TV

Question 1

What is TV

Answer 1

Trichomonas vaginalis is a flagellated protozoon (=a single-celled microscopic animal of a group of phyla of the kingdom Protista).

Question 2

Where is TV found in women

Answer 2

Vagina
Urethra
Paraurethral glands

Urethral infection is found in 90% of infected cases although is the sole site in less that 5%

Question 3

Where is TV found in men

Answer 3

Urethra mainly

[although trichomonads have been isolated from the subpreputial sac (foreskin) and lesions of the penis]

Question 4

How is TV transmitted

Answer 4

Exclusively through sex

Question 5

Symptoms and signs in women

Answer 5

10-50% asymp
- Vaginal discharge [70% - varies in consistency - the classic frothy yellow discharge in 10-30%]
- Vulval itching
- Dysuria
- Offensive odour
- Occasionally lower abdo pain or vulval ulceration
Signs: vulvitis and vaginitis, 2% strawberry cervix with naked eye. 5-15%= no signs on examination

Question 6

Signs and symptoms men

Answer 6

15-50% asymp
Men usually present as the sexual partners of infected women
- Urethral discharge and/or dysuria = commonest presentation
- Urethral irritation
- Urinary frequency

Signs: urethral discharge occasionally

Question 7

Complications

Answer 7

1. Detrimental outcome on pregnancy and preterm delivery and birth weight - further research needed to confirm associations and prove causal link. Some studies have shown no link so asymp TV testing not done routinely in pregnant women.
2. TV infection at delivery can = maternal postpartum sepsis
3. TV may enhance HIV transmission and may be inc risk TV in those that are HIV positive
4. can rarely cause prostatitis

Question 8

Testing as per BASHH guidelines should be for:

Answer 8

• pts c/o vaginal d/c or vulvitis, or found to have these O/E
• TV contacts
• persistent penile urethritis

Question 9

What characteristics is TV associated with

Answer 9

older age
non white
current GC or CT in women

Question 10

Testing site

Answer 10

female - posterior fornix swab for microscopy, self taken swab for NAAT, urine test [sensitivity 88-90%]

male - urethral swab - 80% sensitivity. NAATs of penile meatus [urethra]. Urine only approved for one NAAT atm.

Question 11

What investigations are available

Answer 11

Microscopy
POCTs - OSOM TV rapid test
NAATs - molecular detection
Culture

Question 12

Microscopy - what is the sensitivity

Answer 12

40-60% in vaginal samples and lower in men so a negative result should be approached with caution

Must read within 10 min

Question 13

POCT OSOM
What is the sensitivity and specificity
What detecting

Answer 13

Sensitivity= 80-94%
Specificity = >95%

Detects the antigen, for vaginal swabs. Not for use with urine with men.

Provides result within 10 minutes
False positives may occur esp in populations with a low prevalence of disease so consideration should be given to confirming positive results in that situation

Question 14

NAAT testing
Sensitivity

Answer 14

Gold standard
88-100% vaginal specimens

Detection of TV in male specimens [urine/urethral] is currently out the scope of most NAATs so local validation would be needed - although high sens and spec have been found

Question 15

culture sensitivity

Answer 15

88%

Question 16

Management TV - advice and meds

Answer 16

1. partners treated simultaneously
2. metronidazole 400-500mg BD for 7d (in SHAC handbook is 400mg BD for 5/7)
3. SHAC advises no sex until TOC (7d later) and referral to HA’s for this with review of contact tracing / complaince/ sx/ partner management