However, false positives need to be excluded.

Syphilis is a common sexually transmitted disease caused by Treponema pallidum infection, which has a history of hundreds of years and is currently distributed all over the world. This is a very important sexually transmitted disease. It can be divided into acquired syphilis, congenital syphilis and pregnancy syphilis.

Suggestion: serological examination of syphilis includes non-specific treponema pallidum antibody and specific treponema pallidum antibody detection. (1) Nonspecific Treponema pallidum antigen serum test is used to screen syphilis and observe the activity of syphilis. This method mainly detects IgG and IgM antibodies against lipids on the cell membrane of Treponema pallidum. The commonly used clinical detection methods include VDRL (slide test in STD research laboratory), USR (serum unheated slide test) and RPR (rapid plasma reagin ring card test). The false positive rate of this test is 1% ~ 2% in the general population, but it can be as high as 10% in drug addicts. In addition, the false positive rates of tuberculosis, connective tissue disease and pregnant women have increased to varying degrees. Generally speaking, the titer of 90% false positive patients is lower than 1: 8, but it should be noted that the positive titer of latent syphilis and advanced syphilis is also low. It should be pointed out that half of the non-specific serum positive people in low-risk population are false positive, so specific antibody testing is needed to confirm the diagnosis. In primary syphilis, VDRL can be positive after 14 days of chancre. At the time of diagnosis, 30 ~ 50% VDRL test was negative. Therefore, those who are suspicious should be reviewed at least twice in the follow-up process.