Trichomonas vaginalis infection among women in a low prevalence setting

Trichomonas vaginalis has become rare in Australian cities but remains endemic in some remote regions. We describe the prevalence and associations of infection among women attending an urban Australian sexual health clinic.

A retrospective case control study was conducted with women diagnosed with T. vaginalis at Sydney Sexual Health Centre between January 1992 and December 2006. Proforma medical records for all women were reviewed to extract demographic, behavioural and diagnostic variables using a predefined data collection instrument.

Over the 15-year period, 123 cases of T. vaginalis were diagnosed, with a prevalence of 0.40%. Factors independently associated with infection were older age, vaginitis symptoms (adjusted odds ratio (AOR) 6.47; 95% confidence interval (CI), 3.29-12.7), sex with a partner from outside Australia (AOR 2.33; 95% CI, 1.18-4.62), a concurrent (AOR 3.65; 95% CI, 1.23-10.8) or past (AOR 2.67; 95% CI, 1.28-5.57) sexually transmissible infection, injecting drugs (AOR 7.27; 95% CI, 1.43-36.8), and never having had a Papanicolaou smear (AOR 7.22; 95% CI, 2.81-18.9).

T. vaginalis infection was rare in women attending our urban clinic. Rarity, combined with an association with sex outside Australia, points to imported infections accounting for a large proportion of T. vaginalis infections in an urban population. The association with never having had cervical cancer screening, along with injecting drug use, likely reflects an increased prevalence in those with reduced access to health services or poor health seeking behaviours.