ANSES issued the alert on Tuesday June 20, 2023. On the Basque coast, microalgae called Ostreopsis are proliferating. Since 2021, they have caused nearly 900 poisonings. How to recognize them? What symptoms should alert? Top Santé tells you more.
Notice to vacationers! Be careful if you have decided to swim on the Basque coast. You are not immune to one poisoning by microalgae Ostreopsis. In a press release dated June 20, 2023, ANSES warned of this toxic algae causing flu-like symptoms. There is no need to be in contact with the algae: the main route of poisoning is inhalation sea spray. “ It is enough to be a few meters from the sea to be intoxicated “, adds ANSES.
Blooms of microalgae Ostreopsis have caused nearly 900 poisonings on the Basque coast since 2021, according to estimates.
What symptoms should alert after poisoning?
” Ostreopsis is a microscopic algae of tropical origin which arrived in the Mediterranean about twenty years ago. In France, the range of this microalga is expanding, with a presence on the Basque coast for a few years », Explains ANSES. It proliferates especially in summer, when the temperature of the water exceeds 20°C. ” Because of the toxins it produces, Ostreopsis causes poisoning “.
What are you risking? Of the flu symptoms after inhaling sea spray. In other words, you don’t need to swim to be intoxicated.
Among the symptoms, ANSES cites skin irritations and gastric disorders. They appear a few hours after inhaling the microalgae and its toxins and disappear after a few days.
Can you recognize Ostreopsis?
Ostreopsis can accumulate on the surface of the water to form “algal blooms”. These blooms can create brown slicks that can reach several square meters. ” However, these can disappear quickly and it is not because they are not visible that there is no risk. “, adds ANSES.
However, you can rely on a distinctive sign: if you have the feeling of a metallic taste in the mouthit means the seaweed may be nearby.
Poisoning can affect holidaymakers but especially professionals working on or near the beaches, such as lifeguards or restaurateurs. Prolonged exposure to Ostreopsis may lead to a lengthening of the duration of symptoms.
Toxins can build up in the digestive tract
To combat this microalgae, ANSES recommends regular water sampling to find out where it is concentrated. ” We know that the presence of Ostreopsis can be very localized: it can be present at one end of the beach but not at the other », Specifies ANSES.
As a precaution, experts advise to do not take shellfish or other seafood in case of proliferation of Ostreopsis. ” Rare cases of food poisoning have been reported outside of Europe, but the link to Ostreopsis remains unclear “. Toxins accumulate in the digestive tract.