Thoracic Filariasis

Introduction to chest filariasis Thoracic filariasis (filariasisthorax) is caused by parasitic filariasis, malaysia, and filariasis or microfilariae in the lymphatics of the chest, causing lymphatic obstruction, drainage disorders, or by microfilaria or filariasis Chest organ lesions caused by heat; or although there are no obvious clinical symptoms, but found in pleural effusions, sputum, lymph nodes, etc., called silkworms or microfilariae. Clinically, there are often fever, cough, blood stasis, chest pain, shortness of breath, asthma, chyle, chylothorax, blood eosinophilia, filarial nodules or filarial granuloma. basic knowledge Sickness ratio: 0.0001% Susceptible people: no special people Mode of infection: mosquito bite spread Complications: septic shock

Cause of chest filariasis

(1) Causes of the disease

The terminal host of the silkworm and the malaria worm is human. The patient with microfilaria in the blood or the worm is the main source of infection of this disease, but some people are in the lymphatic system of monkeys, dogs, pigs and some wild animals. It is also found that there are two kinds of filarial insects, so the animal insect-preserving host may also exist. The main mosquito species that transmit the filariasis are Culex pipiens, which causes Culex pipiens, followed by Anopheles sinensis, which mainly spreads the malaria worm. Mosquito species are subspecies of Anopheles sinensis and Anopheles sinensis, and Aedes aegypti in coastal areas can also spread Ban and Malay filariasis.

(two) pathogenesis

The pathogenesis of chest filariasis is mainly divided into two phases: 1 early: mostly allergic reactions and inflammatory reactions mainly due to exudation, metabolites of microfilariae and adults, molting and molting, secretions in adult uterus The dead worm body and its decomposition products can cause systemic or local allergic reactions in the body, which can be expressed as eosinophil infiltration in the lungs, and respiratory symptoms such as asthma, dry cough, chest pain, blood stasis, and shortness of breath; Chronic phase: due to the specificity of lymphatic circulation, the deep lymphatic system in the chest is blocked by eosinophilic granuloma or fibrosis, lymphatic reflux disorder, blockage of lymphatic vessels below the expansion, pressure increase or even rupture, so chylothorax, chyle Wait.

Chest filariasis prevention

1. Using methotrexate powder and salt to process 0.3% drug salt, generally eaten in popular areas for 6 months, each person takes about 9g total amount of ethamazine.

2. In the popular areas, the patients are given intermittent doses of ethamazine. Adults take 6mg/kg each time, once a week or once a month for a total of 12 times.

The above two methods can greatly reduce the infection rate of the population and Culex pipiens, and the positive rate of microfilaria is reduced from 10% before treatment to 1%. The prevention effect is reliable, and the principle of anti-mosquito is eliminated. Very important.

Chest filariasis complications Complications septic shock

Combine bacterial infections.

Symptoms of chest filariasis Common symptoms Chest pain, fatigue, chills, vomiting, chest tightness, chills, pleural effusion, low heat, screaming

About half of the pulmonary filariasis has no clinical symptoms, and about half of the clinical manifestations have periodic cold-like chills, chills, fever, that is, filarial fever, body temperature can be as high as 40 ° C, self-return after 2 to 3 days, or only low fever No chills, in addition to fatigue, general malaise, chest tightness, long-term cough, chest pain, hemoptysis, shortness of breath, asthma, recurrent rash and angioedema, physical examination may have lung wheezing, dry and wet voice, such as With pleural effusion, respiratory sounds can be reduced. For example, filarial worms (mostly filaria) can cause parasitic lymphangitis and eosinophilic granuloma caused by adult metabolites or worm fragments. Therefore, there may be unilateral or bilateral breast nodules or lumps, soy beans to broad beans, early soft and late soft and no tenderness, nodules more common in the upper quadrant, easily misdiagnosed as breast fibroids, lobular hyperplasia or breast cancer.

Examination of chest filariasis

1. In the early allergic reaction, the total number of white blood cells in peripheral blood increased by (10-20)×109/L, and eosinophils reached more than 20%, but the increase of eosinophils in chronic phase was less than 10%, such as infection. Neutrophils can also be elevated.

2. Blood test microfilariae is the only reliable method for early diagnosis of filariasis. Peripheral blood is usually used. The blood collection time is from 9:00 pm to 2 am. If the microfilaria in the nighttime blood exceeds 150/60l, then Microfilaria can also be detected in the blood during the day. 3 drops (about 60 l) can be used to collect thick blood tablets, or 1 large drop (about 20 l) of blood can be used to detect microfilaria, or venous blood sampling. After the red blood cells are dissolved, the method of centrifugation and concentration is used to absorb the sediment, and the micro-filaria can be found in the pleural fluid, the pericardial fluid or even the chyle.

3. The chyle test is suspected to be chyle, chylothorax effusion and other specimens, which are confirmed by Sudan III staining.

4. Immunological tests have been controversial due to the existence of false positives, but the immunological diagnosis of filariasis has made some progress in recent years.

(1) Antigen skin test: using a dog test, Ban's or Malay microfilariae, an antigen produced by aphids or adults during the infection period, the positive rate is over 90%, and the antigen specificity is also high, but Schistosomiasis has a mild cross-reactivity.

(2) Indirect immunofluorescence assay (IFAT) and enzyme-linked immunosorbent assay (ELISA): both have a high positive rate and can be used for epidemiological investigation, but because of the longer time of turning negative, it is impossible to assess the curative effect. It also does not distinguish between past infections or active infections.

(3) Dot-ELISA (Dot-ELISA) and monoclonal antibody ELISA (Sandwich-ELISA): detection of antigens in serum of filarial patients, the specificity of 96%, 94%, and both Patients with active infections were detected.

In addition, non-radiolabeled DNA probes, PCR plus non-radiolabeled DNA probes or recombinant antigen-antibody assays are helpful in the diagnosis of filariasis.

X-ray examination: X-ray chest radiograph showed increased lung texture, scattered in the miliary (canine microfilariae often accumulate in the lung to form eosinophilic foci), flaky shadow or pleural effusion sign, parasitic in the pulmonary artery After the death of the dog filaria, it is washed by the bloodstream to the lungs, often causing pulmonary infarction or pulmonary granuloma, forming an isolated, round, clear border, no calcification or void, coin-like shadow of 1 to 2 cm in diameter, which occurs in Lower lobe of both lungs, but more common in the right lower lung, easily misdiagnosed as primary or metastatic lung cancer.

Fiberoptic bronchoscopy: Although domestic reports of suspicious patients with fiberoptic bronchoscopy biopsy found microfilaria, but in fact, the value of diagnosis is not large, but for lung cancer, pneumonia and other identification will be helpful.

Diagnosis and diagnosis of chest filariasis

Diagnosis can be made by examining parasites in blood and tissues almost exclusively by parasitic techniques in people in endemic areas.

Mainly thrombophlebitis and infectious phlebitis, advanced filariasis should be differentiated from heart failure, lung tumors.

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