Food poisoning from raw fish occurs when you consume raw fish that has become too warm before serving or been contaminated with an infectious organism—a virus, parasite or bacterium—or a toxin from an infectious organism. Contamination of the fish can occur at any time during its storage, handling or preparation, according to MayoClinic.com.
Different types of food poisoning can occur from the consumption of raw fish. One of the most common is referred to as Scromboid poisoning. This type of food poisoning occurs when the fish become too warm after they are caught. As a result, a chemical substance called histamine builds up in the fish. When consumed, this substance causes a food poisoning reaction similar to an allergic reaction.
Food poisoning from raw fish can also occur as a result of contamination of the fish with infectious organisms. Since the fish is not cooked, these organisms are not killed, and instead, are allowed to invade the body. Some common infectious organisms that can infect raw fish include hepatitis A, noroviruses and Vibrio vulnificus, according to MayoClinic.com.
Symptoms of Scromboid poisoning usually begin within a half hour of consuming the fish, according to the American Academy of Family Physicians. These symptoms include facial flushing, nausea, vomiting, hives and stomach pain.
Symptoms of food poisoning with an infectious organism can begin several hours after consumption or several days later, according to MayoClinic.com. These symptoms include nausea, vomiting, diarrhea, abdominal pain, stomach cramps, loss of appetite, fatigue and fever.
Scromboid poisoning is treated with an antihistamine. The antihistamine blocks the action of histamine in the blood and reduces symptoms within 24 hours, according to the American Academy of Family Physicians. Antihistamines are available over the counter.
Treatment is ineffective for food poisoning that occurs as a result of an infectious organism. Bed rest and increased fluid intake are recommended during the course of the illness. According to MayoClinic.com, symptoms can last from one to 10 days but usually last around three.
If fluid intake is not increased, the chronic diarrhea and vomiting associated with food poisoning can lead to dehydration. Dehydration can be a medical emergency that leads to hospitalization. Children and older adults are the most susceptible to complications from food poisoning and dehydration.
When eating raw fish, always make sure that it has been stored at the correct temperature until it is ready to be served. If eating raw fish at a restaurant, make sure the restaurant is reputable and has the proper qualifications to be serving raw fish.