Treatment for latent tuberculosis infection in low- and middle-income countries: progress and challenges with implementation and scale-up.

Introduction: Treatment of latent tuberculosis infection (LTBI) is a crucial but neglected component of global tuberculosis control. The 2018 United Nations High-Level Meeting committed world leaders to provide LTBI treatment to at least 30 million people, including 4 million children<5 years, 20 million other household contacts and 6 million HIV-infected people by 2022.Areas covered: This review searched MEDLINE between 1990 and 2019 and discussed: i) high-risk groups to be prioritized for diagnosis and treatment of LTBI; ii) challenges with diagnosing LTBI in programmatic settings; iii) LTBI treatment options including isoniazid monotherapy, shorter regimens (rifampicin-monotherapy, rifampicin-isoniazid and rifapentine-isoniazid) and treatments for contacts of drug-resistant patients; iv) issues with programmatic scale-up of treatment including policy considerations, ruling out active TB, time to start treatment, safety, uninterrupted drug supplies and treatment adherence; and v) recording and reporting.Expert opinion: In 2017, <1.5 million persons were reported to be treated for LTBI. This must rapidly increase to 6 million persons annually. If HIV programs focus on HIV-infected people already accessing or about to start antiretroviral therapy and TB programs focus on household contacts, these targets could be achieved. Isoniazid remains the current treatment of choice although shorter courses of rifapentine-isoniazid are possible alternatives.