This is one of the most common causes of food poisoning worldwide. Usually found in poultry, eggs, unprocessed milk, meat and water, salmonella bacteria attacks the stomach and intestines. Symptoms include diarrhoea without blood, headaches, stomach cramps, nausea, vomiting and fever. Most mild infections clear up within a week with rest and plenty of fluids.
Highly contagious, this spreads easily in closed and crowded areas such as hospitals and schools. The virus spreads in the faeces of infected humans and animals, and is transferred by infected food handlers and contaminated food and water. Symptoms include diarrhoea, abdominal pain and vomiting within 24 to 48 hours of exposure.
This virus lives in brackish salt water and causes gastrointestinal illness in humans. Most people are infected by eating raw or undercooked shellfish, especially oysters. The bacterium can also cause skin infections when an open wound is exposed to warm sea water. Watery diarrhoea, abdominal cramps, nausea, vomiting, fever and chills develop with 24 hours of exposure and last no longer than three days.
This is found in coral reef fish such as groupers, which eat algae that accumulate the toxin. In turn, it accumulates in the head, skin, viscera and roe of the fish, and it cannot be destroyed by cooking, refrigeration, drying or digestion. Symptoms include numbness in the mouth and limbs, vomiting, diarrhoea, and joint and muscle pain. In cases of excessive exposure, the circulatory and nervous systems will be affected.
Escherichia coli is transmitted to humans primarily through eating infected meat, unpasteurised milk, cheese and juices, and vegetables. Symptoms usually begin within five days of infection and include cramps, abdominal pain, nausea, headaches and watery and bloody diarrhoea. Some patients may develop haemolytic uraemic syndrome, a series of complications that can lead to acute kidney failure, haemolytic anaemia (anaemia resulting from the abnormal breakdown of red blood cells) and thrombocytopenia (abnormally low platelet count, compromising blood clotting).