Carnivore nematodes. Symptoms of nematodes in humans
Diagnosis - detection of helminth eggs in feces or helminths directly attached to the mucous membrane. Pinworm eggs are detected by microscopy of an adhesive tape previously applied to the patient's perianal area. Treatment is with albendazole or mebendazole. Note: Whipworm induces a pronounced Th2-OTBeT and minimizes the Th1 response, which has led to a study of porcine whipworm infection in people suffering from inflammatory bowel disease. The method has shown promising initial results.
Helminthiasis begins in the gastrointestinal tract, the larva enters the bloodstream and is carried to the lungs, migrates to the pharynx, is swallowed and matures in the intestines.
An adult Ascaris lumbricoides can reach 10-25 cm in length. Helminthiasis is widespread (about 1.2 billion people worldwide are infected, the disease does not spread in regions with a cold, dry climate). Clinical signs associated with the migration of larval forms into the lungs include bronchospasm, bronchiolitis, urticaria, and other manifestations of hypersensitivity. Massive invasion is manifested by acute intestinal obstruction and obstruction of the bile ducts. Diagnosis - detection of eggs in the feces. Treatment is albendazole and mebendazole.
The larva penetrates the skin, migrates to the lungs, then is swallowed and matures in the intestines.
Pathogens: Ankylostoma, Necator and Stronglyoides.
Helminths secrete anticoagulants and often change their location. They cause severe iron deficiency anemia. Spread is facilitated by walking barefoot and using human feces as fertilizer. Clinical signs include a rash at the site of invasion and pulmonary hypersensitivity reactions. Helminthiasis leads to the development of iron deficiency anemia and a decrease in the concentration of albumin. Eosinophilia is often found. Diagnosis - detection of eggs in the feces. Treatment is albendazole and mebendazole.
Sources of the disease
The source of nematodosis is eggs and larvae of various nematodes (Dictyocaulus, Haemonchus, Ostertagia, Thelazia, Trichostrongylus, Nematodirus, etc.), which enter the body of an animal along with feed mixture or water on infected pastures. Carriers of larvae can also be horseflies, earthworms.
Common nematodes
Scientists number about 25 thousand species of nematodes. Many of them cause severe diseases, among which the most common in animals are:
Cattle and sheep - nematodosis, bunostomiasis, marshallagiasis, hemonchosis, protostrongilosis, dictyocaulosis;
pigs - trichinosis, ascariasis, trichocephalosis, metastrongylosis;
horses - alfortiosis, parascariasis, trichostrongylosis, dictyocaulosis, oxyurosis, strongylosis, delafondiosis;
birds - amidostomiasis, echinuriosis, heterokidosis, ascaridiosis, tetramerosis.
Symptoms of nematodes
There are a number of common signs that determine the infection of animals with nematodes:
The animal coughs abruptly, especially when moving.
Mucus is secreted from the nostrils, inflammation of the lungs and bronchi are often observed.
A dramatic decrease in appetite is followed by an equally dramatic weight loss.
Often there is vomiting, diarrhea is replaced by constipation.
The abdomen is very swollen, there may be intestinal ruptures.
The animal looks oppressed, exhausted, moves a little.
- In young animals, nervous convulsions, seizures may occur, development is delayed.
On average, nematode larvae that enter the body mature within 10-15 days, and after the same period they become sexually mature. When infected with adult nematodes, the first signs of the disease appear after 5-7 days.
Diagnostics
Most often, eggs and adult nematodes are found when examining the feces of animals under a microscope.
In a pathoanatomical study, nematodes are found in the intestines, and bleeding and inflammation are found in the tissues themselves.
Preparations for the treatment of nematodosis
For the treatment of nematodosis, NITA-FARM offers its own development that has passed clinical trials. He proved the high efficiency of deworming in nematode and mixed invasions, as well as in such intractable diseases as fascioliasis, paramphistomatosis, dicroceliosis.
The injectable form is based on ricobendazole. This is an active metabolite of albendazole, which simultaneously has an effect on all helminths.
A single injection is sufficient. The maximum effectiveness of the drug reaches after 8 hours.
The action extends to sexually mature and immature nematodes, as well as cestodes and sexually mature trematodes.
Rikazol has 98-100% effect. Equally effective in nematodosis of cattle, pigs, sheep.
- The drug is 100% bioavailable, easily excreted with bile. Cow's milk can be used after 5 days, meat - 30 days after injection.
Prevention of nematodosis
It is necessary to carry out melioration of pastures and periodically change them.
Manure should be taken out only after storage and aging.
In general, nematodes are characterized by an elongated spindle-shaped body. Sizes range from 1 mm to several centimeters. The body of helminths is covered with a cuticle, the structure of which plays an important role in the differentiation of nematode species, since it can have outgrowths or spines, ridges, papillae, etc., characteristic of individual genera and species.
Nematodes - dioecious helminths, have a nervous, excretory, digestive and reproductive system. Females are always larger than males.
Among nematodes there are geohelminthes (developmental biology occurs without the participation of intermediate hosts) and biohelminths (develop with the participation of intermediate hosts).
Nematodes in the body of animals are localized in a variety of organs and tissues (in the stage of adults and larvae). With the faeces of animals, females excrete eggs or larvae. Larvae in the external environment molt and become invasive, i.e. able to infect definitive hosts. In some nematodes (ascarids), the larva does not hatch from the egg. Infection of animals occurs through the mouth with food, water, etc. or the larvae themselves are actively introduced through the skin (strongyloidos, hookworms).
Diagnostic studies for nematodes during the life of animals are carried out mainly according to the Fülleborn method (ovoscopy) and the Berman method (larvoscopy - detection of larvae).
Canine toxocariasis (Toxocaros canum)
Toxocariasis is a disease of dogs and other carnivores caused by roundworms of the Anisakidae family. Helminths parasitize in the small intestine, sometimes found in the bile ducts of the liver and pancreas.
The causative agent - Toxocara canis - is gray-yellow in color, the length of females is 10-18 cm (males are smaller), at the anterior end of the body there are cuticular wings, noticeably protruding in a semi-arc. The tail end of the male is curved. Between the esophagus and the intestines is the "ventricle" - a sign of the species. The eggs are dark gray, rounded (0.068-0.075 mm) with a well-defined cellularity.
Biology of development. Eggs shed outside by sick animals reach infectivity under favorable conditions of temperature and humidity in 8-15 days. The larva, released from the egg that has entered the intestines of the animal, is introduced into the submucosa, where it enters the blood vessels and is transferred with the blood flow to the liver, then to the heart and lungs. From the bronchi with mucus enters the oral cavity and is swallowed by animals. In the small intestine, the helminth reaches puberty in 20-21 days (the roundworm type of development ends). However, some larvae during the period of migration in the body with blood enter the tissues of the liver, heart, kidneys and muscles, where they are encapsulated and remain viable for more than a year. In the future, when pregnancy occurs in bitches, some of these larvae become active and migrate through the placenta into the bloodstream, causing intrauterine infection of puppies. This process can be repeated many times. After the birth of puppies, the larvae migrate from the lungs and liver to the intestines, reaching sexual maturity in 20-21 days.
Infection. Dogs become infected by eating the meat of foxes, arctic foxes, as well as mice and rats, in the body of which the larvae remain in a state of diapause for a long time. The life expectancy of helminths is 5 months or more.
The disease is widespread everywhere, especially in large cities. Mostly puppies and young animals that are lagging behind in growth and development are ill, and the death of animals is sometimes noted.
In urban areas, children's playgrounds and walking areas for dogs are especially unfavorable, where eggs are stored in large quantities for months.
Symptoms. With age, the infestation of dogs and fur-bearing animals decreases (approximately from 76.5-85.0% to 8.0%). In older animals, no pronounced clinical signs can be found. In puppies, diarrhea, vomiting, perversion of appetite, flatulence, and nervous phenomena are recorded. Puppies squeal, bark for no reason, bite, lose weight. Often, when they vomit, toxocars are thrown out in balls. Affected puppies lag behind in growth and development. The blood picture is deeply disturbed: the number of erythrocytes, hemoglobin decreases, leukocytes and eosinophils increase.
Diagnosis. The disease is diagnosed in a complex manner, the final diagnosis is made by examining feces according to the Fülleborn method (to detect eggs). In prenatally infected puppies, helminth eggs are found already by 21-24 days after birth.
Treatment and prevention. Piperazine salts, nilverm (levamisole, decaris), tividine (pyraitel tartrate), morantel tartrate, febantel (rintal), mebendazole, fenbendazole, pyrantel pameate, azinox plus, droncit, etc. are used.
Piperazine (diethylenediamine) - colorless hygroscopic crystals that can volatilize. They dissolve well in water (15:100). The most commonly used piperazine salts are:
- piperazine adipate - colorless prisms, odorless, with a weak pleasant taste, slowly soluble in water, non-hygroscopic;
- piperazine sulfate - white crystalline powder, readily soluble in water, non-hygroscopic;
- piperazine phosphate is a white crystalline powder, poorly soluble in cold, better in warm water (1:10).
Nilverm (tetramizol, krasverm, cytarin, ascaridil, decaris, veterinary vermizol, etc.). Stable, odorless white powder, soluble in water. It is prescribed at a dose of 0.02 g/kg once. In young animals, this dose sometimes causes vomiting, so the drug should be prescribed at a dose of 0.01 g / kg of body weight once a day for 2 consecutive days in the form of a 1% solution (1 ml / kg).
Tividin (pyrantel tartrate-balmint, strongid, etc.). White crystalline powder, odorless, soluble in water. Store in a dark container. As an anthelmintic, it is used in the form of salts: tartrate, pamoate, embonate. Pyrantel tartrate is the best nematocidal preparation. Tividin is prescribed at a dose of 0.015 g/kg of body weight once a day for 2 days with food or as a 1.5% solution at a dose of 1 ml/kg.
Morantel tartrate (analogous to pyrantel). White, odorless, soluble in water (16.3% at 23°C) crystalline mass. Low toxicity. The therapeutic index is 20. In the form of a 12.5% granulate, it is used at a dose of 0.15 g / kg of body weight (0.0188 g / kg according to ADV) once a day for 2 days with food or in the form of 7.5 % solution at a dose of 2 ml/kg of body weight (the solution is prepared by heating).
Febantel (rintal). White crystalline powder, tasteless. Practically insoluble in water, soluble in dimethyl sulfoxide. Assign orally at a dose of 0.01 g/kg of body weight (ADV) once a day for 3 days with food or in the form of a suspension.
Mebendazole (mebenvet). Small (particles no more than 5 microns) yellowish powder, tasteless and odorless. Insoluble in water, alcohol and chloroform. The drug is of medium toxicity. It is widely used in the country in the form of a Hungarian drug - a 10% granulator. It is used at a dose of 0.015 g/kg of body weight once with food.
Fenbendazole (panakur, Noe-881, oxylur). Dark yellow powder, tasteless and odorless, insoluble in water. Soluble in dimethyl sulfoxide, more difficult in methanol, chloroform. It is produced in the form of a 10% and 2.5% suspension, in powder or granules (1 g of granules contains 222 mg of fenbendazole). Low toxicity, highly effective drug. It is administered orally with food at a dose of 25 mg/kg once a day for 5 days.
Pyrantel pamoat. Available in the form of tablets and suspensions for oral administration. It acts on sexually mature and immature ascaris. Applied at a dose of 5 mg/kg of body weight. Repeat after 3 weeks.
Droncit is used orally with food at a dose of 5 mg/kg once.
Azinox-plus is produced by the scientific center "Agrovetzashchita". Composition of the drug: praziquantel, tetramizole and chlorpromazine. Produced in the form of tablets, it is used at a dose of 1 tablet per 10 kg of body weight of a dog or cat. Azinox plus is effective against tapeworms and roundworms.
Drontal plus is available in the form of tablets. One tablet contains 50 mg of praziquantel, 144 mg of pyrantelembenate and 150 mg of febantel. Dose for dogs - tablet per 10 kg of body weight once, orally with food. Effective against tapeworms and roundworms.
Cuticle. Outside, the body of the nematodes is covered with a dense cuticle with transverse or longitudinal striation. In addition, there are nematodes with a smooth cuticle. Often, spines, ridges, papillae, lateral wings, and other formations are distinguished on the cuticle. The structure of the cuticle as a whole and its individual elements, as well as the structure of the head end of the body, the esophagus, the accessory genital organs of the male, the location of the vulva in the female are of great differential diagnostic significance. Under the cuticle is a thin epithelial layer and well-developed muscles. Together they form a skin-muscular sac in which the organs of the nervous, reproductive, digestive and other systems are located.
Organs of fixation in nematodes - lips, oral capsule, cuticular outgrowths in the form of spikes, ridges and other adaptations.
Nervous system consists of a nerve ring located around the anterior end of the esophagus, and nerve branches extending from it to various parts of the body.
Sensory system represented by papillae (genital, head, cervical, etc.).
Circulatory and respiratory systems nematodes are absent.
reproductive system males and females of a tubular structure. Females of many species have two ovaries, two oviducts, two or more uteri, which form a vagina that opens on the ventral surface of the body with a female genital opening - the vulva. The vulva can be located in the anterior (in oxyurids, trichinella), posterior (in strongylids) or middle (in ascarids) parts of the female body. Females of trichocephalates and dioctophymates have a single reproductive apparatus. The male genital organs consist of one testis, which imperceptibly passes into the vas deferens, which opens into the rectum, forming a cloaca. Near the excretory canal of the male genital organs are the auxiliary organs of the reproductive system: spicules, ruci, preanal sucker, sometimes caudal bursa. Spicules serve to hold the female during copulation and expand the external opening of the vulva. Most males have two spicules. There are nematodes with one spicule and without spicules. The rulek (gubernaculum) gives direction to the spicules during copulation; with the preanal sucker or caudal bursa, the male also holds the female during copulation.
Most female nematodes are oviparous (they secrete eggs). The eggs of nematodes of different species differ in size, shape, and other features. There are also species of ovoviviparous nematodes (the larva emerges from the egg in the host organism - dictyocaulas, protostrongyls, etc.) and viviparous, i.e. giving birth to larvae (Trichinella, etc.).
development of nematodes. Depending on the characteristics of development, all nematodes are divided into two large groups: roundworms that develop in a direct way, i.e. without the participation of intermediate hosts (geohelminths), and nematodes that require a change of hosts (definitive and intermediate); they are called biohelminths.
The development of nematodes in a direct way is as follows. The eggs or larvae laid by the female, together with the excrement (faeces) of the host, enter the external environment, where, under favorable conditions (the presence of oxygen, moisture and heat), their further development occurs. A larva is formed inside the egg, which in some nematodes does not leave the egg (pork roundworm), in others it leaves the egg shells outside the host organism (horse strongylides). The larva molts twice and becomes invasive; capable of infecting a specific host when it enters its body. Often, animals are also infected when invasive eggs are swallowed with food or water (with heterakidosis of chickens, etc.).
Geohelminths develop according to oxyuroid, ascaroid, ascaridioid, toxocaroid, strongyloid, delafondioid, trichostrongyloid, trichocephaloid, trichonematoid, hookworm, dictyocauloid and amidostomatoid types.
Biohelminths develop according to anisacoid, protostrongyloid, gabronematoid, thelyazioid, aquaroid, filarioid, trichinelloid and dioctophymoid types. They are described in detail in the presentation of the respective diseases.
Systematics of nematodes. Numerous species of nematodes are included in seven suborders: Oxyurata, Ascaridata, Strongylata, Spiruta, Filariata, Trichocephalata, Dioctophymata, characterized by the following anatomical and morphological features.
In representatives of Oxyurata, the esophagus is provided in the back with only one thickening - the bulb (there is no pre-bulb).
Species of the suborder Ascaridata have three lips and a cylindrical esophagus at the head end.
In nematodes of the suborder Strongylata, males have a cuticular caudal bursa supported by costiform papillae and two spicules.
Nematodes of the suborder Filariata are also equipped with a double esophagus, but are localized in cavities and tissues that do not communicate with the external environment ( abdomen, subcutaneous tissue, tendons); ovoviviparous and viviparous.
Species of the suborder Trichocephalata have a very long esophagus, surrounded throughout by bead-like gland cells.
A characteristic feature of nematodes from the suborder Dioctophymata is the presence in males of a muscular genital bursa (without ribs) and one spicule.
Each suborder of nematodes includes several families, which are divided into genera, and the latter into species. The presentation of the material on nematodes and the diseases they cause is given in a systematic order (by suborders).
Roundworms are a spindle-shaped body of a round section, these have all the main systems of vital activity such as: digestive, reproductive, nervous, excretory, not only the circulatory and respiratory systems.
Observations have shown that the larvae and eggs of nematodes are stable in the natural environment.
Symptoms in humans and animals
The main localization in mammals is the gastrointestinal tract, during such an invasion it is noted:
- abdominal pain;
- diarrhea;
- lack of appetite;
- nausea;
- vomit.
With infection of the lungs and respiratory tract, it is noted:
- cough;
- dyspnea;
- pneumonia.
When the eyes are affected by larvae, the disease is accompanied by:
- conjunctivitis;
- tearing;
- decreased vision;
- In some cases, complete loss of vision is possible.
Common signs of finding nematodes in the body include an allergic reaction in the form of rashes, itching, redness, often a reaction to a foreign protein. Blood changes its parameters, there is an increase in eosinophilia. Toxic waste products cause general weakness, drowsiness, and mental breakdowns.
Diagnostics
Specialists use the biopsy method to identify complex invasions, as well as other methods of obtaining material for morphological diagnosis. The diagnosis of MRI, ultrasound, X-ray is not excluded. In addition, immunological diagnostics has been developed for the presence of antibodies to certain pathogens of nematoses in organisms using the methods of ELISA, RIF, RMP.
Treatment of nematodes
Drugs used for nematodes:
Prevention consists in observing the basic rules of personal hygiene. Pets and farm animals must be subject to mandatory periodic deworming.
In addition, the following activities are used:
- high-quality disposal of weeds;
- the use of individual inventory in certain areas / greenhouses (especially when diseased plants are detected);
- correctly alternate watering and drying the soil;
- properly fertilize the land with manure and plant plants.