A person can accidentally ingest maggots if they eat spoiled food contaminated with fly larvae. Accidental ingestion of maggots is usually not a cause for concern, but it can sometimes lead to health complications, such as bacterial poisoning.
A maggot is the larva of a common housefly. Maggots are about 3 to 12 millimeters long, have no legs, and are white or cream. An adult female housefly can lay up to 130 eggs at a time, and each of them will develop into a single larva. Flies lay their eggs in decaying organic matter, such as spoiled food and animal waste, which serves as food for developing larvae.
In this article, we explore some of the potential health effects of eating maggots and explain what to do and when to seek medical attention after accidentally ingesting one. We also look at whether people eat maggots intentionally and whether this practice is safe.
Food poisoning is a potential risk of eating maggots. Flies can visit multiple food sources throughout the day, and they can carry harmful bacteria that they pick up from human or animal waste. They can transmit these bacteria to the food people eat.
The larvae that develop in the contaminated food can ingest these bacteria. People who eat these contaminated foods or the larvae are also exposed to the bacteria and can get sick.
Salmonella and Escherichia coli are examples of bacteria that flies and maggots can transmit to humans.
Salmonella is one of the most common causes of foodborne illness. Symptoms of a Salmonella infection can include:
nausea and vomiting
Symptoms usually appear between 12 and 72 hours after ingesting the bacteria, and the illness usually lasts 4 to 7 days.
People with Salmonella poisoning often recover without treatment. However, frequent vomiting and diarrhea can lead to severe dehydration and, sometimes, hospitalization. It is therefore important that people with Salmonella poisoning drink plenty of fluids, especially clear broths and fruit juices, to replace lost fluids and electrolytes.
E. coli poisoning
There are many different strains of E. coli. Although most strains are harmless, some can make a person very sick.
Symptoms of an E. coli infection may include the following:
diarrhea, which may contain blood
a mild fever, usually less than 101°F
These symptoms usually appear between 1 and 10 days after ingesting the bacteria and can last for 5 to 7 days. The severity of an E. coli infection can range from very mild to severe, and can even be life-threatening at times. As with Salmonella poisoning, it is essential to drink plenty of fluids to avoid dehydration.
Myiasis occurs when a person is infested with fly larvae. The larvae live on or inside the person and survive by feeding on its tissues.
Intestinal myiasis is a type of myiasis that can occur when a person ingests larvae that survive inside the gastrointestinal tract. Some people with intestinal myiasis have no symptoms and only realize they are infected after noticing the larvae in their stool.
However, the symptoms of intestinal myiasis can be as follows
nausea and vomiting
itching in the anus
bleeding from the rectum
Myiasis is not common in Europe and tends to occur mainly in tropical and subtropical countries, including some countries in Africa and South America. However, one can contract myiasis while traveling to these countries.
What to do ?
Accidental ingestion of maggots usually causes no lasting damage. However, if a person has ingested maggots while eating spoiled food, they are at risk of food poisoning. Symptoms of food poisoning can range from very mild to severe, and can sometimes last for several days.
People at higher risk of food poisoning include:
people with weakened immune systems, such as people undergoing organ transplants.
It is essential that people with severe vomiting and diarrhea due to food poisoning drink plenty of fluids to avoid dehydration.
When to consult a doctor
A person should see a doctor if any of the following signs and symptoms appear after ingesting maggots:
visible larvae in stool
persistent abdominal pain
symptoms of bacterial poisoning that worsen or do not improve
diarrhea lasting more than 3 days
diarrhea and fever
signs of dehydration
severe or persistent vomiting
Do people intentionally eat maggots?
In some countries, it is not uncommon to eat insects. Many people in countries outside of Europe and North America eat insects. Scientists estimate that there are nearly 2,000 species of edible insects. Besides the insects themselves, the eggs and larvae of some species are edible.
Casu marzu is a Sardinian cheese that contains thousands of maggots. At the start of cheese production, the cheese maker removes the outer rind, which encourages flies to enter and lay their eggs. For several months, the larvae eat the rotten cheese. The droppings of the larvae give the cheese its unique, pungent flavor.
Due to the health risks of consuming live maggots, the European Food Safety Authority has banned the sale of casu marzu. However, a small number of Sardinian farmers continue to make this cheese for personal consumption.
Can maggots be eaten safely?
Maggots are particularly high in protein and fat. This is why scientists are currently studying the possibility of cultivating, harvesting and processing the fly’s maggots for human consumption. They suggested heating, drying and microwaving the larvae to reduce the risk of bacterial contamination. Currently, however, there is no guaranteed, risk-free way to safely consume maggots.
For most people living in milder climates, accidental ingestion of maggots is unlikely to cause harm. People can suffer from temporary food poisoning after eating either the contaminated maggots or the spoiled food that contains them. However, most cases of food poisoning go away without treatment after several days. It is advisable to consult a doctor if serious or disturbing symptoms appear after accidental ingestion of maggots.
Caparros Megido, R., et al. (2014). Edible insects acceptance by Belgian consumers: Promising attitude for entomophagy development [Abstract].
Chapter 6: Houseflies. (nd).
Daeschlein, G., et al. (2015). Maggots as potential vector for pathogen transmission and consequences for infection control in waste management.
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