Increase in marine bacteria on beaches “a danger to public health”

Porto professor warns “most serious situations” “can lead to death”

Respected hydrobiologist from the University of Porto, Adriano Bordalo e Sá, has warned of a new threat emanating from climate change/ warming sea temperatures: the increase of ‘non-faecal pathogenic bacteria’ which, in worst case scenarios, can lead to death.

Those most at risk are people who swim in the water who are immuno-compromised, or who have cuts or sores on their skin.

According to the professor, “we have to address this situation because it is a risk and people can actually get infected and then not be diagnosed correctly. And if the correct diagnosis is not made, the treatment will not be either, because there are no universal treatments.”

He stressed that the occasional ingestion of seawater,  “is not necessarily a source of contamination, due to the relatively low dose of bacteria in the volume of water ingested in these situations”.

The professor’s warnings come in the wake of a study by ICBAS, the Institute of Biomedical Sciences Abel Salazar, subsidised by the Foundation for Science and Technology (FCT), on the quality of beachwater in the north region, explains Lusa.

The study, performed in 2020, showed that coastal waters between “Aveiro and Viana do Castelo revealed an increase of certain marine bacteria”.

“Potentially pathogenic marine bacteria, such as vibrios, can have a highly pathogenic behaviour during the summer, which is when water temperatures are higher, and are not detected in the official analysis of the Portuguese Agency for the Environment (APA) and the regional health administrations (ARS), becoming a danger to public health,” explains Bordalo e Sá.

He believes health authorities should make “an immediate diagnosis at national level” of the levels of marine bacteria “because the situation found on northern beaches (three years ago) may now be happening along the coast, which is about 900 kms long.

“Those in the field, and those who design health policies” should have an “urgent dialogue” because the most serious situations of this kind of infection “can lead to death”, he said.

Regarding the findings of the ICBAS study, “we see that it is in August, at the peak of the summer season, that we find these pathogenic bacteria in large quantities”.

These bacteria can provoke septicemia, explains Bordalo e Sá, which “can lead to the amputation of fingers infected by these bacteria/ these vibrios”.

The name of the vibrios detected this far are vulnificus (which can cause tissue necrosis and septicemia), parahaemolyticus (acute gastroenteritis) and cholerae (acute gastroenteritis).

Bordalo e Sá added that the low level of salinity in the sea is “very good for emerging and pathogenic bacteria, because they like a slightly higher temperature and slightly lower salinity”.

This change, like so many others in evidence right now, is a direct consequence of climate change, he concluded.

Source material: LUSA