Category Archives: Algal Toxin

Research – The monitoring program for algal toxins in shellfish 2021

Mattilsynet

In general, less poisonous shells were detected during the covid-19 years 2020 and 2021 than in the three previous years. We cannot determine whether this is due to fewer samples or less blooms of toxic algal plankton.

In 2021, a total of 723 shell samples were taken and analyzed for various toxins; 384 samples from the Norwegian Food Safety Authority’s annual monitoring program (including the Mussel Alert) and 339 samples from the producers’ own control samples. 

The number of samples from the industry was somewhat fewer in 2021 because demand for shells was lower due to covid-19 with closed restaurants and hotels.

On the monitoring of algal toxins in shellfish

The Norwegian coast is monitored throughout the year for marine algal toxins in shells in connection with commercial harvesting and trade in addition to the Mussel Alert.

The shell samples are analyzed for both the fat-soluble toxins DSP (OA group), AZA, YTX and PTX and the water-soluble toxins with the neurotoxin PSP (STX group), and for the amnesia toxin ASP (DA group).

What did we investigate? Mostly mussels, but also some scallops, flat oysters, Pacific oysters, cockles, knife clams, O-clams, carpet clams, sand clams, circle clams, king snails and sea urchins
Time range: 2021
What were we looking for? The algae toxins DSP, YTX, PTX and AZA, PSP and ASP.
What did we find? Around 98 per cent of all submitted mussels were below the limit value for DSP (OA group).

For PSP (STX group) around 95 per cent were below the limit value, while around 99 per cent were below the limit value for ASP.

For the toxin groups YTX, PTX and AZA, all samples were below given limit values.

Mussels: Had the most detections of DSP and PSP above the limit value, but ASP was also detected above the limit value

Scallops : PSP and ASP were detected above the limit value

Flat oysters : PSP was detected above the limit value in Western Norway for a period in April

PSP : As in previous years, was mainly detected in the spring and early summer.

DSP : The detections above the limit value were distributed throughout the year from April to October with a peak in September. This is consistent with previous years where DSP mainly performs in late summer and autumn.

Research – Illnesses Linked to Harmful Algal Blooms

Graphic showing 2020 data about illnesses in people caused by harmful algal blooms

Highlight

  • Thirteen states reported 227 harmful algal blooms (HABs) that resulted in a total of 95 human illnesses and at least 1,170 animal illnesses.
  • The first human death reported in OHHABS was associated with paralytic shellfish poisoning.
  • A HAB event in September killed at least 1,000 fish (carp).
  • 22 human illnesses (23%) were associated with national parks, with 21 illnesses attributed to a single HAB event.

Background

Harmful algal blooms (HABs) that result from the rapid growth of algae or cyanobacteria (sometimes referred to as blue-green algae) in natural waterbodies can harm people, animals, or the environment. HAB events of public health concern are primarily caused by microalgae called diatoms and dinoflagellates, cyanobacteria, and the toxins they can produce. HAB events, which can be intensified by factors such as nutrient pollution and warmer water temperature, can have public health, environmental, and economic impacts.

HABs are a One Health issue—they affect the health of people, animals, and our shared environment. One Health is a collaborative and multi-sectoral approach that involves engagement across disciplines including public health, animal health, and environmental health. Using a One Health approach, CDC collects data about HAB events and associated human or animal illnesses through the One Health Harmful Algal Bloom System (OHHABS) to inform public health prevention efforts.

Within the context of OHHABS, the term HAB event describes the identification of a bloom or the detection of HAB toxins in water or food (i.e., absent a visual bloom). Human illnesses are reported individually. Animal illnesses are reported as single cases of illness or in groups, such as flocks of birds. The reporting system can link HAB event data with human or animal illness data. OHHABS uses standard definitions [PDF – 3 pages] to classify HAB events as suspected or confirmed and human or animal illness as suspected, probable, or confirmed.

OHHABS is available for voluntary reporting by public health agencies and their designated environmental health or animal health partners in the United States, District of Columbia, Federated States of Micronesia, Guam, Marshall Islands, Northern Mariana Islands, Palau, Puerto Rico, and U.S. Virgin Islands. Public health agencies use standard forms to report HAB events, human cases of illness, and animal cases of illness to OHHABS. Public health agencies do not need to submit all three types of forms to participate.

Data collected for HAB events include general information (e.g., observation date), geographic information, water body characteristics (e.g., salinity), observational characteristics (e.g., water color, scum), and laboratory testing. Data collected for cases of illness include general demographic characteristics, exposure information, signs and symptoms, medical care, and health outcomes. OHHABS is a dynamic electronic reporting system; data within individual reports are subject to change over time. Data included in this report are from a specific point in time.

RASFF Alerts – Marine Lipophilic – Biotoxin- Algal Toxin

RASFF

Lipophilic biotoxins in cockles from Portugal in Spain

Norway -Crab shells in Agder: DSP below limit value

Matportalen

On 22 September, the Norwegian Food Safety Authority received a response to new samples of crabs in Agder. The random samples show that diarrhea toxin (DSP) in the crabs is now below the limit value, but there is no guarantee that all crabs in the area are below the danger limit. The Norwegian Food Safety Authority recommends following the mussel warning, as the crab likes to eat mussels.

Earlier in September, the Norwegian Food Safety Authority found high concentrations of the algae poison DSP (Diarrhetic Shellfish Poisoning) in crab from Agder, and thus warned people to eat the contents of crab shells.

DSP is one of the most common types of mussel poisoning in Norway. Once the crab has eaten mussels with DSP, the crab becomes poisonous to people who eat it. DSP causes diarrhoea, nausea, vomiting and abdominal pain. It takes from half an hour to a few hours from the time you eat until you get sick. The symptoms disappear by themselves after 2-3 days.

Since the beginning of July this year, high levels of the algal toxin DSP have been detected in mussels along the Sørland coast and in Agder.

New Zealand – Public health warning for shellfish reduced for West Coast, North Island – PSP Toxins

MPI

New Zealand Food Safety today reduced a public health warning against collecting shellfish in the Waikato and Taranaki region. The public health warning now extends from Albatross Point south to Oakura Beach and no longer applies to Kawhia and Aotea Harbours. More testing is being undertaken to determine the levels of paralytic shellfish toxins in the affected area.

Routine tests on shellfish samples taken from the Aotea/Kawhia Harbour area have shown levels of Paralytic Shellfish Poisoning (PSP) toxins are now within the safe limit of 0.8 mg/kg set by New Zealand Food Safety.

Mussels, oysters, tuatua, pipi, toheroa, cockles, scallops, catseyes, kina (sea urchin), and all other bivalve shellfish should not be eaten.

Note, cooking shellfish does not remove the toxin.

Pāua, crab, and crayfish may still be eaten if the gut has been completely removed prior to cooking, as toxins accumulate in the gut. If the gut is not removed, its contents could contaminate the meat during the cooking process.

Symptoms typically appear between 10 minutes and 3 hours after ingestion and may include:

  • numbness and a tingling (prickly feeling) around the mouth, face, and extremities (hands and feet)
  • difficulty swallowing or breathing
  • dizziness
  • headache
  • nausea
  • vomiting
  • diarrhoea
  • paralysis and respiratory failure and in severe cases, death.

If anyone becomes ill after eating shellfish from an area where a public health warning has been issued, phone Healthline for advice on 0800 61 11 16, or seek medical attention immediately. You are also advised to contact your nearest public health unit and keep any leftover shellfish in case it can be tested.

Monitoring of toxin levels will continue and any changes will be communicated accordingly. Commercially harvested shellfish – sold in shops and supermarkets, or exported – is subject to strict water and flesh monitoring programmes by MPI to ensure they are safe to eat.

Luxembourg – REMINDER: TELLINES – BULK SALE ON FISH STALL- DSP

SAP

Presence of lipophilic toxins (DSP) exceeding the regulatory health threshold

Auchan is recalling the following product

Last name Tellines (medium and large)
Mark Unbranded – Bulk Sale
Sale period from September 7 to 9, 2022

Danger  : Presence of lipophilic toxins (DSP) exceeding the regulatory health threshold

DSP toxins cause intoxication in the consumer, the effects of which appear within 2 to 18 hours after ingestion of the contaminated shellfish. The main symptoms are gastrointestinal: diarrhea, nausea, vomiting, abdominal pain, and chills.

Sale in Luxembourg by: Auchan on a fish stall

A sale by other operators cannot be excluded.

Source of information: Auchan recall notification

Communicated by: Government Commission for Quality, Fraud and Food Safety .

RASFF Alert – Shellfish Toxins – Oysters

RASFF

Azaspiracid toxins above the regulatory limit in oysters from Ireland in France

Norway -Do not eat the contents of crab shells in Agder – DSP Algal Toxin

Matportalen

The Norwegian Food Safety Authority warns people in Agder against eating the contents of the crab’s shells, following the discovery of diarrhea poison. The meat from the claws is safe to eat.

The Norwegian Food Safety Authority has found high concentrations of the algae poison DSP (Diarrhetic Shellfish Poisoning) in crab from Agder.

DSP is one of the most common types of mussel poisoning in Norway. Once the crab has eaten mussels with DSP, the crab becomes poisonous to people who eat it. DSP causes diarrhoea, nausea, vomiting and abdominal pain. It takes from half an hour to a few hours from the time you eat until you get sick. The symptoms disappear by themselves after 2-3 days.

Since the beginning of July this year, high levels of the algal toxin DSP have been detected in mussels along the Sørland coast, and in Agder the levels of the toxin have increased significantly in recent times. This is the reason why the Norwegian Food Safety Authority has also tested crabs in Agder for DSP. 

New Zealand – Public health warning for shellfish extended for West Coast, North Island – PSP – Toxins

MPI

Map of the affected area in the Kawhia Harbour area, West Coast, North Island

New Zealand Food Safety today extended a public health warning against collecting shellfish in the Waikato region and have extended this south to the Taranaki region. The public health warning now applies to the coastline from Papanui Point (south of Raglan), south to Oakura Beach. Paralytic shellfish toxins have been detected at levels above the safe limit set by MPI.

Routine tests on shellfish samples taken from this region have shown levels of Paralytic Shellfish Poisoning (PSP) toxins above the safe limit of 0.8 mg/kg set by New Zealand Food Safety. Anyone eating shellfish from this area is potentially at risk of illness.

Mussels, oysters, tuatua, pipi, toheroa, cockles, scallops, catseyes, kina (sea urchin), and all other bivalve shellfish should not be eaten.

Note, cooking shellfish does not remove the toxin.

Pāua, crab, and crayfish may still be eaten if the gut has been completely removed prior to cooking, as toxins accumulate in the gut. If the gut is not removed, its contents could contaminate the meat during the cooking process.

Symptoms typically appear between 10 minutes and 3 hours after ingestion and may include:

  • numbness and a tingling (prickly feeling) around the mouth, face, and extremities (hands and feet)
  • difficulty swallowing or breathing
  • dizziness
  • headache
  • nausea
  • vomiting
  • diarrhoea
  • paralysis and respiratory failure and in severe cases, death.

If anyone becomes ill after eating shellfish from an area where a public health warning has been issued, phone Healthline for advice on 0800 61 11 16, or seek medical attention immediately. You are also advised to contact your nearest public health unit and keep any leftover shellfish in case it can be tested.

Monitoring of toxin levels will continue and any changes will be communicated accordingly. Commercially harvested shellfish – sold in shops and supermarkets, or exported – is subject to strict water and flesh monitoring programmes by MPI to ensure they are safe to eat.

New Zealand – Consumers urged not to eat illegal mussels

MPI

New Zealand Food Safety is urging consumers not to eat mussels being sold illegally at independent retailers or online.

The sale of imported mussels is carefully controlled to ensure they meet New Zealand’s food safety requirements. While mussels from Fiji may be brought into New Zealand for personal use, they cannot be sold.

Deputy director general Vincent Arbuckle says Fijian mussels have been removed from sale at some smaller retailers catering to Pacific Island communities, and online.

“As New Zealand Food Safety has not assessed Fiji’s growing, harvesting and processing controls for mussels we cannot be confident that the mussels don’t pose a food safety risk to consumers.”

The mussels are also known as: Nakai, Naakai, Nakaai, Kai, Batissa violacea and Fresh Water Mussels.

“It’s vital that mussels available to buy for members of the public are safe to eat. Knowing where the mussels you want to buy have come from can help reduce the risk of any potential health problems.

“Our message to people buying mussels is that if you are in any doubt, ask the retailer where the product has come from. If it is from Fiji, the mussels should not be for sale.”

Mussels are a higher risk food because of the way they feed, which increases the likelihood of contamination from bacteria, viruses, toxins and chemicals.