What is Filariasis?

Filariasis is a parasitic disease caused by filamentous parasites in lymphoid tissue, subcutaneous tissue, or serosa. In our country, there are only Bancroft worms (Banner's) and Malay blue worms (Malaysia filariasis). The disease is transmitted by blood-sucking insects. The symptoms and signs of filariasis vary depending on the worm's parasitic site. The early manifestations are mainly lymphangitis and lymphadenitis, and later stage a series of symptoms and signs caused by lymphatic obstruction. Diagnosis is based on the detection of microfilariae in the blood or skin tissue. The prevention method is to eliminate the vector, strengthen personal protection, treat patients and infected persons, and take medicine to eliminate the source of infection.

Basic Information

English name

filariasis

Visiting department

Infectious Diseases

Common symptoms

Lymphangitis

Contagious

Have

way for spreading

Blood-sucking insects spread

Causes of filariasis

The filariasis belongs to the nematode class, the order of filariasis, and the family Hiddenidae. Body slender as silk. Filariasis is endemic in Asia, Africa, and Oceania. In China, only filariasis and Malaria filariasis are found. Popular regions in China are Shandong, Henan, Jiangsu, Zhejiang, Fujian, Jiangxi, Guangdong, Guangxi, Sichuan, Guizhou and other places. Sources of infection are early patients with microfilariae in the blood and asymptomatic carriers (microfilariae). More than 30 species of mosquitoes of 4 genera, such as Anopheles sinensis, Anopheles minimus, Culex pipiens pallens and Culex pipiens quinquefasciatus.

Clinical manifestations of filariasis

Acute filariasis

(1) Lymphangiitis, such as lymphangitis , lymphadenitis, and erysipelas dermatitis, are characterized by retrograde, and a red line under the skin develops centrifugally during the attack, commonly known as "liquid fire" or "red line". Both upper and lower limbs can occur, but the lower limbs are more common. When the inflammation spreads to the superficial fine lymphatic vessels of the skin, diffuse redness and swelling appear on the local skin, the surface is bright, and there is tenderness and burning sensation.

(2) spermatic cord, epididymitis, or orchitis can cause spermatiditis , epididymitis, or orchitis if the adult parasites are in the lymphatics of the scrotum.

(3) Filaria fever periodically fights chills and high fever, which subsides for 2 days to 1 week. Some patients only have low fever but no chills. After repeated attacks, local symptoms gradually emerge.

2. Chronic filariasis

Chronic obstructive disease due to different obstruction sites, the clinical manifestations of patients also vary: including lymphedema and elephantiasis, testicular sheath fluid, chyluria and so on.

In addition to the above-mentioned lesions, filamentous nodules in female breasts are not uncommon in endemic areas. In addition, filariasis can occasionally cause ocular filariasis, filamentous granuloma of the spleen, chest, back, neck, arms, etc., filamentous pericarditis, chylous pleural effusion, chyle hemosputum, and microscopic Silkworm disease and so on.

3. Recessive filariasis

Clinical manifestations are nocturnal asthma or cough, with fatigue and low fever.

Filariasis check

Divided into pathogenic diagnosis and serological diagnosis. The former includes checking microfilariae and adult worms from peripheral blood, chyluria, and extracts; the latter is detecting filariasis antibodies and antigens in serum.

Etiological examination

Blood test microfilariae, due to the periodicity of the night, it is appropriate to take blood from 9 pm to 2 am the next day.

(1) Positive blood microfilaria test at night

(2) In the worm examination method , microfilaria were found in urine, hydrocele, lymph fluid, ascites, and chyluria . Adults were found in lymphatic vessels and lymph nodes, or filamentous sections were found in pathological tissue sections.

(3) Specific DNA probe

2. Serological examination

A rapid immunochromatographic test was used to detect positive F. banneri antigens or an enzyme-linked immunosorbent assay to detect filariasis-specific antibodies, IgG.

Filariasis diagnosis

It is consistent with epidemiological history and has typical clinical manifestations. At the same time, a serological or pathogenic test can be diagnosed.

Filariasis treatment

Pathogen treatment

(1) The therapeutic drug is mainly Haiqunsheng (also known as ethamizine). Hai Qunsheng has a killing effect on both types of filamentous worms. It has a better effect on Malaria filariasis than that of Banella filariata and a better effect on microfilariae than adults. The commonly used therapies in China are 7-day therapy to treat filariasis; 4-day therapy to treat male filariasis. After taking the medicine, patients can cause allergic reactions due to the death of a large number of microfilaria, and symptoms such as fever, chills, and headache should be treated in time. In order to reduce the side effects of Haiqunsheng, Haiqun's crude medicinal salt is widely used in prevention and treatment. After half a year of consumption, the positive rate of microfilariae in the middle and low endemic areas is less than 1%, and the side effects are slight.

(2) Albendazole, twice daily, can kill adults, but has no direct effect on microfilaria.

(3) In recent years, a new anti-filariam drug, furanopyrone, has been successfully developed in China, which has a killing effect on both microfilariae and adults, and has good effects on both types of silkworms. It has better curative effect on Bancian filariasis than Hai Qunsheng.

Symptomatic treatment

For acute lymphadenitis, give local care to the affected area, such as foot care, clean the infected area, give timely antibacterial treatment, and apply antifungal ointment to the foot every day. In addition to administering Haiqunsheng insecticide, the subject's edema patients can also be combined with traditional Chinese medicine and mulberry leaf injection plus bandaging therapy or baking therapy. For patients with scrotal elephantiasis and hydrothorax, surgical resection can be performed. For patients with chyluria, the light can heal by rest; it can also be treated with 1% silver nitrate renal pelvis. In severe cases, microsurgical treatment for lymphatic-vascular anastomosis can achieve better results.

Filariasis prognosis

Once suffering from this disease, Hai Qunsheng treatment in the early enough foot course can often be cured. Late cases are difficult to achieve quickly. Insecticide treatment alone is not enough. Other adjuvant therapies are also needed. Surgical treatment can also be performed when necessary, but the surgical results are not always ideal. Hai Qunsheng's repeated treatments are still expected to cure.

Filariasis prevention

Census

Early detection and cure of patients and carriers can ensure the health of the people and reduce and eliminate the source of infection.

2. Mosquito control

3. Epidemiological surveillance

To strengthen epidemiological surveillance in areas where the basic filariasis target has been reached, attention should be paid to the surveillance work:

(1) Re-examination and treatment of the original positive patients, it was found that the patients were treated in time until they turned negative.

(2) Strengthen the monitoring of mosquito vectors in blood-positive households and find that infected mosquitoes, that is, the mosquito-infected households are the center, expand the blood check and kill mosquitoes to the surrounding people to clear the epidemic point and prevent further transmission.