Paragonimiasis

Introduction to pulmonary paragonimiasis Paragonimiasis, also known as paragonimiasis, is an acute or chronic endemic parasitic disease caused by Paragonimus. The worm is mainly parasitic in the lungs, with cough, cough, red and red sputum as the main performance, but also parasitic In a variety of tissues and organs, such as the brain, spinal cord, gastrointestinal tract, abdominal cavity and subcutaneous tissue, etc., the corresponding symptoms. basic knowledge Sickness ratio: 0.0001% Susceptible people: no special people Mode of infection: fecal mouth spread Complications: pleural effusion

Cause of pulmonary paragonimiasis

(1) Causes of the disease

There are nearly 40 species of paragonimus in the world, among which 8 species are pathogenic to human body, mainly Paragonimus sinensis and Paragonimus sichuan.

The first intermediate host of Paragonimus pygmaea is more than 20 kinds of freshwater snails, the second intermediate host is crabs, and the crustaceans are found. The final host is human or dog, mammals such as cats and pigs, except for humans. Also known as the insect-preserving host, it is the main source of infection that constitutes a natural foci.

(two) pathogenesis

The cystic sputum enters the human body from the mouth, and is decapsulated into a child worm in the intestine. The worm enters the chest cavity through the intestinal wall, penetrates the diaphragm into the chest cavity, develops into an adult in the lung, moves the worm, and spawns stimulate the tissue, causing Tissue damage and immunological pathological reaction of the human body lead to tissue necrosis and formation of abscess. The granulation tissue around the lesion proliferates to form a cyst wall, which becomes a cyst. The cyst fluid is brown-red jam-like, containing insects, Charcot-Ryden crystal and hobby. Acidic cells, worms die, contents are discharged or absorbed, and cysts are replaced by fibrous tissue to form scars. Since the eggs do not develop into burrs in the human body, they do not secrete soluble antigens, causing only mechanical or foreign body stimulating effects. The cell infiltrates into a miliary-sized pseudonodule, which is a foreign body granuloma reaction, which gradually becomes fibrotic, and the worm body has migratory properties, which can cause various tissues and multiple sites of lesions.

Pulmonary paragonimiasis prevention

Do a good job in health education, do not eat raw or unripe crabs, Lama and other second intermediate hosts, do not drink the irrigated area of the river, thoroughly treat patients, control the source of infection, prevent eggs from entering the water, killing and destroying the intermediate host.

Pulmonary paragonimosis complications Complications pleural effusion

Combined pleural effusion.

Symptoms of pulmonary paragonimiasis Common symptoms Abdominal pain Chest pain Lower abdominal pain Pleural effusion Pleural hypertrophy Diarrhea Liver eosinophilic granuloma

Its clinical manifestations are also diversified, and the incubation period is several days to 20 years. Most of them are within 1 year. According to the main organs invading, they can be divided into 4 types clinically:

1. Chest type: The lung is the most common parasitic part of the parasitic worm of the Wei's lung. Cough, blood stasis and chest pain are the most common. The typical scorpion is brown for several years. If the lung tissue is necrotic, it is rotten peach-like blood stasis. When paragonimiasis migrates into the chest, it can cause chest pain, exudative pleurisy or pleural hypertrophy. Paragonimus in Sichuan causes chest pain, more pleural effusion, and less cough and blood stasis.

2. Abdominal type: abdominal pain, diarrhea, hepatomegaly as the main performance, abdominal pain is the most common right lower abdominal pain, light and heavy, may have diarrhea, brown pus and bloody stools, urgency and weight, umbilical tenderness, occasional sputum and nodules Or lump, the migration of the worm in the abdominal cavity can cause peritoneal effusion or extensive inflammatory adhesions. Paragonimus in Sichuan often invades the liver and forms eosinophilic granuloma in the liver.

3. Nodular type: The most common subcutaneous or muscular nodules, about 20% of patients with Paragonimiasis have this sign, mostly located in the lower abdomen to the subcutaneous muscles between the thighs, visible adult eggs in the nodules, eosinophils And Charcot-Ryden crystal, the main manifestation of paragonimiasis in Sichuan is migratory, subcutaneous nodules or masses, the incidence rate is 50% to 80%, nodules and masses 1 to 6 cm, the predilection site is The abdominal wall, followed by the chest wall, the back and the inner thigh.

4. Chest type: more common in children and adolescents, early headache, vomiting, meningeal irritation and intracranial hypertension, later epilepsy, visual hallucinations, paresthesia and other localized symptoms, spinal cord compression, lower limbs Feeling, abnormal movement, urinary retention, paraplegia and other symptoms.

Examination of pulmonary paragonimiasis

1. Blood: Peripheral blood leukocytosis, eosinophilia, generally in 5% to 20%, acute phase can be as high as 85% or more, caused by Sichuan paragonimus more significant, more than half of the ESR increased.

2. Pathogen examination: In patients with paragonimiasis, the eggs can be found in the sputum. Some patients can find the eggs because of the pharyngeal sputum. The stool can be found in the feces, and the cerebrospinal fluid and pleural effusion can also find eggs and more eosinophils. .

Tissue biopsy subcutaneous masses, especially migratory masses or nodular tissue biopsies, can be found in children and eosinophilic granuloma. Paragonimus is more common in Sichuan.

3. Immunological examination

(1) Intradermal test: simple and easy to use, often used for epidemiological investigation and screening, the positive rate is as high as 99%, but the specificity does not cross-react with other trematode diseases, once the infection reaction lasts for a long time.

(2) Complement binding test: It is diagnostic for early paragonimiasis and sputum-negative eggs. The serum complement-binding test can be positive 2 to 4 weeks after infection, and the positive rate is 98%, but it has cross-reactivity to other trematode diseases. .

(3) The sensitivity of the enzyme-linked adsorption test can reach 100%, and no cross-positive reaction has been observed. The positive person may be infected recently or is suffering from disease.

4. X-ray showed early pleural reaction and pleural effusion, late pleural adhesion thickening, lung lesions mainly in the middle and lower lung fields, due to different stages of disease development, and different X-ray signs:

1) Early abscess: 1~2cm blurred infiltrating shadow, center has a small translucent area, the pathological basis is the early hemorrhage or inflammatory infiltration caused by adult swim in the lung.

2) Cyst stage: For nodules or masses with vacuoles, single or multiple rooms, the walls are thin and the edges are blurred. The old lesions are thicker and the edges are clear. This is the most A characteristic sign, which is caused by the formation of a tunnel when paragonimus in the lungs migrates.

3) Fiber scar period: It is a rounded nodular shadow with sharp boundary, which can be accompanied by small vacuoles, or dense speckled strip shadows and calcifications. It is a fibrous proliferative lesion caused by worms. Moving, the above performance can occur at the same time.

Diagnosis and identification of pulmonary paragonimiasis

According to epidemiological data, especially in epidemic areas and have the opportunity to swallow live cysts; the above clinical manifestations, chest X-ray signs, eosinophils should be considered, diagnosis, sputum, feces, subcutaneous nodules biopsy found Eggs or worms can be diagnosed, and immunological tests have diagnostic significance for those with negative pathogen tests.

Due to the complex clinical manifestations of paragonimiasis, it is easy to be misdiagnosed. It should be distinguished from tuberculosis, lung tumor, tuberculous pleurisy, peritonitis and brain tumor.

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