Seafood is an important part of a balanced diet, valued for its high-quality protein, omega-3 fatty acids and essential nutrients. However, when fish and shellfish are improperly handled, stored or prepared, they can become a serious source of foodborne illness. Health experts warn that seafood poisoning is often dismissed as a minor digestive issue, but in certain cases it can escalate into a life-threatening condition if not recognised and treated promptly.

Food poisoning is usually suspected when several people who consumed food from a common source – such as a restaurant, feast, canteen or social gathering – begin experiencing similar symptoms within hours. In coastal regions, where seafood is consumed frequently, outbreaks linked to contaminated fish or shellfish are a recurring public health concern.

What Are the Health Risks?

Seafood poisoning can range from mild illness to severe medical emergencies, depending on the type of contamination and the individual’s health status.

Common Symptoms

Most cases begin with gastrointestinal distress. Symptoms may appear within minutes to several hours after consumption and include:

• Abdominal pain and cramps
• Diarrhoea
• Nausea and vomiting
• Fever
• Body aches
• Extreme fatigue
• Dehydration

While many cases resolve within a few days with rest and adequate fluid intake, dehydration can become dangerous, particularly for children, elderly individuals and those with weakened immune systems. Persistent vomiting, high fever, confusion or blood in stools require immediate medical attention.

Severe and Rare Complications

Among the most dangerous forms of foodborne illness is botulism, caused by the bacterium Clostridium botulinum. It is commonly associated with improperly stored or canned marine and packaged foods. Unlike typical food poisoning, botulism primarily affects the nervous system. Early symptoms may include blurred vision, difficulty swallowing, slurred speech and muscle weakness. If untreated, it can progress to paralysis and respiratory failure. Severe cases carry a mortality rate of up to 30%, highlighting the need for urgent medical intervention.

In addition to poisoning, seafood can trigger serious allergic reactions in certain individuals. Fish such as mackerel and sardines, and shellfish like crab and prawns, are common allergens. Symptoms may include itching, swelling of the lips or face, skin rashes and breathing difficulty. In extreme cases, a life-threatening reaction known as anaphylaxis can occur.

How Does Seafood Poisoning Occur?

Seafood is highly perishable and vulnerable to contamination at multiple stages—from harvesting to serving.

Microbial Contamination

Bacteria, viruses and parasites can contaminate seafood when hygiene standards are inadequate. Poor sanitation during cleaning, cutting or cooking increases the risk. Cross-contamination from raw seafood to cooked food is another common cause.

Naturally Occurring Toxins

Some toxins may already be present in seafood due to environmental factors such as polluted waters. Certain toxins are heat-stable, meaning they are not destroyed even by thorough cooking.

Temperature Mismanagement

Seafood spoils rapidly if not kept at proper refrigeration temperatures. Interruptions in the cold chain during transport or storage allow bacteria to multiply quickly. Repeatedly removing seafood from the refrigerator and reheating it further increases the risk.

Contaminated Marine Environments

Shellfish such as mussels, oysters, prawns and crabs filter large volumes of water and can accumulate harmful microorganisms and toxins from polluted coastal waters.

Prevention: Safe Handling Is Key

Preventing seafood poisoning requires vigilance at both the consumer and food service levels.

• Buy seafood from licensed and reliable vendors.
• Ensure continuous refrigeration from purchase to preparation.
• Cook seafood thoroughly to the recommended temperatures.
• Avoid consuming raw or undercooked shellfish.
• Do not repeatedly reheat refrigerated seafood.
• Maintain strict kitchen hygiene to prevent cross-contamination.
• Wash hands, utensils and surfaces before and after handling raw seafood.

Consumers should prioritise hygiene and food quality rather than focusing solely on taste or convenience. Restaurants and catering establishments must adhere to strict food safety standards to protect public health. Seafood offers undeniable nutritional benefits. However, without proper storage, hygiene and awareness, it can quickly become a serious health hazard. Recognising the risks, understanding how contamination occurs and following preventive practices remain the most effective safeguards against seafood poisoning.