Many people have pet mice or encounter wild mice in their homes, yards, and other places. A common concern is whether mice can transmit worms or other parasites to humans. This article will examine the types of worms mice can carry, how humans can get infected, symptoms of worm infections, and ways to prevent transmission.
Types of Worms Mice Can Carry
There are several parasitic worms that mice can carry and potentially transmit to humans:
- Pinworms – Pinworms, also known as threadworms, are one of the most common worms found in mice. The pinworm species that infects mice is Syphacia obvelata. These small, white worms live in the intestines and can cause anal itching in infected mice. Pinworm eggs are hardy and can survive for weeks to months in the environment.
- Tapeworms – Mice are intermediate hosts for certain tapeworm species, such as Hymenolepis nana and Hymenolepis diminuta. These tapeworm larvae develop in mice after they ingest tapeworm eggs. The tapeworm larvae form cysts in mice tissue. If a human eats the infected mouse, the tapeworm can complete its lifecycle and mature into an adult tapeworm in the human intestines.
- Roundworms – Mouse roundworm species including Aspicularis tetraptera and Syphacia muris can also occasionally infect humans. Roundworm larvae develop in mice after ingesting roundworm eggs. The larvae migrate through mouse tissues and form cysts. Humans who eat infected mice meat or ingest eggs from mouse feces can become infected.
- Rat lungworm – The rat lungworm, Angiostrongylus cantonensis, can rarely cause human infection. Infected rats or mice pass first-stage larvae in their feces. Snails and slugs can then ingest the larvae, which develop into infectious third-stage larvae. Humans typically get infected by accidentally eating infected snails or slugs on produce.
- Toxoplasmosis – The Toxoplasma gondii parasite causes toxoplasmosis in humans. Cats are the definitive host, but mice and other animals can serve as intermediate hosts and harbor tissue cysts of the parasite. Ingesting undercooked infected mouse meat could potentially transmit toxoplasmosis.
How Do Humans Get Infected?
There are several ways humans can pick up worm infections from mice:
- Ingesting eggs – Many worm species shed microscopic eggs that pass out in mouse feces. Accidentally ingesting pinworm, tapeworm, or roundworm eggs from contaminated surfaces, food, or soil can lead to infection.
- Eating infected meat – Consuming undercooked or raw mouse meat that contains worm larvae or cysts could result in tapeworms, roundworms, rat lungworms, or toxoplasmosis.
- Contaminated hands – Touching mice or surfaces contaminated with mouse feces then touching the mouth without proper handwashing can transmit pinworm or other worm eggs.
- Bite wounds – Although rare, worm larvae could theoretically migrate into human tissues through a mouse bite wound.
- Snail/slug hosts – Accidentally ingesting raw snails or slugs that have eaten rat lungworm larvae can infect humans with rat lungworms.
Symptoms of Worm Infections in Humans
Signs and symptoms of acquiring a mouse-related worm infection may include:
- Itching around the anus or vagina from pinworms migrating to lay eggs
- Digestive symptoms like nausea, vomiting, diarrhea from intestinal worms
- Abdominal pain or distension from roundworm or tapeworm infection
- Coughing, wheezing, neurological issues from rat lungworm infection
- Muscle and joint pain, fatigue, fever, rash from toxoplasmosis
- Visible worm segments or eggs in the feces
- Anemia, malnutrition, or weight loss from intestinal worms
However, many worm infections cause no symptoms at all, especially if there is only a small number of worms. Tapeworms only occasionally cause mild digestive upset. Rat lungworm and toxoplasmosis infections are more serious and can lead to severe illness.
Preventing Worm Transmission from Mice
You can take these precautions to avoid acquiring a worm infection from mice:
- Practice good hygiene – Wash hands thoroughly after contact with mice or rodent droppings. Disinfect surfaces mice may have contaminated.
- Sanitize fruits and vegetables – Thoroughly wash produce to remove any possible parasites.
- Avoid eating raw snails/slugs – Only eat snails and slugs that are thoroughly cooked to kill rat lungworm larvae.
- Cook meat fully – Make sure any mouse meat is cooked to an internal temperature of 165°F to kill worms and other pathogens.
- Control mice – Reduce any mouse infestations, droppings, nests etc. using humane methods and by sealing up entry points in the home.
- Deworm pets – Have cats, dogs, and other pets regularly dewormed to prevent spreading worms in feces.
- See a doctor – If you develop any gastrointestinal or flu-like symptoms after cleaning up mice, visit your doctor and mention the rodent exposure.
By taking proper precautions, the risk of acquiring a worm infection from mice is very low for most people. However, certain high risk groups like children, pregnant women, and those with weakened immune systems should take extra care to avoid mouse parasites.
Conclusion
Mice do carry several types of worms that can be transmitted to humans under the right circumstances. Pinworms, tapeworms, roundworms, rat lungworms, and toxoplasmosis parasites from mice can all occasionally infect people. Consuming contaminated food or water, eating infected mouse meat, contact with feces, and ingesting slugs/snails are ways the worms can spread to humans. Symptoms range from mild to severe. Practicing good hygiene, thoroughly cooking any rodent meat, controlling mice, and deworming pets can help prevent worm infections. While not common, worms from mice should not be completely ignored as a potential health risk.