How to avoid infections from contaminated seawater

Surfer looks out at the sea on top of a cliff in Cornwall, UK

Pathogens including bacteria, viruses, fungi and parasites can be found in our coastal waters due to pollution. Contact with contaminated coastal water can cause ear infections, skin rashes, respiratory illness, diarrhea and stomach cramps, as well as more serious infections in some cases.

Pathogens are becoming increasingly resistant to antibiotics, meaning that some types of medication will lose effectiveness. Antibiotic resistant infections, known as antimicrobial resistance (AMR), are predicted to become the leading cause of death by 2050. This week for World AMR Awareness Week, we are helping to raise awareness and understanding of AMR so together we can prevent antimicrobial resistance.

How can infections enter our bodies?

Pathogens can enter the body through cuts or open wounds. Ingesting water or food that has been contaminated with pathogens is another route. Pathogens can also be inhaled or enter the body through the eyes, nose, or mouth. It’s also worth noting that discoloured or murky water doesn’t mean it’s polluted, crystal clear waters can still be contaminated. And water with lots of suspended sediment/plankton can be safe.

Common pathogens found in coastal waters

  • Vibrio bacteria, can cause wound infections and illness through consumption of contaminated shellfish.
  • E. coli and other fecal coliform bacteria can be present at high levels after heavy rain, from agricultural runoff or sewage spills. Many E. coli subtypes are harmless, but some are responsible for serious infections, and these can sometimes be found in coastal waters.
  • Parasites, like Cryptosporidium and Giardia can cause gastrointestinal illness.
  • Norovirus, a highly contagious virus that causes vomiting and diarrhea, can be spread through fecal contamination of water and from eating contaminated shellfish.
  • Adenovirus, causing fever, sore throat, diarrhea, pink eye, and respiratory issues, can enter coastal waters through untreated sewage discharge and stormwater runoff.
  • Rotavirus, causing diarrhea and dehydration, can be caused by fecal contamination in sewage overflow.
  • Hepatitis A is a viral infection that affects the liver, and can spread through fecal contamination, sewage pollution and consuming raw or undercooked seafood from contaminated water.
  • Bacteria that carry transferable antimicrobial resistance genes, that may be passed to bacterial pathogens, making infections difficult or impossible to treat.

How to avoid infections from contaminated seawater

  • Beach warning signs: Pay attention to beach warning signs, flags and lifeguards to stay safe
  • Check for online pollution alerts: Find out if there is an app for your local area with pollution alerts
  • After heavy rain: Avoid swimming in coastal water for 48 hours following heavy rain
  • Open wounds and tattoos: Avoid contact with coastal water if you have an open wound or new tattoos
  • Shower: Shower after swimming or paddling in coastal water
  • Keep your mouth closed: Avoid swallowing seawater
  • Safe seafood: Do not eat raw or undercooked shellfish from contaminated waters. Shellfish should only be harvested from classified waters and depurated (made free of impurities) before being sold. If you know where your shellfish has come from you can see the classification.
  • Stop pollution: Help to prevent coastal pollution in the first place

How to help minimise resistance to antibiotics

  • Only use antibiotics when necessary and when prescribed by a doctor, as this increases the AMR in our gut bacteria which then enters our coastal waters.
  • Don’t dispose of unused medicine at home or down the toilet. This leads to pollution in our rivers and coastal waters. instead return unused medicine to your local pharmacy for safe disposal.
  • Don’t flush wet wipes and other non-biodegradable items down the toilet. This can contribute to sewage blockages which then cause sewage overflow discharges of raw sewage into our rivers and oceans.
  • Consider how the meat you buy is produced and try to buy organic products if available to you. More antibiotics are used in livestock production globally than in human medicine, and antibiotics and resistant bacteria from farm animals can enter our rivers and coastal waters.

What can you do to help?

By increasing public awareness of the dangers of pathogens in coastal waters, we can work together to protect our health and the environment. Our research will help to inform policymakers, educators and the public on how to keep our coastal waters safe for people across Europe. But you can also do your bit.

Here are just some of the organisations across Europe helping you to check for pollution alerts and take action to reduce pollution:

www.savethewaves.org (Global)
www.eea.europa.eu/themes/water/interactive/bathing/state-of-bathing-waters (Europe)
www.climateforesight.eu (Europe)
www.sas.org.uk (UK)
www.theriverstrust.org/sewage-map (UK)
www.beachguardian.org (UK)
www.pharmapollutionhub.org (UK)
www.beaches.ie (Ireland)
www.epa.ie (Ireland)
www.cleanbeachinitiative.org (Spain)
www.ratujmyrzeki.pl (Save the Rivers Coalition, Poland)
www.dbamyowode.pl/koalicja (We Care for Water Coalition, Poland)
www.waternet.nl/en/our-water/safe-swimming (Netherlands)

 

Thank you to our research team who informed this blog, including Professor Will Gaze, Dr Anne Leonard, Professor Davey Jones, Dr Jessica Kevill and Professor Shelagh Malham.

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