Parasitic infections are not going anywhere, but there are steps travelers can take to avoid them and keep their health up. First, let’s look at the types of parasitic infections and the different ways that they can spread.

How Parasitic Infections Spread

When it comes to parasitic infections, there are three ways that they spread: through contaminated food or water, vector-borne transmission, or person-to-person contact.

Contaminated Food or Water

When traveling, it’s always best to be cautious of the food and water you ingest, specifically ensuring that it has been prepared correctly (and ideally by yourself). Otherwise, you might be consuming more than just food or water.

There’s a rule of thumb to follow when it comes to what you eat and drink: cook it, boil it, peel it, or leave it! By following these guidelines, you ensure you do all you can to avoid and remove contaminants such as parasites.

Just what might be lurking in ill-prepared food or nearby water? Some of the more common illnesses include giardiasis, cyclosporiasis, or cryptosporidiosis. Giardia, in particular, is a common cause of traveler’s diarrhea, and it most commonly gets people sick when they swallow contaminated drinking water or recreational water such as rivers, lakes, or pools.

Vector-Borne Transmission

These parasitic infections result from other animals through blood feeding. While this sounds like something out of a fantasy (or perhaps horror) novel, it simply refers to animals that bite, such as mosquitos or ticks.

One of the most common––and dangerous–– vector-borne illnesses is malaria, which is transmitted through the bite of an infected mosquito. Since these bugs are sneaky, it’s always best to know if you are traveling somewhere where vector-borne transmission, such as malaria infection, is common so that you can take the proper precautions.

For mosquito or tick-borne illnesses, this includes wearing long clothing, sleeping with a mosquito net, and using bug spray during the day.

Person-To-Person Contact

This method of transmission occurs when an infected individual spreads an illness to another individual, usually through close contact.

One such example of this is trichomoniasis, a sexually transmitted infection (STI). In cases such as this, the best method of prevention is using a condom while engaging in sexual intercourse, no matter which type of intercourse you are having. Not only will this prevent against parasitic STIs, but it will also protect against other types like gonorrhea and chlamydia.

Symptoms of Parasitic Infections

Unfortunately, symptoms of parasitic infections vary based on the organism causing the infection. Let’s take a look at some of the most common:

Giardiasis: can cause gas, diarrhea, upset stomach, or dehydration.

Trichomoniasis: often produces no symptoms, but in some cases, it may cause redness, itching, and an unusual discharge in the genital area.

As you can see, each infection has different symptoms. However, for a general guide, some of the common symptoms of infection include:

• Muscle aches
• Fever
• Nausea
• Vomiting
• Diarrhea
• Fatigue

Some parasitic infections may also cause a severe headache, itching, seizures, disorientation, rash, or sores.

If you are experiencing any of the above symptoms or anything concerning, it’s best to visit a healthcare provider to determine the cause of your symptoms and begin treatment if necessary.

How to Avoid Parasites

It may seem overwhelming - all the ways that parasitic infections may spread - but there are steps that you can take to protect yourself and others. 

Practice Good Hand Hygiene

When traveling, wash your hands often with soap and water, especially when you are more likely to spread germs, such as when eating or preparing food.

It’s also important to remember that some parasites, such as Giardia, can be found in soil, so make sure to wash your hands after doing any fieldwork, even if you wear gloves.

Swim Responsibly

If you’re going to a lake, pool, or any other place to swim, do not swallow the water. Additionally, it’s good practice to shower before getting in the water to help wash away any germs that may be lingering on your skin.

Do not go swimming if you or a child are sick with diarrhea. Additionally, if you are with a young child, take them on frequent bathroom breaks or check their diapers every hour. When changing diapers, do so in a bathroom or diaper-changing areas, not by the water, to help keep poop and germs out of the water.

Avoid Contaminated Food and Water

When it comes to what you ingest, take extra care that it is safe to consume. Avoid untreated water, including ice made with water from rivers, lakes, springs, streams, ponds, or shallow wells. If you cannot guarantee that your drinking water is safe, opt for bottled water, use a filter certified for “cyst” and “oocyst” reduction, or boil your water for one minute first to make it safe to drink.

As for your food, you want to peel or wash any produce, but again, don’t use water that might be contaminated. Also, avoid eating raw foods; if you’re unsure if your food is fully cooked, pass on it. 

Risk Factors of Parasitic Infections

Anyone can get a parasitic infection, but some individuals are at a greater risk. As such, if you fall into these categories, it’s recommended to reach out to a travel medicine specialist to determine what you should do to best protect yourself.

Those at a greater risk of parasitic infection include those who:

• Are traveling to a tropical or subtropical area.
• Have a compromised immune system.
• Swim in lakes, ponds, or rivers where Giardia or other parasites are common.
• Lack a clean supply of water for drinking.
• Work with soil.

Staying Proactive Against Parasites

Because of the many ways that parasites can spread, it is best to know what you might be susceptible to based on your travel location. For example, are you traveling somewhere where malaria or giardiasis are common? Knowing this before your trip ensures you take proper precautions to protect yourself from infection.

To best understand everything you might be at risk of, it’s always recommended to book a travel consultation. During this meeting, a travel medicine specialist will provide information specific to you and your trip, keeping you safe while traveling and preventing any parasites from calling you their host.

References

Cox F. E. (2002). History of human parasitology. Clinical microbiology reviews, 15(4), 595–612. https://doi.org/10.1128/CMR.15.4.595-612.2002

NHS Choices. Prevention - Trichomoniasis. https://www.nhs.uk/conditions/trichomoniasis/prevention/

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CDC - Parasites - Travelers. https://www.cdc.gov/parasites/travelers.html