Parasitic infections are a major concern in tropical and sub-tropical areas across the world. These types of infections can spread through contaminated water, food, a waste product, blood and many other ways. 

Want to know more about diseases caused by parasites? Read the following section to understand parasitic infection, causes, symptoms, and treatment.

Parasites are organisms that live on or inside an organism (host) and survive at the host’s expense. It means parasites benefit from the host by getting nutrients for their survival. 

Parasites can be of different sizes, such as microscopic or large enough to be seen through naked eyes. These parasites can grow, breed, and infect other organs, leading to parasitic infection and, in worst cases, sepsis.

Sepsis can occur from infections such as urinary tract infection and pneumonia. A report says one-third of the population (globally) who have sepsis die. Those who survive suffer from life-changing organ malfunction, post-traumatic stress disorder (PTSD), or amputation.

Now that the basic definition of parasitic infection is clear to individuals let’s focus on causes, symptoms, risk factors, treatment, prevention and other areas.

Below is a list of worms that commonly causes parasitic infection,

• Flatworms (e.g., Tapeworm, Flukes)
• Roundworms (e.g., Hookworms, Pinworms/Threadworms, Trichinosis).

Depending on the organism living on or inside the host, the common diseases caused by parasites and their symptoms may vary. The generic symptoms include:

• Nausea
• Weight loss
• General weakness
• Lack of appetite
• Diarrhoea
• Abdominal pain
• Lumps or bumps
• Allergic reaction
• Itchy rash
• Fatigue
• Anaemia
• Fever and headache
• Light sensitivity
• Conjunctivitis
• Muscle pain and tenderness
• Swelling of the face

Parasitic infection can develop in any individual, but some individuals have a greater risk of getting affected. They are:

• Individuals who have a poor immune system or suffer from other illnesses.
• Individuals who nurture a habit of swimming in rivers, lakes or ponds where parasites like Giardia or other variants are usually found.
• People living in areas that do not get a supply of clean drinking water.
• Individuals living in tropical or sub-tropical regions or frequently travel there.
• Individuals whose profession (such as childcare, soil-related work) involves coming into contact with faeces regularly.

Further, individuals who have pets like cats have higher chances of developing parasitic infection as these cats come into contact with infected birds or rodents during outdoor activities. Wondering how?

Cat owners can contact a certain type of protozoa named Toxoplasmosis. Toxoplasmosis related infections can spread through cat faeces and are very dangerous for pregnant women and developing babies. Hence, to avoid such infections, cat owners must clean litter boxes on a regular basis.

Three types of organisms are primarily responsible for diseases caused by parasites in humans. These are as follows,

• Protozoa
• Ectoparasites
• Helminths

Protozoa: These are single-celled organisms that can grow and multiply inside a body. This organism can come in different sizes and shapes and are available in a wide variety of habitats such as soil, freshwater and marine environments.

Browsing the internet for the name of two parasitic protozoa that cause diseases in humans?   These are,

• Trypanosoma Protozoa (can cause sleeping sickness, a disease common in Africa)
• Giardia Protozoa (can cause Giardiasis, a disease that can spread through contaminated (food and water. This contamination can occur through the faeces of infected animals or people).

Ectoparasites:  Ectoparasites are multi-celled organisms that live on the skin of the host and derive nutrients for survival. Examples of these organisms include fleas, mosquitos, ticks etc. 

Helminths: These are multi-celled large macroparasites. These organisms are commonly known as worms and can live in or outside the body. Organisms such as tapeworms, flatworms, and roundworms fall under this category.

There are several ways doctors can diagnose diseases caused by parasites. These are as follows,

• Blood test: Doctors prescribe such tests to look for parasites in the blood.
• X-rays/ Magnetic resonance imaging (MRI)/ Computerized Axial Tomography (CAT): Doctors prescribe these scans to check for signs of lesions or injury to your organs due to parasites.
• Endoscopy/Colonoscopy: If doctors cannot identify the results of the stool exam, they prescribe for this test. Through this test, doctors examine the intestinal tract.
• Faecal Exam: Here, health care providers collect a sample of stool and check for parasites and their eggs.

The treatment of parasitic infection depends on the type of infection and the report of diagnosis. In such cases, doctors usually prescribe medication. For instance, doctors prescribe medications to treat infections such as Giardiasis, Cryptosporidiosis, Trichomoniasis etc.

On the other hand, doctors do not prescribe medication to treat Toxoplasmosis for pregnant women unless they have severe infections.

Further, doctors may recommend surgery and additional medications in case of severe parasitic infection where infections have invaded other organs.

Additionally, doctors can recommend other modes of treatment to reduce parasitic infection-related symptoms. For instance, several parasitic infections can cause diarrhoea, further resulting in dehydration. Doctors may recommend drinking more water or fluid to balance bodily liquid in such cases.

To prevent parasitic infection, individuals have to follow safety measures. These are as follows,

• Avoid eating raw or undercooked meat, fish, or poultry.
• Regularly disinfect utensils, all cutting boards, and other cooking materials that came into contact with raw meat.
• Do not eat watercress or other raw freshwater plants.
• Avoid cross-contamination while preparing food, especially meat.
• Do not walk barefoot, especially in those places where soil may come into contact with animal faeces.
• Clean up animal waste.
• Do not come near cat litter and faeces, especially during pregnancy.
• Wash your hands frequently while touching uncooked food or handling faeces.
• Do not cook food at a lower than recommended internal temperature.
• Always drink clean water. While travelling, make sure you drink bottled water.
• Be careful while swimming in lakes, streams, or ponds and avoid swallowing water from there.

The above-mentioned piece gives a detailed overview of the diseases caused by parasites. Read these details carefully and contact a doctor if you start experiencing any of the symptoms mentioned above.