and liquid culture techniques accelerates the accurate diagnosis of TB and susceptibility testing against first-line drugs in a significantly shorter time, and is less expensive. The implementation of this new algorithm could significantly and accurately improve the screening and treatment follow-up of patients affected with TB and MDR-TB.