Seroepidemiology of Chlamydia trachomatis Infection in the General Population of Northern China: The Jidong Community Cohort Study

Abstract

A longitudinal serological study to investigate the seropositive frequency, incidence, and antibody dynamics of Chlamydia trachomatis infection in the general population of China is urgently needed in order to optimize the strategies for surveillance and precise prevention of C. trachomatis infection. This longitudinal study enrolled 744 subjects aged 18–65 years from Jidong Community of Northern China from 2014 to 2018. Seropositive frequency, incidence, and reinfection of C. trachomatis were determined by detecting antibody against C. trachomatis Pgp3 using “in-house” luciferase immunosorbent assay (LISA). The dynamic of anti-Pgp3 antibody was analyzed using the Generalized Estimating Equation (GEE) model. The overall Pgp3 seropositive frequency among the 18–65-year-old population was 28.1% (95% CI 24.9–31.5), and significantly increased from 12.0% in those aged 18–29 years to 48.6% in the 60–65 years old. The seropositive frequency was slightly higher in women than in men (31.3% vs. 25.4%) without statistical significance. The C. trachomatis incidence and reinfection rate were 11 and 14 per 1,000 person-years, respectively, and showed no significant difference with respect to age, gender, ethnicity, marital status, and education levels. Furthermore, anti-Pgp3 antibody remained detectable in 93.3% (195/209) of the seropositive subjects during the 5 years of follow-up. The overall decay rate for anti-Pgp3 antibody for CT-infected persons was −0.123 Log2 RLU/year, which was dramatically slower than in CT new infection (−3.34 Log2 RLU/year) or reinfection (−1.1 Log2 RLU/year). In conclusion, at least one quarter of the people aged 18–65 years have been infected with C. trachomatis over their lifetime while all age groups are susceptible to C. trachomatis infection in the community of Northern China. Therefore, comprehensive prevention strategies are urgently needed.

Characterization of genital chlamydia trachomatis infection among women attending infertility and gynecology clinics in Hunan, China

“…The prevalence rates of C. trachomatis DNA and pgp3 antibody in a representative sample of Southern Chinese women aged 13–87 years were 3.76% and 47.46%, with the highest DNA prevalence among women aged 14–20 years and the highest seroprevalence rate among women aged 21–30 years, which was in line with the results reported from developing countries [ 7 ]. A relatively low pgp3 seropositive rate of 28.1% was previously reported among individuals aged 18–65 years from northern China [ 19 ], which may be due to an unbalanced age distribution and regional differences.…”

“…We found a high prevalence of C. trachomatis infection in young women aged < 30 years, with the prevalence decreasing at older ages. The highest prevalence was reported in adult women aged 18–24 years in the general population in Germany [ 19 ]. In southwest China, C. trachomatis infection was more common in women aged 25–34 years [ 23 ], suggesting that young women were more susceptible to C. trachomatis infection, which may be due to their sexual activities, low educational status, absence of appropriate sexual education, and poor vaginal hygiene [ 25 ].…”

“…Luciferase immunosorbent assay (LISA) was used to detect C. trachomatis -specific antigen pgp3, as described previously [ 19 , 20 ], which was more sensitive than enzyme-linked immunosorbent assay (ELISA) [ 20 ]. Briefly, the C. trachomatis pgp3 gene was amplified and sub-cloned into the pNLF1-N luciferase expression vector (Promega, Madison, WI, United States) downstream of the Nluc luciferase gene, which was then transfected into HeLa cells.…”

The serodiagnositic value of Chlamydia trachomatis antigens in antibody detection using luciferase immunosorbent assay

“…Second, the C. trachomatis NAAT positive sera were all from women, we did not evaluate the influence of gender on assay performance. Nevertheless, our previous longitudinal study on the seroepidemiology of C. trachomatis infection in the general population of China revealed no significant gender differences in terms of the prevalence of anti-C. trachomatis antibody (72). Third, the anti-C. pneumoniae antibody status was determined by only one commercial C. pneumoniae ELISA without additional assessment.…”