摘要:Background Chlamydia infection in acute pelvic inflammatory disease (PID) is associated with serious complications including ectopic pregnancy, tubal infertility, Fitz-Hugh-Curtis syndrome and tubo-ovarian abscess (TOA). This study compared clinical and laboratory data between PID with and without chlamydia infection. Methods The medical records of 497 women who were admitted with PID between 2002 and 2011 were reviewed. The patients were divided into two groups (PID with and without chlamydia infection), which were compared in terms of the patients’ characteristics, clinical presentation, and laboratory findings, including inflammatory markers. Results The chlamydia and non-chlamydia groups comprised 175 and 322 women, respectively. The patients in the chlamydia group were younger and had a higher rate of TOA, a longer mean hospital stay, and had undergone more surgeries than the patients in the non- chlamydia group. The erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and CA-125 level were higher in the chlamydia group than in the non-chlamydia group, but there was no significant difference in the white blood cell count between the two groups. The CA-125 level was the strongest predictor of chlamydia infection, followed by the ESR and CRP level. The area under the receiving operating curve for CA-125, ESR, and CRP was 0.804, 0.755, and 0.663, respectively. Conclusions Chlamydia infection in acute PID is associated with increased level of inflammatory markers, such as CA-125, ESR and CRP, incidence of TOA, operation risk, and longer hospitalization.