Travel vaccination – dengue fever

Title: Aedes aegypti Detection in Puerto del Rosario, Canary Islands, December 2017
To: Travel Physicians, DFAT, DoH, Dr Kevin Kelleher, HPSC Op Support, HPSC-GZV Team
Cc: –
From: HPSC – EWRS National Contact Point
Urgency*: For Information
Date: 22/12/2017
Time: 1350
Reference No: 20171220ES0001
Content: EWRS Message – Spanish Authorities
On Tuesday, December 12th, Public Health Authorities from Canary Islands and the National Entomological Surveillance Project for Points of Entry and imported vectors, reported the first detection of Aedes aegypti mosquitoes in Fuerteventura. Enhanced entomological surveillance is carried out in Canary Islands since the dengue outbreak reported in Madeira in 2012. Surveillance in Fuerteventura begun in 2015.
Following an alert from the regional System for notification of mosquito bites complaints, reported by the citizens in Puerto del Rosario municipality, the Public Health authorities identified a female adult Aedes aegypti from a mosquito trapped in the area. A. aegypti confirmation was made by cytochrome oxidase gene DNA sequencing and the Basic Local Alignment Search Tool (BLAST, MEGABLAST version).
Public Health and Environmental local health authorities placed traps and ovitraps to determine if the mosquito was established in the area and the extension of the affected area. Neighbours were questioned about nuisance mosquito bites.
A second female adult and one larva obtained from the traps were identified as Aedes aegypti by the Medical Entomology Laboratory of the Tropical Diseases and Public Health Institute at Canary Islands. Confirmation was made by gene sequencing.
Neither Aedes albopictus nor Ae. aegypti have been found in any other surveillance point in Canary Islands.
A multi-sectoral Task force including Public Health authorities of the Canary Islands, Local authorities of Fuerteventura, the Ministry of Health, Social
Services and Equality and independent experts in entomology was created, to coordinate field investigation and propose specific and adapted control and public communication measures.

Comment: Aedes aegypti is a competent vector of a range of arboviruses, notably Dengue fever virus, Chikungunya virus, Zika virus and Yellow Fever virus. Highly climate-sensitive, Ae. aegypti has encroached more deeply into the continental United States (currently in the US, Ae. aegypti is naturally found south of a line from Northern California to El Paso –TX, and south of another line from El Paso to Washington DC).

The Canaries event, however, represents the first recent detection of Ae. aegypti into the EU. As of September 2017, ECDC’s distribution maps of greater Europe indicated that this species was absent from Europe. In the past however, Ae. aegypti was endemic in Europe (largely in Spain and Portugal), until the first half of the 20th century, and although there have since been sporadic introductions (in Italy in the 1970s and , more recently, in a tyre yard in the Netherlands, by means of stagnant waters contained in tyres, imported from Florida); the species has not yet gained a firm foothold in the EU.

This is in contradistinction to Aedes albopictus, a hardier, more widespread cousin, which is a competent vector for a similar range of arboviruses as those carried by Ae. aegypti; namely Yellow Fever virus, Dengue fever virus, Chikungunya virus and Zika virus. Ae. albopictus has become firmly established in most areas of Italy below 600m. In addition, Ae. albopictus has become established on the Cote d’Azur in France and in Albania, and is spreading in extent in Spain (particularly along the Mediterranean coast around Barcelona) , Greece and in certain Balkan countries. Netherlands has reported a number of importations (all successfully controlled) associated with imported bamboo plants.

Climate and vector modelling suggest the current distribution patterns for each are likely to change, and that both species have the potential to encroach farther north within Europe, as temperatures progressively rise, which will require the more aggressive application of detection and control methods.

Actions Requested: For information only.

*Immediate: Cascade within 6 hours; Urgent: Cascade within 24 hours; Non-urgent: Cascade within 2 working days; For information: There is no need to cascade the information and only those who receive the message directly need to be aware of its content.

For and on behalf of Dr Kevin Kelleher
A/Director, HSE Health Protection Surveillance Centre
Ireland’s National IHR Focal Point
25-27 Middle Gardiner Street
Dublin, 1