“If there are infected human beings, there is potentially a risk of introducing dengue into mainland Portugal, which has not yet been recorded”, said the researcher from the Institute of Hygiene and Tropical Medicine (IHMT) to Lusa.

Marcelo Urbano Ferreira indicated that the number of cases registered in mainland Portugal – all imported – does not exceed a dozen per year and refers to “travellers who, in some way, exposed themselves to transmission outside the country”.

The risk, however, is present through “infected people and climatic or environmental conditions for the proliferation of mosquitoes capable of transmitting the dengue virus. In this case, unfortunately not only Portugal, but several southern European countries already have potential dengue vectors adapted to local conditions.”

“The risk exists and of two types. We have Brazilians who live in Portugal, going to Brazil and eventually returning infected, and Portuguese people who, for tourism or other reasons, travel to areas of high transmission,” he added.

The researcher considers that “what helps Portugal and other countries in the northern hemisphere is that, at a time when there are major outbreaks in the southern hemisphere, the abundance of mosquitoes here [in Portugal] – as it is a colder time of the year – is smaller. This helps a lot, but dengue transmission is not restricted to the southern hemisphere, quite the opposite; we have several countries in Asia, in the northern hemisphere, with a large number of dengue cases”.

“Of course, in the case of Portugal, what is happening in Latin America and particularly in Brazil draws a lot of attention because of the ties and frequent mobility of the population between these two regions, but there is a relatively large number of Portuguese people who go on business or in tourism to countries in Southeast Asia, South Asia, countries where there is dengue transmission in the season corresponding to summer in Portugal, the summer of the northern hemisphere”, he added.