Worms in humans: photos, symptoms, treatment
- Ways of human infection with helminths
- Factors affecting the manifestations of helminthiasis
- Worms in humans: symptoms
- Types of helminths, parasitic in humans
- Diagnosis of helminthiasis
- Worms in humans: treatment
- Prevention of helminth infections
Today, science knows about 280 species of worms that can develop and live in the human body, parasitizing in various organs and tissues. The frequency of human infection with worms depends on the climatic and socio-economic conditions of specific territories (in underdeveloped countries, especially in those located in the tropical and subtropical zones, the level of parasitic infections is much higher than in economically developed countries). According to statistics, only in Russia, which is the habitat of 20 species of worms that can parasitize in the human body, about 15 million people are infected annually, of which 80% are children.
Ways of human infection with helminths
- Biohelminthoses (infection from animals).
- Contagious helminthiasis (transmitted from person to person).
- Geohelminthiasis (diseases caused by parasites that conduct one of the life cycles in the earth).
Factors affecting the manifestations of helminthiasis
- The way the parasite penetrates the body;
- The degree of adaptation of the helminth to the human body;
- Population density (number) of parasitic individuals;
- The habitat of the worm (tissue parasites live in the thickness of the soft tissues, and luminal live in the lumens of hollow organs). Some helminths in different phases have both luminal and tissue forms. The larval and developing stages of worms, as a rule, cause more pronounced pathological changes.
In the absence of re-infection, the number of adult parasites in the human body does not increase. This feature significantly distinguishes helminthic invasions from diseases caused by bacteria, viruses, fungi and protozoa.
Worms in humans: symptoms
Helminthiasis is a disease characterized by 2 stages of the course (acute, from two weeks to two months) and chronic (from several months to several years).
Symptoms of the acute phase of helminthiasis
The first signs of the disease can manifest themselves at different times (most often in 2-3 weeks, with ascariasis after 2-3 days, and with filariasis, the incubation period can last 6-18 months).
In the acute stage of parasitic invasion, the most characteristic symptom is an allergic reaction (the production of antibodies against the antigens of the migrating parasite larvae occurs). Often, people infected with worms on the skin appear itchy rashes, prone to relapsing course, increased regional lymph nodes, possibly the occurrence of generalized or local edema, muscle and joint pain. Also, the parasite's migratory larvae can cause chest pain, coughing, choking attacks, stool disorders, nausea and vomiting.
At the same time, the acute phase of helminthiasis may be accompanied by more serious disorders (severe forms of pneumonia, hepatitis, allergic myocarditis, hepatosplenomegaly (enlargement of the liver and spleen), meningoencephalitis).
In the blood, the number of eosinophils increases (eosinophilia) and the normal proportion of the protein fractions (dysproteinemia) is disturbed.
Signs of chronic helminthiasis
The symptomatology of the chronic phase directly depends on which organ is “inhabited” by parasites, and their size and quantity play an important role.
So, when parasitizing in the intestines of single individuals, the disease may be asymptomatic (with the exception of cases of infection with very large parasites). Characteristic features of the chronic phase of intestinal helminthiases are dyspeptic disorders. In children, asthenoneurotic and pain syndrome are more pronounced. With massive ascaris invasion, intestinal obstruction, obstructive jaundice and pancreatitis may develop.
By consuming all the necessary substances for their vital functions from the host's body, helminths cause digestive disorders, absorption of vitamins, minerals, carbohydrates, proteins and fats. At the same time, the waste products of the worms inhibit the normal intestinal microflora and reduce the immune forces of the body.
In people suffering from helminthiasis, due to weakened immunity and an enhanced process of cell division (the consequences of the permanent restoration of parasitic tissues), the risk of malignant tumors increases significantly.
Types of helminths, parasitic in humans
The causative agents of human helminthiases are 2 types of worms: round (nematodes) and flat (tape and flukes).
Parasites that cause enterobiosis are small (up to 10 mm) thin half-worms with a grayish-white coloration. Infection occurs by the alimentary route (through the mouth). The reason for this - dirty hands. Parasite eggs can be found in the ground, on the fur of infected animals, unwashed vegetables and fruits, etc. However, during enterobiosis, there are frequent cases of self-infection (especially in children), resulting from scratching itchy areas and subsequent ingestion of eggs. Pinworm larvae develops within two weeks in the digestive tract. Transformed into an adult, the worm parasitizes the lower portions of the small and upper colon.
Even in the larval stage, the pinworm begins to harm the organism of its host, producing enzymes that irritate the intestinal walls and lead to the development of the inflammatory process. Adult parasites stick or penetrate into the deeper layers of the intestinal mucosa, violating its integrity and facilitating the accession of a secondary bacterial infection. In the case of pinworm perforation of the small intestine wall, peritonitis may develop. Also, due to irritation of the intestinal receptors, the motor and secretory functions of the gastrointestinal tract, resulting in the formation of gastroduodenitis, enteritis, etc., are disturbed. In childhood, long-term enterobiosis can cause nervous disorders and physical development lag.
Ascaris is a large parasite of a spindle-shaped form of red-yellow color, reaching 40 cm (females) and 15-25 cm (males) in the adult state. Not having suckers or other mounting devices, ascaris is able to move independently towards food masses. Eggs laid by the female parasite are excreted along with feces.
Infection with ascariasis occurs when mature eggs are swallowed with water or unwashed vegetables and fruits with soil particles. After penetration of eggs into the intestines, mature larvae emerge from them. Then, penetrating the intestinal wall, they reach the heart through the bloodstream, and from there they enter the lungs. Through the pulmonary alveoli, the larva of the roundworm enters the oral cavity through the respiratory tract. After repeated ingestion, the parasite reaches the small intestine, where it develops into an adult. The worm lives for 12 months, then dies and is released along with the feces. In the intestines of one host can live as one, and several hundred individuals.
In the intestinal phase of its existence, roundworms, endowed with the ability to spiral movements, can penetrate even the narrowest holes. This feature of the parasite often leads to the development of quite serious complications (obstructive jaundice or pancreatitis). Allergens secreted by ascaris can cause severe allergic reactions. A large number of adults can cause intestinal obstruction, and worms that have entered the respiratory tract sometimes cause choking.
The whipworm, the causative agent of trichocephalosis, is a white-colored helminth, parasitic in the initial part of the large intestine and reaching 4-5 cm in size. It feeds on the parasite with blood and tissues of the rectal mucosa.
Vlasoglava eggs laid by the female on the intestinal walls, go out together with feces. Their development occurs in the environment (optimally - in the soil). Eggs with parasite larvae that have ripened into them enter the body through the alimentary route, through dirty hands, with water or unwashed vegetables and fruits.
With small numbers of worms, trichocephalosis is asymptomatic. In the severe stage (with massive invasion), the patient has abdominal pain, develops severe diarrhea, sometimes accompanied by prolapse of the rectum. This condition is most often observed in weak children. In the moderate phase of trichocephalosis, a child’s growth may be delayed.
The causative agent of trichinosis is a small round helminth, reaching 2-5 mm in length. Infection occurs when eating poorly roasted meat (pork, bear meat, wild boar). Penetrating into the intestine, the larva of the parasite matures for 3-4 days to the state of a mature individual. The life span of the worm is 40 days, after which the parasite dies. Piercing the intestinal wall, the larvae penetrate into the bloodstream and spread through all organs of the human body, settling in the muscles. In this case, respiratory and facial muscles, as well as flexor muscles of the extremities, are most often affected.
In the first days after invasion, patients complain of abdominal pain. Then, after about 2 weeks, the body temperature rises to 39-40 C, itchy rashes appear on the skin, muscle pain develops, and the face swells. In this period, in the case of massive infection, there is a significant risk of death. In about a month, recovery begins. The parasite is encapsulated in a spiral shape, after which it dies within two years.
Hookworm and necator
These two parasites are similar in biological characteristics, as well as in the diseases they cause. In this regard, they are usually combined under the common name (hookworm). Worms reaching a length of 10-15 mm, parasitic in 12-p. the gut. It should be noted that this is one of the most common, but at the same time, quite rarely detected parasites. The larvae of worms penetrate the human body through the skin when in contact with contaminated soil. Then, getting into the bloodstream, they, as well as roundworms, migrate to the lungs, and then, through the bronchi, along with expectorant sputum - into the digestive tract. Hookworm is parasitic in the intestines, attaching to the intestinal wall. The parasite, which feeds exclusively on blood, bites through the blood vessels piercing the mucous membrane, injecting the anticoagulant there. During the day, an adult individual on average can absorb 0.05-0.35 ml of blood. Therefore, the most characteristic symptom of this helminthiasis is iron deficiency anemia, as well as a change in the ratio of protein fractions (dysproteinemia).
This is one of the largest worms, reaching a length of 10-20 meters. The disease caused by this parasite is called diphyllobotriosis. The development cycle of the worm begins with freshwater fish or crustaceans. In the human body, which is the final owner of a wide tapeworm, the larva enters along with caviar or infected fish fillets. Reaching the small intestine, the parasite attaches to its wall and within 20-25 days grows to a mature individual.
Diphyllobotriasis occurs on the background of disorders of the digestive tract and B12-deficiency anemia.
The parasite that causes opisthorchiasis is a flatworm, reaching a length of 7-20 mm. It should be noted that more than 50% of cases of infection by the liver fluke (also called a cat fluke) are in the inhabitants of Russia. The larvae of the parasite begin to develop after the eggs fall into fresh water (from the snails that have swallowed them). Then they penetrate into the body of the fish (carp, crucian carp, bream, roach). Infection of a person occurs when eating infected fish meat that has not undergone sufficient heat treatment. The larva of the hepatic fluke from the small intestine penetrates the bile ducts and the gallbladder, fixing there with the help of two suckers.
In the acute phase of helminthiasis, the patient has pain in the upper abdomen, body temperature rises, nausea, muscle pain develops, diarrhea, skin rashes are possible. The chronic course of opisthorchiasis is manifested by symptoms of hepatitis, inflammation of the bile ducts, cholecystitis, dysfunction of the digestive tract, nervous disorders, weakness and increased fatigue. The parasite leads to the development of irreversible changes, and even after its expulsion from the patient chronic inflammatory processes and functional disorders do not pass.
Bovine and pork tapeworm
These parasites are almost identical in structure and reach a length of 5-6 meters. Infection with teniarinhoz and teniasis occurs due to the consumption of cattle meat or pork contaminated by Finns (one of the intermediate forms of helminthiasis). Viable Finns, presented in the form of whitish bubbles, reaching 0.5 cm in size, are attached to the wall of the human small intestine and in 3 months are transformed into an adult. The tape parasite, consisting of more than 2000 segments, is constantly growing. At the same time, the final segments containing the eggs, detach themselves and move through the large intestine to the anus, and then crawl out of the anus, or are released into the external environment along with the feces. The most characteristic symptoms of helminthiasis is a violation of the digestive tract.
For this parasite, man is an intermediate host. The worm is parasitic in the human body in the form of Finns. The final owner of echinococcus - a wolf, a dog or a cat. Infection occurs by alimentary through contact with animals and with environmental objects, inseminated with echinococcus eggs. After entering the intestines, oncospheres (six-hook larvae) develop from them. From the intestines, they enter the bloodstream and spread throughout the body.
The "favorite" places of parasitism of the worm are the liver and lungs. Having settled in these organs, the larva turns into a Finn (echinococcus cyst), which, gradually increasing in size, begins to destroy nearby tissues. Often in the process of diagnosis, echinococcosis is mistaken for a tumor of benign or malignant origin. In addition to mechanical stress (squeezing of organs and blood vessels), sometimes an echinococcal cyst ruptures. This condition can cause toxic shock or the formation of multiple new cysts.
This parasite, which is considered a type of echinococcus, is the cause of one of the most dangerous helminth infections (alveococcosis), which is similar in severity to cirrhosis and liver cancer. Infection occurs when oncospheres (eggs with ripe larvae) enter the intestine. There, the embryo leaves the egg and, penetrating the intestinal walls, penetrates the bloodstream. Further, with the blood flow, the parasite spreads through all tissues and organs of the body (most often it is localized in the liver). It is there in the larvae that the main stage of development begins (a multi-chamber bubble, a laurel cyst is formed). Each chamber contains the germinal head of the parasite, which continues to gradually develop. Aurochists are very aggressive formations, constantly growing due to increasing bubbles, as well as having the ability to grow into the liver, like cancer metastasis. The nearby tissues, due to the disruption of the blood vessels, undergo necrotic changes. Spreading to nearby structures, alveococcus forms fibrous nodes with inclusions of multi-chamber bubbles. This condition can last for several years, and therefore it requires mandatory surgical intervention.
Diagnosis of helminthiasis
Diagnosis of helminthic invasions includes the following activities:
- a thorough history taking to help identify possible causes of infection;
- laboratory studies of feces, blood, 12p intestinal contents, rectal and perianal mucus, muscle tissue, pulmonary sputum, bile. During the analysis, eggs, segments or parasitic fragments can be detected. However, elevated blood levels of eosinophils is also a signal of the presence of helminthiasis.
- in the diagnosis of diseases caused by larval stages or tissue parasites, serological studies are carried out (ELISA, RSK, indirect agglutination reaction, immunofluorescence analysis, etc.).
- Ultrasound, CT, and endoscopic examinations are prescribed to detect helminths affecting liver tissue.
Worms in humans: treatment
In the acute phase of a parasitic infection, the patient is given detoxification and desensitization therapy. При тяжелом течении болезни (трематодозы печени, трихинеллез) по врачебным показаниям используются глюкокортикоиды.
В качестве препаратов специфической терапии с учетом природы возбудителя назначаются специальные противогельминтные химиотерапевтические средства.
Параллельно больному рекомендуется прием антигистаминных препаратов и энтеросорбентов. Заключительный этап лечения включает в себя использование пробиотиков, нормализующих микрофлору кишечника.
Также назначается специальная щадящая диета (пища должна быть легкоусвояемой и содержать мало жиров).
В период противоглистной терапии от больного требуется неукоснительное соблюдение личной гигиены (во избежание повторного заражения). В то же время при многих гельминтозах лечение должны пройти все члены семьи и лица, находящиеся с зараженным в постоянном контакте.
- Соблюдение личной и общественной гигиены;
- Строгое соблюдение технологии приготовления пищи;
- Регулярное обследование и профилактическое лечение домашних животных;
- Тщательное мытье свежих овощей, фруктов и зелени;
- Правильная обработка речной рыбы;
- Отказ от потребления сырой, слабосоленой и вяленой рыбы.
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- Глисты у детей: симптомы и лечение, профилактика
- Аскаридоз: симптомы, лечение аскаридоза у взрослых
- Lice and nits
- Токсоплазмоз: симптомы и лечение