Why do parasites appear in the body?

Parasites are organisms that live off another living being, known as a host, from which they obtain nutrients to survive. They can appear in the human body for various reasons, and although they are often associated with poor hygiene or contaminated water, the truth is that parasites can affect anyone, regardless of their environment. Understanding why they appear and how to prevent them is key to protecting our health.

1. Water and food contamination

One of the main routes parasites enter the body is through the consumption of contaminated water or food. In many regions of the world, access to safe drinking water is limited, increasing the risk of individuals ingesting microorganisms, such as protozoa or parasite eggs, present in untreated or poorly treated water. Food, especially raw fruits and vegetables, can also be contaminated if not washed properly.

The most common parasites transmitted this way include helminths (worms) and protozoa , such as Giardia or Entamoeba histolytica , which cause gastrointestinal infections.

2. Contact with contaminated surfaces

Another important source of parasitic transmission is contact with contaminated surfaces or objects. Parasites, such as roundworm eggs, can be found in soil, public areas, bathrooms, or bedding, and are transmitted when hands come into contact with these surfaces and then touch the mouth or food.

In rural areas or developing countries, walking barefoot on soil contaminated with human or animal feces is a common route for infestation with parasites such as hookworms .

3. Poor personal hygiene

Personal hygiene is essential to prevent the appearance of parasites in the body. Poor hygiene practices, such as not washing your hands after using the bathroom or before eating, significantly increase the risk of ingesting parasitic eggs. Children in particular, due to their tendency to touch everything and put their hands in their mouths, are more susceptible to parasitic infections.

4. Travel to endemic regions

Traveling to areas with poor sanitary conditions or where certain parasitic infections are common can increase the risk of infestation. Regions in Africa, Latin America, and Asia have a higher prevalence of parasites due to a lack of access to clean water and adequate sewage systems. It is crucial for travelers to take precautions, such as drinking only bottled water and avoiding raw foods, in these areas.

5. Contact with animals

Some parasites are transmitted from animals to humans (zoonoses). Pets, especially cats and dogs, can carry parasites such as tapeworms and intestinal worms . Close contact with them or their feces can facilitate the transmission of these parasites. Therefore, it is essential to maintain regular deworming of pets and avoid contact with animals without veterinary supervision.

6. Weakened immune system

A weakened immune system can make a person more susceptible to parasitic infections. Conditions such as HIV, cancer, or long-term use of immunosuppressive medications can reduce the body's ability to fight parasites, which makes them more likely to proliferate and can worsen symptoms.

Symptoms of the presence of parasites

The presence of parasites in the body can manifest in different ways, depending on the type of parasite and its location. Some of the most common symptoms include:

• Abdominal pain

• Diarrhea or constipation

• Unexplained weight loss

• Constant fatigue

• Itching in the anal area (especially in the case of worms)

• Skin problems, such as rashes or pimples

Prevention and care

To avoid parasite infestation, it is important to:

• Drink only potable or bottled water.

• Wash your hands before eating and after using the bathroom.

• Cook food thoroughly, especially meat.

• Wash fruits and vegetables thoroughly before eating them.

• Maintain adequate personal hygiene.

• Deworm pets regularly.

Parasites can enter the body in multiple ways, primarily through contaminated food or water, dirty surfaces, or contact with infected animals. Maintaining hygiene habits and being aware of risk factors, especially when traveling, is essential to preventing parasitic infections. By taking care of our environment and maintaining good hygiene, we can avoid these annoying and sometimes dangerous visitors.