Aedes aegypti, the mosquito that causes yellow fever
The risk is real. The study’s conclusions were surprising. It’s not a warning about yellow fever – it’s about diseases caused by mosquitoes.
A yellow fever is a disease transmitted by Aedes aegypti – which is a mosquito that easily adapts to urban environments and tropical and subtropical climates.
Once the mosquito establishes itself in the area where it “attacks”, it is very difficult to eliminate.
Yellow fever usually becomes an epidemic in Africa. Far from the African continent, epidemics essentially emerged in port cities – the mosquito (and the virus) arrived via the transatlantic slave trade. Lisboa was an example, in 1857; More than 5 thousand people died.
Now, Nuno Faria led an international team of researchers dedicated to yellow fever, precisely with this focus in Lisbon: “Spatial and social determinants of the 1857 yellow fever epidemic in Lisbon”.
And the results were surprising: “Some results were particularly striking. Despite being an epidemic from the 19th century, the transmission standards that we observed are similar to those we today associate with urban outbreaks of yellow fever in tropical regions”.
In this interview with , Nuno Faria highlights that Portugal has no transmission of yellow fever, nor autochthonous casess. The mosquito Aedes aegypti is not established in mainland Portugal.
Portugal has a reduced risk of contagion from the disease but “the global context has changed and there is always a risk, which must be monitored carefully”.
“Our study shows that, in the past, there were urban and ecological conditions that allowed the transmission of the disease in Lisbon. Today, although the risk for yellow fever remains very low, the global context has changed: there is greater international mobility and climate changes that favor the expansion of mosquitoes”.
In other words, it is not an imminent warning, but yellow fever could return to Europeincluding Portugal.
And, in Portugal, the mosquito is already established Aedes albopictus, which also “is a vector of other important diseases, such as dengue, zika e chikungunya. And this shows that there is a real risk associated with the establishment of diseases transmitted by mosquitoes in Portugal and that this risk must be monitored carefully”.
Therefore, this study is not exactly a warning about yellow fever – it is more of a broad warning about mosquito-borne diseases.
It is important to maintain “continuous surveillance, preparedness of health services and early response capacity for a wider range of arbovirus diseases, such as dengue, zika and chikungunya”.
The researcher considers that it is also essential to “invest more in communication with the population and in health education, including in schools, as well as in reducing mosquito breeding sites, such as containers with stagnant water in urban environments”.
Because “small individual and community actions can have a huge impact on reducing risks”.
