Intradermal test for schistosomiasis

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 method of intradermal testing with high sensitivity, specificity and extensive use is now presented. The schistosomiasis intradermal test is an auxiliary test for examining bloodsucking worms. The diluted schistosomiasis (or egg) antigen is injected intradermally to detect whether the patient has the corresponding antibody. If the skin test is positive, the patient may have a schistosomiasis infection, which may assist in clinical diagnosis or as a screening test in the schistosomiasis screening. Through this examination, the corresponding symptoms can be judged. Basic Information Specialist classification: Infectious disease inspection and classification: pathogenic microorganism inspection Applicable gender: whether men and women apply fasting: not fasting Analysis results: Below normal: Normal value: no Above normal: negative: Normally negative. Positive: Normally negative. Tips: Maintain a normal diet and rest. Patients with acute infection, fever, acute infectious disease, local damage to skin diseases, etc. are not suitable for this examination. Normal value negative. Clinical significance (1) This test has high sensitivity. The positive rate of skin test positive test is about 95%, and the healthy person's false positive reaction is about 2% to 3%. The cross-reaction with paragonimiasis is 7% to 15%, and children sometimes have false negative reactions. (2) This test is generally used as a census screening method, and the positive person will be further examined. (3) Intradermal tests can be performed on the low-age group to check for new infections and to assess the effects of prevention and treatment. (4) Clinically, patients with suspected schistosomiasis with no history of schistosomiasis may be treated with an intradermal test as an auxiliary diagnosis. If the intradermal test is positive, consider further diagnosis. (5) After the patient is cured, the endothelium test always maintains a positive reaction for a long time, so the method cannot be used to evaluate the curative effect. High results may be diseases: schistosomiasis, pulmonary schistosomiasis, vaginal schistosomiasis precautions (1) The non-inoculated area was positive with 5mm as the lower boundary, and the BCG inoculation area was positive with 10mm as the lower boundary. (2) The concentration of the schistosomiasis antigen solution should not be too large, and it must be diluted to an appropriate concentration for skin test to avoid causing systemic reactions or aggravating local reactions. Patients with suspected cellular immune function or immunodeficiency can be tested with a 1:2000 concentration reagent. If it is diagnosed with or without schistosomiasis infection, it should be used in a relatively rare concentration such as 1:10000 or 1:100000, but it is not suitable for this test. (3) It is judged that the skin test results are mainly indurated, only redness and no induration may be caused by deep injection site, and the test should be repeated if necessary. Inspection process 1, according to the material: blood. 2, the principle of schistosomiasis intradermal test It is a type I allergy test. When the schistosomiasis antigen is injected intradermally, the antigen binds to the corresponding IgE antibody, causing degranulation of mast cells and basophils, releasing histamine to dilate the capillaries, enhancing the permeability of the blood vessel wall, and causing reactions such as papules and blush. 3, reagents There are two types of schistosomiasis test antigens supplied domestically. One is 1:8000 adult dry powder hot and cold immersion antigen, male one is 1:3000 fresh adult homogenate antigen. 4, the operation method Inject the schistosomiasis antigen 0.03ml into the forearm flexion side of the subject by aseptically using a tuberculin syringe. The skin can also be imprinted on the forearm with a 0.5cm-diameter seal. The injected antigen fills the entire round area and is injected. The amount is equivalent to 0.03 ml. After 15 minutes, the results were observed and the maximum diameter of the papules was measured. Any positive or greater than 0.8 cm was a positive reaction. Not suitable for the crowd Contrained population: acute infection, fever, acute phase of infectious disease, local damage to skin diseases and other diseases. Adverse reactions and risks 1, subcutaneous hemorrhage: due to pressing time less than 5 minutes or blood draw technology is not enough, etc. can cause subcutaneous bleeding. 2, discomfort: the puncture site may appear pain, swelling, tenderness, subcutaneous ecchymosis visible to the naked eye. 3, dizzy or fainting: in the blood draw, due to emotional overstress, fear, reflex caused by vagus nerve excitement, blood pressure decreased, etc. caused by insufficient blood supply to the brain caused by fainting or dizziness. 4. Risk of infection: If you use an unclean needle, you may be at risk of infection.