The paradigm shift in the approach to management of latent tuberculosis infection in high tuberculosis burden countries

ABSTRACT

Introduction: Addressing the reservoir of Latent Tuberculosis Infection (LTBI) is critical to TB elimination because if left untreated LTBI can progress to active TB disease. This additional burden can prevent achieving the global targets of TB elimination. Management of LTBI has been a low priority target for National TB Elimination Programs (NTEP) due to various challenges in the field settings.

Areas covered: This article reviews the most recent advances in the field of LTBI management including newer diagnostics, treatments, vaccines, programmatic challenges, and gaps and suggests a way forward that can be adopted by NTEPs for LTBI. We searched the electronic databases of PubMed, Scopus, and Web of Science for studies published between 2010 to 2020 using MeSH terms: Latent TB Diagnosis, TB preventive therapy, Vaccines, LTBI, and HIV/ COVID.

Expert opinion: NTEPs of developing countries should offer a better, point-of-care diagnostic, and effective treatment for LTBI to reduce the number of new TB cases arising from people infected with M.tb. Awareness about LTBI should be increased among the health system staff and the public. More funding is needed to advance research as well as implement the newer findings in the NTEP to achieve the End TB targets by 2035.

KEYWORDS:

• Latent TB infection
• preventive therapy
• shorter regimen
• drug resistant TB
• diagnosis of LTBI
• vaccine

Article highlights

• Good point-of-care diagnostic test with high specificity is essential to scale up TPT to all high-risk groups of the population. Tests that differentiate the TB spectrum and better predict future TB risk are needed.

• Treatment of LTBI is only one component of the TB prevention effort. Airborne infection control practices at health care facilities and congregate settings, cough etiquette, etc require more attention to reduce TB transmission.

• Development and widespread use of a safe and effective TB prevention vaccine, either POD or POI, will pave way for remarkable transformation in the field of TB prevention.

• Preventive treatment can be individualized and targeted to high-risk contacts in case of contacts of MDR TB patients.

• Social factors like over-crowding and indoor air pollution, Co-morbid conditions like malnutrition, and diabetes mellitus besides immunodeficient conditions. A complete package for LTBI strategy needs to be developed with community engagement for demand generation, patient literacy, and address factors like stigma and awareness for implementing a successful plan for ending TB in the country.

Acknowledgments

We acknowledge all the authors and their team of all the publications used to write this review article on Latent TB infection. We also acknowledge the efforts of the Programme Managers involved in scaling up LTBI management in the field settings for sharing their thoughts and inputs while drafting this manuscript.

Declaration of interest

Disclosure Statement: The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.