Can You Get Parasites From Traveling?

Yes, you can pick up parasites while traveling, most often from food, drinking water, soil or insect bites in places where sanitation is limited. Most stomach upsets on a trip are caused by bacteria or viruses rather than parasites, but a few intestinal worms and other parasites can cause symptoms that show up weeks or even months after you get home.

This page explains how travelers are exposed, which worms are most often linked to travel, why symptoms can be easy to miss, and what a clinician will want to know when you get back. It is general education, not medical advice.

How travelers are exposed to parasites

The CDC's travel-medicine guidance for clinicians describes a handful of everyday exposures behind most travel-related parasite infections:

• Food. Raw or undercooked food, including fresh vegetables and salads that may have been rinsed in contaminated water.
• Drinking water and ice. Water that has not been treated can carry parasite eggs and cysts.
• Soil and sand. Some worm larvae live in soil that has been contaminated with human stool and get in through bare skin, most often the feet.
• Freshwater. A few parasites enter the body through the skin after direct contact with lakes, rivers or streams.
• Insect bites. Some parasites are carried by biting insects, such as the blackflies that spread river blindness.

The risk depends on where you went, how long you stayed, what you ate and drank, and what you did there. A short hotel stay carries different risks from months of rural travel, volunteer work, or farm or field work.

Is it a parasite or ordinary travelers' diarrhea?

Most cases of travelers' diarrhea are caused by bacteria or viruses and clear up on their own, often before the trip is over. The CDC notes that when stomach symptoms last two weeks or longer after a trip, a parasite becomes one of the possibilities a clinician will look into, along with a second infection or a bowel condition that the trip brought to light.

Many of the parasites behind long-lasting travel diarrhea are single-celled organisms called protozoa, such as Giardia and Cryptosporidium. These are not worms, and they are treated with a different group of medicines than the ones Get It Prescribed offers. That is one reason a stool test, rather than a guess, is the usual next step.

Worms linked to travel

The intestinal worms below are uncommon in the United States and are mostly linked to living in, or traveling to, warm places where sanitation is poor.

• Hookworm. The CDC says people get hookworm by walking barefoot on, or swallowing, contaminated soil. The first sign is often an itchy, localized rash where the larvae went through the skin. Many people have few or no symptoms. See hookworm in humans.
• Roundworm (Ascaris). Caught by swallowing eggs from soil, usually on produce that was not washed, peeled or cooked, or on unwashed hands. See roundworm in humans.
• Whipworm. Spread the same way as roundworm, through eggs that have matured in soil. See whipworm in humans.
• Strongyloides. The CDC says it is usually found in tropical regions, particularly Southeast Asia and the South Pacific, and gets in through exposed skin such as bare feet. Most people have no symptoms. See strongyloidiasis symptoms and treatment.
• River blindness (onchocerciasis). Spread by repeated bites of infected blackflies near rivers, mostly in rural sub-Saharan Africa. The CDC says it rarely affects casual travelers; people at higher risk are those who stay for long periods. See onchocerciasis (river blindness).

Pinworm is different. It is common in the United States and spreads between people at home, school or childcare, so it is not considered a travel infection. Our page on whether worms in humans are contagious explains how each worm spreads.

Why symptoms can show up long after the trip

The CDC points out that parasitic infections can be hard to recognize in returning travelers for a few reasons:

• The symptoms are vague. Belly pain, bloating, diarrhea, tiredness, a cough or a rash can come from many causes.
• The timing varies. Some parasites take weeks or months to cause symptoms, and by then the trip may not seem connected.
• Exposures are easy to forget. People often don't remember one salad, a walk on a beach without shoes, or a bite they barely noticed.
• Early tests can be negative. Stool tests look for eggs from adult worms, so they can come back negative while larvae are still moving through the body. With Strongyloides, the CDC notes that stool tests are often negative and a blood test is needed instead.

A blood count can also give a clue. The CDC explains that a raised level of eosinophils, a type of white blood cell, is often what prompts clinicians to consider a worm infection after travel, though it is not a perfect sign.

What to tell a clinician after travel

A clinician will usually ask for a full travel history. It helps to have this ready:

• Every country and region you visited, with dates, and whether the stay was urban or rural
• How long you were away, and whether you lived or worked there
• What you ate and drank, including street food, raw produce, untreated water or ice
• Any time you walked barefoot on soil or sand, or swam or waded in freshwater
• Insect bites, rashes or skin changes during or after the trip
• When your symptoms started, and whether anyone you traveled with is unwell
• Any medicines that weaken the immune system, such as steroids

Depending on the answers, the clinician may order a stool test for parasites, blood tests, or refer you to a travel or tropical medicine specialist. Our guide to what kind of doctor treats parasites explains who does what.

Lowering your risk while you travel

The CDC's general advice for travelers is short:

• Avoid raw or undercooked food, including fresh vegetables or salads that may have been washed in untreated water
• Wash your hands with soap, or use hand sanitizer, as often as you can and especially before meals
• Wear shoes when walking on soil or sand that may be contaminated
• Use insect repellent and cover your arms and legs to prevent bites
• See a travel medicine specialist before the trip for the vaccines and medicines recommended for where you're going

When to get in-person care

See a clinician in person, rather than online, if you have a fever during or after travel abroad, blood in your stool, severe or worsening belly pain, signs of dehydration, a new rash that is spreading, eye symptoms, a weakened immune system, or you are pregnant or breastfeeding. A fever after travel needs prompt in-person care, because some travel infections, such as malaria, can become serious quickly.

Getting a prescription through Get It Prescribed

If a clinician has diagnosed one of the worm infections above after your trip, a licensed provider can review a written health assessment through Get It Prescribed and decide whether mebendazole or ivermectin is appropriate for a labeled use. Mebendazole's labeled uses are pinworm, whipworm, roundworm and hookworm; ivermectin's are intestinal strongyloidiasis and onchocerciasis. Get It Prescribed does not treat protozoa such as Giardia, or other travel infections. No prescription is guaranteed, and the provider may recommend testing or an in-person visit instead. How it works shows each step.

The medicines dispensed through Get It Prescribed are compounded preparations made by a licensed compounding pharmacy. They are not FDA-approved, the FDA has not reviewed them for safety, effectiveness or quality, and they are not generics of, or substitutes for, the brand-name products.

The cost is a one-time $50 provider consultation fee, plus $3.00 per ivermectin tablet or $3.50 per mebendazole capsule if a prescription is issued, with the quantity decided by the provider. The service is for adults and is available in all 50 states and the District of Columbia; some states require a live phone or video visit.

This article is general education, not medical advice. It does not replace an evaluation by a licensed clinician who knows your history.

Related questions

Can you get worms from walking barefoot?

Yes. The CDC says hookworm and Strongyloides larvae live in soil contaminated with human stool and can get in through bare skin, most often the feet. Wearing shoes on soil or sand that may be contaminated is the CDC's main advice for avoiding them.

How long after traveling can parasite symptoms start?

It varies by parasite. Some cause symptoms during the trip, while others take weeks or months, and some cause no symptoms at all. Because the timing is so variable, tell any clinician you see about travel abroad in the past several months, even if the trip seems unrelated.

Can a stool test miss a parasite after travel?

Yes. Stool tests look for eggs from adult worms, so they can be negative early in an infection, and the CDC notes that stool tests are often negative for Strongyloides, which usually needs a blood test. A clinician may repeat a test or order a different one.

Is diarrhea after a trip usually caused by a parasite?

Usually not. Most travelers' diarrhea is caused by bacteria or viruses and clears up on its own. When symptoms last two weeks or longer after returning, a clinician will look at parasites among other causes.

Should I get tested for parasites after travel if I feel fine?

That depends on where you went, how long you stayed and what you were exposed to. Many people have no symptoms, especially with Strongyloides, so talk to a clinician or travel medicine specialist about whether screening makes sense for your trip.

Sources

• CDC Yellow Book: Post-Travel Parasitic Disease Including Evaluation of Eosinophilia — exposures, delayed symptoms, travel history, eosinophilia, and travelers' prevention advice.
• CDC Yellow Book: Post-Travel Diarrhea — most travelers' diarrhea is bacterial or viral; parasites as a cause of persistent symptoms.
• CDC: About Hookworm — spread by walking barefoot on contaminated soil; skin rash as an early sign.
• CDC: About Soil-transmitted Helminths — how roundworm, whipworm and hookworm spread through soil.
• CDC: About Strongyloides — where it is found, skin entry, and risk with immune-weakening medicines.
• CDC: About Onchocerciasis — spread by blackfly bites; rare in casual travelers.
• MedlinePlus: Traveler's Health — consumer overview from the National Library of Medicine.
• DailyMed: mebendazole chewable tablet prescribing information — labeled uses: pinworm, whipworm, roundworm and hookworm.
• DailyMed: ivermectin tablet prescribing information — labeled uses: intestinal strongyloidiasis and onchocerciasis.
• FDA: Compounding and the FDA — Questions and Answers — what compounded preparations are and how they are regulated.