Ciguatoxins and other marine biotoxins

7 minutes read

Marine biotoxins are chemical contaminants naturally produced by certain types of algae and other microorganisms, e.g. bacteria. They can enter the food chain mainly through the consumption of fish and other seafood such as molluscs and crustaceans. Climate and temperature strongly influence their presence in marine and freshwater environments.

Ciguatera fish poisoning (CP) is the most common type of marine biotoxin food poisoning worldwide, with an estimated 20,000-50,000 cases per year. Studies indicate that less than 10% of actual cases are ever reported.

It is typically caused by the consumption of fish that have accumulated ciguatoxins (CTX) in their flesh. CTX are produced by two families of microalgae called Gambierdiscus spp. and Fukuyoa spp. Consumers eating CTX contaminated fish can suffer from a range of short and long-term symptoms including gastrointestinal, cardiovascular and neurological effects.

Mainly found in tropical and subtropical areas, CP was first recorded in the Spanish and Portuguese Macaronesia islands (the Canaries and Madeira) of the Atlantic Ocean in 2004. Gambierdiscus has also been found in several Mediterranean islands including Crete, Cyprus and the Balearics.

Transcript

Climate change and ciguatera food poisoning - Contaminants. Natural toxins produced on tropical and subtropical coral reefs are eaten by fish and enter the food chain, poisoning consumers. Rising sea surface temperature probably contributed to its emergence in the Canary Islands and Madeira in 2008. Climate change is likely to severely increase the emergence of ciguatera fish poisoning with 44% chance of a moderate impact. Scientific experts estimated the effect of climate change comparing future climate projections to the recent past. Learn more about CLEFSA - a method for mapping climate change effects on food safety.

Latest

The first meeting of the EuroCigua II project took place in Las Palmas de Gran Canaria in October 2022. The attendees comprised coordinators, partners and members of the Advisory Board Including EFSA, the European Centre for Disease Control and Prevention, the European Environment Agency, the European Commission, the United Nations Food and Agriculture Organization, and experts from the USA and Japan.

Milestones

2022
EuroCigua II project, coordinated by the Spanish Ministry of Health, gets underway with a consortium of international, European and national partners from public institutions, academia and research.
2021
A series of four external scientific reports on ciguatera in Europe signal the completion of the first phase of the Eurocigua project.
2020
The CLEFSA project includes ciguatera as an emerging risk A risk to human, animal or plant health resulting from a new source or increased susceptibility or exposure to an existing source. linked to climate change.
2017
EFSA’s experts conclude EU consumers are not currently at risk from Tetrodotoxin poisoning in shellfish.
2016
EFSA and the Spanish Food Safety Authority (AESAN) jointly fund the four-year EuroCigua project to investigate emerging risks to consumers from ciguatera fish poisoning.
2010
The last of nine assessments of risks to consumers from marine biotoxins comes out.
2009
EFSA’s experts give advice on risks for consumers from marine biotoxins in shellfish.
EFSA advises on the impact of cooking and other types of food processing on the safety of bivalve molluscs.
2008
EFSA publishes its first of nine scientific assessments of marine biotoxins; this one deals with the group okadaic acid and related toxins.

EFSA's role

EFSA provides scientific advice and carries out risk assessments on a wide range of chemicals that can be present in food and feed due to food production, distribution, packaging, as well as those that might be present in the environment naturally or as a result of man-made activity. This work is carried out by EFSA’s Panel on Contaminants in the Food Chain.

The Authority also collects occurrence data on contaminants in food and feed and supports the coordination of data collection and monitoring by Member States.

European Union risk managers use EFSA’s scientific advice to support decision-making about the safety of these substances for human and animal health.

Emerging risks

EFSA cooperates with national partners, scientific organisations and stakeholder organisations in the EU to identify and respond to emerging risks, such as CP in Europe. You can read more about our role in this area in a separate topic on emerging risks.

EU framework

Since contamination generally has a negative impact on the quality of food and feed and may imply a risk to human and animal health, the EU has taken measures to minimise contaminants in food and feed. Regulations (EU) 2017/625 and (EU) 2019/627 require that no products of animal origin including fish and other seafood including crustaceans and molluscs containing CTX are placed on the market.

The European Centre for Disease Prevention and Control (ECDC) provides general information on ciguatera fish poisoning.

Facts on ciguatera fish poisoning – ECDC website

EuroCigua project I

To better understand the risks of CP in Europe, EFSA and the Spanish Food Safety Authority (AESAN) jointly funded the EuroCigua project between June 2016 and January 2021. The project defined the main health impacts of ciguatera in Europe; analysed the presence of CTX in microalgae and in fish; and developed analytical methods to identify and quantify the presence of CTX. A series of five external scientific reports signalled the completion of the first phase of the project.

The EuroCigua project recorded a total of 34 outbreaks and 209 cases in Europe between 2012 and 2019. It found Gambierdiscus and another microalgae genus A recognised way of categorising closely related species of organisms. The genus is the first part of the Latin name of a species; for example, Homo Sapiens (human being) is part of the genus Homo. called Fukuyoa spp. not only in the Spanish and Portuguese Atlantic islands but also in several Mediterranean islands including Crete, Cyprus and, for the first time, the Balearics.

EuroCigua confirmed that CP is becoming endemic Consistently present in a population or region, whether dormant or active as measured by clinical tests. in the Macaronesia area. Climate change and globalisation of trade are the main drivers of the spread of CP, which is intensified by travel to tropical areas. The project ended with a call for further data collection, analytical method standardisation and development of predictive modelling to inform adequate risk management The management of risks which have been identified by risk assessment. It includes the planning, implementation and evaluation of any resulting actions taken to protect consumers, animals and the environment. of CP in Europe.

A video of the final project workshop provides a detailed overview:

EuroCigua project II

The first EuroCigua project improved scientific understanding of the current and potential risks posed by CP in Europe as well as underlying environmental drivers such as climate change. It also brought together the global scientific community and public authorities in a network of excellence and raised awareness among food safety professionals, doctors and EU citizens to improve reporting of CP.

The results of EuroCigua I and the lack of harmonised methodologies or limits needed to fulfil the requirement of the Regulation 854/2004 (that forbids fish products containing CTX) encouraged EFSA and the Spanish Ministry of Health to jointly fund a follow-up three-year project. EuroCigua II is running from 2022 to 2025 and aims to prepare for future assessments and help predict future scenarios for ciguatera in Europe. It covers several areas, including capacity building for example of laboratories, harmonisation of methods, development of predictive modelling under climate change, and identification of other major drivers influencing ciguatera and CTX toxicity The potential of a substance to cause harm to a living organism.. The assessments will also take account of risks from imported fish.