Comparison of phylogenetic metrics of transmission between symptomatic and asymptomatic tuberculosis in individuals who were incarcerated in Brazil in 2008–24: a retrospective genomic epidemiology study
The Lancet Microbe·
- DOI
- 10.1016/j.lanmic.2026.101407
- PMID
- 42276094
- PMCID
- —
- OpenAlex
- W7164309383
- Study type
- Cohort study
- Publisher
- Elsevier BV
- Article type
- journal-article
- Integrity
- current
Why this research matters now
Exclusive reliance on clinical symptoms for identifying infected persons may overlook a major driver of ongoing dissemination, indicating that systematic screening protocols are essential in congregate environments.
Structured evidence summary
Research question
The investigation examines whether symptomatic and asymptomatic tuberculosis cases differ in their respective contributions to recent pathogen dispersal within a high-transmission environment.
Study design
Researchers conducted a retrospective genomic epidemiology analysis by performing whole-genome sequencing on Mycobacterium tuberculosis isolates and linking the genetic data to existing surveillance records.
Population and setting
The cohort consisted of incarcerated persons in Mato Grosso do Sul, Brazil, specifically focusing on individuals identified through active screening initiatives in three male-only correctional facilities.
Main findings
Genomic transmission metrics demonstrated equivalent dispersal potential between symptomatic and asymptomatic patients, showing no statistically significant variations in clustering rates, evolutionary density, branching indices, or estimated secondary infections. These outcomes indicate that asymptomatic carriers sustain disease spread at levels comparable to symptomatic individuals.
Public-health relevance
Exclusive reliance on clinical symptoms for identifying infected persons may overlook a major driver of ongoing dissemination, indicating that systematic screening protocols are essential in congregate environments.
Important limitations
Generalizability is constrained by the exclusive inclusion of high-quality lineage 4 genomes and participants recruited solely through targeted prison screening programs.
GIDS interpretation
This publication outlines analytical approaches for quantifying pathogen dispersal patterns using phylogenetic modeling and genomic clustering. It provides a reference framework for contextualizing transmission network structures without referencing active monitoring systems.
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 8 auditable classifier relationships to diseases, places, topics, and study design.