Jaw mouth nematode
Introduction
Introduction to sputum nematode The gnathostomiasis is a rare worm-like migration in China. The pathogen is the third larva of Gnathostomaspinigerum. Clinically, it is characterized by a migratory subcutaneous mass and blood eosinophilia. In addition, the third stage larvae of the larvae can also invade deep tissues and organs, such as the brain, lungs, eyes, liver, kidneys, etc., causing internal organs. . basic knowledge The proportion of illness: the incidence rate is about 0.002%-0.007% Susceptible people: no special people Mode of transmission: insect vector transmission Complications: epilepsy cerebral palsy
Cause
Cause of nematode
Causes:
The adults of the larvae of the larvae are bright red, slightly translucent and shiny. The length of the males is 11 to 25 mm, and the females are longer, 25 to 54 mm. They are round and linear, and the head is hemispherical. The surface has 4-8. The small hook, the neck is narrow, and there are many small skin spines in the front half and the near end. The adult parasitizes in the terminal host cat, the dog's stomach mucosa, forms a mass, and the eggs are discharged from the feces, and the eggs are oval. The size is 40m×70m, and the smaller end has a cap-shaped transparent plug. The eggs in the first stage larvae hatch in the water, and after being swallowed by the first intermediate host, the second stage larvae are developed after 7-10 days. When the sword otter is swallowed by the second intermediate host fish, frog, snake, turtle, cockroach, loach, etc., it can develop into the third larvae after about 1 month, when the host is transferred, such as chicken, duck, pig. When the tiger, leopard, wolf, etc. swallow the infected second intermediate host, the third stage larvae can be decapsulated in the stomach and passed through the gastrointestinal wall of the infected animal, and migrated to the liver, muscles and connective tissue. However, it cannot develop into an adult. If it is a suitable terminal host, such as a cat or a dog, the third stage larva can be in its gastric mucosa. The mass is formed and developed into adult worms in 6-8 months. Female and male adults mate to lay eggs. The eggs are moved from the stomach cavity and the intestinal cavity downwards, excreted with the feces, from the infection to the eggs in the feces of the final host. It usually takes 8 to 12 months. Humans often get infected by eating fresh or uncooked freshwater fish containing third-stage larvae. However, humans are not the proper end-host of Echinococcus chinensis, so infection The nematode can only stay in the early stage of the third stage larvae or sexually immature adults, and travels in the human body. Its life span can reach several years, and the elderly can reach more than 10 years. In China, in addition to the discovery of the larvae of the genus Ranunculus, Gnathostoma hispidum and Gnathostoma doloresi are also found, which can also cause similar helminth rickets.
Pathogenesis:
The third stage larvae of the larvae of the larvae of the larvae are released in the stomach by digestive and vesicles, and then pass through the stomach wall and migrate to the liver and other tissues. The human being is not the ultimate host of the worm, and can only become a transitory host. The larvae are in humans. The body can not develop into an adult, can only cause long-term migration in the human body and cause tissue damage and lesions. The infected larvae are mostly one, but there are also several, the pathological changes are parasitic granulomas, by eosinophils, fibroblasts. Cells, tissue cells and macrophages are formed. When larvae migrate in tissues, in addition to mechanical damage, they can secrete and excrete some substances that are toxic to the human body, induce poisoning and allergic reactions in the body, thereby aggravating pathological damage. .
Prevention
Prevention of nematode disease
The disease generally has a good prognosis, but the prognosis of cerebral sputum nematode is poor, and the mortality rate can reach 2.5% to 7.7%, and sequelae can occur. The focus of prevention is not to eat raw or uncooked freshwater fish, oysters, turtles, frogs and other meats, as well as chicken and pork.
Complication
Mite nematode complications Complications, epilepsy, cerebral palsy
The larvae of the larvae can penetrate the skin and cause secondary bacterial infection. The central nervous system can cause epilepsy, limb paralysis and cerebral palsy. In the eyeball, retinal hemorrhage, vitreous opacity, retinal detachment and blindness can occur.
Symptom
Symptoms of nematode disease common symptoms low fever abdominal pain bloody nausea diarrhea rash
After 24 to 48 hours of infection, the patient may have symptoms such as hypothermia, general malaise, urticaria, nausea, vomiting, and upper abdominal pain. According to the difference in the part of the human body, the nematode can be divided into skin worm and nematode. Two clinical types of sputum nematode.
1. skin worm nematode
Most of the larvae migrate in the subcutaneous tissue 3 to 4 weeks after infection, resulting in symptoms and signs. The most common signs are transitional masses in the local skin, which may appear intermittently. Each occurrence lasts for 1 to 2 weeks, local skin. Non-recessed edema, accompanied by pain, itching or erythema, the path of migration may be pigmentation, with the prolonged course of the disease, the number of episodes can be reduced, the symptoms are also reduced, the onset time is shortened, the disease sometimes manifests as a rash, skin knot Knots or abscesses, occasionally, larvae can drill their own skin.
2. Visceral fistula nematode
(1) Liver lesions: larval migration to the liver can cause pain or pain in the right upper quadrant, liver, often accompanied by loss of appetite, nausea, fatigue and other symptoms.
(2) central nervous system lesions: nerve root-myelitis, meningoencephalitis and subarachnoid hemorrhage are more common, if the larva migrates to the spinal cord cavity, it can stimulate the nerve roots, causing severe pain with burning sensation, a few days later There are limb paralysis or sputum, and paraplegia is mainly caused by paraplegia. If the larva is drilled into the skull, it may cause meninges, brain tissue lesions, severe headache, jet vomiting, disturbance of consciousness, cranial nerve spasm or paralysis of the limbs. The larvae can easily cause bleeding after drilling into the subarachnoid space. The patient presents with sudden severe headache, vomiting, and meningeal irritation. The cerebrospinal fluid is bloody and contains many eosinophils. The disease is often more serious than A. cantonensis. It is also higher and the sequelae are more common.
(3) Pulmonary lesions: often occur in skin sputum nematode disease for several months or years, cough, chest pain, shortness of breath and hemoptysis, can cause pleural effusion or blood, occasionally the worm can be coughed with sputum Out.
(4) Eye lesions: can cause external eye lesions and intraocular lesions. The former manifests as inflammation around the eyelids, eye pain, tearing, fear of light, redness around the eyeball, etc., the latter manifests as iritis, anterior chamber or glass Volumetric blood, retinal detachment, etc., can cause blindness in severe cases, and can be found in the conjunctiva, anterior chamber or vitreous by using the slit lamp.
(5) Gastrointestinal lesions: larvae parasitize in the intestinal wall, forming a mass of intestinal wall, which can cause incomplete intestinal obstruction, abdominal pain, abdominal distension, diarrhea, blood in the stool, vomiting and other symptoms, even in the abdomen and mass.
(6) urinary tract lesions: less common, larvae can pass through the bladder tissue, with the discharge of urine, at this time can appear hematuria, urinary foreign body sensation.
Examine
Examination of sputum nematode
The total number of peripheral white blood cells increased slightly, the proportion of eosinophils was often significantly increased, and the biopsy pathological examination of subcutaneous masses was eosinophilic granuloma. If it can be found in the nematode, the diagnosis can be confirmed. The larvae as antigens, the use of ELISA and other immunological methods to detect specific antibodies in the serum of patients to help the diagnosis of this disease, however, immunological studies have found that the echinococcosis and some of the cross-immunogenicity of A. cantonensis.
Examination with an ocular slit lamp can be found in the conjunctiva, in the anterior chamber or in the vitreous.
Diagnosis
Diagnosis and identification of nematode
Diagnostic criteria
1. Epidemiological data: Pre-disease patients have a history of eating fresh or uncooked freshwater fish, turtles, frogs, chickens, etc.
2. Clinical manifestations: patients with skin fistula nematode have a migratory subcutaneous mass, which may be associated with fever, urticaria, itching, etc., and patients with visceral echinococcosis have lung, eye, brain, liver and other organ lesions. Clinical symptoms and signs, patients can have both skin nematode and visceral nematode disease.
3. Laboratory data: the total number of white blood cells in the peripheral blood increased slightly, the proportion of eosinophils was often significantly increased, and the biopsy pathological examination of subcutaneous masses was eosinophilic granuloma. If the nematode is found, the diagnosis can be confirmed. Using the third-stage larvae of Echinococcus elegans as an antigen, it is helpful to detect the specific antibodies in the serum by immunological methods such as ELISA, which is helpful for the diagnosis of this disease. However, immunological studies have found that the larvae of Echinococcus elegans and A. cantonensis There is partial cross-immunogenicity.
Differential diagnosis
1. Angiostrongylus cantonensis: Before eating, there is a history of uncooked freshwater snails, which often causes central nervous system diseases, often with persistent headache, body aches, loss of appetite, nausea, vomiting, and mental abnormalities. The headache is severe and the meningeal irritation is often mild. Some patients may have fever, rash, local skin hyperalgesia, chest pain, and apathy, limb paralysis, pathological reflex, vision loss, cranial nerve damage, lethargy and coma. Encephalitis manifestations, fundus examination may appear optic disc edema, retinal vein dilatation, more skinless downstream walking mass, peripheral leukocytosis, increased eosinophil ratio, serum anti-Anopheles sinensis IgG and IgM antibody positive.
2. Cysticercosis of pigs: There is a history of eating raw vegetables before the onset, which often causes central nervous system diseases, often with persistent headache, epilepsy, and mental abnormalities as the main clinical manifestations. Patients can have multiple subcutaneous nodules at the same time. Examination showed that cystic space-occupying lesions were found in brain tissue. Subcutaneous nodule biopsy revealed cysticercosis, peripheral leukopenia, elevated eosinophils, and positive anti-intestinal IgG and IgM antibodies in serum.
3. Mann's split rickets: Before the onset of the disease, the patients had uncooked freshwater prawn, crab, fish history, fever, rash, and more subcutaneous edema, subcutaneous nodule biopsy can be found in the schistosomiasis, peripheral Leukocytosis, an increase in the proportion of eosinophils, positive for anti-Manganese split IgG and IgM antibodies in serum.
4. Streptomyces sinensis: Before the onset, the patient had uncooked freshwater prawn, crab, fish history, fever, rash, cough, chest pain, vomiting blood stasis, and few subcutaneous lumps. Chest X-ray examination revealed patchy or cord-like lesions in the lungs, peripheral leukocytosis, elevated eosinophils, and positive IgG and IgM antibodies in the serum.
5. Canine bow worm: Before the onset, patients often have close contact with dogs. Frequent fever, rash, decreased appetite, fatigue, pain in the right upper abdomen, etc. There are few subcutaneous lumps, and the fever is mostly 37.5. ~39 °C is often intermittent heat type, ultrasound diagnostic apparatus can be found in the liver with flaky or strip-like substantial lesions, a few days after the liver lesions can move, peripheral blood leukocytes, eosinophils ratio is obvious Elevated, serum is positive for anti-canis scorpion scorpion IgG and IgM antibodies.
