Paralytic Shellfish Poisoning
What is Paralytic Shellfish Poisoning?
Paralytic Shellfish Poisoning (PSP) is a disease caused by eating shellfish containing paralytic shellfish toxins.
Paralytic shellfish toxins are produced by some naturally occurring algae.*
Algae are consumed by shellfish including mussels, oysters, clams, pipis, scallops, abalone, rock lobster and crab. The toxins build up in their flesh or organs and can be dangerous to humans when eaten.
What are the symptoms?
Symptoms of PSP begin within minutes or up to 24 hours after eating shellfish.
Initial symptoms include tingling and numbness around the mouth which can spread to the face, neck, arms and legs.
Other symptoms include:
- nausea and vomiting
- blurred vision
- change in temperature sensation
- loss of balance
- difficulty speaking or swallowing
- in severe cases difficulty breathing, paralysis and death can occur.
How is it spread?
People get PSP from eating shellfish containing paralytic shellfish toxins.
It cannot be spread from person to person.
How is it diagnosed?
PSP is diagnosed by clinical symptoms in a person who has eaten contaminated shellfish before the onset of their symptoms. To confirm the diagnosis a urine test is sometimes used.
How is it treated?
There is no specific antidote for PSP. Treatment involves supportive care. In severe cases people are monitored in hospital and may need breathing support.
How is it prevented?
Commercial shellfish growing areas are monitored for algae and shellfish toxins. Tasmanian recreational waters are not routinely monitored for algae that cause PSP. This means collecting and eating wild shellfish always carries some risk.
Wild shellfish from unmonitored areas may also be contaminated by viruses and/or heavy metals.
It is especially unsafe to eat wild shellfish from:
- marinas or other areas potentially subject to boat discharges
- areas near outfalls from sewage, septic tanks, stormwater or industrial sites
- areas affected by recent heavy rainfall
- areas affected by toxic algal blooms
- the Derwent and Tamar estuaries.
Cooking or freezing the shellfish does not destroy the toxins that cause PSP.
Commercial (shop-bought) shellfish are safe to eat because of close monitoring for paralytic shellfish toxins and other contaminants.
What should I do if I have had contact with someone who has Paralytic Shellfish Poisoning?
If you are with a person with suspected PSP ensure they receive urgent medical attention by calling emergency services or 000.
Also call the Public Health Hotline to notify the Public Health authorities.
Do not eat any shellfish that may be contaminated.
If possible keep samples of the shellfish that may be tested later for toxins.
What should I do if I have suspected Paralytic Shellfish Poisoning?
If you think you have PSP seek urgent medical attention.
Most cases will be transferred to the nearest emergency department and observed until their symptoms resolve.
For further information call the Public Health Hotline – Tasmania on 1800 671 738 to speak to a clinical nurse consultant.
*Algae such as Alexandrium tamarense and Gymnodiniumcatenatum.