Symptoms, diagnosis and treatment of the most common human helminthiases

In this article we will try to figure out what symptoms are most common in helminthiasis in adults, whether they can be asymptomatic and what types of helminthic infestations are most common in our country.

Introduction to terminology

Human helminth infections are usually caused by parasitic worms from three classes: Nematoda (nematodes) - roundworms, Cestoda (cestodes) - tapeworms, Trematoda (trematodes) - flukes.Depending on the class of pathogen, all human helminthiases are conventionally divided into:

1. Nematodes are helminth infections that are associated with infestation by roundworms or their larvae.The most well-known nematodes are enterobiasis, ascariasis, hookworm disease, toxocariasis and strongyloidiasis.
2. Cestodoses are caused by parasitism of tapeworms or their larval forms.The most common cestodiasis are diphyllobothriasis, taeniasis and teniarinchiasis, hymenolepiasis and echinococcosis.
3. Trematodes are helminthic infections caused by various species of leeches.The most common diseases in our country are opisthorchiasis, clonorchiasis, less often fascioliasis and, very rarely, paragonimiasis.

Based on the territory of our country, all helminthiasis can be divided into:

1. Typical, that is, often found in the population of our country;
2. Exotic, caused by population migration and tourism to other countries.

Detection and treatment of exotic helminth infections is a more complex and time-consuming process because laboratories may not have the necessary reagents to perform laboratory tests.The following types of helminthic infestations are typical for the territory of our country.

Which population groups are most vulnerable to infection?

Helminth infestations occur more frequently in the following groups:

1. Small children due to active knowledge of the world and lack of personal hygiene skills.
2. Children organized in groups (kindergartens, schools, camps, sanatoriums, etc.).Close interaction, shared habitat and toy exchange contribute to the spread of geohelminthiasis with a simple life cycle.
3. Adults who have close contact with and work with children, including teachers and parents.
4. People with certain dietary habits: consumption of raw or poorly processed meat, fish, seafood, herbs, etc. Great emphasis is placed on national cuisine (sushi, stroganina, yukola, porsa and other dishes), love of drying, salting and smoking.
5. People living in endemic areas, tropics and subtropics.
6. Individuals living in poor sanitation conditions and lacking access to quality water resources and sanitation.
7. People closely associated with agriculture and livestock farming and living near animals.

When and who needs to be tested?

Depending on the membership of risk groups and the characteristics of the course of helminthic infestation, an examination for helminthiasis must be carried out in the following cases:

1. Children, organized and disorganized, at least once a year unless symptoms are present.
2. Adults who work with children and in catering establishments, doctors, sellers of children's items and food.
3. Children and adults entering educational institutions, sanatoriums, hospitals, boarding houses, hospices and other institutions that provide for the presence of a large number of people in one area.
4. Children and adults with skin and bronchopulmonary allergic diseases resistant to traditional methods of therapy and an elimination diet.
5. Children and adults with symptoms of chronic damage to the gastrointestinal tract: nausea, vomiting, diffuse abdominal pain, diarrhea, pain in the upper abdomen and umbilical region, malabsorption syndrome.
6. Children and adults with symptoms of damage to the hepatobiliary system – hepatosplenomegaly, jaundice, pain in the right hypochondrium, increased AST, ALT, GGTP, alkaline phosphatase, portal hypertension.
7. Children and adults have been suffering from low-grade fever of unknown etiology for some time.
8. Children and adults with severe asthenic syndrome: frequent headaches, weight loss, bulimia or loss of appetite, unmotivated weakness, fatigue, sleep disorders.
9. Children and adults with microcytic and normocytic anemia resistant to conventional treatments.B12 deficiency anemia accompanies 2-4% of cases of diphyllobothriasis, less often teniarinchiasis, ascariasis and other helminthiasis.

Features of the course of helminthic infestation

The course of a helminth infestation can be divided into several periods:

1. Infection and its clinical manifestations.In most helminth infections there are no symptoms of infection, but in strongyloidiasis, hookworms and some others, so-called cercarioses occur - diseases that arise as a result of the penetration of larvae into the skin.
2. The incubation period is the time from the time of infection to the first clinical manifestations.
3. The acute phase is most often caused by the migration of larvae in the human body, their molting, maturation into sexually mature individuals, the first laying of eggs and the first encounter of the human body with unknown antigens.The duration of the acute phase is usually several days to several weeks.Sometimes the acute phase is absent or mild, which is more commonly observed in low levels of invasion or in indigenous peoples with an “immune memory”.
4. The chronic phase occurs when there is no or ineffective treatment and is associated with the direct influence of sexually mature individuals.

The duration of the infestation depends on the lifespan of the helminths and the likelihood of self-infection.

From this point of view, the course of all helminthiases can be presented in the form of several basic schemes.

1. Scheme 1: The course of the disease has the shape of a sine curve.Onset (moment of infection) – increase in symptoms to a certain degree (severity) – transition to the chronic phase with periodic exacerbations.This course is characteristic of opisthorchiasis, clonorchiasis, fascioliasis and strongyloidiasis.
2. Scheme 2: The course of helminthiasis has the form of a plateau.Infection with subsequent increase in symptoms to a certain point, after which the patient finds that the symptoms remain constant or decrease and disappear.A similar course is typical for many invasions: trichinosis, taeniasis, diphyllobothriasis, ascariasis.
3. Scheme 3: The course of helminthiasis is characterized by a continuous increase in symptoms, which can ultimately lead to the death of the patient.These are usually massive invasions or helminthiasis that occur with dissemination against a background of immune deficiency (disseminated strongyloidiasis).

Next, let's look at where worms live in the human body.Helminth infections can affect any human organ.However, for systematization, several main “preferred” localizations in the host's body can be identified:

1. The intestine is the most logical habitat for many human worms, for example roundworms, pinworms, whipworms, hookworms, beef and pork tapeworms, etc. Here the parasite attaches itself to the intestinal wall in one of the following ways and carries out its "subversive" activity, mostly stealing nutrients from the host's food.
2. The liver and bile ducts are the preferred habitat of opisthorchids, clonorchids and fascioles.The liver is also often affected by the migration of helminth larvae, for example lung flukes, echinococci, etc.
3. Lungs and bronchi.The life cycle of many nematodes (Ascaris, hookworm, intestinal eel) cannot occur without the migration of the larvae through the bronchopulmonary system.For other helminths, the lungs are the final destination and habitat of adult individuals (paragonimiasis).
4. Central nervous system.It is most commonly affected by cysticercosis, echinococcosis, toxocariosis, paragonimiasis and other invasions.This is usually due to the migration of the larval forms and their spread via the bloodstream.
5. The skin usually becomes the habitat of larval forms as well as various filariae.
6. Eyes - filariasis, toxocariasis.
7. Venous plexuses of the bladder, uterus and intestines in schistosomiasis.

Symptoms of helminthiasis

In general, the clinical picture of helminthic infestation consists of the following syndromes:

1. Toxic-allergic.The main causes of the development of allergic and toxic reactions are metabolic products of adult individuals and larval forms and their release of toxic substances.Worms can cause skin rashes in humans such as urticaria, allergic and atopic dermatitis, and sometimes eczema.The rashes recur and are difficult to respond to conventional treatment.
2. Dyspeptic.Dyspeptic symptoms include nausea, vomiting, heartburn, belching, bitterness in the mouth, and flatulence.Diarrhea or loose stools without increased stool frequency are common.Dyspepsia is more typical of helminths living in the intestine (ascariasis, trichuriasis, etc.) and rarely occurs with tissue helminthiasis (echinococcosis, cysticercosis, toxocariasis, etc.).
3. Maldigestion and malabsorption syndrome.It is also more typical of intestinal invasions, especially those in which sexually mature parasites live in the small intestine and duodenum (taeniasis, diphyllobothriasis, etc.).
4. Abdominal pain: in children - more often diffuse, in the navel area, in the right pelvic area, simulating appendicitis.In adults, the location of pain is more specific.Sometimes the pain syndrome due to helminthic infestation can mimic an “acute abdomen”.
5. Bronchopulmonary.Most often caused by the migration of parasite larvae into the alveoli, followed by movement into the bronchial tree, trachea and oropharynx.The main symptoms in this phase are a cough, usually productive, with mucous or mucopurulent sputum, the appearance of wet and dry wheezing, a change in the nature of breathing too hard or hard with prolongation of exhalation.In such invasions (ascariasis, strongyloidiasis, hookworm disease) Loeffler syndrome can be observed.In some invasions (e.g. paragonimiasis), the lung is the usual habitat of adult individuals.The clinical manifestations in this case are different.Chronic cough with sputum and blood, hemoptysis, radiological changes such as pneumofibrosis, cystic lesions of lung tissue often mimic the picture of pulmonary tuberculosis.
6. Worms can cause anemic syndrome in humans.The development of anemia can be caused by direct consumption of the host's blood (hookworm), theft from the host (ascariasis, taeniasis, diphyllobothriasis, etc.), dysfunction of the stomach and intestines (taeniarinosis, taeniasis, etc.), and exposure to toxins.Anemia is more commonly microcytic iron deficiency and some helminthiasis is macrocytic and B-12 deficiency.
7. Asthenia, as a sign of the presence of worms in the human body, is characterized by sleep disorders, sleep disorders, increased irritability, aggressiveness, increased fatigue, hyperactivity and attention deficit in children.The patient finds it difficult to concentrate and concentrate on work.An infected person may experience unexplained weight loss and loss of appetite (or, conversely, increased appetite).
8. Intoxication-inflammatory syndrome is manifested by an increase in temperature to 38 degrees and more, myalgia and arthralgia, leukocytosis and an increase in ESR in the blood count.The severity depends on the immune status of the patient and the phase of invasion.The acute phase occurs more often than the chronic phase with fever and a flu-like condition.The chronic phase is more likely to be characterized by a mild fever or normal body temperature.
9. Worms in humans are often the cause of unexplained asymptomatic eosinophilia.Eosinophilia is most characteristic of nematodes and trematodes and may be accompanied by generalized leukocytosis.

In the table below we have attempted to summarize the available information about the symptoms of worm infection associated with the most common helminthic infestations in humans.

Helminthiasis	Symptoms of infection	incubation period	Acute phase	Chronic phase
Enterobiasis	No	10-15 days	Perianal itching, diffuse abdominal pain, rarely diarrhea, nausea, vomiting.Insomnia, screaming and crying at night in children.Persistent vulvovaginitis, synechiae of the labia. The total duration of the invasion is approximately one to two months (unless reinfection occurs).
Ascariasis	No	About a week	The acute phase is caused by the migration of the larvae for up to 2 weeks.Symptoms during this period include fever, muscle and joint pain, rash and itching, signs of bronchitis or pneumonia (eosinophilic infiltrative changes in lung tissue).Bronchoobstruction may occur.	Decreased appetite, nausea, vomiting, abdominal pain (near the navel, right pelvic region), rumbling in the intestines and bloating.Symptoms of asthenia include persistent headaches, weakness and fatigue.Symptoms of anemia and hypovitaminosis.Total duration of invasion (without reinfection) – 1 year
Trichocephalosis	No	1-1.5 months	Pain along the colon, right pelvic region, nausea, vomiting, salivation, flatulence, stool instability, presence of blood and mucus in the stool (total duration of invasion is up to 5-7 years).
Diphyllobothriasis	No	Deleted as the clinical picture of invasion gradually develops	There is no acute phase as such.Symptoms appear and progress slowly.General asthenia that increases over time, skin rashes, diffuse abdominal pain, sometimes in the right pelvic area, nausea, vomiting, loss of appetite and progressive weight loss, stool instability, signs of anemia, glossitis, hepatosplenomegaly, neurological symptoms (paresthesias, impaired sensitivity and motor function, etc.). The duration of the invasion is up to 10 years or more.
Taeniasis and Teniarinhoz	No	Deleted as the clinical picture of invasion gradually develops	There is no acute phase as such.The following symptoms occur and increase: weakness, fatigue, headache and other symptoms of asthenia, mild or moderate anemia, diffuse abdominal pain and discomfort, bulimia or loss of appetite, progressive weight loss, salivation, nausea, vomiting, skin rashes such as urticaria, rarely nervous system damage such as Menière's syndrome, epileptiform seizures.
Opisthorchiasis	No	2-4 weeks	Increased temperature, weakness, fatigue, eosinophilia and leukocytosis, abdominal and liver pain, loose stools, allergic rash, hepatosplenomegaly, jaundice.	Symptoms of intestinal and hepatobiliary dyspepsia, hepatomegaly, jaundice, pain in the liver, biliary colic, girdle pain (pancreatitis) and a gradual increase in liver failure may occur.
Clonorchiasis	No	2-3 weeks	The same as opisthorchiasis, but more pronounced	The same as opisthorchiasis.High probability of developing cirrhosis and cholangiocarcinoma
Hookworm and necatoriosis	2-3 days after infection, a papular or urticarial itchy rash appears at the site of invasion by the larvae, often resembling tortuous passages.The duration of this period is up to 1.5 - 2 weeks.	Practically non-existent	Due to the larval migration approx. 2-4 weeks.Fever, rashes, symptoms of bronchitis, bronchopneumonia - productive cough, wet, dry wheezing, sometimes bronchial obstruction.The formation of volatile eosinophilic infiltrates in the lung tissue (Leffler syndrome) is characteristic.	The main clinical sign is moderate to severe iron deficiency anemia.The second important criterion is hypoalbuminemia, edema syndrome.Nausea, vomiting, upper abdominal pain, flatulence, fatigue, headache, general asthenia.The total duration of the invasion is up to 20 years.
Hymenolepiasis	No	It is implicitly expressed that for the maturation of an adult from a larva, 2-3 weeks are enough	Therefore, the acute phase is not pronounced;Symptoms worsen and are characterized by nausea, vomiting, salivation, diffuse abdominal pain and loose stools.Damage to the nervous system in the form of headaches, dizziness, fainting.Allergic manifestations – rash of rash type, urticaria, Quincke's edema, allergic rhinitis.Pale skin with an icteric tint.Body temperature is often normal.
Fascioliasis	No	1-8 weeks	Fever, liver and upper abdominal pain, jaundice, hepatomegaly, loose stools, allergic rash, eosinophilia and leukocytosis	Hepatomegaly, liver pain, hepatobiliary dyspepsia, progressive liver failure, secondary cholecystitis and pancreatitis
Strongyloidiasis	On days 1-2, a slight itching and a papular rash appear at the site of penetration of the larvae, which quickly disappears.	Practically non-existent	On the 3rd-4thDay after infection, fever, myalgia, joint pain, cough with sputum, wet and dry wheezing occur, and bronchial obstruction is possible.The x-ray shows fleeting eosinophilic infiltrates (Leffler syndrome).An allergic rash often appears on the skin.	Pain in the epigastric and periumbilical areas, less often in the liver, belching, heartburn, nausea, vomiting, loss of appetite and weight, biliary dyspepsia, diarrhea (usually of the enteritis type, impurities in the feces are rare, usually with massive invasion), hepatomegaly, jaundice.Due to regular self-infection, the infestation lasts for years.
Trichinosis	Abdominal pain, nausea, vomiting and diarrhea may occur	From 1-2 days to 4-5 weeks, on average 10-25 days	After the infection, the intestinal phase begins first - abdominal pain, nausea, diarrhea, then generalized - severe muscle pain, swelling of the eyelids, face, less often the trunk, depending on the type of rash Rash, in severe cases hemorrhagic, high fever (sometimes mild fever) lasting several weeks.	Encapsulation of larvae and their preservation in skeletal muscle for 10 years or longer.
Paragonimiasis	No	2-3 weeks, can be shortened to several days	Abdominal pain, acute abdominal pain, diarrhea.Gastroenterological symptoms are replaced by symptoms of damage to the bronchi and lung tissue – cough with sputum, chest pain, pneumonia, exudative pleurisy	Fever or persistent low-grade fever, persistent cough with sputum and blood, hemoptysis, chest pain, shortness of breath, weight loss, X-rays show pulmonary fibrosis, pleural adhesions, thin-walled cysts in the lower parts of the lungs

How to confirm the presence of worms in the body?

We have reached the most frequently asked questions when visiting a doctor.How can you tell if there are worms in the human body?Is it possible to do this yourself without leaving home?

Therefore, it is possible to determine the presence of helminthic infestation at home only in the following cases:

1. Visualization of worms in feces (adult live or dead helminths, their fragments).Of course, only the helminths that live in the human intestine are found in feces.As a rule, helminths are detected in massive infestations.
2. Visualization of tapeworm segments in feces.

In all other cases, the diagnosis can be confirmed using two main methods of laboratory diagnostics:

1. Various modifications of ovoscopy.Worm eggs exhibit morphological differences and microscopic sizes;Trying to examine them in feces is useless.
2. Serological reactions, including PCR.

For different invasions, the spectrum of laboratory tests is different.It is important to understand that standard stool analysis for worm eggs and curettage for enterobiasis are screening methods aimed at identifying the most common intestinal worm infections in risk groups.At the same time, single microscopy is only about 50% informative.You can see what worm eggs look like under the microscope in the image below.The vertical scale indicates the size in µm.

Drug treatment and chemoprophylaxis

Treatment of human helminthiasis includes the prescription of appropriate anthelmintics, symptomatic and pathogenic agents.In this article we will not go into detail about the dosages and treatment regimens for individual helminthic infestations;We only point out that the prescription of medications by a doctor (pediatrician, therapist, infectious disease specialist, parasitologist) should be made in accordance with the clinical picture, laboratory test data and the patient's condition.

Chemoprophylaxis of helminthiasis is the prophylactic administration of anthelmintics against geohelminthic infections in risk groups and endemic areas.Since the overall incidence of geohelminthiases in the general population is low, chemoprophylaxis can be performed once a year, preferably in autumn or spring. 

Preventive measures

Measures to prevent infection with worms are conventionally divided into individual and public measures.Individual prevention includes:

1. Compliance with the rules of personal hygiene among family members and in groups, teaching the rules to children and monitoring their implementation.
2. Thorough processing of vegetables, vegetables and fruits before direct consumption.
3. Refusal to eat raw, poorly cooked meat of pigs, cattle and other animals, salted, dried and smoked meat that has not passed sanitary and epidemiological control.
4. Refusal to eat fish that has not passed sanitary and epidemiological control, including salted, smoked, dried fish, caviar and other fish products.
5. Only drink high-quality water for drinking and cooking, even when traveling.
6. Before departure to tropical and subtropical countries, consultation with an infectious disease specialist (parasitologist) and recommendations for laboratory diagnostics upon return are required.The infectiologist also decides whether chemoprophylaxis is necessary.
7. Refusal to swim in fresh water, walk barefoot, or lie on the grass in endemic tropical countries.
8. Refusal to eat on the street, in uninspected cafes and other public catering establishments.
9. Annual clinical examination with performance of OAC, OAM, standard coproovoscopy and curettage for enterobiasis.These events are especially relevant for families with children, adults working in organized children's groups, hospitals, sanatoriums, etc.

Public prevention includes organizing control over food sold in stores and markets, timely identification of sick pets and infected people, and their treatment.Of great importance is monitoring water resources, improving populated areas, assessing the degree of infection of wild mammals, controlling the limits of natural focal helminthiasis and the number of stray animals.