EN
19 024 girls (aged: from 0 to 18) attending the Pediatrie Gynaecology Outpatient Department and the Center for Treatment of Parasitic and Mycotic Diseases were examined. The diagnosis of infection with T. vaginalis was based on preparations using various methods and cultures on specific media, from vaginal content and urine. It was found that the frequency of T. vaginalis invasions in girls had lessened 2-6 times in different groups from 1960 till 1985 and the higher percent of T. vaginalis in girls over 10 years old had been observed than in younger ones. There exists the statistically significant correlation (P < 0,02) between T. vaginalis invasions in girls and other persons from their environment (families).