Vaginal and endocervical microorganisms in symptomatic and asymptomatic non-pregnant females: risk factors and rates of occurrence

Physiological or non-physiological factors may affect the vaginal flora. The occurrence of genital microorganisms in non-pregnant females of all ages was studied, as were the risk factors associated with each microorganism. A retrospective analysis of vaginal and endocervical cultures and wet smears from 27 172 non-pregnant women, between 1996 to 2005, was performed taking into consideration clinical and socio-demographic characteristics. No microorganisms were observed in 55.7% of the individuals studied and 44.3% had positive cultures. There was no microbiological aetiology in 49% of women with genital symptoms. Poor hygiene, chemical irritants, sexual behaviour, vaginal blood, birth control type, and/or the lack of an oestrogen effect may have caused the symptoms. The highest occurrence of Gram-negative bacteria (p <0.01), mainly Escherichia coli, was observed in prepubescent girls. The highest occurrence of Candida species (p <0.01) was in women of childbearing age, and of Gram-positive bacteria (p <0.01) in menopausal women. Adolescents, particularly asymptomatic girls, carried more frequently Ureaplasma urealyticum and Chlamydia trachomatis (p <0.01). Hormonal contraception and consistent condom use was protective against bacterial vaginosis and U. urealyticum colonization. Users of intrauterine devices had an increased risk of bacterial vaginosis or of contracting U. urealyticum, Mycoplasma hominis and Candida species. Genital complaints were an independent indicator of Candida species, Gram-negative and Gram-positive bacteria, Trichomonas vaginalis and bacterial vaginosis. Chlamydia trachomatis infections were often asymptomatic. It is concluded that the hormonal milieu and non-physiological factors are major determinants of the vaginal flora. If diagnosis of genital infections is based on symptoms alone and not on culture results, it may be erroneous. Sexual abuse should be investigated when a child presents with a sexually transmitted disease.