Lymphatic Filariasis

Introduction

Introduction to Lymphatic Filariasis Lymphatic filariasis is caused by Ban, Malay and Timorese. Its clinical features are mainly lymphangitis and lymphadenitis in the acute phase, as well as lymphatic obstruction in the chronic phase and a series of symptoms, and there are also no obvious symptoms and only microfilaria in the blood, so-called " Filaria infection." These microfilariae have a more stringent nighttime appearance in peripheral blood flow. basic knowledge The proportion of disease: this disease is more common in patients with history of contact with water, with regional, the overall incidence is about 0.0005%-0.0009% Susceptible people: no special people Mode of transmission: insect vector transmission Complications: orchitis

Cause

Cause of lymphatic filariasis

Microfilaria infection (20%):

It is mainly born in the peripheral blood, swimming like a snake. The microfilaria is about 280m long and about 7m wide. The Malay microfilaria is shorter than the microfilaria, and the microfilaria is visible under the optical microscope. Slender, rounded at the tip end, sharp at the end, sheathed outside, with a round body nucleus in the body, the headless space in the head is called the head end space, and the nerve ring is located 1/5 in front of the worm body, followed by Excretion holes, excreted cells, four cells of G, R2, R3 and R4 at the back of the worm, followed by anal holes in the ventral side, tail crests in the tail, and the morphology of Ban's and Malay microfilariae are significantly different. The ultrastructure of silkworm is basically the same as that seen under light microscopy. The body wall is similar to adult, including multi-layered cornea, dorsal, abdomen and lateral cord, subcutaneous layer and muscle cells, non-differentiated prosthetic cavity, microfilament The life span of cockroaches can live for 2 to 3 months in the human body. For those who have reached 3 years, the microfilariae of the genus Ficus can live for more than 9 months in experimental animals.

Prevention

Lymphatic filariasis prevention

1. General census: Organized and systematically conducted a survey of people over 1 year old in the endemic area, those with symptomatic or asymptomatic patients who were positive for microfilaria, or those with negative microfilariae but with typical filariasis history and signs All should be carried out in general, in filariasis, high-prevalence areas, the implementation of universal census combined with the national (over 5 years old) taking ethylamine or ethylamine salt, the national dose of ethylamine, Banffia Disease 3g therapy (3 days or 5 days of treatment) or 4.2g therapy, Malay filariasis 0.5 ~ 1.0g, 1 or 2 times, repeated in the second year.

2. Cut off the route of transmission: Mainly to kill mosquitoes, master the principle of killing early, destroying small, destroying, killing mosquito areas, focusing on the vast rural areas, doing a good job in environmental sanitation, cleaning the barns, filling in the depressions, and inhabiting mosquitoes. More places, with drug retention spray, combined with agricultural production to control pests and other measures to control larvae in rice fields.

Complication

Lymphatic filariasis complications Complications orchitis

(1) Lymph nodes and lymphatic varices: Lymph node varices are lymph nodes in the lymphatic vessels and lymphatic sinus expansion in the lymphatic vessels. They are common in the groin and thigh, one or both sides, and there is a hard core in a sponge capsule during palpation. Lymphatic varices, common in the spermatic cord, scrotum and inner thigh, occasionally seen in the upper limbs. Lymphatic varices can have varicose veins at the same time, and scrotal lymphatic varices can coexist with lymphatic scrotum. Lymphatic varices can also occur in the deep, and it has been reported that the diameter of the irritated thoracic duct is 1.5 cm.

(2) hydrocele, lymphouria, lymphatic ascites: lymphatic fluid flow into the sheath cavity due to obstruction of the spermatic cord and testicular lymphatic vessels. The skin and subcutaneous tissue of the scrotum are often edema due to obstruction of lymphatic drainage, forming a scrotal lymphatic effusion. The hydrocele is asymptomatic, and the effusion is more sag and even difficult to walk. At the time of examination, the volume of the scrotum was enlarged, and the mass of the scrotum was often tensioned, the wrinkles disappeared, the penis was retracted, and the light transmission test was often positive. If the sheath was extremely thickened and accompanied by scrotal elephant skin swelling, the light transmission test Negative.

Symptom

Symptoms of Lymphatic Filariasis Common Symptoms Acute abdomen peritonitis Joint pain Low heat chills Milk Abdominal abdomen abdominal pain Diarrhea Chest

The incubation period of the disease is from the infected larvae invading the human body until the microfilaria is found in the blood, usually about 1 year, but it can be as early as 4 months or as late as 1.5 years. The incubation period for Timorian filariasis is 3 months. From the human lymph node examination, the adult silkworm was found to be 3 months after infection. The clinical manifestations of filariasis vary widely, with 50% to 75% of "asymptomatic" infected individuals in endemic areas. Male worms are mainly parasitic in the superficial lymphatic system, so lymphadenitis and cutaneous swelling of the extremities are most obvious. The filariasis not only parasitizes the lymphatic vessels of the limbs, but also parasitizes the urinary and reproductive organs of the deep lymphatic system, causing inflammation and nodules of the spermatic cord, epididymis, testis, and scrotum.

Examine

Lymphatic filariasis

1. White blood cell count and classification: The number of white blood cells and eosinophils increased in patients with early allergic reactions. The former is mostly between (10 ~ 20) × 109 / L, the latter is more than 20%, if there is bacterial secondary infection In addition to the increase in the total number of white blood cells, neutrophils also increased significantly.

2. The discovery of blood microfilariae depends on the discovery of microfilariae, usually using peripheral blood examination, most of which are most easily found from 10 pm to 2 am, such as nighttime blood. 150 strips / 60l, white enamel can also be found.

(1) Blood method: 20 l of earlobe blood is taken with a hemoglobin pipette, and microfilaria is found under a low power microscope. The positive person can see that the microfilaria is free to swing, curled before and after, and is quite active.

(2) smear method: three drops of blood from the earlobe (about 60l) placed in the center of the slide, painted into a thin rectangular or elliptical thick blood plate with a uniform edge, about 2cm × 3cm size, since the 1980s From the beginning, it is uniformly stipulated as 120l, that is, six large drops of two-piece method, dyeing can be blue or borax methylene blue staining method. If it is difficult to identify the insect species, it can be dyed with Giemsa or hematoxylin. The dyeing method can also increase the detection rate of microfilaria.

(3) Concentration method: There are many methods for the concentration of microfilaria, which are to dissolve the red blood cells in the blood, centrifuge and precipitate, and absorb the sediment to find the microfilaria that is concentrated in the sediment. The commonly used hemolytic agent is distilled water.

Diagnosis

Diagnosis and identification of lymphatic filariasis

The identification of three types of lymphatic filariasis depends on the pathological history and clinical manifestations of the epidemic area, mainly relying on pathological morphology and immunological methods. Lymphocytitis and lymphadenitis in the acute stage of filariasis should be differentiated from bacterial lymphangitis. Bacterial lymphatic vessels develop from the bottom to the local lymph nodes. Generally, local lesions can be found, and the symptoms of poisoning are heavier. Local pain and tenderness are also significant, and blood neutrophils are significantly increased.

Spermitis and epididymitis should be distinguished from epididymal tuberculosis. The history of tuberculosis is available for reference. The epididymal tuberculosis is nodular, swollen, hard and tender, and can be biopsied if necessary.

Inguinal or femoral lymph node varices should be differentiated from hernias. According to lymphatic varices, there is no empty sound in percussion, no bowel sounds hyperthyroidism, and the size changes little with body position. Impulse does not exist when coughing. Lymph and lymph in the puncture. Identification of microfilariae can be found in the liquid.

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