Common Parasites and Travel-Related Infectious Diseases

Marcela OteroMar 7, 2017

You’ve just stepped off a plane. You are beset with chills, nausea, exhaustion & aching pain.

You chalk it up to a combination of jet lag and traveler’s tummy, but two weeks in, you still feel awful. The cramps haven’t gone away, and the abdominal issues have only gotten worse. 

You keep taking different meds and going to the doctor, but nothing they do works for more than a few days. At this point it’s practically certain: you’ve contracted some sort of parasitic infection. 

After running a battery of tests at the ER, doctors finally determine that the culprit is parasitic. They still can’t positively identify which one, though, so they start treating you with broad spectrum antibiotics. 

The perfect trip can sometimes leave you with unwelcome souvenirs. The CDC has very up-to-date information on their website, detailing possible exposure hubs or outbreaks.

This story is far more common than we’d like to think. As of 2014, more than 700 million people in the world do not have access to improved sources of drinking water. 

We frequently underestimate the importance that clean water can have on education and income, let alone on health.

In fact, drinking or using contaminated water is the main cause of parasitic diseases worldwide. Whenever we travel, whether it be just across the border to beautiful Mexico or halfway across the world to an exotic location like Nepal, we put ourselves at risk for contracting a disease. 

Truthfully, any time and any place you travel (even somewhere innocuous like Canada or Maine), you expose yourself to unfamiliar micro-organisms, some of which can be more harmful than others.

The world is full of scary, creepy-crawly, microscopic species of bacteria and parasites that can provoke awful consequences and have even worse treatments. There’s even a popular television show on the subject. 

Since the symptoms of a parasitic infection frequently overlap with other, more common diseases, it’s rare that doctors even think of parasites in the first place.  Most of the time, they’ll test for other infections and treat accordingly. 

Compounding the problem, many hosts don’t begin to exhibit symptoms until one to three weeks after getting infected, further complicating obtaining an accurate exposure history. 

And, even though they’re usually associated with marginalized communities and underdeveloped countries, some are also prevalent in the United States.

Common parasites to be careful of:

Giarda / Giardiasis 

This is the most common parasite affecting people in the U.S. Infection occurs through close contact with an infected person or animal, or by ingestion or contact with contaminated water. 

Symptoms generally begin between one to three weeks from the moment of infection, and include diarrhea, gas, cramps, upset stomach, nausea, and dehydration.

Chagas disease 

Also referred to as American trypanosomiasis, Chagas disease is transmitted by insect vectors commonly found in rural areas with widespread poverty. 

The acute phase of symptoms begins during the first few weeks or months of infection and is characterized by mild fever, fatigue, body aches, headache, rash, loss of appetite, diarrhea, and vomiting, which usually fade away on their own. 

If untreated, the infection persists and develops into the chronic phase, which can include cardiac and intestinal problems.

Cysticercosis 

A major cause of adult-onset seizures in developing countries, people develop Cysticercosis by ingesting the larval cysts of the tapeworm Taenia solium. 

Once infected, the disease provokes cysts in the muscles, the eyes, the brain, and/or the spinal cord. There are at least 1,000 hospitalizations for this per year in the U.S.

Toxocara / Toxocariasis 

Also known as roundworm, most infected people never develop any symptoms, unless it’s present in very high numbers. Infection occurs through the larvae of two species of Toxocara, which are transmitted by either dogs or cats. 

The larvae can travel through the liver, lungs, or central nervous system, causing fever, coughing, enlarged liver or pneumonia. When they target the eye, it can result in blindness.

Toxoplasma gondii

This is another one that’s spread through our pets (specifically cats), and that can present no symptoms, as a healthy immune system can usually keep the parasite at bay. 

It can also be transmitted through eating undercooked, contaminated meat. The main worry is for pregnant women or people with a compromised immune system. 

Symptoms and potential consequences include swollen lymph nodes, muscle aches and an increased risk for a stillbirth or miscarriage.

Trichomoniasis

This incredibly common and treatable sexual disease affects an estimated 7.4 million people a year in the United States. Many of these people will remain asymptomatic and unwittingly pass this protozoan parasite onto other partners. 

It is more common in women than in men, and when there are symptoms, they include unusual discharge and a burning sensation when passing urine. If left untreated, it puts one at greater risk for contracting or spreading other STDs.

 

Image: Elephant Bath Time - Hampi, India (Source: Jordan Steinberg)

Parasites are uniquely adapted to survival, generally through their complex life cycles, and in some cases have been known to go so far as to change their host’s behavior. They can infect through direct exposure to contaminated water or contact with someone exposed. 

They can enter your body via a vector (a biting insect like a fly or mosquito), and they can also be transmitted through ingestion of contaminated meats or other foodstuffs. 

This doesn’t mean you should actually cancel that amazing, two-month and eight-country tour of Southeast Asia you’ve been planning since senior year with your BFF, it just means you should take some sensible precautions.

What You Should Do

See your doctor 

Before actually stepping foot on a plane, visit your health care provider with an itinerary of your trip (ideally, four to six weeks in advance, as some vaccines need time to work). 

Some colleges and universities also have travel clinics which may be open to the general public, and feature clinicians trained in travel immunizations.

Educate yourself 

The CDC has a handy guide, divided by country, informing you which diseases you ought to watch out for.

Then, be smart 

Depending on where you go, you may be more at risk for certain types of contagion rather than others:

In places where water-borne diseases are common, try to minimize your contact (don’t swim, wade, or bathe in freshwater sources or in the ocean). Avoid ice, fresh fruit, and vegetables you haven’t peeled yourself, and only drink bottled water.

If mosquitoes and vector-borne transmissions are an issue, wear protective clothing and insect repellent to keep the pesky little skeeters away. Stay inside during their most active times, around dawn or dusk.

When infection can come through the soil, be sure to wear appropriate footwear at all times and clean thoroughly with heated water. Some parasites can take months to manifest, so just because you walked around barefoot for a bit and feel fine, don’t take it for granted that nothing’s wrong.

Use common sense, no matter where you go

Things your grandma used to tell you still hold true:

  • Clean your hands often and thoroughly for 20 seconds, (and sing the happy birthday song twice in your head while doing so!)

  • Drink enough (bottled) water. Dehydration affects your ability to get toxins out of your system.

  • Rest. There is no easier way to compromise your immune system than by not getting enough sleep.

  • Get medical care if symptoms persist, such as fever or diarrhea.

  • Be careful if you do decide to eat food from street vendors. While some of the best meals of my life have been eaten on a street corner, there are several rules of thumb I always follow. To insure the food’s freshness, make sure it’s prepared in front of you. For the same reason, try to always go during peak hours, and stick to stalls that are crowded. See if everything looks clean and that the person preparing the food isn’t also handling money.

  • Use prophylactics when engaging in intercourse abroad.

Additional precautions

A good travel insurance policy can help you protect yourself, in the event you actually do contract something during your travels and require medical assistance. 

Most health insurance coverage actually won’t cover you outside of the U.S., but if you take the time to buy insurance, you’re guaranteed a hospital bed and attending doctor at a designated hospital or medical center at your destination.

With the risk of contact so prevalent at home, nevermind some exotic location, the only thing to do is take safety precautions. 

Wash hands frequently, peel fruits and vegetables, ask for meat to be cooked to at least 145°F (medium), don’t drink the water or the ice, and above all, do some research ahead of time! 

Though most travel illnesses aren’t life-threatening or even a concern, some can have truly serious consequences.

With that in mind, be careful out there!!!