Boston University's Center for Global Health & Development (CGHD)’s work is driven by a deep commitment to use the power of science to promote social change and improve the health of populations worldwide. The CGHD’s faculty and professional staff currently manage more than 50 research projects and programs in over 20 countries. The Opti-Q study will determine the levofloxacin dose and exposure that achieve the greatest reduction in TB bacterial burden with acceptable tolerability by studying 100 adults with MDR-TB at sites in Peru and South Africa.