The project, unique in Portugal, aims to test the sterile insect technique (SIT) to reduce the population of the “Aedes albopictus” mosquito, a species that poses a potential threat for the transmission of several diseases, including dengue, zika and chikungunya.
Recommended by the World Health Organization (WHO) to reduce the population of these mosquitoes and prevent the emergence of diseases, the SIT technique consists of releasing sterile males that, when mating with females, make new generations unfeasible.
The two-year project is led by researchers from the Instituto Nacional de Saúde Doutor Ricardo Jorge (INSA) in collaboration with the public health service of the Regional Health Administration (ARS) of the Algarve, within the scope of the National Health Network Vector Surveillance (REVIVE), funded by the International Atomic Energy Agency (IAEA).
The regional coordinator for the Algarve of the REVIVE program, Nélia Guerreiro, told Lusa that the monitoring of the population of the insects is being carried out in a specific area of 40 hectares in the Gambelas area, near Faro international airport, where the species was identified in 2020.
“For three weeks, field activities were carried out, with the release of about 90,000 insects sterilised in the laboratory and marked, so that the SIT technique can be validated, as a complementary ecological tool for vector control”, she pointed out.
The results to understand whether the eggs that are produced by mosquitoes released into the environment "are sterile or not should only be known near the end of the year", said the official.
Nélia Guerreiro said that monitoring carried out since 2020 on the mosquito population in the Gambelas area “has enabled the collection of very robust data, namely its density, when the mosquito is active and when it loses activity”.
"Due to the data collected, it was possible to submit a project of this type that intends to validate the sterile mosquito technique as a complementary ecological tool for a vector control program, so that in the future it can be used for the suppression of the mosquito population that exists in a given region", he concluded.
Originating in Southeast Asia, “Aedes albopictus” has been spreading globally through the passive transport of eggs originated in commercial activities, namely, the global trade of used tires and ornamental plants.
The Asian tiger mosquito arrived in Europe via Albania in 1979, and since then has been detected in several countries, such as Italy, France or Spain, being capable of transmitting diseases such as dengue, zika and chikungunya, as well as filarial parasites,
Presence in Portugal
The invasive species was first detected in Portugal in September 2017 at a tire factory in the north of the country, which triggered a surveillance response by public health authorities at local, regional and national levels.
A year later, the same species was detected in the Algarve in very specific areas, and it is not known precisely how it was introduced.