Infections
Parasitoses
The Invisible Danger To Our Health
Parasitoses are infectious diseases that arise from infestation with parasites. These organisms live on or in a host from which they deprive nutrients or damage through tissue destruction. While viruses and bacteria are often the focus of public attention, parasites are often neglected – yet they represent a serious health problem worldwide [1].
According to estimates by the World Health Organization (WHO), around two billion people are affected by parasitic infections [2]. Especially in tropical and subtropical regions, but increasingly also in temperate climate zones, parasites constitute a medical challenge. Travel, climate change, globalisation, pet ownership and changing hygiene conditions have led to an increase in parasitoses in Europe. The increasing use of antibiotics, changes in agricultural structures and the international movement of goods also promote the risk of parasitic infections. It should be taken into account that many parasitic diseases can be transmitted from animals to humans.
What Parasites Are There?
Simply explained: Parasites are living beings that live in or on another organism – for example in or on humans – and feed on it. These unpleasant roommates can cause diseases. A distinction is made between two main groups:
1. Parasites in the body (endoparasites)
These parasites live inside the human body – for example in the intestines, blood, liver or brain. Here are the most important types:
Single-celled parasites (protozoa)
They are so small that you can only see them under a microscope. Examples are: Giardia lamblia (leads to diarrhea), Entamoeba histolytica (can cause bloody intestinal inflammation) or Plasmodium, which causes malaria.
Worms (helminths)
These parasites are usually larger and can be visible to the naked eye. There are several types:
- Roundworms such as Ascaris (roundworm)
- Sucker worms such as Schistosoma
- Tapeworms such as Taenia or the dwarf tapeworm (Hymenolepis nana). Some tapeworms can even reproduce directly in humans without an intermediate host and survive in the body for a long time.
2. Parasites on the skin (ectoparasites)
These parasites live on the skin or in the hair and can sometimes be seen with the naked eye.
Examples are lice, fleas, ticks and mites. They often feed on human blood. Some can transmit diseases. Ticks can cause Borreliosis (Lyme disease) or Tick-borne encephalitis (TBE). Mites, for example, can cause scabies – a skin disease that is very itchy and can become chronic if left untreated.
Why Is This Important To Know?
Some parasites cause immediately noticeable symptoms such as itching, diarrhea or show a changed complexion. Others go unnoticed for a long time and can become chronic.
The good news: Many parasites can be treated well if they are detected in time. Hygiene, safe drinking water, hand washing and protection against insects (e.g. by mosquito spray or tick control) are important preventive measures.
How Parasites Are Transmitted — And What To Look Out For
Parasitic pathogens can enter the human organism in a wide variety of ways. This often happens through the consumption of contaminated food, especially unwashed fruit and vegetables or undercooked meat. Unclean drinking water also plays an important role – especially in regions with inadequate infrastructure. In addition, parasites can be transmitted through insect bites (e.g. malaria, leishmaniasis) or skin contact (e.g. hookworms).
Travel to endemic areas, poor hygienic conditions, contact with infected animals and a weakened immune system significantly increase the risk of infection. Occupational fields such as agriculture, fish processing or medical personnel are also particularly at risk if there is a lack of caution. Certain diets, such as the regular consumption of raw fish (e.g. sushi), also carry risks – infections with fish tapeworms (Diphyllobothrium latum) can occur here.
What Symptoms Occur?
The symptoms of parasitic diseases are extremely diverse and depend on the respective causative organism and the affected region in the body. Common complaints are fatigue, indigestion, abdominal pain, diarrhoea or itching. Some parasites cause skin changes, others cause systemic symptoms such as fever, anemia or neurological abnormalities.
Infections that go unnoticed and become chronic – such as liver amoebiasis or echinococcosis – are particularly dangerous. In children, chronic parasitoses can lead to growth and developmental delays. Psychological symptoms such as irritability, insomnia or concentration disorders are also described in the case of prolonged infestation.
Some patients develop allergic reactions or autoimmune complications as a result of parasitic persistence. In rare cases, parasites lead to life-threatening complications – for example, when tapeworm larvae enter the central nervous system and trigger neurocysticercosis.
How Is The Infection Diagnosed?
The diagnosis of parasitic diseases requires a high degree of attention and experience. First and foremost is a detailed anamnesis: travel, eating habits, animal contact and any symptoms provide important information. Depending on the suspicion, laboratory tests follow – especially stool, urine and blood analyses.
The microscopic detection of worm eggs, cysts or parasite larvae continues to be a standard procedure, but is increasingly being supplemented by serological and molecular genetic methods (e.g. PCR). Imaging techniques such as sonography, computed tomography (CT) or magnetic resonance imaging (MRI) are used when organs are affected. In the case of skin infestation, direct smears or adhesive tape preparations can provide information.
In addition, dark-field microscopy provides evidence of parasitic contamination in the blood. Innovative methods such as ELISA (“enzyme-linked immunosorbent assay”) allow the quantitative detection of specific antibodies against various pathogens and increase diagnostic certainty.
Prevention of Parasitic Infections: What Really Protects
Basics of hygiene
Prevention is particularly effective in the case of parasitosis in order to avoid infection altogether. One of the most important measures is good personal and public hygiene: this includes regular and thorough hand washing, especially after going to the toilet, before eating and after contact with animals.
Food safety
Food should always be prepared carefully. Fruit and vegetables should be washed thoroughly – ideally with baking soda water or vinegar solutions to remove possible parasites or eggs. Meat and fish should be eaten well cooked, because raw or semi-raw protein (e.g. sushi, tartare, carpaccio) carry a risk of infection. In countries with inadequate water treatment, drinking water should be boiled, filtered or obtained from safe sources.
Travel protection in risk areas
In travel areas with a high risk of infection (e.g. tropical or subtropical regions), protection against insect bites is particularly important. Mosquito nets, body-covering clothing and repellents help here to prevent transmission by vectors such as mosquitoes or sand flies. Contact with contaminated soil or water (e.g. when walking barefoot or bathing in stagnant water) should also be avoided.
Pets and home environment
If you have pets – especially dogs and cats – you should deworm them regularly, because they can be carriers of certain parasites. In kindergartens and schools, children should be regularly checked for head lice infestation, and school examinations as well as hygiene training help to raise awareness of the risks of infection at an early stage.
Medical facilities
Consistent hygiene protocols and disinfection measures must be followed in medical facilities in order to prevent so-called nosocomial (hospital-acquired) infections with parasites.
Social measure
In addition, health policy measures are key: The expansion of sanitation infrastructure in developing and emerging countries, awareness campaigns about infection routes, as well as access to clean water and regular medical care are the most effective protective mechanisms in the long term.
What To Do In Case Of Parasite Infestation?
Parasites can infect the human body in different ways – depending on the species and the severity of the infestation. The general state of health of the affected person also plays an important role in choosing the right treatment. Fortunately, there are now effective drugs, natural substances and alternative forms of therapy for many parasitic diseases.
Unicellular parasites, so-called protozoa – such as Giardia lamblia (causes giardiasis), Entamoeba histolytica (causes amoebic dysentery) or Plasmodium (the causative agent of malaria) – are usually treated with special agents such as metronidazole, tinidazole or nitazoxanide.
Worms (medically: helminths), which include roundworms, tapeworms or hookworms, can be combated with so-called worm remedies – anthelminthics. Frequently used preparations are albendazole, mebendazole or praziquantel.
Parasites that live on the skin, so-called ectoparasites – for example head lice or scabies mites – can also be treated. Here, externally applicable agents such as permethrin are usually used. In more severe cases, additional treatment with tablets, such as ivermectin, may be necessary.
Severe infections often require hospital treatment. There, those affected can be closely monitored and, if necessary, given intensive medical care.
Naturopathic And Herbal Accompanying Therapies
Certain herbal active ingredients have proven themselves in naturopathy as supportive and effective remedies for parasite cures. For example, wormwood (Artemisia absinthiurn) is often used as an ingredient in antiparasitic mixtures and is also used in the accompanying therapy of malaria. The black walnut (Juglans nigra) is traditionally considered a proven remedy for worm infestation.
Clove oil is valued in empirical medicine because it can inhibit the development of parasitic eggs. Other natural substances such as garlic, oregano oil, papaya seeds or pumpkin seeds have an antimicrobial effect and can support digestion.
Such herbal remedies are often used as part of parasite cures over several weeks. In addition, an intestinal strengthening accompanying therapy is recommended to promote the balance of the intestinal microbiome and support the body in elimination.
Frequency Therapy (Complementary Medicine)
Some patients also use so-called frequency therapy (e.g. according to HuIda Clark or Royal Rife), in which electrical impulses or vibrations are used to try to influence parasites energetically.
The aim is to disrupt the individual frequency of the parasites. Devices such as “zappers”, Rife machines or frequency devices are used. Even though the effectiveness is scientifically controversial, there are numerous positive testimonials
Orthomolecular Support
The targeted supply of micronutrients – i.e. vitamins, trace elements and healthy fatty acids – can strengthen the immune system, regulate inflammatory processes and support the regeneration of the body. Zinc, Vitamin C, Selenium, Vitamin D and Omega-3 fatty acids are particularly recommended.These substances have an antioxidant effect, strengthen the body’s own defenses and can help to bring the organism back into balance after an infection.
Such orthomolecular support can be particularly useful in the recovery phase after acute infections or in the case of prolonged stress. In combination with classic conventional medical treatment, naturopathic measures and – if appropriate – complementary approaches such as frequency therapy, a holistic therapy concept can be created. This is especially helpful in the case of chronic or recurrent parasite infestations. However, it is important to note: Expert support and clear, well-founded diagnostics are essential to avoid misdiagnoses.
How Research Aims To Better Combat Parasites
Significant successes have been achieved in recent years through advances in diagnostics and therapy as well as international cooperation. The integration of parasitological content into medical education and training is becoming increasingly important worldwide. This is because with growing global mobility and climatic changes, the risk of new parasites is also increasing in regions that have not yet been affected
Research projects to combat resistant pathogens, to develop plant-based active ingredients as well as to combine conventional medicine and complementary approaches show new perspectives for the treatment of future parasitoses. Artificial intelligence and big data could help with early detection and monitoring in the future. The global networking of laboratory data and epidemiological reporting systems contribute to detecting outbreaks at an early stage and initiating targeted measures.
When Parasites Stay In The Body Longer
If parasitosis is not detected in time or incompletely treated, it can become chronic and cause permanent damage. These include liver and lung damage, neurological impairments, anemia or severe deficiencies. Infants, the elderly and immunocompromised patients are particularly affected. In Africa and Southeast Asia, parasitosis is one of the main causes of school absenteeism, inability to work and poverty. Psychosocial consequences – such as stigmatization in visible skin diseases – should not be underestimated. Chronic intestinal parasitosis can cause lasting damage to the intestinal microbiome, block the absorption of nutrients and lead to increased susceptibility to infections.
The social and economic consequential costs of parasitic diseases are estimated at several billion euros annually worldwide. As a result of many years of exposure to parasites, some patients develop chronic fatigue syndromes, nutrient deficiencies and secondary diseases such as irritable bowel syndrome or autoimmune diseases. Interdisciplinary aftercare is required here.
Result
Parasitosis is a serious medical issue with global relevance. They affect millions of people – often the most vulnerable – and lead to enormous health, social and economic burdens. Through better diagnostics, effective medication, consistent prevention and targeted education, many of these infections can be prevented or successfully treated.
This makes it all the more important to raise awareness of these often underestimated diseases – in the population as well as in medicine. After all, only those who are informed can effectively protect themselves – and make a contribution to ensuring that parasites no longer operate in secret. A holistic approach that integrates conventional medicine, prevention, nutrition, hygiene and naturopathy could help to significantly reduce the global burden of parasitoses in the future.
Jürgen Lueger
Keywords: immune system, infections, parasites, parasitoses
Complete literature available from CO’Med.
An Exclusive Translated Article for P2P Supporters
From the Monthly Publications of P2P
Published December 2025
From an article in CO’Med, Volume 31, October 2025
Translation & redaction by: Carolyn L. Winsor, P2P Consulting
© Copyright 2025, CO‘Med, Jürgen Lueger, Germany
AI Digital and online translation assistance utilized.
