Parasites in Children: Causes, Types, Symptoms, Treatment, Complications and Prevention

Parasitic diseases include infections by protozoa (unicellular organisms such as malaria), helminths (worms) and arthropods (such as mange).

A parasite is an organism, or small animal, that lives in or on and takes its food from another organism.

A parasite can not live alone. Parasites include fleas, lice and worms.

Parasitic infection or infestation can occur in children of all ages.


Parasites pose a significantly greater danger to children than to adults, especially those in low-income countries.

If you live in a high-income country, you probably have not spent much time worrying about the parasites.

But for young people in economically less developed countries, the risk of parasitic infection is a daily and deadly concern.

Diseases caused by parasites, which include diarrheal diseases, nutritional deficiencies , malaria and intestinal infections, often kill children in these countries.

Malaria was the leading cause of death among children under five in West Africa in 2013, causing an estimated 627 deaths per 100,000 children.

But in Europe, North America and Australasia, malaria did not kill a single child under five years of age that year.

Parasites contribute to a large difference in infant mortality rates.

In 2015, the overall under-five mortality rate in high-income countries was only 6 children per 1,000.

The figure in low-income countries? An amazing 47 for every 1,000, almost eight times as high.


Babies, toddlers, and very young children in day care are at risk for the parasitic disease called giardiasis that causes diarrhea and is spread through contaminated feces.

Infection with intestinal worms ( enterobiasis ) also occurs in pre-school and school-age children.

Both pre-school and school-age children can become infected with lice (pediculosis) or scabies, which are spread by close person-to-person contact, as is common during children’s play.

Children of all ages can develop parasitic diseases such as giardiasis and cryptosporidiosis by ingesting contaminated water during swimming, play and other activities in polluted recreational waters (eg, swimming pools, springs, lakes, rivers and streams, etc.).

Pets and other animals can be a potential source of parasites that can affect children.

Toxoplasmosis is transmitted by ingesting soil or the contents of the litter box with infectious cat feces.

Children can also be born with this infection if their mother became infected during pregnancy.

Several parasitic diseases that occur occasionally and more frequently in developing countries, but its prevalence has not been well studied.

They include strongyloidiasis, caused by a worm infection that is particularly dangerous for children with a compromised immune system.

It is acquired when the larvae (immature worms) in the soil contaminated with infected human feces come into contact with the skin and penetrate it.

They also include visceral toxocariasis, they spread when children ingest dirt contaminated with dog or cat feces containing round cat or dog worm eggs and cutaneous larva migrans, transmitted when children walk barefoot on soil contaminated with cat hookworm larvae or dog that penetrate the skin.

Other parasitic diseases are rare among children, but they are widespread and represent a significant burden of morbidity among children in developing countries.

The most important of these is malaria. Children in countries with endemic malaria are at high risk of suffering the harmful effects of malaria infection.

The schistosomiasis , another important parasitic disease among children in some countries, can also cause problems of growth and development and can lead to serious health problems later in life.

It is caused by a helminth that spends part of its life cycle in certain types of snails and penetrates the skin of people when they stop or swim in the water where the snails live.

The helminth that causes onchocerciasis (“river blindness”) is transmitted by the bite of a type of black fly that breeds near flowing water.

It can cause itching and vision problems in children and lead to blindness in adulthood.

Children are infected with helminths causing lymphatic filariasis through mosquito bites.

Damage to the lymphatic system in children is mostly asymptomatic, but it can become symptomatic at puberty and cause swelling of the arms and legs and a dilated and fluid-filled scrotum in adulthood.

Previous diseases (STH, onchocerciasis, schistosomiasis, and lymphatic filariasis) are considered Neglected Tropical Diseases because they disproportionately affect impoverished people.


Most parasitic infections share some symptoms, among them are:

  • Watery diarrhea
  • Soft, greasy stools
  • Fatigue.
  • Cramps in the stomach
  • Swelling.
  • Nausea.
  • Severe weight loss
  • Blood and mucus in the stool.

However, for children suffering from intestinal worm, dientamoeba and amoebiasis (only symptoms if it becomes a severe infection) will not present any symptoms beyond a simple itching.

Why are parasites so dangerous for children?

Even when they do not result in death, the parasites still pose a significant danger to children.

Many endoparasites cause diseases, such as malaria, schistosomiasis or leishmaniasis, which have their own harmful symptoms.

By disrupting the inner workings of children’s bodies, parasites also constantly waste nutrients and energy, which can hamper mental development and body growth. For example:

  • Helminths can cause diarrhea:  leading to nutrients being excreted before being absorbed.
  • They can also cause blood loss in the intestine:  leading to iron deficiency (anemia).
  • Some helminths and protists actually eat their host’s tissues, which then have to be replaced.
  • Viruses destroy cells to reproduce:  remember that bacteria and viruses also show parasitic behavior.

Parasites and their actions can also trigger problems in a child’s immune system, which in turn needs energy to function, creating an even greater energy deficit.

This means that fuel is diverted away from where it is needed, as in the developing brain of a child eager for energy.

The brains of newborn babies require 87 percent of the energy produced by their bodies, compared to 44 percent in five-year-olds and 25 percent in adults.

Any energy deficit suffered during childhood has a significant effect on cognitive development.

The researchers also found a strong negative correlation between the severity of the disease and the average IQ of a country.

In other words, what they think is happening in low-income countries, but they have not yet shown it, is that parasites so impede children’s cognitive development that this has a long-term effect on the population .

They believe that this could be one of the reasons behind the mysterious Flynn effect , the tendency for a country’s average IQ to increase as time passes (and suggest that economic development leads to a decrease in parasitic disease) .

Why are parasites a big problem in low-income countries?

There are two reasons, the first is the weather.

Many disease-causing organisms prefer to live in warm, humid habitats near the Earth’s equator, which is where many low-income countries are.

High-income countries are often more temperate, so they harbor fewer parasites, and those that are present are generally less virulent.

These routes of infection are much more prevalent in low-income countries, where outdoor lifestyles, poor sanitation, lack of protective footwear and overpopulation of housing, often as a result of rapid urbanization, are more common.

A child in a low-income country is also less likely to have access to adequate medical care to treat a parasitic infection, and is more likely to suffer from malnutrition, which reduces the ability of their immune system to fight the parasites as they become infected. invade


Intestinal parasites in children can be treated with a variety of herbs, homeopathic treatments, nutritional supplements and over-the-counter or prescription medications.

Paso 1:

Intestinal parasites can cause a wide range of symptoms, including diarrhea, loss of appetite, joint pain, mucus in the stool, fever, listlessness, malodorous stools, stomach cramps, coughing and vomiting.

If you suspect that your child may be suffering from intestinal parasites, collect a sample of your stool in a small plastic container that can be sealed and take it to your doctor for testing.

Paso 2:

If the results of the test are positive, the doctor will prescribe a medication to kill the parasites.

In accordance with the recommendations of the World Health Organization, the medicines Mebendazole and Albendezol are suitable for children under 2 years of age.

The medicines Prazinquantel and Invermectin are suitable for children who are at least 2 years old.

The medication prescribed by your doctor will depend on the type of parasitic infection or worm your child has.

Doses will vary depending on the type of medication.

Some medications, such as Mebendazole, are only taken for three days, while others, such as Albendezol, are taken over the course of 28 days.

Paso 3:

After receiving treatment for intestinal parasites, if your child is older than 2 years, you should give a probiotic supplement in the form of powder or drink to stimulate the formation of beneficial bacteria in the gastrointestinal tract.

This will help with digestion and improve the immune system.


As worm populations accumulate over time, many of the health problems caused by these worms become chronic.

Worms can cause malnutrition by stealing food from the body, either by reducing appetite or by preventing food from being absorbed properly once it has been eaten.

Children with chronic worm infections and a large number of worms can become stunted and underweight.

Strong infections with intestinal worms can cause intestinal obstruction.

Intestinal worms, especially hookworms, can contribute to anemia by causing intestinal hemorrhage and, therefore, blood loss.

The greater the number of worms, the more likely there is to make a person sick.

Chronic infections can cause a long-term delay in mental and physical development and, in very serious infections, even death.

The long-term presence of parasites can contribute to the development of food allergies.


There are a number of possible methods. Some are already being used, others are still in development.

Some do not involve fighting the parasites directly.

In contrast, when a parasite also uses other host species, protection focuses on controlling the species that releases the parasite to children.

The most common methods to prevent infections of parasites, derive from hygiene.

Teach your children basic hygiene habits and educate them about the worms that enter their body and make them sick.

Here are some more tips to keep parasitic infestation at bay:

  • Instill the habit of washing your hands frequently and thoroughly with a good antibacterial soap.
  • Teach your child to drink clean, filtered or boiled water. Practice the same at home.
  • Make sure your children change their underwear every day.
  • Wash your bedding, pillowcases, blanket, etc., regularly.
  • Sterilize your child’s toys.
  • Encourage your child to play in dry areas and do not splash in muddy puddles since there are millions of germs in these.
  • Make sure the vegetables and meat are well cooked before serving them to your child.
  • Keep your child’s fingernails trimmed well. Show them how dirt builds up under long fingernails and should be kept clean.
  • Washing your hands thoroughly before eating something should be the rule.
  • Teach urinal hygiene.
  • Do not share towels and underwear.
  • Teach your child to shower regularly. Practice thorough cleaning of private parts.
  • Clean your house thoroughly and with the right disinfectants.
  • Allow plenty of sun in your child’s room, as some parasites are sensitive to light.

If left untreated, worms infections can sometimes take a severe form of blocking the intestine, attacking other organs and inhibiting the growth of your child.

The good news is that this can be largely avoided.