condition icon
condition

Lungworms in Humans: Symptoms, Causes, and Treatment

Dr Karen Martin
Reviewed by Dr Karen MartinReviewed on 15.06.2025 | 5 minutes read
EmailFacebookPinterestTwitter

What Are Lungworms?

Lungworms are tiny parasites (worms) that usually live in the lungs of animals like rats, dogs, and cats. Sometimes, these worms can accidentally infect humans too.

The most common type that affects humans is called "rat lungworm" or Angiostrongylus cantonensis. Although these infections don't happen often in humans, they can cause serious health problems if not treated.

Lungworms have a life cycle that normally involves animals. The worms first live in rats, then move to snails or slugs, and then back to rats. Humans get infected accidentally when they eat something that has lungworm larvae (baby worms) on it.

How Do People Get Lungworms?

People can get lungworm infections in several ways:

  • Eating unwashed produce: If you eat fruits or vegetables that haven't been washed properly and have tiny snails, slugs, or their slime on them

  • Eating undercooked food: Eating raw or undercooked snails, slugs, or other carriers

  • Drinking contaminated water: Water that has lungworm larvae in it

  • Traveling to certain areas: Infections are more common in Southeast Asia and Pacific Islands

Signs and symptoms

The symptoms of a lungworm infection depend on where the worms are in your body and how many there are. You might not notice symptoms right away, but they can get worse over time.

Common symptoms include:

Breathing Problems

General Symptoms

  • Fever

  • Feeling very tired

  • Weakness

Brain and Nerve Problems

If the worms move to your brain or spinal cord, you might have:

When lungworms affect the brain, they can cause a condition called eosinophilic meningitis, which is inflammation of the covering of the brain.

Important: If you have headaches, a stiff neck, confusion, or seizures, get medical help right away. These could be signs of a serious problem.

How Doctors Diagnose Lungworm Infections

Finding out if someone has a lungworm infection can be tricky because the symptoms look like many other illnesses. Doctors use several methods:

  1. Medical history: The doctor will ask about your symptoms and if you might have been exposed to lungworms (like travel history or eating raw snails)

  2. Blood tests: These can show if your body is fighting a parasite infection

  3. Spinal tap: If doctors think the infection might be affecting your brain, they might take a sample of fluid from around your spine to check for signs of infection

  4. Imaging tests: X-rays or CT scans can show if there are problems in your lungs

  5. Stool tests: Sometimes doctors check your poop for signs of lungworm larvae

Treatment and prevention

Treatment Options

Treatment for lungworm infections depends on how serious the infection is and which parts of your body are affected. The sooner treatment starts, the better.

Medications to Kill the Parasites

Doctors usually prescribe anti-parasite drugs like albendazole or mebendazole. These medicines kill the worms and stop the infection from getting worse.

Medicines for Inflammation

If the infection has spread to your brain, doctors might give you steroids (like prednisone) to reduce swelling and help prevent damage.

Hospital Care

People with severe infections might need to stay in the hospital, especially if they have trouble breathing or serious brain symptoms.

Pain Relief

Over-the-counter pain relievers like ibuprofen or acetaminophen can help with fever and discomfort.

How to Prevent Lungworm Infections

You can take steps to protect yourself from lungworm infections:

Food Safety

  • Cook food thoroughly, especially if it might contain snails or slugs

  • Wash all fruits and vegetables carefully with clean water

  • Peel fruits when possible

Avoid Carriers

  • Don't eat raw or undercooked snails or slugs

  • Keep pets safe from lungworms with regular vet check-ups

Water Safety

  • Only drink water from safe sources

  • Avoid swimming in water that might be contaminated

Lungworm infections in children

Children can get lungworm infections too, and sometimes their symptoms might be more serious because their bodies are smaller and still developing.

Why Children Might Be at Higher Risk

  • Playing outside in dirt or water where snails and slugs live

  • Not washing hands before eating

  • Putting dirty hands or toys in their mouths

Signs in Children

Children with lungworm infections might have:

  • Coughing that doesn't go away

  • Trouble breathing

  • Fever

  • Being very tired

  • Headaches or seizures if the infection reaches the brain

Protecting Children

  • Teach children to wash hands after playing outside

  • Supervise young children outdoors

  • Make sure they don't put dirty things in their mouths

  • Wash their toys regularly

When to see a doctor

You should see a doctor if:

Breathing Problems

  • Coughing that doesn't go away

  • Trouble breathing that doesn't get better with normal treatments

Brain Symptoms

  • Severe headaches

  • Stiff neck

  • Fever

  • Seizures: These could mean the infection has spread to your brain and needs urgent treatment

Stomach Problems

  • Ongoing stomach pain

  • Feeling sick or throwing up

  • Especially if you also have other symptoms

Common Myths About Lungworms

There are some misunderstandings about lungworm infections that need to be cleared up:

Myth: "Only animals get lungworms."

Fact: While lungworms are more common in animals, humans can get infected too, especially in areas where these parasites are common.

Myth: "You can only get lungworms by eating snails or slugs."

Fact: You can also get infected from unwashed vegetables, fruits, or contaminated water that have tiny snail or slug slime on them.

Myth: "Lungworm infections are always severe."

Fact: Many lungworm infections are mild if treated early. However, without treatment, they can become serious, especially if the infection spreads to the lungs or brain.

Remember, even though lungworm infections in humans are rare, it's important to know about them, especially if you live in or travel to areas where they're more common. If you think you might have a lungworm infection, see a doctor right away.

The AI in healthwords.ai refers to conversational search, while the only AI tools used for articles are grammar and language improvements -  medical content remains rigorously authored by healthcare professionals.

Was this helpful?

This article has been written by UK-based doctors and pharmacists, so some advice may not apply to US users and some suggested treatments may not be available. For more information, please see our T&Cs.
Dr Karen Martin
Reviewed by Dr Karen Martin
Reviewed on 15.06.2025
EmailFacebookPinterestTwitter