Rickettsia agglutination test
In 1961, Weil-Felix found that Proteus OX19 has a common antigen with typhus, endemic typhus, and locust typhus. The OXK and tsutsugamushi pathogens share a common antigen, and Proteus OX19 can be used instead of Platts. Rickettsia is used as a serological test for the diagnosis of epidemic typhus. At the same time, three kinds of bacterial liquids are used for the treatment of rickettsial disease.Basic Information
Specialist classification: Infectious disease inspection and classification: pathogenic microorganism inspection
Applicable gender: whether men and women apply fasting: fastingTips: Do not wear clothes that are too small or too tight, so as to avoid the sleeves being too tight when blood is drawn or the sleeves are too tight after blood drawing, causing blood vessels in the arms. Normal value
Normal value: < 1:40.Clinical significance
Normal human agglutination titer ≤ 1:40; ≥ 1:80 is positive. When the interval is 5-7 days, the titer is obviously increased or the single titer is higher than the reference interval, which is the indication of the recent rickettsial infection.
The serum agglutination titer of most patients with typhus increased rapidly, and it was positive on the 5th day of the disease course and reached the peak at 2 weeks. The positive rate was 95%. The titer of the recovery period decreased rapidly. People who received antibiotic treatment or vaccination against typhus in the early stage often did not develop agglutination. The positive rate of patients with recurrent typhus is only 20%. The rickettsial antibody of tsutsugamushi disease is only 30% at the first weekend of the disease, 63% at the second weekend, 87% at the third weekend, and the titer can reach 1:80~l:640, occasionally l:l280 Those who were positive began to decline at the 4th week and turned negative at 8 to 9 weeks. Proteus OX19 agglutination titer above 1:80 can help diagnose, but a small number of patients are always negative, if necessary, animal vaccination for diagnosis. The serum of patients with various rickettsial infections is different from the agglutination reaction of Proteus OXl9, OX2 and OXK strains, and can be used as one of the indicators for differential diagnosis.Positive results may be diseases: typhus rickettsial pneumonia, epidemic typhus
Inappropriate people: generally no special population.
Taboo before the examination: It is necessary to cooperate with the doctor to write the correct name, neat and tidy, to avoid confusion caused by the same name or similar names. With these in mind, blood draws are more convenient and faster, and you can better save yourself time for diagnosis.
Requirements for inspection: Do not wear clothes that are too small or too tight in cuffs to avoid the sleeves being too tight when blood is drawn or the sleeves are too tight after blood drawing, causing blood vessels in the arms. Different laboratory items should be asked by the doctor and treated differently.Inspection process
1, laboratory materials
2, the principle of rickettsial agglutination test
The O antigen of Proteus OX19, OX2 and OXK has a common antigen component with rickettsia typhimurium and rickettsia rickettsia, and three Proteus are used as antigens to detect antibodies in the serum of rickettsial infection patients, ie Foreign Fiji reaction.
See the kit. Including: Proteus OX19, OX2, OXK bacterial antigen.
4, the operation method
(1) Take 21 tubes of 12mm × 100mm and arrange them in 3 rows, 7 in each row.
(2) Another tube, add 0.15ml of serum, 2.85ml of normal saline, and dilute to 1:20. 0.5 ml of each tube was taken out and added to the first tube of each row, and the remaining 1.5 ml was added with 1.5 ml of physiological saline, and mixed to make a 1:40 dilution. 0.5 ml of each tube was added to the second tube of each row, and thus diluted to the sixth tube. No serum was added to the seventh tube of each row, and 0.5 ml of physiological saline was added as an antigen control tube.
(3) Add 0.5 ml of each of the first, second, and third rows of Proteus OX19, OX2, and OXK, shake well, and set a 37 ° C water bath for 16 to 20 hours. The maximum dilution factor of the test serum capable of exhibiting 2+ agglutination is the agglutination titer.Not suitable for the crowd
Those who do not have an indication for examination should not do this check.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. Risk of infection: If you use an unclean needle, you may be at risk of infection.