Schistosoma cercariae membrane reaction

In the immunological diagnosis of schistosomiasis, almost all kinds of immunological tests have been tried. In addition, there are cercaria membrane test and ring egg sedimentation test using Schistosoma cercariae and eggs as antigens. A clinically common test method with high sensitivity, specificity and wide use is now introduced. Basic Information Specialist classification: Infectious disease examination and classification: blood examination Applicable gender: whether men and women apply fasting: fasting Analysis results: Below normal: Normal value: no Above normal: negative: normal. Positive: abnormal. Tips: The number of eggs to be added should be appropriate, and too many or too few eggs will have a certain impact on the reaction results. When calculating eggs, no immature eggs and broken eggs are counted. Normal value Negative reaction No reaction around the surface of the cercariae or only granular precipitation. Clinical significance CHR has high sensitivity and specificity, and the positive rate is generally over 95%, and it has early diagnostic value, but it seems to have no therapeutic value. Cross-reactivity can occur in patients with rice dermatitis infected with livestock and poultry. Positive results may be diseases: visceral schistosomiasis, pulmonary schistosomiasis, schistosomiasis, vulvar schistosomiasis, cercariae cercaria dermatitis, schistosomiasis intestinal disease precautions (1) The number of eggs to be added should be appropriate, and too many or too few eggs have a certain effect on the reaction results. When calculating eggs, no immature eggs and broken eggs are counted. (2) For each batch of serum samples, a positive serum control should be performed at the same time. (3) This test can be used for the reaction of blood-dropping filter paper instead of serum, but when the blood droplets are eluted, the intensity of the diluted reaction of the blood is thus lowered. Dry blood filter paper is generally not recommended in China. At present, there are heat-treated ultrasonic dry eggs, PVC film ring egg reaction and double-sided tape strip egg reaction. Inspection process (1) Using a molten paraffin, draw two straight lines of about 20 mm on a clean glass slide, and add 2 drops of the serum of the subject between the wax lines. (2) Pick 100-150 dry eggs from the needle tip and add them to the serum, and mix them to cover 24mm×24mm coverslips. The coverslips are sealed with paraffin. (3) After 48 hours in a 37 ° C incubator, the reaction results were observed with a low power microscope. Suspected positives should be identified under a high power microscope. (4) The result of the interpretation, the typical positive reaction is the appearance of a bubble-like, finger-like or slender curled band-shaped sediment around the eggs, the margins are relatively neat, and there is obvious refraction. The vesicular precipitate must be greater than 10 [mu]m (approximately 2 cell sizes). 1 The reaction intensity is represented by (+) to (+++). (+++) The area of ​​vesicular deposits around the eggs is larger than the area of ​​the eggs, and the banded sediments are equivalent to or more than twice the long diameter of the eggs. (++) The area of ​​the bubble-like precipitate around the egg is larger than 1/2 of the area of ​​the egg, and the band-shaped sediment corresponds to or exceeds the long diameter of the egg. (+) The area of ​​the bubble-like precipitate around the egg is less than 1/2 of the area of ​​the egg, and the band-shaped sediment is smaller than the long diameter of the egg. 2 Negative reaction: There is no sediment around the eggs, or there are vesicular precipitates smaller than 10μm and spherical regardless of size (spherical, slightly dilated, non-connected with eggs) and shadow (the shape is not very regular) , the light is light, and the particles are visible under high magnification. For the positive reaction specimens, 100 mature eggs were observed, and the number of eggs in response and the intensity of the reaction were recorded, and the ring-up rate was calculated. Negatives must look at the complete film. Not suitable for the crowd There are no special taboos. Adverse reactions and risks No relevant records.

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