Arbovirus surveillance: first dengue virus detection in local Aedes albopictus mosquitoes in Europe, Catalonia, Spain, 2015

Carles Aranda,Raúl Escosa,Roger Eritja,Núria Busquets,Esther Bigas,Sandra Talavera,Miguel J Martínez,Mari Paz Sánchez-Seco,Eva Herreros,Núria Torner,Irene Corbella,Lluís Picart,Mireia Jané,Ana Vázquez,Jessica Navero-Castillejos,Tomas Montalvo,Eduard Marqués,Irene Barrabeig

doi:10.2807/1560-7917.es.2018.23.47.1700837

Abstract

Dengue has emerged as the most important viral mosquito-borne disease globally. The current risk of dengue outbreaks in Europe appeared with the introduction of the vector Aedes albopictus mosquito in Mediterranean countries. Considering the increasing frequency of dengue epidemics worldwide and the movement of viraemic hosts, it is expected that new autochthonous cases will occur in the future in Europe. Arbovirus surveillance started in Catalonia in 2015 to monitor imported cases and detect possible local arboviral transmission. During 2015, 131 patients with a recent travel history to endemic countries were tested for dengue virus (DENV) and 65 dengue cases were detected. Twenty-eight patients with a febrile illness were viraemic, as demonstrated by a positive real-time RT-PCR test for DENV in serum samples. Entomological investigations around the viraemic cases led to the detection of DENV in a pool of local Ae. albopictus captured in the residency of one case. The sequence of the DENV envelope gene detected in the mosquito pool was identical to that detected in the patient. Our results show how entomological surveillance conducted around viraemic travellers can be effective for early detection of DENV in mosquitoes and thus might help to prevent possible autochthonous transmission.

Highlights

The rapid geographical spread of invasive mosquitoes and vector borne diseases (VBD) as well as their increasing burden are global concerns [1]
Following national and regional guidelines for arbovirus surveillance, travellers returning from endemic areas with a clinical syndrome compatible with an arboviral infection were screened for dengue virus (DENV) and chikungunya virus (CHIKV) in 2015
Sixty-six patients resulted negative by RT-PCR and IgM testing and 65 dengue cases were detected between April and December

Summary

Introduction

The rapid geographical spread of invasive mosquitoes and vector borne diseases (VBD) as well as their increasing burden are global concerns [1]. Dengue has emerged as the most important viral mosquito-borne disease globally. In a study from 2013, Bhatt et al [2] estimated that there were 390 million human dengue infections per year worldwide, including 96 million with clinical manifestations. DENV is transmitted through the bites of infected Aedes mosquitoes [3] and is present in tropical and subtropical regions of the world. Demographic- and anthropogenic-driven environmental changes combined with globalisation and inefficient public health measures are considered the principal driving forces for the emergence and global spread of dengue in the past 40 years [4]

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Results

Conclusion