1. Trichomonas Vaginalis
Michael Addidle

2. Trichomonas vaginalis

3. Anatomy
No cyst form
Replicates by binary fission

4. Basic Facts Almost exclusively sexually transmitted
Prevalence approx 1% (max) in NZ pop.
Humans are the only natural host
Incubation period 4-28 days.
30% women asymptomatic.
Can be carried asymptomatically for prolonged periods of time.
Also trichomonas tenax
And trichomonas foetus

5. Clinical Features Pruritis, dyspareunia Dysuria and frequency
Malodourous thin discharge (70% of cases)
Men are usually asymptomatic

6. Colpitis macularis, or “strawberry cervix.” (Courtesy, CDC.).
Swygard H et al. Sex Transm Infect 2004;80:91-95
©2004 by BMJ Publishing Group Ltd

7. Diagnostic Methods Which method is best? Wet film
Acridine Orange Stain
Culture (microtitre plate or full test tube culture)
Rapid Antigen test (OSOM® Trichomonas Rapid Test)
Nucleic Acid probe (BD Affirm™ VPIII Assay)
PCR- expensive, good for males, ?incorporate into NG/chlamydia PCR
Which method is best?
Cost v speed v performance
(Think about culture v PCR for Bordetella)

9. Comparison of Diagnostics for Trichomoniasis in Women
Test
Sensitivity
Specificity
Cost
Ease of Use
Time to Results
Wet mount
45-60%
>90%
low
easy
minutes
Culture
75-85%
>95%
medium
days
In-Pouch™
80-90%
minutes to days
Pap smear
57%
97%
PCR
100%
99.9%
high
difficult
Affirm™
92%
98%
OSOM®
>83%
>99%

10. Comparison of Diagnostics for Trichomoniasis in Men
Test
Sensitivity
Specificity
Cost
Ease of Use
Time to Results
Culture
20-30%
high
medium
days
PCR
100%
99.9%
difficult
Wet mount
≈ 30%
low
easy
minutes

11. Complications
Recently been implicated as a cause of low birth weight, premature rupture of membranes and pre-term delivery.
Hypothesis is that cytokine release from infection triggers labour.
However no evidence as yet that treating trichmoniasis during pregnancy reduces this risk.
Trichomonas infection also enhances HIV transmission.

12. Colpitis macularis, or “strawberry cervix.” (Courtesy, CDC.).
Swygard H et al. Sex Transm Infect 2004;80:91-95
©2004 by BMJ Publishing Group Ltd

13. Guidelines for treating metronidazole resistant trichomoniasis.
Treatment of Trichomoniasis Infection
Metronidazole
Guidelines for treating metronidazole resistant trichomoniasis.
©2004 by BMJ Publishing Group Ltd

14. This presentation will be available on the Clinical Intranet for review
Any suggestions as to how we can do things better/more efficiently in the lab are very welcome.