The frequency of trichomonas vaginalis in pap smear and liquid-based cytology (SurePathTM) between 2013 and 2018 in a reference laboratory in Fortaleza, Brazil

Abstract

Introduction: Trichomonas vaginalis (Tv) is a parasite responsible for the most frequent non-viral sexually transmitted infection and causes more than 250 million new cases around the world each year. Frequently, Tv is identified in cervical cancer screening. Objective: To assess the frequency of Tv identified on cytology between 2013 and 2018 in a private Laboratory at Fortaleza, Brazil. Methods: Cases from the files of a laboratory in Fortaleza, Brazil, were searched for diagnoses of Tv on cytology (Pap smear and SurePathTM [SP]) between 2013 and 2018, and the frequency of infection in each year, as well as differences between the years, were calculated. A linear regression test was performed to analyze the relationship between time and infection with a 95% confidence interval. The research was approved by an ethics committee. Results: The mean age of the patients was 35.9 (+12.5) years in the Pap smear group and 33.4(+11.9) years in the liquid-based cytology group. Tv was diagnosed in 281 of 207,863 patients (0.14%) (113 [0.12%] in the Pap smear group and 168 [0.15%] in SP cytology). Assessing year by year differences, it was observed that Tv was identified on cytology in 36 of 33,193 in 2013 (0.1%) (Pap smear=19/ 19,734 [0.1%]; SP=17/ 13,459 [0.13%], 50 of 34,661 in 2014 (0.14%) (Pap smear=22/ 16,358 [0.13%]; SP=28/ 18,303 [0.15%]), 34 of 33,623 in 2015 (0.1%) (Pap smear=10/ 14,501 [0.07%]; SP=24/ 19,122 [0.13%]), 29 of 34,492 in 2016 (0.1%) (Pap smear=9/ 15,629 [0.06%]; SP=20/ 18,863 [0.1%]), 52 of 35,446 in 2017 (0.15%) (Pap smear=22/ 15,948 [0.14%]; SP=30/ 19,498 [0.15%], and 80 of 36,448 in 2018 (0.22%) (Pap smear=31/ 15,408 [0.2%]; SP=49/ 21,040 [0.23%]). Conclusion: There was a tendency towards increased frequency of Tv diagnosis in the gynecologic cytology group (Pap smear or SP), mainly in the last year, reflecting what is observed using more sensitive methods.