The current and future distribution of the yellow fever mosquito (Aedes aegypti) on Madeira Island

PLoS Negl Trop Dis. 2022 Sep 12;16(9):e0010715. doi: 10.1371/journal.pntd.0010715. eCollection 2022 Sep.

Abstract

The Aedes aegypti mosquito is the main vector for several diseases of global importance, such as dengue and yellow fever. This species was first identified on Madeira Island in 2005, and between 2012 and 2013 was responsible for an outbreak of dengue that affected several thousand people. However, the potential distribution of the species on the island remains poorly investigated. Here we assess the suitability of current and future climatic conditions to the species on the island and complement this assessment with estimates of the suitability of land use and human settlement conditions. We used four modelling algorithms (boosted regression trees, generalized additive models, generalized linear models and random forest) and data on the distribution of the species worldwide and across the island. For both climatic and non-climatic factors, suitability estimates predicted the current distribution of the species with good accuracy (mean area under the Receiver Operating Characteristic curve = 0.88 ±0.06, mean true skill statistic = 0.72 ±0.1). Minimum temperature of coldest month was the most influential climatic predictor, while human population density, residential housing density and public spaces were the most influential predictors describing land use and human settlement conditions. Suitable areas under current climates are predicted to occur mainly in the warmer and densely inhabited coastal areas of the southern part of the island, where the species is already established. By mid-century (2041-2060), the extent of climatically suitable areas is expected to increase, mainly towards higher altitudes and in the eastern part of the island. Our work shows that ongoing efforts to monitor and prevent the spread of Ae. aegypti on Madeira Island will have to increasingly consider the effects of climate change.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aedes*
  • Animals
  • Dengue* / epidemiology
  • Dengue* / prevention & control
  • Humans
  • Mosquito Vectors
  • Portugal / epidemiology
  • Yellow Fever* / epidemiology
  • Yellow Fever* / prevention & control

Grants and funding

JMS was supported by a PhD grant from the Fundação para a Ciência e Tecnologia (FCT), Portugal (https://www.fct.pt) [SFRH/BD/139753/2018]. CC was supported by FCT [CC: CEECIND/02037/2017; ACH: GHTM-UID/Multi/04413/2013]. CC, CAS, JR were supported by FCT under the framework of the project “TRIAD - health Risk and social vulnerability to Arboviral Diseases in mainland Portugal” [PTDC/GES -OUT/30210/2017] and the project “WARDEN - An operational early WARning system for DENgue and other arboviral diseases in Madeira Island” [PTDC/SAU-PUB/30089/2017]. JMS, CC, JR were financed by the Research Unit UIDB/00295/2020 and UIDP/00295/2020. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.