A maggot is the larva of the common housefly. Maggots are around 3–12 millimeters in length, have no legs, and are white or cream.
An adult female housefly can lay up to 130 eggs at a time, and each one of these 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 the developing larvae.
In this article, we explore some of the potential health effects of eating maggots and explain what to do and when to see a doctor after accidentally ingesting them. We also discuss whether people eat maggots intentionally and if it is safe to do so.
Flies can visit multiple food sources throughout the day, and they may carry harmful bacteria that they have picked up from human or animal waste. They can transmit these bacteria to foods that people eat.
Larvae that develop in the contaminated food can ingest these bacteria. People who eat this contaminated food or the larvae will also get exposure to the bacteria and may become unwell.
Salmonella and Escherichia coli are examples of bacteria that flies and maggots may transmit to humans.
Salmonella is one of the most common causes of foodborne illness. Symptoms of Salmonella infection can include:
Symptoms typically begin between 12 and 72 hours after a person ingests the bacteria, and the illness usually lasts for 4 to 7 days.
People with Salmonella poisoning often get better without treatment. However, frequent vomiting and diarrhea can lead to severe dehydration and, sometimes, hospitalization. It is, therefore, important for people with Salmonella poisoning to drink plenty of liquid, including 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 cause a person to become very sick.
Symptoms of E. coli infection may include:
- stomach cramps
- diarrhea, which may contain blood
- slight fever, usually less than 101°F
These symptoms usually develop between 1 and 10 days after ingesting the bacteria and may last for 5–7 days.
An E. coli infection can range in severity from very mild to severe, and it can sometimes even be life-threatening. As with Salmonella poisoning, it is essential for people to drink plenty of liquid to prevent dehydration.
A person may consume maggots accidentally in spoiled food.
Myiasis occurs when a person becomes infested with fly larvae. The larvae live on or inside the person and survive by feeding off their 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 do not experience any symptoms and may only realize that they have an infestation after noticing larvae in their stools.
However, symptoms of intestinal myiasis can include:
Myiasis is not common in the United States and mainly tends to occur in tropical and subtropical countries, including some of those in Africa and South America. However, people can get myiasis from traveling to these countries.
What to do
Accidentally ingesting maggots does not generally cause any lasting harm. However, if a person has ingested maggots through eating spoiled food, they may be at risk of food poisoning. Symptoms of food poisoning can range from very mild to serious, and they can sometimes last for several days.
People with a higher risk of developing food poisoning include:
- young children
- older adults
- those with weakened immune systems, such as people living with HIV or those undergoing an organ transplant
It is essential for people who develop severe vomiting and diarrhea from food poisoning to drink plenty of fluid to prevent dehydration.
When to see a doctor
A person should see a doctor if any of the following signs and symptoms occur after ingesting maggots:
- visible larvae in stools
- persistent abdominal pain
- symptoms of bacterial poisoning that worsen or do not get better
- diarrhea lasting more than 3 days
- diarrhea and a fever of more than 102˚F
- bloody stools
- signs of dehydration
- severe or persistent vomiting
Do people eat maggots intentionally?
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 close to 2,000 species of edible insect. As well as the insects themselves, the eggs and larvae of certain species are edible.
Casu marzu is a Sardinian cheese that contains thousands of maggots. In the early stages of cheese production, the cheesemaker removes the outer crust, which encourages flies to enter and lay their eggs. Over several months, the larvae eat the rotting cheese. Excrement from the larvae gives the cheese its unique, pungent flavor.
Due to the health risks of eating live maggots, the European Food Safety Authority have banned the sale of casu marzu. However, a small number of Sardinian farmers continue to make the cheese for personal consumption.
Is it safe to eat maggots?
Maggots are particularly high in protein and fat. As such, scientists are currently investigating the possibility of growing, harvesting, and processing black soldier fly maggots for human consumption.
Scientists have suggested heating, drying, and microwaving the larvae to reduce the risk of bacterial contamination. At present, however, there is no guaranteed risk-free way to consume maggots safely.
For most people living in milder climates, such as the U.S., accidentally ingesting maggots is unlikely to cause harm.
People may experience a temporary bout of food poisoning from eating either the contaminated maggots or the spoiled food containing them. However, most cases of food poisoning resolve without treatment after several days.
People should visit a doctor if they experience severe or concerning symptoms after accidentally ingesting maggots.