Trichomonas Vaginalis Infection - Management of Infection Guidance for Primary Care

Publication: 30/09/2010  --
Last review: 01/03/2016  
Next review: 05/12/2020  
Clinical Guideline
ID: 2246 
Approved By:  
Copyright© Leeds Teaching Hospitals NHS Trust 2016  


This Clinical Guideline is intended for use by healthcare professionals within Leeds unless otherwise stated.
For healthcare professionals in other trusts, please ensure that you consult relevant local and national guidance.

Trichomonas Vaginalis Infection

STI Screening

People with risk factors should be screened for Chlamydia, Gonorrhoea, HIV, HepB, Syphilis. Refer to GUM service or GP with level 2 or 3 expertise in GUM.  Risk factors: < 25y, no condom use, recent (<12mth)/frequent change of partner, symptomatic partner, area of high HIV1,2



Preferred option


Trichomonas vaginalis infection

Refer to GUM service for contact tracing1B+
In pregnancy or breastfeeding:
Avoid 2g single dose Metronidazole electronic Medicines Compendium information on Metronidazole 2B-.  Consider Clotrimazole electronic Medicines Compendium information on Clotrimazole for symptom relief (not cure) if Metronidazole electronic Medicines Compendium information on Metronidazole declined 3B+


Metronidazole electronic Medicines Compendium information on Metronidazole
400mg BD
5-7 days 4A+
Metronidazole electronic Medicines Compendium information on Metronidazole
2g single dose 4A+

Clotrimazole electronic Medicines Compendium information on Clotrimazole 
100mg pessary nocté
6 nights 3B+

Back to top

Principles of Treatment

  1. This guidance is based on the best available evidence but its application must be modified by professional judgement.
  2. A dose and duration of treatment is suggested. In severe or recurrent cases consider a larger dose or longer course
  3. Choices are given as Preferred option or Alternative for patients intolerant of the preferred option and 2nd Line for when an alternative is required because of treatment failure
  4. Only send microbiology specimens if there is a clinical suspicion of infection. Inappropriate specimens (e.g. routine ulcer swab or routine catheter specimen of urine) lead to inappropriate antibiotic prescribing.
  5. Prescribe an antibiotic only when there is likely to be a clear clinical benefit.
  6. Limit prescribing over the telephone to exceptional cases.
  7. Use simple generic antibiotics if possible. Avoid broad spectrum antibiotics (e.g. Co-Amoxiclav (Amoxicillin-Clavulanate), quinolones and cephalosporins) when narrow spectrum antibiotics remain effective, as they increase risk of Clostridium difficile, MRSA and resistant UTI's.
  8. Avoid widespread use of topical antibiotics (especially those agents also available as systemic preparations).
  9. In pregnancy AVOID tetracyclines, aminoglycosides, quinolones, and high dose metronidazole. Short-term use of trimethoprim (unless low folate status or taking another folate antagonist such as antiepileptic or proguanil) or nitrofurantoin (at term, theoretical risk of neonatal haemolysis) is unlikely to cause problems to the foetus.
  10. Where a ‘best guess’ therapy has failed or special circumstances exist, microbiological advice can be obtained from LTHT Microbiology (Mon-Fri 9am-5pm and Sat and Sun 9am-1pm: 0113 39 23962/28580; Otherwise via LTHT switchboard - ask for the On call Microbiology Registrar)


Note: Doses are oral and for adults unless otherwise stated. Please refer to BNF for further information.
Letters indicate strength of evidence:
A+ = systematic review: D = informal opinion

Back to top


Record: 2246
  • to provide a simple, empirical approach to the treatment of common infections
  • to promote the safe, effective and economic use of antibiotics
  • to minimise the emergence of bacterial resistance and reduce the incidence of Healthcare Associated Infections in the community
Clinical condition:

Trichomonas Vaginalis Infection

Target patient group:
Target professional group(s): Primary Care Doctors
Adapted from:

This guidance was initially developed in 1999 by practitioners in South Devon, as part of the S&W Devon Joint Formulary Initiative, and Cheltenham & Tewkesbury Prescribing Group and modified by the PHLS South West Antibiotic Guidelines Project Team, PHLS Primary Care Co-ordinators and members of the Clinical Prescribing Sub-group of the Standing Medical Advisory Committee on Antibiotic Resistance. It was further modified following comments from Internet users. The guidance has been updated annually as significant research papers, systematic reviews and guidance have been published. The Health Protection Agency works closely with the authors of the Clinical Knowledge Summaries.

Evidence base

Grading of guidance recommendations

The strength of each recommendation is qualified by a letter in parenthesis.

Study design


Good recent systematic review of studies


One or more rigorous studies, not combined


One or more prospective studies


One or more retrospective studies


Formal combination of expert opinion


Informal opinion, other information


A+ = systematic review: D = informal opinion.

STI screening

  1. National Chlamydia Screening Programme here
  2. BASHH and MedFASH. Standards for the management of sexually transmitted infections (STIs). British Association of Sexual Health and HIV and the Medical Foundation for AIDs and Sexual Health. 2010.


  1. BASHH. UK National Guideline on the Management of Trichomonas vaginalis. British Association for Sexual Health and HIV. 2007. Accessed 23.09.14. RATIONALE: Treatment of partners: the recommendation to also treat partners for trichomoniasis, irrespective of the results of investigations is based on two prospective RCTs.
  2. UKTIS. Use of metronidazole in pregnancy. The UK Teratology Information Service. 2008. (Tel: 0844 892 0909,RATIONALE: Metronidazole was shown to be mutagenic and carcinogenic in some animal studies. However available data, which is almost exclusively based on oral exposure, does not indicate an increased risk of adverse fetal effects associated with metronidazole use in human pregnancy. Where possible, the results of culture and sensitivity tests should be available before making a treatment choice. However if treatment is required before test results become available, then penicillins or cephalosporins may be used if considered clinically appropriate. The manufacturer advises avoidance of the 2g stat regimen during pregnancy.
  3. Du Bouchet I, Spence MR, Rein MF, Danzig MR, McCormack WM. Multicentre comparison of clotrimazole vaginal tablets, oral metronidazole, and vaginal suppositories containing sulphanilamide, aminacrine hydrochloride, and allantoin in the treatment of symptomatic trichomoniasis. Sex Transm Dis 1997;24:156-160. RATIONALE: In this randomized, open-label trial (n=168) clotrimazole vaginal tablets were not found to effectively eradicate trichomoniasis. However, a reduction in symptoms was reported. The numbers of patients who had positive cultures after treatment were 40/45 (88.9%) in the clotrimazole group, 35/43 (81.4%) in the AVC suppository group, and 9/45 (20%) in the metronidazole group (P < 0.001).
  4. Forna F, Gulmezoglu MU. Interventions for treating trichomoniasis in women. Cochrane Database of Systematic Reviews. 2003. Issue 2. Accessed 23.09.14. RATIONALE: Pooled data from two RCTs (n=294) found an 88% cure rate in women treated with metronidazole 2g stat compared with a 92% cure rate in women treated with metronidazole for 5 or 7 days. Relative risk of no parasitological cure 1.12, 95% CI 0.58 to 2.16.

Back to top

Document history

LHP version 1.0

Related information

Not supplied