Symptoms, diagnosis and treatment of the most common human helminthiases

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

Introduction to Terminology

Human helminth infections are usually caused by parasitic worms of three classes: Nematoda (nematoda) - roundworms, Cestoda (cestodes) - tapeworms, Trematoda (trematoda) - worms.According to the pathogen class, all human helminthiases are conventionally divided into:

1. Nematodes are helminth infections associated with infestation by roundworms or their larvae.The most famous nematodes are enterobiasis, ascariasis, hookworm disease, toxocariasis, and strongyloidiasis.
2. Cestodos are caused by tapeworm parasitism or its larval form.The most common cestodiasis are diphyllobothriasis, taeniasis and teniarynchiasis, hymenolepiasis, and echinococcosis.
3. Trematodes are helminth infections caused by various types of flukes.The most common diseases in our country are opisthorchiasis, clonorchiasis, less common fascioliasis, and very rarely paragonimiasis.

In relation to the territory of our country, all helminthiasis can be divided into:

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

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

Which population groups are most vulnerable to infection?

Helminthic attacks are more common in the following groups:

1. Small children because of active knowledge of the world and lack of personal hygiene skills.
2. Children are organized in groups (kindergarten, school, camp, sanatorium, etc.).Close interactions, shared habitats and exchange of toys contribute to the spread of geohelminthiasis with a simple life cycle.
3. Adults who have close contact and work with children, including teachers and parents.
4. People with certain dietary habits: consumption of raw or less processed meat, fish, seafood, herbs, etc.Great importance is attached to national cuisine (sushi, stroganina, yukola, porsa, and other dishes), likes drying, salting and smoking.
5. People living in endemic, tropical and subtropical areas.
6. People living in poor sanitation, with a lack of access to quality water and sanitation.
7. People who are closely related to agriculture and cattle breeding, live close to animals.

When and who should be tested?

Based on belonging to the risk group and the characteristics of the course of helminthic attacks, examination for helminthiases must be performed in the following cases:

1. Children, regular and irregular, at least once a year if there are no symptoms.
2. Adults who work with children and in catering establishments, doctors, sellers of children's goods and food products.
3. Children and adults enter 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 allergic skin and bronchopulmonary diseases that are resistant to traditional methods of therapy and elimination diets.
5. Children and adults with symptoms of chronic damage to the gastrointestinal tract: nausea, vomiting, diffuse abdominal pain, diarrhea, pain in the epigastric and peri-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 with low-grade fever of unknown etiology for a relatively long time.
8. Children and adults with severe asthenic syndrome: frequent headaches, weight loss, bulimia or lack of appetite, unmotivated weakness, fatigue, sleep disturbances.
9. Children and adults with microcytic and normocytic anemia resistant to traditional treatment.B12 deficiency anemia accompanies 2-4% of cases of diphyllobothriasis, less often teniarinchiasis, ascariasis and other helminthiasis.

Features of the course of helminthic attacks

The course of any helminthic attack can be divided into several periods:

1. Infection and its clinical manifestations.The majority of helminth infections have no symptoms of infection, but with strongyloidiasis, hookworm and some others, the so-called cercarioses occur - a disease caused by the penetration of larvae into the skin.
2. The incubation period is the time from the moment of infection to the first clinical manifestation.
3. The acute phase, most often caused by the migration of larvae in the human body, their molting, maturation into sexually mature individuals, the first egg laying and the first encounter of the human body with an unknown antigen.The duration of the acute phase usually ranges from a few days to a few weeks.Sometimes the acute phase is absent or poorly expressed, which is more often observed with a low level of invasion or in natives with "immune memory".
4. The chronic phase occurs without treatment or ineffectiveness and is associated with the direct influence of sexually mature individuals.

The duration of the attack depends on the lifespan of the helminths and the possibility of self-infection.

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

1. Scheme 1: the course of the disease has a sinusoidal shape.Onset (moment of infection) - increase in symptoms to a certain level (severity level) - transition to the chronic phase with periodic exacerbations.This type of course is characteristic of opisthorchiasis, clonorchiasis, fascioliasis, and strongyloidiasis.
2. Scheme 2: the course of helminthiasis has a plateau form.Infection with subsequent increase in symptoms up to a certain level, after which the patient notes that the symptoms remain constant or decrease and disappear.The same 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 eventually lead to the death of the patient.This is, as a rule, a massive invasion or helminthiasis, which occurs with dissemination against the background of immune deficiency (disseminated strongyloidiasis).

Next, let's see where worms live in the human body.Helminth infection can affect any human organ, however, for systematization, several main "favorite" 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, bovine and porcine tapeworms, etc.Here the parasite attaches to the intestinal wall in one of the ways and carries out its "subversive" activity, most often stealing nutrients from the host's food.
2. The liver and bile ducts are favorite habitats of opisthorkids, clonorkids, and fasciola.Also, the liver is often affected during the migration of helminth larvae, for example, pulmonary fluke, echinococcus, etc.
3. Lungs and bronchi.The life cycle of many nematodes (ascaris, hookworms, intestinal eels) cannot continue without larval migration through the bronchopulmonary system.For other helminths, the lungs are the final target and the habitat of the adult individual (paragonimiasis).
4. Central nervous system.It is most often affected by cysticercosis, echinococcosis, toxocariasis, paragonimiasis and other invasions.This is usually due to the migration of the larval form and its spread through the bloodstream.
5. The skin, as a rule, becomes the habitat of larval forms, as well as various filaria.
6. Eyes - filariasis, toxocariasis.
7. Bladder, uterus, and intestinal venous plexus in schistosomiasis.

Symptoms of helminthiasis

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

1. Toxic-allergic.The main reason for the development of allergic and toxic reactions is the metabolic products of adult individuals and larval forms and the release of toxins by them.Worms in humans can cause skin rashes such as urticaria, allergic and atopic dermatitis, and sometimes eczema.The rash has a recurring course and is difficult to respond to traditional treatment.
2. Dyspeptic.Dyspeptic symptoms include nausea, vomiting, heartburn, belching, bitterness in the mouth, and flatulence.Diarrhea or loose stools without increasing the frequency of bowel movements is normal.Dyspepsia is more typical for helminths living in the intestines (ascariasis, trichuriasis, etc.), and rarely occurs with tissue helminthiasis (echinococcosis, cysticercosis, toxocariasis, etc.).
3. Indigestion and malabsorption syndrome.It is also more typical for intestinal invasion, especially where sexually mature parasites live in the small intestine and duodenum (taeniasis, diphyllobothriasis, etc.)
4. Abdominal pain: in children - more often diffuse, in the umbilical region, right iliac region, imitating appendicitis.In adults, the localization of pain is more specific.Sometimes the pain syndrome due to helminthic attack can imitate "acute stomach".
5. Bronchopulmonary.Often caused by the migration of parasite larvae into the alveoli, followed by movement into the bronchial tree, trachea and oropharynx.The main symptom in this phase is a cough, usually productive, with mucus or mucopurulent sputum, the appearance of wet and dry wheezing, a change in the nature of breathing to hard or harsh with prolonged exhalation.With such an invasion (ascariasis, strongyloidiasis, hookworm disease), Loeffler's syndrome can be observed.In some invasions (for example, paragonimiasis), the lungs are the normal habitat of the adult individual.Clinical manifestations in these cases are different.Chronic cough with sputum and blood, hemoptysis, radiological changes such as pneumofibrosis, cystic lesions in lung tissue often mimic the picture of pulmonary tuberculosis.
6. Worms in humans can cause anemia syndrome.The development of anemia can be caused by direct ingestion of the host's blood (worms), theft from the host (ascariasis, taeniasis, diphyllobothriasis, etc.), stomach and intestinal dysfunction (taeniarinosis, taeniasis, etc.), and exposure to toxins.Anemia is more often microcytic iron deficiency, and in some helminthiasis it is macrocytic and B-12 deficient.
7. Asthenia, as a sign of the presence of worms in the human body, is characterized by sleep disturbances, dyssomnia, increased irritability, aggressiveness, increased fatigue, hyperactivity and attention deficit in children.It is difficult for the patient to focus on work and concentrate.Infected people may experience unexplained weight loss, loss of appetite (or, conversely, increased appetite).
8. The intoxication-inflammatory syndrome manifests itself in the form of an increase in temperature to 38 degrees and above, myalgia and arthralgia, leukocytosis and an increase in ESR in the CBC.Its severity depends on the patient's immune status and the phase of the invasion.The acute phase more often than the chronic phase occurs with fever and flu-like conditions.The chronic phase is more characterized by low-grade 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 tried to summarize the available information about the symptoms of worm infection accompanying the most common helminthic attacks in humans.

Helminthiasis	Symptoms of infection	Incubation period	Acute phase	Chronic phase
Enterobiasis	Nope	10-15 days	Perianal itching, diffuse abdominal pain, rarely diarrhea, nausea, vomiting.Dyssomnia, nocturnal screaming and crying in children.Persistent vulvovaginitis, synechiae labia. The total period of invasion is about one or two months (if there is no re-infection)
Ascariasis	Nope	About a week	Up to 2 weeks, the acute phase is caused by larval migration.Symptoms during this period are fever, muscle and joint pain, skin rash and itching, signs of bronchitis or pneumonia (eosinophilic infiltrative changes in lung tissue).Bronchial obstruction may occur.	Decreased appetite, nausea, vomiting, abdominal pain (near the navel, right iliac region), rumbling in the intestines and flatulence.Symptoms of asthenia are constant headaches, weakness, fatigue.Symptoms of anemia and hypovitaminosis.The total period of invasion (if there is no re-infection) - 1 year
Trichocephalosis	Nope	1-1.5 months	Pain along the colon, right iliac region, nausea, vomiting, salivation, flatulence, stool instability, the presence of blood and mucus in the stool (the total period of invasion is up to 5-7 years).
Diphyllobothriasis	Nope	Deleted, when the clinical picture of invasion develops gradually	There is no acute phase as such.Symptoms occur and develop slowly.General asthenia, increasing over time, skin rash, diffuse abdominal pain, sometimes in the right iliac region, nausea, vomiting, loss of appetite and progressive weight loss, stool instability, signs of anemia, glossitis, hepatosplenomegaly, neurological symptoms (paresthesia, impaired sensitivity and motor function, etc.). The period of invasion is up to 10 years or more.
Taeniasis and teniarynchosis	Nope	Deleted, when the clinical picture of invasion develops gradually	There is no acute phase as such.The following symptoms appear 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, drooling, nausea, vomiting, rashes such as urticaria, rarely damage the nervous system such as Meniere.seires syndrome.
Opisthorchiasis	Nope	2-4 weeks	Increased temperature, weakness, fatigue, eosinophilia and leukocytosis, pain in the stomach and liver, loose stools, allergic rash, hepatosplenomegaly, jaundice.	Symptoms of intestinal and hepatobiliary dyspepsia, hepatomegaly, jaundice, pain in the liver, there may be biliary colic, back pain (pancreatitis), gradual increase in liver failure.
Clonorchiasis	Nope	2-3 weeks	Similar to opisthorchiasis, but more pronounced	Same as opisthorchiasis.High probability of getting cirrhosis and cholangiocarcinoma
Mine worms and necatoriasis	2-3 days after infection, a papular itchy rash or urticaria appears at the site of larval penetration, often resembling a tortuous path.The duration of this period is up to 1.5 - 2 weeks.	Almost absent	Due to larval migration, about 2-4 weeks.Fever, skin rash, symptoms of bronchitis, bronchopneumonia - productive cough, wet wheezing, dry, sometimes bronchial obstruction.The formation of irregular eosinophilic infiltrates in lung tissue (Leffler's syndrome) is characteristic.	The most important clinical sign is moderate to severe iron deficiency anemia.The second important criterion is hypoalbuminemia, edema syndrome.Nausea, vomiting, epigastric pain, flatulence, fatigue, headache, general asthenia.The total period of invasion is up to 20 years.
Hymenolepiasis	Nope	It is implicitly stated, for adult maturation from larvae, 2-3 weeks is enough	Therefore, the acute phase is not specified;symptoms increase and are characterized by nausea, vomiting, salivation, diffuse abdominal pain, and loose stools.Damage to the nervous system in the form of headache, dizziness, fainting.Allergic manifestations - rash type exanthema, urticaria, Quincke's edema, allergic rhinitis.Pale skin with icteric color.Body temperature is usually normal.
Fascioliasis	Nope	1-8 weeks	Fever, pain in the liver and epigastrium, jaundice, hepatomegaly, loose stools, allergic rash, eosinophilia and leukocytosis	Hepatomegaly, pain in the liver, hepatobiliary dyspepsia, increased liver failure, secondary cholecystitis and pancreatitis
Strongyloidiasis	On day 1-2, itching and a papular rash appear at the site of larval penetration, which quickly disappear.	Almost absent	On the 3-4th day from the moment of infection, fever, myalgia, joint pain, cough with sputum, moist and dry wheezing occur, and bronchial obstruction is possible.Radiographs reveal a diffuse eosinophilic infiltrate (Leffler's syndrome).Allergic rashes often appear on the skin.	Pain in the epigastric, periumbilical region, less often in the liver, belching, heartburn, nausea, vomiting, loss of appetite and weight, biliary dyspepsia, diarrhea (usually enteritis type, impurities in the stool are rare, usually with massive invasion), hepatomegaly, jaundice.The infection lasts for years due to frequent self-infection.
Trichinosis	There may be stomach pain, nausea, vomiting, diarrhea	From 1-2 days to 4-5 weeks, on average 10-25 days	After infection, the intestinal phase begins first - abdominal pain, nausea, diarrhea, then general - severe muscle pain, swelling of the eyelids, face, less often the trunk, rash according to the type exanthema, in severe cases bleeding, high fever (sometimes low-grade fever) for several weeks.	Encapsulation of larvae and their preservation in skeletal muscle for 10 years or more.
Paragonimiasis	Nope	2-3 weeks, can be reduced to a few 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	Prolonged fever or low-grade fever, prolonged cough with sputum and blood, hemoptysis, chest pain, shortness of breath, weight loss, X-ray showing pulmonary fibrosis, pleural adhesions, thin-walled cysts in the lower part of the lungs

How to confirm the presence of worms in the body?

We have come to the most frequently asked questions when visiting the 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 (live or dead adult helminths, their fragments).Naturally, only helminths that live in the human intestine can be found in feces.As a rule, helminths are detected during mass attacks.
2. Visualization of tapeworm segments in stool.

In all other cases, the diagnosis can be confirmed using 2 main laboratory diagnostic methods:

1. Various modifications of ovoscopy.Worm eggs have differences in morphology and microscopic size;trying to check them in the feces is futile.
2. Serological reactions, including PCR.

For different invasions, the range of laboratory tests is different.It is important to understand that standard stool analysis for helminth eggs and scraping for enterobiasis are screening methods aimed at identifying the most common intestinal worm infections in risk groups.At the same time, a single microscope is only 50% informative.You can see what worm eggs look like under a microscope in the diagram below.Vertical scale represents size in µm.

Drug treatment and chemoprophylaxis

Treatment of human helminthiases involves the prescription of appropriate anthelmintics, as well as symptomatic and pathogenetic agents.In this article, we will not consider in detail the dosage and treatment regimen for individual helminthic attacks;we will only note that the prescription of drugs should be carried out by a doctor (pediatrician, therapist, infectious disease specialist, parasitologist) according to the clinical picture, laboratory test data and the patient's condition.

Chemoprophylaxis of helminthiasis is the prophylactic administration of active anthelmintic drugs against geohelminthic infections in risk groups and endemic areas.Since the overall incidence of geohelminthiases among the population as a whole is low, chemoprophylaxis can be carried out once a year, preferably in autumn or spring. 

Preventive measures

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

1. Compliance with personal hygiene rules among family members and in groups, teaching children the rules and monitoring their implementation.
2. Thorough processing of vegetables, fruits and vegetables before direct consumption.
3. Refusal to consume raw, poorly cooked meat from pigs, cows and other animals, salted, dried and smoked meat that has not passed sanitary and epidemiological control.
4. Refusal to consume fish that has not passed sanitary and epidemiological control, including salted, smoked, dried, caviar and other fish products.
5. Drink only high-quality water for drinking and cooking, including when traveling.
6. Before leaving for tropical and subtropical countries, it is necessary to seek advice from an infectious disease specialist (parasitologist) and recommendations for laboratory diagnostics after returning.Infectious disease specialists also decide on the need for chemoprophylaxis.
7. Reluctance to swim in fresh water, walk barefoot, or lie on grass in endemic tropical countries.
8. Refusal to eat street food, uncertified cafes and other public catering establishments.
9. Annual clinical examination by performing OAC, OAM, standard coproovoscopy and scraping for enterobiasis.This event is especially relevant in families with children, adults working in organized children's groups, hospitals, sanatoriums, etc.

Public prevention consists of organizing control over food products sold in stores and markets, timely identification of sick pets and infected people, and their treatment.Of particular importance are the monitoring of water sources, the improvement of populated areas, the assessment of the level of infection of wild mammals, the control of the borders of natural focal helminthiases, and the number of abandoned animals.