OBJECTIVETo summarize the clinical features and analyze the serologic test results of latent syphilis.

METHODSThe clinical data of 601 patients with latent syphilis who were treated in the sexually transmitted disease centre of Peking Union Medical College Hospital between January 2001 and November 2007 were retrospectively analyzed.

RESULTSOf the 601 cases of latent syphilis, there were 174 cases of early latent syphilis(EL), 170 cases of late latent syphilis(LL), and 257 cases of unknown latent syphilis. Male to female ratio was 0.74:1256 males and 345 females, respectively). Patients aged 20-39 years accounted for the largest proportion. Non-marital sexual intercourse was the main route of infection. Forty-six patients (7.65%) were co-infected with other sexually transmitted diseases. A total of 251 cases of latent syphilis (41.76%) were confirmed when the patients were receiving tests for other sexually transmitted diseases or suspected sexually transmitted diseases. Of the 601 patients with EL, LL and unknown latency, the proportion of serum rapid plasma reagin(RPR) titers higher than or equal to 8 were 72.99% (127/174), 52.94% (90/170), and 60.31%(155/257), respectively. Compared with the early syphilis, serological negative conversion rate was significantly lower after treatment for l2 months in the early latent syphilis patients (P=0.044).

CONCLUSIONEducation and awareness raising on syphilis should be strengthened to lower the prevalence of latent syphilis.

Adult ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Syphilis, Latent ; blood ; diagnosis ; immunology ; therapy ; Young Adult

OBJECTIVETo investigate the incidence of seroresistance of syphilis and analyze its relevant factors.

METHODSThe clinical data of 131 patients with syphilis were retrospectively analyzed. The incidence of seroresistance was investigated and the correlation between seroresistance and factors including age, gender, original titer, disease course, and medications were analyzed.

RESULTSThe incidence of seroresistance was not significantly different among patients with different ages and genders, but was significantly different among patients with different disease courses, antibody titers, and medications. Patients with a baseline serum rapid plasma reagin (RPR) titer of greater than 1: 8, a latent course, or a macrolide therapy history had higher incidences of seroresistance (i. e., 61%, 45.6%, and 72.7% respectively) than those who had a lower RPR titer, a primary course, or a benzathine penicillin therapy history.

CONCLUSIONSyphilis patients with a high baseline RPR titer, a latent course, and a macrolides therapy are prone to be seroresistant.

Adolescent ; Adult ; Aged ; Female ; Humans ; Macrolides ; therapeutic use ; Male ; Middle Aged ; Reagins ; blood ; Syphilis ; blood ; diagnosis ; drug therapy ; immunology ; Syphilis Serodiagnosis ; methods ; Young Adult

The changes of serum IgG antibody reactivity to protein antigens of Treponema pallidum after treatment of syphilis were observed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot. Until 9 to 12 months after treatment, it was seen that there was a loss of several antibodies and some diminution in their reactivity in primary, secondary and early latent syphilis, but no changes occurred in late latent and reinfected syphilis. In primary syphilis, there was a significant loss of two IgG antibodies to the treponemal antigens of molecular weights 68,500 and 47,000 at 11 months after treatment. According to our previous study, the treponemal antigen of molecular weight 68,500 was T. pallidum specific and appeared only in primary syphilis, and that of molecular weight 47,000 was one of the major antigens of T. pallidum. The reaction between serum IgG antibodies of 14 patients who had been treated for secondary, early latent and late latent syphilis 2 to 14 years ago and major antigens of T. pallidum was observed and any loss or decrease in reactivity was not discovered. From the results obtained, it was concluded that the observation of serum IgG antibody reactivity to protein antigens of T. pallidum is not helpful in evaluating the efficacy of treatment in secondary, early latent, late latent and reinfected syphilis. However, serum IgG antibodies to treponemal antigens of molecular weights 68,500 and 47,000 could possibly be useful in the assessment of the efficacy of treatment in primary syphilis.
Antibodies, Bacterial/*immunology ; Antigens, Bacterial/*analysis ; Blotting, Western ; Electrophoresis, Polyacrylamide Gel ; Humans ; Immunoglobulin G/*analysis ; Recurrence ; Syphilis/*diagnosis/immunology/therapy ; Time Factors ; Treponema pallidum/*immunology