What is ciguatera poisoning?

Ciguatera poisoning is a type of food poisoning. You get it by eating some types of fish. These fish feed in warm waters and can carry the ciguatera toxin (poison).

Many species of fish have been linked to ciguatera poisoning outbreaks around the world. These regions include:

• South Pacific
• Hawaii
• the Caribbean
• the Gulf of Mexico
• the western Indian Ocean

In Australia, ciguatera toxin is found in fish that live in the coral reefs of tropical and sub-tropical waters in:

• northern Queensland
• the Northern Territory

More recently, some cases have been reported in New South Wales. These have mostly been linked to Spanish mackerel.

What are the symptoms of ciguatera poisoning?

Symptoms of ciguatera poisoning usually appear 1 to 30 hours after eating contaminated fish.

Symptoms can vary, depending on how much fish you have eaten. They may include typical food poisoning symptoms:

• abdominal (tummy) cramps
• nausea
• vomiting
• diarrhoea
• tiredness

Other symptoms of ciguatera poisoning are:

• joint and muscle pains with muscle weakness
• tingling and numbness in your fingers and toes, around your lips, tongue, mouth and throat
• reversal of temperature sensation — so hot water feels cold or a cold drink feels hot
• headache and fainting
• extreme itchiness — often made worse by drinking alcohol
• dizziness
• low blood pressure and heart palpitations

You may have difficulty breathing in severe cases.

Some symptoms can last for up to 3 months. Some symptoms can last several years for some people.

What causes ciguatera poisoning?

Ciguatera poisoning is caused by eating warm water fish that carry ciguatera poison. Generally, these are fish that spend some or most of their life on coral reefs.

Fish eat the natural marine toxin that is made by algae called gambierdiscus toxicus.

The toxin builds up in the food chain. Small fish eat the algae and are then eaten by bigger fish.

Which fish cause ciguatera poisoning?

There are more than 300 types of fish that are suspected of causing ciguatera poisoning. The type of fish that may carry the toxin are usually large and found in warm waters, such as Spanish Mackerel.

To find out more about the types of fish that may have this toxin, contact your state or territory health or food authority department.

How can I tell if a fish has the ciguatera poison?

You can't tell if a fish has the ciguatera toxin. It doesn't affect the fish's:

• appearance
• smell
• taste

Ciguatera toxin can only be found by laboratory tests. This test is expensive, so it is only used in cases of suspected poisoning.

At the moment, there is no way to test all fish for ciguatera toxin before it's sold.

When should I see my doctor?

See your doctor or go to your local emergency department if you get ciguatera poisoning symptoms after eating fish.

Do not eat any more of the fish.

How is ciguatera poisoning diagnosed?

Your doctor will ask you about your symptoms and the food you have been eating.

There is no test to diagnose ciguatera poisoning. If you have leftover fish from your meal, this may be tested to confirm ciguatera poisoning.

How is ciguatera poisoning treated?

There is no specific treatment for ciguatera poisoning. However, there are treatments that can help ease your symptoms.

If you've had vomiting and diarrhoea, you may need extra fluids so that you don't become dehydrated.

Recovering from ciguatera poisoning

If you are recovering from ciguatera poisoning, you should not:

• eat warm water ocean fish for at least 6 months
• drink alcohol for at least 3 months — alcohol can cause your symptoms to come back

Once you're better, only eat a small portion of fish — no more than 200g. If your symptoms come back, see your doctor.

Can ciguatera poisoning be prevented?

To prevent ciguatera poisoning:

• do not fish in areas known to have ciguatera
• do not eat fish that weigh more than 2.5kg and may have ciguatera
• eat small portions of warm water ocean fish — no bigger than 200g
• do not eat the head, roe, liver or other viscera (guts) of warm water fish as the toxin is more concentrated in these parts
• vary the type of warm water fish you eat

You can't get rid of the ciguatera toxin by:

• freezing
• cooking
• cleaning

What are the complications of ciguatera poisoning?

Unfortunately, if you have been exposed to the ciguatera toxin before, it doesn't protect you from it in the future. In fact, it may make you more sensitive to the toxin in future.

In severe cases of ciguatera poisoning, you can die due to respiratory paralysis or cardiovascular shock. This is very rare.

Resources and support

Read more about ciguatera at QLD Health and NSW Health.

You can read more about food safety.

The Sydney Fish Market's Seafood Handling Guidelines lists:

• fish to avoid eating
• high risk fishing areas

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with 24 hours a day, 7 days a week.