10. Surveillance of invasive mosquito species in islands with focus on potential vectors of zoonotic diseases

Abstract

The invasive species (IS) introduced in islands cause important impacts due to the vulnerability of their ecosystems. The invasive potential of certain mosquito species and their role as vectors of pathogens is one of the main concerns for public and animal health. The introduction of IS such as Aedes albopictus (Skuse 1895), Aedes aegypti (Linnaeus 1762) and Culex quinquefasciatus Say 1823 are also related to outbreaks of vector-borne diseases (VBD), such as yellow fever, dengue and Zika. Here, we review the surveillance activities on mosquito IS conducted in several islands of different origin (i.e. volcanic vs continental origin) located in different countries of the world. Those countries included Cabo Verde, Greece, Italy, Portugal, Spain and the USA. In regards to continental islands, Ae. albopictus was detected in the Balearic Islands (Spain) in 2012 despite monitoring at points of entry lead by national authorities since 2008. Greece comprises over 6,000 islands and islets with first record of Ae. albopictus in Corfu in 2003. In Italy, Ae. albopictus was first detected in Sicily in 2004 where several cases of filariasis by Dirofilaria repens in dogs and humans have been reported. Volcanic origin islands are characterised by having all mosquito fauna introduced from the continent. In Cabo Verde, Anopheles arabiensis is the main vector of malaria and can also transmit lymphatic filariasis. Ae. aegypti is also present in Cabo Verde since 1930 causing several outbreaks of dengue and Zika in 2009 and 2015. In Spain, Ae. aegypti was detected in Fuerteventura (Canary Islands) in 2017, but the fast intervention of local authorities reached its eradication in 2019. In Portugal, Ae. aegypti was first recorded in Madeira in 2006 with a single outbreak of dengue in 2012. In the USA, the islands of Hawaii have currently six established IS of mosquitoes including the four top vector species Ae. albopictus, Ae. aegypti, Aedes japonicus and Cx. quinquefasciatus, which have been implicated in outbreaks of dengue and transmission of Dirofilaria immitis and Plasmodium relictum.