Reacción a "Reactions to the cases of autochthonous dengue fever detected in Ibiza in German tourists"

The public health alert concerning two outbreaks of dengue fever in Ibiza initiated in early February 2023 is related to the transmission of this virus on the island thanks to the existence of a competent vector, Aedes albopictus.  

The origin of these outbreaks has been attributed to the existence of an index case that stayed in the same area of the island as the German tourists, and with high probability the presence of the vector and the sufficient viraemia of the index case favoured these cases of autochthonous transmission detected.  

It should be noted that the aforementioned invasive mosquito species was first detected on the island in 2014 and is now established in the region.  

The Iberian Peninsula and the Balearic Islands meet the necessary conditions for the circulation of the virus and, therefore, the appearance of autochthonous cases of dengue: the presence of a competent vector (Ae. albopictus) and a significant flow of travellers from endemic areas or areas with active dengue transmission that can introduce the virus. This means that the risk of new autochthonous cases is moderate between May and November. For this reason, constant and enhanced entomological surveillance is important during periods of increased mosquito vector activity.  

The majority of dengue cases are asymptomatic, although strict measures are required for severe cases (less than 5 %). On the other hand, events of this type support the need for strict entomological surveillance and control measures in the country and for raising public awareness of individual protective measures to avoid bites, especially in regions where invasive mosquito species such as A. albopictus or A. aegypti have not yet become established.  

Events of this type can affect the region's economy (tourism) as well as public health and it should be noted that, although the risk of new cases in Ibiza is currently low, the coming months (May to November) will see the beginning of the period of greatest activity of the mosquito vector. These events should be taken into account in order to avoid more serious transmission events and especially to protect those regions where these invasive mosquitoes have not yet established themselves, such as the Canary Islands.