The rarity of Trichomonas vaginalis in urban Australia.

OBJECTIVES

Infection with Trichomonas vaginalis has declined dramatically in urban Australia but remains endemic in some predominantly indigenous rural regions. The objective was to determine T vaginalis positivity rates in clinical specimens by PCR detection, from a large community-based private pathology laboratory servicing rural and urban Australian populations.

METHODS

Retrospective analysis of data from 44 464 specimens referred for T vaginalis PCR testing over 8 years from 2004 to 2011.

RESULTS

44 464 consecutive specimens (37 137 female, 7242 male, 85 sex-unspecified) were analysed: T vaginalis was detected in 633 specimens. The overall community T vaginalis positivity rate was 1.4% (95% CI 1.3% to 1.5%). Overall rates were 2.1-fold higher in women than in men (1.5% vs 0.7%). Positivity rates were highest in the 10-14 year age group (p<0.0001). Referrals from urban areas of South-East Queensland accounted for 52% of specimens (23 121): the T vaginalis positivity rate in this urban cohort was 0.7% (95% CI 0.6% to 0.8%). Referrals identified to be from indigenous patients accounted for 48% of positive cases (304/633), and came from predominantly rural and regional areas of northern Queensland. Where follow-up testing was available 21% of patients (14/66) remained T vaginalis PCR positive when tested again within 3 months and 25% (26/101) within 6 months of the initial diagnosis.

CONCLUSIONS

This study confirms that T vaginalis is rare in the urban non-indigenous Australian setting. Guidelines need to be developed to allow targeted testing. Follow-up testing 3 months after treatment should be considered.