Mycobacterium leprae transmission characteristics during the declining stages of leprosy incidence: A systematic review
PLOS Neglected Tropical Diseases·
- DOI
- 10.1371/journal.pntd.0009436
- PMID
- 34038422
- PMCID
- PMC8186771
- OpenAlex
- W3165176481
- Study type
- Systematic review
- Publisher
- Public Library of Science (PLoS)
- Article type
- journal-article
- Integrity
- current
Why this research matters now
The review highlights control strategies (BCG, active case finding, MDT adherence, post-treatment surveillance) associated with substantial incidence declines, and characterizes the profile of cases persisting in low-endemic settings, relevant to leprosy elimination planning.
Structured evidence summary
Research question
The review investigated whether ongoing leprosy transmission in declining-incidence contexts is driven mainly by undiagnosed/untreated new cases or by incompletely treated or relapsing cases.
Study design
A systematic review of the literature conducted via a January 2020 electronic database search, yielding 134 retained articles from 4318 records, with quantitative synthesis of case records (PROSPERO ID: CRD42020178923).
Population and setting
Analysis drew on 3950 leprosy case records across 22 low-endemic countries, supplemented by contextual evidence on incidence decline in multiple settings.
Main findings
About half of cases in low-endemic settings were suspected to be imported, most were multibacillary (64.4%), and 122 suspected relapses were recorded; family history was noted in 18.7%, with other suspected exposures including travel to endemic areas and armadillo contact. Strategies common to countries achieving substantial incidence reductions included BCG vaccination, active case finding, multidrug therapy adherence, and post-treatment surveillance. No country analyzed reported a recent increase in incidence, and suspected relapses or incompletely treated cases did not appear to drive a rise in secondary cases.
Public-health relevance
The review highlights control strategies (BCG, active case finding, MDT adherence, post-treatment surveillance) associated with substantial incidence declines, and characterizes the profile of cases persisting in low-endemic settings, relevant to leprosy elimination planning.
Important limitations
This summary is limited to the supplied single-article abstract and metadata; the original paper is required for decision-grade interpretation, including appraisal of inclusion criteria, data quality, and potential reporting or classification biases across the included studies.
GIDS interpretation
Within the GIDS framework, the article provides background on transmission dynamics, surveillance, and control strategies for leprosy in declining-incidence settings, which could help contextualize future disease signals but does not itself confirm any surveillance finding.
Related GIDS surveillance
Literature context does not validate, explain, or change a surveillance signal. Exact and contextual relationships are shown separately.
Evidence relationships
This article has 10 auditable classifier relationships to diseases, places, topics, and study design.