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

Area of Science:

• Clinical diagnostics
• Microbiology
• Public health

Background:

• The uptake of World Health Organization-endorsed tests for multidrug-resistant tuberculosis (MDR-TB) detection is insufficient in low-income countries.
• Accurate and timely diagnosis of MDR-TB is critical for effective patient management and disease control.

Purpose of the Study:

• To validate the implementation of line-probe assays (LPA) and liquid culture for MDR-TB detection in Haiti.
• To develop and assess a diagnostic algorithm for MDR-TB in a resource-limited setting.

Main Methods:

• Proficiency testing and validation of 221 acid-fast bacilli positive specimens through the EXPAND-TB partnership.
• Analysis of sensitivity, cost, and processing time for liquid culture and LPA.
• Comparison of turnaround times between liquid and solid culture methods.

Main Results:

• Liquid culture shortened turnaround time from 54 to 19 days with 100% sensitivity compared to 98.6% for solid culture, reducing costs by 13%.
• Line-probe assays (LPA) detected all tuberculosis (TB) and MDR-TB cases.
• LPA offered a lower cost and faster detection time (mean 7.5 days) compared to culture.

Conclusions:

• The combined use of molecular (LPA) and liquid culture techniques accelerates accurate TB and MDR-TB diagnosis and susceptibility testing.
• This integrated approach is more cost-effective and significantly reduces diagnostic turnaround time.
• Implementation of this algorithm can substantially improve patient screening and treatment follow-up for TB and MDR-TB.