Parasitic Infections

By Medically reviewed by hellodoktor


What are Parasitic Infections?

Parasites are organisms that live off other organisms, or hosts, to survive. Some parasites don’t noticeably affect their hosts. Others grow, reproduce, or invade organ systems that make their hosts sick, resulting in a parasitic infection.

How common are Parasitic Infections?

Parasitic infections are a big problem in tropical and subtropical regions of the world. They are more common in rural or developing areas than in developed areas. Please discuss with your doctor for further information.


What are the symptoms of Parasitic Infections?

The symptoms of parasitic infections vary depending on the organism. For example:

  • Trichomoniasis is a sexually transmitted infection caused by a parasite that often produces no symptoms. In some cases, it may cause itching, redness, irritation, and an unusual discharge in your genital area.
  • Giardiasis may cause diarrhea, gas, upset stomach, greasy stools, and dehydration.
  • Cryptosporidiosis may cause stomach cramps, stomach pain, nausea, vomiting, dehydration, weight loss, and fever.
  • Toxoplasmosis may cause flu-like symptoms, including swollen lymph nodes and muscle aches or pains that can last for over a month.

There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.

When should I see my doctor?

If you have any signs or symptoms listed above or have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.


What causes Parasitic Infections?

Parasitic infections can be caused by three types of organisms:

  • Protozoa
  • Helminths
  • Ectoparasites

Protozoa are single-celled organisms that can live and multiply inside your body. Some infections caused by protozoa include giardiasis. This is a serious infection that you can contract from drinking water infected with Giardia protozoa.

Helminths are multi-celled organisms that can live in or outside of your body. They’re more commonly known as worms. They include flatworms, tapeworms, thorny-headed worms, and roundworms.

Ectoparasites are multicelled organisms that live on or feed off your skin. They include some insects and arachnids, such as mosquitos, fleas, ticks, and mites.

Parasitic infections can be spread in a number of ways. For example, protozoa and helminths can be spread through contaminated water, food, waste, soil, and blood. Some can be passed through sexual contact. Some parasites are spread by insects that act as a vector, or carrier, of the disease. For example, malaria is caused by parasitic protozoa that are transmitted by mosquitos when they feed on humans.

Risk factors

What increases my risk for Parasitic Infections?

There are many risk factors for Parasitic Infections, such as:

  • Have a compromised immune system or are already sick with another illness
  • Live or travel in tropical or subtropical regions of the world
  • Lack a clean supply of drinking water
  • Swim in lakes, rivers, or ponds where giardia or other parasites are common
  • Work in childcare, work with soil regularly, or work in other contexts where you come into contact with feces on a consistent basis

Outdoor cats can come into contact with infected rodents and birds. This makes their owners more likely to contract toxoplasmosis, a type of protozoa. Toxoplasmosis can be very harmful for pregnant women and their developing babies. The infection is spread through cat feces. If you’re pregnant, it’s important to have someone else clean the litter box daily.

Diagnosis & treatment

The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.

How are Parasitic Infections diagnosed?

Doctors suspect a parasitic infection in people who have typical symptoms and who live in or have traveled to an area where sanitation is poor or where such an infection is known to occur.

Laboratory analysis of specimens, including special tests to identify proteins released by the parasite (antigen testing) or genetic material (DNA) from the parasite, may be needed. Samples of blood, stool, urine, or phlegm (sputum) may be taken.

Doctors may test blood samples for antibodies to the parasite. Antibodies are proteins produced by the immune system to help defend the body against a particular attack, including that by parasites.

Doctors may also take a sample of tissue that may contain the parasite. For example, a biopsy may be done to obtain a sample of intestinal or other infected tissue. A sample of skin may be snipped. Several samples and repeated examinations may be necessary to find the parasite.

If parasites live in the intestinal tract, the parasite or its eggs or cysts (a dormant and hardy form of the parasite) may be found in the person’s stool when a sample is examined under a microscope. Or parasites may be identified by testing the stool for proteins released by the parasite or genetic materials from the parasite. Antibiotics, laxatives, and antacids should not be used until after the stool sample has been collected. These drugs can reduce the number of parasites enough to make seeing the parasites in a stool sample difficult or impossible.

How are Parasitic Infections treated?

Your treatment plan will depend on your specific diagnosis. Typically, your doctor will prescribe medications. For example, they may prescribe medications to treat trichomoniasis, giardiasis, or cryptosporidiosis. They probably won’t prescribe medications for toxoplasmosis if you’re not pregnant and otherwise healthy, unless you have a severe and prolonged infection.

Your doctor may also recommend other treatments to relieve your symptoms. For example, many parasitic infections can cause diarrhea, which often leads to dehydration. Your doctor will likely encourage you to drink plenty of fluids to replenish those you lose.

Lifestyle changes & home remedies

What are some lifestyle changes or home remedies that can help me manage Parasitic Infections?

The following lifestyles and home remedies might help you reduce your risk of Parasitic Infections:

  • Practice safe sex, using a condom.
  • Wash your hands regularly, especially after handling uncooked food or feces.
  • Cook food to its recommended internal temperature.
  • Drink clean water, including bottled water when you’re traveling.
  • Avoid swallowing water from lakes, streams, or ponds.
  • Avoid cat litter and feces when you’re pregnant.

If you have any questions, please consult with your doctor to better understand the best solution for you.

Hello Health Group does not provide medical advice, diagnosis or treatment.


Review Date: August 23, 2018 | Last Modified: September 13, 2019

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