LAUSR

BACKGROUND Chlamydia trachomatis infections remain a burden worldwide. The goals of this study were to determine the number of C. trachomatis infections per year, characterize the demographic traits of the infected population and identify the associated sexually transmitted infections (STI), over the last 11 years, in Lisbon main Hospital Centre. MATERIALS AND METHODS Laboratorial confirmed C. trachomatis infections diagnosed between January 1st, 2009 and December 31st, 2019 were evaluated. RESULTS A total of 6404 samples were collected, with 602 being positive for C. trachomatis, corresponding to 550 patients. 60% of diagnoses were made by dermatovenereologists and most cases occurred in males (n = 371; 67.5%), with a median age of 26.1 years (standard deviation 7.98), ranging from 13 to 68 years. More than half the cases (51.3%) occurred below the age of 25 years. In 87 patients (15.8%) there was previous history of STI, in 198 patients (36%) a concomitant STI was present and 43 patients (7.8%) developed a posterior STI. Concerning follow-up, 196 patients (corresponding to 35.6% of total patients) did not show for a re-evaluation after the diagnosis was made. CONCLUSION Confirmed cases of C. trachomatis infection have risen along the years, affecting mainly people younger than 25 years. C. trachomatis infection is especially associated with Neisseria gonorrhoeae infection, but other STI are also very prevalent. Considering the potential complications of C. trachomatis infection, screening and treatment are necessary. The high percentage of diagnoses made by dermatovenereologists support the pivotal role of dermatovenereology in diagnosing C. trachomatis infections.