Case-control investigation of invasive Salmonella disease in Malawi reveals no evidence of environmental or animal transmission of invasive strains, and supports human to human transmission
PLOS Neglected Tropical Diseases·
- DOI
- 10.1371/journal.pntd.0010982
- PMID
- 36508466
- PMCID
- PMC9779717
- OpenAlex
- W4311180252
- Study type
- Case-control study
- Publisher
- Public Library of Science (PLoS)
- Article type
- journal-article
- Integrity
- current
Publication version
This article has a linked preprint
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Open linked preprint →Why this research matters now
The study is relevant to understanding invasive Salmonella transmission in a household and One Health context in Malawi. It also highlights the value of household sampling for transmission-oriented epidemiology and the challenge of detecting S. Typhi from the environment.
Structured evidence summary
Research question
To examine how invasive Salmonella disease is transmitted in Malawi by comparing index-case households with matched control households and sampling infected people, household contacts, animals, and the household environment.
Study design
A case-control household study conducted in Blantyre, Malawi. Sixty index cases were recruited and compared with geographically matched control households, with microbiologic sampling across people, animals, and the environment.
Population and setting
Human cases of invasive Salmonella infection in Blantyre, Malawi, enrolled from March 2015 to October 2016. The study also sampled healthy household members, household-associated animals, and household environments.
Main findings
Among 1203 samples from 120 households, 43 non-typhoidal Salmonella isolates were recovered from 25 households. The iNTS cases were caused by three Salmonella Typhimurium sequence types, mainly ST313, and two index-case isolates closely matched isolates from asymptomatic household members. The household environmental and animal isolates did not overlap with the sequence types causing iNTS disease.
Public-health relevance
The study is relevant to understanding invasive Salmonella transmission in a household and One Health context in Malawi. It also highlights the value of household sampling for transmission-oriented epidemiology and the challenge of detecting S. Typhi from the environment.
Important limitations
The abstract does not state formal limitations. A study-specific limitation that is directly evident is the reliance on household sampling in one location, and the abstract notes that additional methodological development is needed for environmental culture of S. Typhi; interpretation here is limited to the supplied single-article abstract and metadata.
GIDS interpretation
This article is discoverable as a peer-reviewed case-control study on invasive Salmonella transmission in Malawi, with classifier links for typhoid fever, climate and environment, One Health, and transmission dynamics. That context supports retrieval for evidence synthesis, but the summary is limited to the supplied abstract and metadata.
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 7 auditable classifier relationships to diseases, places, topics, and study design.