Causes of Human Parasites

Our immune system is a sophisticated mechanism designed to keep us protected from all sorts of harmful alien bodies entering our bodies. However, human parasites have over the years have developed the combatting system that can interact with our bodies and corrupt its immunity in unimaginable ways. Along with human evolution, the parasite has also evolved in the ways they manipulate our system. A lot of times, parasites live in our bodies for decades without even being noticed. They thrive on the nutrition that is meant for our cells and systems.

In a study conducted by WHO in 2010, the parasitic infections resulted in 48.4 million cases with a 95% uncertainty interval. This shows the alarming rate at which people are being infected by this microorganism.

To keep our immune system up and running, we need to be familiar with the things that cause these parasites to enter our system in the first place. A little knowledge about the causes can go a long way in creating awareness about these infections. It would also make you more conscious of your surroundings and help you prevent the risk of getting any parasitic infections.

Causes of human parasites

There are various ways in which a person can be infected by a parasite. We have prepared an exhaustive list of the primary and secondary contributors that can cause parasite infections for our readers. Let’s have a look at each of these causes and discuss them in detail:

1. Raw and under-cooked meat

When infected animals and fishes are eaten raw or are undercooked, they may provide a medium for the parasites to enter our bodies. The presence of parasites in such food is very hard to detect. That is the reason why some raw cut meats have dietary restrictions and ‘ideal sit time’ associated with it.

2. Contaminated water

In the past few years, water-borne diseases have increased exponentially and most of them are caused by parasites that are present in the contaminated water. According to a study done in Iraq by Noor Nihad Baqer and her colleagues, it was found that most of the waterborne parasites are relevant in areas near agricultural lands that are infected by animal waste. The water enters into our household tank and contaminates our system eventually.

However, it is not just limited to drinking contaminated water. Even swimming in a parasite-infected pool or drinking unpasteurized juices can cause the same harm to our system.

3. Contaminated soil

According to WHO, approximately 1.5 billion people are infected with soil-transmitted helminths worldwide. The soil gets infected by the eggs of the parasites and if the land is used for the cultivation of vegetables then these vegetables get infected by eggs and the eventual consumption of it leads to the threat of having parasitic infections. Even kids playing in contaminated soil are at risk of getting these infections.

Parasites such as hookworms present in the soil can penetrate into the skin and infect your body. They feed off your tissues and take up the necessary nutrition for your body.

4. Contact with contaminated feces

When you ingest ineffective eggs or cysts present in feces then you are at a high risk of corrupting your system with dangerous parasites. Having food from roadside food vendors may also increase the possibility of your food being infected by animal feces. It is hence advisable for you to double-check the places from where you eat.

5. Personal hygiene and sanitation

Personal hygiene plays a big role in the spread of parasitic infections. Not washing hands frequently and defecating in open spaces can expose you to various fatal disease-bearing parasites. A lot of the causes of parasitic infection can be kept at bay if your personal hygiene is maintained.

6. Sexual transmission

Diseases like amebiasis and giardiasis can spread through sexual contact. Intimate contacts can pass on the parasites from one human to another and cause acute and chronic illnesses. The symptoms of these diseases are hard to identify and most often stool tests reveal the presence of parasites in our system. The use of external protection helps in controlling the spread of such sexually transmitted parasitic infections.

These were some of the major causes that cause human parasitic infections. Different parasites have different ways to contaminate our bodies. Some of the parasites also can be spread via vectors or carriers like mosquitos and insects. The causes listed above can help you identify the red flags and prevent such infections.

How do you get infected by parasites?

The initial stage of getting infected by a parasite mostly starts when you ingest something that is contaminated. The detailed process of how the parasite enters your system and harms it bit by bit can be referred to from our previous post.

Ingestion of contaminated food is not the only way in which a person can get infected. There are predominantly 4 mediums through which you can get infected by the parasites:

  1. Oral transmission
  2. Sexual transmission
  3. Vector-based transmission
  4. Penetration through skin

Parasites have their way of making homes into your system by the above-listed ways. Some of these mediums are more aggressive as compared to others.

Where do people get infected by parasites the most?

The fastest way for a parasite to make its way into our bloodstream is via oral transmission. More than half of the people suffering from parasitic infections catch these infections because of contaminated food and water.

Through our mouths, parasites have an easy way to target an organ and multiply there.

When these parasites are consumed inadvertently, they colonize your intestines and other major organs of your body and find their target. They then deprive these organs of their nutrition and cause fatalities.

Unwashed hands also pose a threat to our system. Touching your eyes and mouth with infected hands can eventually let the parasite enter your system.

It becomes our utmost priority to takes these few steps to stop oral transmission of parasitic infections:

  1. Wash your hands regularly
  2. Be cautious while cold cuts of meat
  3. Always cook your food properly
  4. Avoid eating stale food and drinking contaminated water

These tips might help you reduce the risk of parasites entering your system.


Knowing the key points about the causes of parasite infection can make you more prudent and help you bring some necessary lifestyle changes that can drastically reduce your chances of getting infected.

This article was not to make you finicky and over-conscious about all your moves but it was to help you gain an insight into parasite transmission mechanism. It is better to be few steps ahead make wise choices when it comes to the food we eat, the water we drink, the surfaces we touch, and the people we come in contact with.

Let’s learn from the old saying “Prevention is better than cure.”