Assessing Seasonal Risks for the Introduction and Mosquito-borne Spread of Zika Virus in Europe

Abstract

The explosive Zika virus epidemic in the Americas is amplifying spread of this emerging pathogen into previously unaffected regions of the world, including Europe (Gulland, 2016), where local populations are immunologically naïve. As summertime approaches in the northern hemisphere, Aedes mosquitoes in Europe may find suitable climatic conditions to acquire and subsequently transmit Zika virus from viremic travellers to local populations. While Aedes albopictus has proven to be a vector for the transmission of dengue and chikungunya viruses in Europe (Delisle et al., 2015; ECDC, n.d.) there is growing experimental and ecological evidence to suggest that it may also be competent for Zika virus(Chouin-Carneiro et al., 2016; Grard et al., 2014; Li et al., 2012; Wong et al., 2013). Here we analyze and overlay the monthly flows of airline travellers arriving into European cities from Zika affected areas across the Americas, the predicted monthly estimates of the basic reproduction number of Zika virus in areas where Aedes mosquito populations reside in Europe (Aedes aegypti in Madeira, Portugal and Ae. albopictus in continental Europe), and human populations living within areas where mosquito-borne transmission of Zika virus may be possible. We highlight specific geographic areas and timing of risk for Zika virus introduction and possible spread within Europe to inform the efficient use of human disease surveillance, vector surveillance and control, and public education resources.

Keywords: Aedes; Air travel; Climate; Globalization, mosquito; ZIKV; Zika.

Figures 1–6

Month specific maps (1 = May to 6 = October) for the predicted basic reproduction number (R0) of Zika for Europe for Aedes albopictus overlaid with monthly estimates of travellers arriving from Zika affected regions in the Americas.

Figures 1–6

Month specific maps (1 = May to 6 = October) for the predicted basic reproduction number (R0) of Zika for Europe for Aedes albopictus overlaid with monthly estimates of travellers arriving from Zika affected regions in the Americas.

Figures 1–6

Month specific maps (1 = May to 6 = October) for the predicted basic reproduction number (R0) of Zika for Europe for Aedes albopictus overlaid with monthly estimates of travellers arriving from Zika affected regions in the Americas.

Figures 1–6

Month specific maps (1 = May to 6 = October) for the predicted basic reproduction number (R0) of Zika for Europe for Aedes albopictus overlaid with monthly estimates of travellers arriving from Zika affected regions in the Americas.

Figures 1–6

Month specific maps (1 = May to 6 = October) for the predicted basic reproduction number (R0) of Zika for Europe for Aedes albopictus overlaid with monthly estimates of travellers arriving from Zika affected regions in the Americas.

Figures 1–6

Month specific maps (1 = May to 6 = October) for the predicted basic reproduction number (R0) of Zika for Europe for Aedes albopictus overlaid with monthly estimates of travellers arriving from Zika affected regions in the Americas.

Fig. 1

Monthly stratified maps (June–Sept) of the potential basic reproduction number (R₀) of Zika virus in Europe via Aedes albopictus overlaid with monthly estimates of airline travellers arriving from areas with potential for year-round Zika transmission in the Americas.

Fig. 2

Potential basic reproduction numbers (R₀) for Zika virus in Madeira, Portugal via Aedes aegypti.