Investment case concepts in leprosy elimination: A systematic review

Leprosy continues to be a global public health problem, but draws less attention because 'prevalence based elimination' has been misinterpreted as eradication. The ongoing transmission of M. leprae has renewed interest in complete elimination. The aim of our study is to review systematically the literature regarding the elimination of leprosy, and to assess this information on its applicability for defining a Leprosy Elimination Investment Case (LEIC) based on Eradication Investment Case guidelines.

A literature search was conducted using the MeSH subheadings and synonyms of leprosy. A total of 1007 articles were considered and 112 were included in the final selection. The search focused on the literature covering leprosy elimination and its public health aspects. The LEIC framework was adapted from an existing "Guide to Preparing an Eradication Investment Case".

The LEIC framework provided 11 topics under which information was synthesized from the literature. The fields were categorised under sections: 1) Proposed investment; 2) Rationale for investing; 3) Issues to consider when moving from control to eradication; 4) Management and governance. Scanty quantitative data are available for developing a LEIC, particularly regarding disease burden, and new interventions that could contribute to elimination are not yet applied routinely.

For monitoring global elimination, it is necessary to measure disease burden comprehensively, and contact centered preventive interventions should be part of a global elimination strategy. The biological and technical feasibility of elimination is not certain and advanced microbiological and operational research is necessary to understand transmission better. The current WHO road map for leprosy elimination is too vague and needs further structuring through a thoroughly prepared LEIC.