Angiostrongyliasis in Guangzhou

Introduction to Angiostrongylus cantonensis Angiostrongylus cantonensis (angiostrongyliasiscantonensis) is a common helminthic mites in China. The pathogen is the larvae of Angiostrongylus cantonensis or the early stage of adult (sexual immature). Clinically, viscera, especially central nervous system infections, cause fever, headache, vomiting, convulsions, coma and other eosinophilic meningoencephalitis or meningitis. basic knowledge The proportion of sickness: 0.01% Susceptible people: no specific population Mode of infection: pathogen infection Complications: hydrocephalus

The cause of angiostrongyliasis in Guangzhou

Cause of the disease (78%):

Humans are infected by raw or semi-raw intermediates and recurrent hosts containing larvae of the larvae, and vegetables, fruits, or raw water contaminated with larvae can also be infected. Animal experiments suggest that the third stage larvae can actively enter the host through the skin. Since the human is an abnormal host of the worm, the worm in the human body stays in the early stage of the fourth stage larva or adult (sexual immature).

Pathogenesis (12%):

After entering the human body, the third stage larvae of A. cantonensis invade the central nervous system, causing brain, brain stem, cerebellum and spinal cord lesions. The main pathological changes are hyperemia, edema, hemorrhage, brain tissue damage and granulomatous inflammatory reaction. In the brain tissue, meninges, spinal cord and pulmonary arterioles of autopsy cases, A. cantonensis has been found, local arterial blood vessels are blocked and granuloma is formed, and there is a large amount of eosinophil infiltration in granuloma due to blood flow supply disorder. The affected brain cells have vacuolar degeneration, softening, eosinophilic meningitis in the meninges, and abscess or granuloma in the lung tissue.

In addition, in the lungs of autopsy cases, more Aphis gossypii were found, mostly in the fourth stage of larvae, and even young adult worms were found.

Guangzhou tubeworm disease prevention

Strengthen health and health education, raise the awareness of the people's self-protection, prevent diseases from entering the mouth, do not eat raw or half-lived snails and re-contained frogs, fish, river prawn, crabs, etc., do not eat lettuce, do not drink raw water. Do not allow infants and young children to crawl on the ground where there are snails and cockroaches. The terminal host of A. cantonensis is mainly rodents, especially rodents. Once it is found to be transmitted by rodents, rodents should be killed to control the source of infection. When processing fresh water snails, prevent larvae from invading the body through the skin and preventing larvae from contaminating kitchen utensils or food.

The main point of prevention of this disease is not to eat raw or undercooked freshwater snails, fish, shrimp, frogs and other meats, so that infants and young children can not crawl on the ground where there are snails and cockroaches.

Complications of Angiostrongylus cantonensis Complications

Infectious polyradiculitis, ie Guillain-Barre syndrome, manifests as flaccid paralysis, with ascending and symmetrical, with sensory disturbances. In addition, cranial nerve damage can occur, unilateral limbs Complications such as sputum and hydrocephalus.

Guangzhou tube round nematode symptoms common symptoms appetite decreased drowsiness nausea expression apathy skin pain chest pain coma

The incubation period is 1 to 25 days, mostly 7 to 14 days. The incubation period of children is about 3 days shorter than that of adults.

Because the central nervous system is more obvious and the symptoms are heavier, clinical cases have more inflammations of the central nervous system infection, accounting for more than 50%, often with persistent headache, body aches, loss of appetite, nausea, vomiting, and mental disorders. The main clinical manifestations, severe headache and meningeal irritation are often mild, some patients may have fever, rash, apathy, local skin hyperalgesia, chest pain, about 30% of patients with limb sensation, hyperalgesia, mild to complete paralysis , large, urinary incontinence, pathological reflex, vision loss, second, third, fourth, sixth and seventh pairs of cranial nerve damage signs, lethargy and coma and other manifestations of meningoencephalitis, early fundus examination, no abnormalities, late optic disc edema Retinal vein dilatation, however, few subcutaneous lumps are found downstream.

Inspection of angiostrongyliasis in Guangzhou

The increase in eosinophils in peripheral blood and cerebrospinal fluid is characteristic.

Non-specific examination

(1) Blood: The total number of white blood cells can be in the normal range, but it is slightly elevated, often exceeding 10×109/L, and eosinophils are increased, accounting for 0.08 to 0.37, often more than 0.15.

(2) Cerebrospinal fluid: the appearance is clear or slightly yellow, the number of white blood cells is increased, reaching (50 ~ 1400) × 106 / L, and the multinucleated cells and mononuclear cells are roughly half, the eosinophils account for 0.10 ~ 0.62, the protein is normal or Increased, 0.27 ~ 1.09g / L, sugar and chloride are in the normal range.

2. Specificity check

(1) Microscopic examination of pathogens: The fourth or fifth stage larvae of A. cantonensis can be found in the cerebrospinal fluid of patients, and the detection rate is 10% to 44%. It was detected in the cerebrospinal fluid of a child 2 years old. There are as many as 44 pieces, which are pale yellow and white cotton-lined, and the length is 1.3-4.5cm. The appearance of the males is black and white, the tail ends are slightly curved to the abdomen, the symmetry of the umbrellas is symmetrical, and the kidneys are shaped. It has a tapered shape, and the horny epidermis of the worm is transparent and smooth, with fine horizontal stripes. The head is slightly rounded, and there are mouth capsules at the front end. The esophagus can be seen, the nerve ring can be seen, the drain hole can be seen, and the yellowish intestine branch can be seen at the back end of the worm. , the vulva and anal orifice, the tail end is slender, slightly tapered, and sometimes, single-cell eggs can be seen in the uterus of the female.

(2) Specific antigen detection: The antigen was prepared from A. cantonensis, the mice were immunized, the spleen cells were isolated, the monoclonal IgG antibody was prepared by cell fusion and cloning techniques, and the patient was detected by enzyme-linked immunosorbent assay (ELSA). The soluble antigen of cerebrospinal fluid and serum in A. cantonensis can be used as a clear diagnosis. The detection rate of soluble antigen in CSF is higher than that in serum. In Taiwan, Shth et al. The mice were immunized with a soluble antigen with a molecular weight of 91×10, and monoclonal antibodies were prepared for ELSA detection of antigens in the cerebrospinal fluid and serum of A. cantonensis. As a result, 35 cases were clinically diagnosed as A. cantonensis. In patients with meningoencephalitis, cerebrospinal fluid was 100% positive, serum 89% (31/35) positive, and the average titer of cerebrospinal fluid was higher than serum.

(3) Specific antibody detection:

1 Indirect fluorescent antibody test (IFAT): Prepare antigen slides with sputum or adult slices of A. cantonensis, incubate with appropriate dilution of patient serum, rinse, and add fluorescein-labeled animal anti-human IgG or IgM The antibody, incubation, and fluoroscopy were examined by fluorescence microscopy. The results showed that the detection rate of specific IgG antibody was more than 90% 2 weeks after infection, and positive at 4 weeks after infection. The specific IgM antibody positive in serum was new. Infection, serum-specific antibody positive, combined with relevant epidemiological data, clinical manifestations and other laboratory findings, can make a clear diagnosis of the disease.

2 Enzyme-linked immunosorbent assay: The soluble antigen is prepared by ultrasonic fragmentation of A. cantonensis or adult, and the specific antibody in the serum is detected. The detection method is mature, and it is considered to be a simple method for clinical case diagnosis. , rapid and specific detection method, improved detection method by dot enzyme-linked immunosorbent assay (Dot-ELISA), avidin-biotin enzyme-linked immunosorbent assay (AB-ELISA), immunoenzymatic staining test (IEST), etc., the detection of specific antibodies in serum by ELISA is the most commonly used immunological method in the diagnosis of this disease in clinical laboratory.

3. Head CT or MRI examination: CT and MRI can be found in the brain tissue with patchy changes, the area is 0.5 ~ 1.0 cm2, the boundary is blurred, not complete.

4. Chest CT examination: There are often small nodular lesions in the lung tissue, scattered in the peripheral part of the two lungs, frosted glass-like infiltration changes around the small nodules.

5. EEG examination: The patient's alpha wave slows down more often.

Diagnosis and diagnosis of Angiostrongylus cantonensis

Diagnostic criteria

1. Epidemiological data

Within 4 weeks before the onset, there are fresh or uncooked freshwater snail meat, snail meat history, raw freshwater fish, shrimp, crab or frog, or infants crawling on the ground.

2. Clinical manifestations

Often manifested as persistent headache, body aches, loss of appetite, nausea, vomiting, mental disorders, etc., headache is severe and meningeal irritation is often mild, some patients may have fever, rash, apathy, local skin feeling dull and hyperalgesia Limb paralysis, chest pain and cranial nerve damage, severe cases can cause drowsiness, coma and optic disc edema.

3. Laboratory inspection

The increase in eosinophils in peripheral blood and cerebrospinal fluid is characteristic.

(1) Non-specific examination

1 blood: the total number of white blood cells can be in the normal range, but with a slight increase, often more than 10 × 109 / L, eosinophils, accounting for 0.08 ~ 0.37, often more than 0.15.

2 cerebrospinal fluid: the appearance is clear or slightly yellow, the number of white blood cells is increased, reaching (50 ~ 1400) × 106 / L, multinucleated cells and mononuclear cells are roughly half, eosinophils account for 0.10 ~ 0.62, protein is normal or elevated , 0.27 ~ 1.09g / L, sugar and chloride are mostly in the normal range.

3 head CT or MRI examination: CT and MRI can be found in the brain tissue with patchy changes, the area is 0.5 ~ 1.0 cm2, the boundary is blurred, not complete.

4 chest CT examination: there are often small nodular lesions in the lung tissue, scattered in the peripheral part of the two lungs, frosted glass-like infiltration changes around the small nodules.

5 EEG examination: the patient's alpha wave slows down more often.

(2) Specific examination

1 microscopic examination of pathogens: the fourth or fifth stage larvae of A. cantonensis can be found in the cerebrospinal fluid of patients, the detection rate is 10% to 44%, and 44 cases have been detected in the cerebrospinal fluid of a 2 year old child. As many as the naked eye, it is light yellowish white cotton thread, 1.3 to 4.5 cm long. The appearance of the male is black and white, the tail is slightly curved to the abdomen, the symmetry of the umbrella is kidney-shaped, and the tail of the female is oblique. Conical, horny horny epidermis is transparent and smooth, visible fine horizontal stripes, slightly rounded at the head, with a mouth at the front end, visible short esophagus, visible nerve ring, drain hole, visible yellowish intestines at the back of the worm, genitals, genital And anal holes, the tail end is slender, slightly tapered, and sometimes, single-cell eggs can be seen in the uterus of the female.

2Specific antigen detection: The antigen was prepared from A. cantonensis, the mice were immunized, the spleen cells were isolated, the monoclonal IgG antibody was prepared by cell fusion and cloning technique, and the cerebrospinal fluid was detected by enzyme-linked immunosorbent assay (ELSA). The soluble antigen of A. cantonensis in serum can be used as a clear diagnostic basis. The detection rate of soluble antigen in CSF is higher than that in serum. In Taiwan, Shth et al. The mice were immunized with a soluble antigen with a molecular weight of 91×10, and a monoclonal antibody was prepared for ELISA to detect the antigen of C. elegans in cerebrospinal fluid and serum. As a result, 35 cases were clinically diagnosed as A. cantonensis. In patients with inflammation, cerebrospinal fluid was 100% positive, serum 89% (31/35) positive, and the average titer of cerebrospinal fluid was higher than serum.

3 Specific antibody detection: A. Indirect fluorescent antibody test (IFAT): Prepare antigen slides with sputum or adult slices of A. cantonensis, add appropriate dilution of patient serum, incubate, rinse and add with fluorescein Animal anti-human IgG or IgM antibody, incubated, washed and examined by fluorescence microscopy. The results showed that the detection rate of specific IgG antibody was more than 90% 2 weeks after infection, and positive at 4 weeks after infection. Positive IgM antibody is a new infection, serum-specific antibody positive, combined with relevant epidemiological data, clinical manifestations and other laboratory findings, can make a clear diagnosis of the disease, B. Enzyme-linked immunosorbent assay: Guangzhou The tuberculosis or adult worm is made into soluble antigen by ultrasonic fragmentation, and the specific antibody in the serum of the patient is detected. The detection method is mature, and it is considered to be a simple, rapid and specific detection method which can be used for clinical case diagnosis. The improved detection method is a dot-linked enzyme-linked immunosorbent assay (Dot-ELISA), avidin-biotin enzyme-linked immunosorbent assay (AB-ELISA), Immunoassay staining test (IEST), etc., using ELISA to detect specific antibodies in patients' serum is currently the most commonly used immunological method in the diagnosis of this disease in clinical laboratories.

Differential diagnosis

1. Man's schizophrenia: Before the onset, the patient had uncooked freshwater prawn, crab, fish history, fever, rash, and more subcutaneous edema. Subcutaneous nodule biopsy found more eosinophils. Cells and Mann's larvae, leukocytosis, elevated eosinophils, and anti-Manganese phlegm IgG and IgM antibodies in serum.

2. Streptomyces sinensis: Before the onset, the patient had uncooked freshwater prawn, crab, fish history, fever, rash, cough, chest pain, vomiting blood stasis, few subcutaneous lumps, chest X Line examination revealed a flaky or cord-like lesion in the lungs, increased leukocytosis, elevated eosinophils, and positive IgG and IgM antibodies in the serum.

3. Canine bowworm mites: Before the onset, patients often have close contact with dogs. Frequent fever, rash, loss of 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 examination can be found in the liver with flaky or strip-like substantial lesions, after a few days can be found in the liver lesions have moved, blood leukopenia, eosinophils The proportion was significantly increased, and the anti-cancer scorpion scorpion IgG and IgM antibodies were positive in the serum.

4. Spinosaurus nematode disease: Before the onset, there are raw or uncooked freshwater fish, turtles, frogs, chickens and other meat history, and patients with skin echinococcosis have a subcutaneous edema, which may be associated with fever. Urticaria, itching, etc., visceral echinococcosis patients have the corresponding clinical symptoms and signs of lung, eye, brain, liver and other organ diseases, the peripheral blood leukocyte count is slightly elevated, the proportion of eosinophils is increased, serum The specific antibody positive is helpful for the diagnosis of this disease. The biopsy pathological examination of the subcutaneous mass is eosinophilic granuloma. If the nematode is found, the diagnosis can be confirmed.

5. Cysticercosis of pigs: There is a history of eating raw vegetables before the onset of the disease, which often causes central nervous system diseases. The main clinical manifestations are persistent headache, epilepsy and mental disorders. Patients may have multiple subcutaneous masses at the same time. Activity, elliptical nodules, cranial imaging examination showed cystic space-occupying lesions in the brain tissue, the diameter of 0.5 ~ 1cm, subcutaneous nodule biopsy can be found in the cysticercosis, blood leukopenia, eosinophil ratio Elevated, serum positive for cytosolic scorpion IgG and IgM antibodies.

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