A framework to assess the risk of yellow fever emergence
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Background
Yellow fever (YF) is a viral hemorrhagic fever transmitted by Aedes aegypti mosquitoes. Symptoms range from mild fever to severe complications such as jaundice and haemorrhages, which can be fatal. Martinique, a French island in the Caribbean, has remained YF-free since 1908. However, the reintroduction of A. aegypti in the 1970s, the limited scope of mandatory vaccination—currently required only for international travellers to endemic areas—and increased connectivity to YF-endemic regions heighten its vulnerability. To inform local preparedness activities, we assessed the risk of YF emergence, defined as introduction and establishment, by looking at vector competence of local native species of A. aegypti in Martinique.
Methods
We developed a framework to evaluate YF emergence risk, integrating multiple contributing factors and taking Martinique as a case study. We used reported cases from 2015 to 2022 to estimate the predicted force of infection in endemic countries and map genotype presence in source countries. In addition, we analyzed flight traffic patterns from 2019 to 2022 and computed genotype-specific transmission efficiency by local mosquito populations.
Results
Before 2020, Brazil represented the greatest YF introduction risk due to high passenger volumes. However, the moderate transmissibility of the South America II YF virus strain in Martinique’s mosquito populations partially mitigated this risk. The COVID-19 pandemic disrupted global travel, temporarily shifting the risk landscape towards African countries such as Ivory Coast and Cameroon, where the West African strain exhibits higher transmissibility. However, this risk remained limited by the low number of travellers from these regions.
Conclusions
There are growing concerns about the risk of YF introduction and emergence in non-endemic territories like Martinique. Climate change, mosquito adaptability (e.g. egg resistance to desiccation, winter diapause) and intensified global travel drive this risk. This integrative risk assessment framework supports YF emergence prevention and could be applied to other at-risk territories.
Yellow fever (YF) is a viral hemorrhagic fever transmitted by Aedes aegypti mosquitoes. Symptoms range from mild fever to severe complications such as jaundice and haemorrhages, which can be fatal. Martinique, a French island in the Caribbean, has remained YF-free since 1908. However, the reintroduction of A. aegypti in the 1970s, the limited scope of mandatory vaccination—currently required only for international travellers to endemic areas—and increased connectivity to YF-endemic regions heighten its vulnerability. To inform local preparedness activities, we assessed the risk of YF emergence, defined as introduction and establishment, by looking at vector competence of local native species of A. aegypti in Martinique.
Methods
We developed a framework to evaluate YF emergence risk, integrating multiple contributing factors and taking Martinique as a case study. We used reported cases from 2015 to 2022 to estimate the predicted force of infection in endemic countries and map genotype presence in source countries. In addition, we analyzed flight traffic patterns from 2019 to 2022 and computed genotype-specific transmission efficiency by local mosquito populations.
Results
Before 2020, Brazil represented the greatest YF introduction risk due to high passenger volumes. However, the moderate transmissibility of the South America II YF virus strain in Martinique’s mosquito populations partially mitigated this risk. The COVID-19 pandemic disrupted global travel, temporarily shifting the risk landscape towards African countries such as Ivory Coast and Cameroon, where the West African strain exhibits higher transmissibility. However, this risk remained limited by the low number of travellers from these regions.
Conclusions
There are growing concerns about the risk of YF introduction and emergence in non-endemic territories like Martinique. Climate change, mosquito adaptability (e.g. egg resistance to desiccation, winter diapause) and intensified global travel drive this risk. This integrative risk assessment framework supports YF emergence prevention and could be applied to other at-risk territories.
Date Issued
2025-08-01
Date Acceptance
2025-08-05
Citation
Journal of Travel Medicine, 2025, 32 (6)
ISSN
1195-1982
Publisher
Oxford University Press
Journal / Book Title
Journal of Travel Medicine
Volume
32
Issue
6
Copyright Statement
©TheAuthor(s) 2025. Published by Oxford University Press on behalf of the International Society of Travel Medicine. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site-for further information please contact journals.permissions@oup.com.
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/40794821
PII: 8223135
Subjects
DISEASE
force of infection
General & Internal Medicine
genetic
Infectious Diseases
Life Sciences & Biomedicine
Medicine, General & Internal
Public, Environmental & Occupational Health
Risk assessment
Science & Technology
vector competence
yellow fever
Publication Status
Published
Coverage Spatial
England
Article Number
taaf081
Date Publish Online
2025-07-29