Changes

December 2024 — minor update. The recommendations for the dose of metronidazole and length of treatment for trichomoniasis have been updated in line with the most recent UK guidelines.

Update

Goals

To support primary healthcare professionals to:

• Recognise symptoms suggestive of trichomoniasis.
• Where possible, refer to a genito-urinary medicine (GUM) clinic or other sexual health specialist. If specialist referral is declined or not possible:
  • Make a diagnosis in primary care.
  • Provide appropriate treatment to the person and current partner(s) and any partner from within the 4-week period prior to presentation.
  • Provide information and advice on trichomoniasis, and advise on measures to reduce the risks of further sexually transmitted infections (STIs).
  • Screen the person, current partner(s), and partner(s) from within the 4-week period prior to presentation for other STIs.
  • Arrange appropriate follow up.

Outcome measures

Audit criteria

QOF indicators

QIPP - Options for local implementation

NICE quality standards

What is it?

• Trichomoniasis is a sexually transmitted infection (STI) caused by the flagellate protozoan Trichomonas vaginalis.
• In adults, transmission of T. Vaginalis is almost exclusively through sexual intercourse. Vertical transmission can occur from an infected mother to baby during vaginal delivery [Fürnkranz, 2021].
• In women, the organism is found in the vagina, urethra, and paraurethral glands.
• In men, the organism is usually located in the urethra but has also been isolated from the subpreputial sac and from lesions on the penis.

[BASHH, 2013; Sherrard, 2021]

How common is it?

•  Trichomoniasis is the most common non-viral sexually transmitted infection (STI) in the world [Field, 2018; Van Gerwen, 2023]  
  • The World Health Organization (WHO) estimated that more than 156 million cases of trichomoniasis occurred in 2016, greater than for either chlamydia (127 million) or gonorrhoea (87 million). However, T. vaginalis diagnosis is relatively rare in the UK, with around 6000 cases reported each year, compared with over 200,000 chlamydia cases [Rowley, 2019; Field, 2018]. 
  • National STI surveillance data in England show that over 90% of diagnosed T. vaginalis cases occur in women, a gender difference attributed to more rapid spontaneous clearance of infection in men.
    • Between 2009 and 2011, just under 50% of T. vaginalis diagnoses were in women of white ethnicity (10.7 per 100,000 population), but the rate of T. vaginalis diagnoses was much higher in black Caribbean women (329.6 per 100,000) and women of other black ethnicities (498.4 per 100,000), and much lower in men (33.9 per 100,000 in black Caribbean men and 0.6 per 100,000 in white men) [Field, 2018].
  • Despite having the highest prevalence of any STI globally, there is a lack of data on the incidence and prevalence of trichomoniasis in the general population, possibly because asymptomatic people may not seek healthcare. Consequently, trichomoniasis is underdiagnosed and, therefore, undertreated [Field, 2018; Van Gerwen, 2023].
  • A cross-sectional study investigating the age-specific prevalence of trichomoniasis in sexually active people found that it is uncommon in the UK [Field, 2018].
    • Urine from 4386 participants aged 16–44 years reporting one or more lifetime sexual partner(s) was tested for T. vaginalis.
    • Urinary T. vaginalis was detected in seven women and no men, giving a weighted prevalence estimate of 0.3% (95% confidence interval [CI] 0.1% to 0.5%).
    • Of the seven women with T. vaginalis detected, four were of black or mixed ethnicity (prevalence 2.7% [95% CI 0.9% to 7.7%]) and 5 reported recent partners of black or mixed ethnicity. 
    • The prevalence of a self-reported history of T. vaginalis (past 5 years) was 0.1% (95% CI 0.0% to 0.2%) in women and 0.0% (95% CI 0.0% to 0.2%) in men.

What are the risk factors?

Risk factors for trichomoniasis infection include:

• Current gonorrhoea or chlamydia infection (in women).
• Having two or more sexual partners in the previous year.
• Lack of consistent condom use.
• Women with bacterial vaginosis.

[Kissinger, 2015; Sherrard, 2021]

What is the prognosis?

• Between 10–50% of trichomoniasis infections are asymptomatic, with the most common symptoms being vaginal discharge, vulval itching, dysuria, and odour in women, and urethral discharge and/or dysuria in men. However, trichomoniasis infection is associated with more severe complications.
• Untreated infection may persist or resolve spontaneously.
  • There is a spontaneous cure rate of 20–25%.
• Recurrence is common, ranging from 5–37% of cases, most likely resulting from reinfection.

[Sherrard, 2021; Kissinger, 2022]

What are the complications?

• Trichomoniasis may be associated with the following complications:
  • In women:
    • Perinatal complications (preterm delivery and/or low birthweight infant) [Van Gerwen, 2021].
    • Predisposition to maternal postpartum sepsis [Sherrard, 2021].
    • Facilitation of HIV transmission, and there is some evidence that there may be an increased risk of Trichomonas vaginalis infection in people who are HIV positive [Sherrard, 2021; Masha, 2019]. 
    • Pelvic inflammatory disease [Wiringa, 2020]. 
    • Alterations to the normal vaginal flora, increasing susceptibility to bacterial vaginosis [Kalia, 2020]. 
    • Increased risk of cervical cancer, including in women co-infected with human papillomavirus. One meta-analysis reported that women who were T. vaginalis positive were over 5 times more likely to develop cervical cancer (RR 5.23, 95% CI 3.03–9.04) [Hamar, 2023].
    • Infertility [Zhang, 2022].
  • In men:
    • Acute and chronic prostatitis. 
    • Facilitation of HIV transmission, and there is some evidence that there may be an increased risk of T. vaginalis infection in people who are HIV positive [Sherrard, 2021; Masha, 2019]. 
    • Increased risk of prostate cancer [Van Gerwen, 2023].
    • Infertility [Zhang, 2022]. 

How should I diagnosis trichomoniasis in women?

When diagnosing women:

• Take a history. 
  • Ask about the symptoms experienced (if any), including the duration, severity, and any exacerbating factors (such as after intercourse, or during menses). 
    • Up to 50% of women with trichomoniasis are asymptomatic.
    • When present, common symptoms include vaginal discharge (in up to 70% of women), vulval itching, dysuria, or offensive odour, but these are not specific to trichomoniasis. Vaginal discharge varies in consistency from thin and scanty to profuse and thick. The classic discharge is frothy and yellow-green, and occurs in 10–30% of infected women.
    • Other symptoms include vulvitis, vaginitis, vulval soreness, vulval ulceration, lower abdominal pain, and dysuria.
  • Ask about:
    • Any treatments tried (prescription or over-the-counter) and their effects.
    • Medical history (past and present).
    • Drug history, including the use of oral contraceptives.
    • Use of new soaps or detergents, and the use of feminine hygiene products such as wipes and sprays.
    • Sexual history, including information about new sexual partners, number of sexual partners in the last year, use of condoms, and history of previous STI. 

When diagnosing men:

• Take a history. 
  • Ask about the symptoms experienced (if any), including the duration, severity, and any exacerbating factors (such as after intercourse). 
    • About 15–50% of men are asymptomatic and usually present as sexual partners of infected women.
    • When present, the most common symptoms are urethral discharge and/or dysuria. Urethral discharge is present in about 20–60% of men and is usually in small or moderate amounts.
    • Other symptoms include urinary frequency and urethral irritation. 
    • Rarely, the man may complain of a copious purulent urethral discharge or complications such as prostatitis. 
  • Ask about:
    • Any treatments tried (prescription or over-the-counter) and their effects.
    • Medical history (past and present).
    • Drug history.
    • Sexual history, including information about new sexual partners, number of sexual partners in the last year, use of condoms, and history of previous STI. 

How should I assess someone with a suspected trichomoniasis infection?

If a woman is suspected of having a trichomoniasis infection, refer the woman to a genito-urinary medicine (GUM) clinic or other local specialist sexual health service for confirmation of the diagnosis. If this is declined or not possible, perform the following examination and investigations (obtain consent and offer a chaperone). 

• Palpate the abdomen (if appropriate) to assess for tenderness or a mass (which may indicate malignancy).
• Inspect the vulva for lesions, discharge, vulvitis, ulcers, and any other changes.
• Perform a speculum examination (except in a pregnant woman with a low-lying placenta) to visualize the cervix and vagina to look for characteristic signs of trichomoniasis.
  • Trichomoniasis, when symptomatic, is characterized by a yellow-green, frothy discharge with a fishy odour.
  • Inflammation of the vulva and vagina, or more rarely a strawberry appearance of the cervix (cervicitis), may be observed on pelvic examination. 
  • About 5–15% of women will have no abnormalities on examination.
• Test the pH of the vaginal discharge to help distinguish between trichomoniasis and other causes for symptoms. 
  • Collect discharge from the lateral wall of the vagina with a swab, and transfer it onto narrow-range pH paper (pH 3.8–5.5).
  • Measure the pH by comparing the colour of the moist test section of pH paper against the graded standard.
  • The normal vaginal pH in a woman of childbearing age is 3.5–4.5.
  • A pH greater than 4.5 is suggestive of trichomoniasis.
• Take a high vaginal swab from the posterior fornix for microscopy (if available) and nucleic acid amplification testing (NAAT), at the time of speculum examination.
  • Place all swabs for bacterial culture in Amies transport medium with charcoal. 
  • Mark the request as 'suspected trichomoniasis infection' if the local laboratory does not routinely perform Trichomonas vaginalis wet microscopy or culture.
  • Transport samples to the laboratory as soon as possible. If there is a delay in transportation, the swab should be refrigerated at 4°C for no longer than 48 hours.
    • If microscopy is not being performed, a self-administered vaginal swab is recommended for NAAT instead.
• In women with vaginal symptoms, consider other causes of vaginal discharge. For more information, see the CKS topic on Vaginal discharge.

If a man is suspected of having a trichomoniasis infection, or they are a sexual partner of an infected woman, refer the man to a genito-urinary medicine (GUM) clinic or other local specialist sexual health service for confirmation of the diagnosis. If this is declined or not possible, it is reasonable to arrange tests in primary care, but the results may not be as reliable.

•  Take a urethral swab sample or arrange a self-taken penile-meatal swab for a NAAT.
  • In most men, there may be no signs, even in the presence of symptoms suggesting urethritis. 
  • Rarely, the man may present with balanitis/balanoposthitis (inflammation of the glans penis and prepuce).
• In men with urethral symptoms, consider other causes of urethritis. For more information, see the CKS topic on Urethritis - male.

For both men and women with a suspected trichomoniasis infection offer tests for:

• Chlamydia. For more information, see the section on Testing to confirm the diagnosis in the CKS topic on Chlamydia - uncomplicated genital.
• Gonorrhoea. For more information, see the section on Confirmation of diagnosis in the CKS topic on Gonorrhoea.
• HIV. For more information, see the section on How to test for HIV in the CKS topic on HIV infection and AIDS.
• Syphilis. For more information, see the section on Management of suspected syphilis in the CKS topic on Syphilis.
• Hepatitis (if the person is at high risk). For more information, see the CKS topics on Hepatitis A, Hepatitis B, and Hepatitis C.

What else might it be?

• Other conditions that may cause vaginal discharge include:
  • Non-infective causes.
    • Inadequate hygiene.
    • Retained foreign body, such as a tampon, condom, or vaginal sponge.
    • Irritant or allergic vaginitis.
    • Desquamative inflammatory vaginitis.
    • Erosive lichen planus.
    • Vaginal fistula.
    • Gynaecological cancers. For more information, see the section on Symptoms suggestive of gynaecological cancers in the CKS topic on Gynaecological cancers.
    • Genitourinary syndrome of menopause. For more information, see the CKS topic on Menopause.
  • Infective causes.
    • Bacterial vaginosis. For more information, see the CKS topic on Bacterial vaginosis.
    • Vulvovaginal candidiasis. For more information, see the CKS topic on Candida - female genital.
    • Chlamydia. For more information, see the CKS topic on Chlamydia - uncomplicated genital.
    • Gonorrhoea. For more information, see the CKS topic on Gonorrhoea.
    • Pelvic inflammatory disease (PID). For more information, see the CKS topic on Pelvic inflammatory disease.
• For more information, see the CKS topic on Vaginal discharge.
• Other conditions that may cause urethritis include:
  • Infective causes.
    • Gonorrhoea. For more information, see the CKS topic on Gonorrhoea.
    • Less common infective causes, such as herpes simplex virus, Chlamydia trachomatis, urinary tract infection, and Mycoplasma genitalium. For more information, see the prodigy topics on Herpes simplex - genital, Chlamydia - uncomplicated genital, and Urinary tract infection (lower) - men for more information.
  •  Non-infective causes.
    • Trauma (such as catheterization).
    • Irritation (for example soaps, lotions, spermicide creams, deodorants).
• For more information, see the CKS topic on Urethritis - male.

Scenario: Management of trichomoniasis

From age 13 years onwards.

Metronidazole

Search strategy

Scope of search

A literature search was conducted for guidelines and systematic reviews on primary care management of trichomoniasis.

Search dates

July 2019 - September 2024

Key search terms

Various combinations of searches were carried out. The terms listed below are the core search terms that were used for Medline.The terms listed below are the core search terms that were used for EBSCOhost MEDLINE (searched 29th July 2019). These were combined with filters to identify guidelines, systematic reviews and primary care relevant literature in EBSCOhost MEDLINE. The strategy was adapted for The Cochrane Library databases.

S4    S1 OR S2 OR S3 
S3    AB ( trichomoniasis* or trichomonas ) OR TI ( trichomoniasis* or trichomonas ) 
S2    (MH "Trichomonas vaginalis") 
S1    (MH "Trichomonas Infections+") 

Sources of guidelines

• National Institute for Health and Care Excellence (NICE)
• Scottish Intercollegiate Guidelines Network (SIGN)
• Royal College of Physicians
• Royal College of General Practitioners
• Royal College of Nursing
• NICE Evidence
• World Health Organization
• Guidelines International Network
• TRIP database
• Agency for Healthcare Research and Quality
• Institute for Clinical Systems Improvement
• National Health and Medical Research Council (Australia)
• Royal Australian College of General Practitioners
• British Columbia Medical Association
• Canadian Medical Association
• Alberta Medical Association
• Michigan Quality Improvement Consortium
• Singapore Ministry of Health
• National Resource for Infection Control
• RefHELP NHS Lothian Referral Guidelines
• Medline (with guideline filter)
• Driver and Vehicle Licensing Agency
• NHS Health at Work (occupational health practice)

Sources of systematic reviews and meta-analyses

• The Cochrane Library:
  • Systematic reviews
  • Protocols
  • Database of Abstracts of Reviews of Effects
• Medline (with systematic review filter)
• EMBASE (with systematic review filter)

Sources of health technology assessments and economic appraisals

• NIHR Health Technology Assessment programme
• The Cochrane Library:
  • NHS Economic Evaluations
  • Health Technology Assessments
• Canadian Agency for Drugs and Technologies in Health
• International Network of Agencies for Health Technology Assessment

Sources of randomized controlled trials

• The Cochrane Library:
  • Central Register of Controlled Trials
• Medline (with randomized controlled trial filter)
• EMBASE (with randomized controlled trial filter)

Sources of evidence based reviews and evidence summaries

• Bandolier
• Drug and Therapeutics Bulletin
• TRIP database
• Central Services Agency COMPASS Therapeutic Notes

Sources of national policy

• Department of Health
• Health Management Information Consortium (HMIC)

Patient experiences

• Healthtalk
• BMJ - Patient Journeys

Sources of medicines information

The following sources are used by CKS pharmacists and are not necessarily searched by CKS information specialists for all topics. Some of these resources are not freely available and require subscriptions to access content.

• British National Formulary (BNF)
• electronic Medicines Compendium (eMC)
• European Medicines Agency (EMEA)
• LactMed
• Medicines and Healthcare products Regulatory Agency (MHRA)
• REPROTOX
• Scottish Medicines Consortium
• Stockley's Drug Interactions
• TERIS
• TOXBASE
• Micromedex
• UK Medicines Information

Stakeholder engagement

Our policy

The external review process is an essential part of CKS topic development. Consultation with a wide range of stakeholders provides quality assurance of the topic in terms of:

• Clinical accuracy.
• Consistency with other providers of clinical knowledge for primary care.
• Accuracy of implementation of national guidance (in particular NICE guidelines).
• Usability.

Principles of the consultation process

• The process is inclusive and any individual may participate.
• To participate, an individual must declare whether they have any competing interests or not. If they do not declare whether or not they have competing interests, their comments will not be considered.
• Comments received after the deadline will be considered, but they may not be acted upon before the clinical topic is issued onto the website.
• Comments are accepted in any format that is convenient to the reviewer, although an electronic format is encouraged.
• External reviewers are not paid for commenting on the draft topics.
• Discussion with an individual or an organization about the CKS response to their comments is only undertaken in exceptional circumstances (at the discretion of the Clinical Editor or Editorial Steering Group).
• All reviewers are thanked and offered a letter acknowledging their contribution for the purposes of appraisal/revalidation.
• All reviewers are invited to be acknowledged on the website. All reviewers are given the opportunity to feedback about the external review process, enabling improvements to be made where appropriate.

Stakeholders

• Key stakeholders identified by the CKS team are invited to comment on draft CKS topics. Individuals and organizations can also register an interest to feedback on a specific topic, or topics in a particular clinical area, through the Getting involved section of the Clarity Informatics website.
• Stakeholders identified from the following groups are invited to review draft topics:
  • Experts in the topic area.
  • Professional organizations and societies (for example, Royal Colleges).
  • Patient organizations, Clarity has established close links with groups such as Age UK and the Alzheimer’s Society specifically for their input into new topic development, review of current topic content and advice on relevant areas of expert knowledge.
  • Guideline development groups where the topic is an implementation of a guideline.
  • The British National Formulary team.
  • The editorial team that develop MeReC Publications.
• Reviewers are provided with clear instructions about what to review, what comments are particularly helpful, how to submit comments, and declaring interests.

Patient engagement

Clarity Informatics has enlisted the support and involvement of patients and lay persons at all stages in the process of creating the content which include:

• Topic selection
• Scoping of topic
• Selection of clinical scenarios
• First draft internal review
• Second draft internal review
• External review
• Final draft and pre-publication

Our lay and patient involvement includes membership on the editorial steering group, contacting expert patient groups, organizations and individuals.

Evidence exclusion criteria

Our policy

Scoping a literature search, and reviewing the evidence for CKS is a methodical and systematic process that is carried out by the lead clinical author for each topic. Relevant evidence is gathered in order that the clinical author can make fully informed decisions and recommendations. It is important to note that some evidence may be excluded for a variety of reasons. These reasons may be applied across all CKS topics or may be specific to a given topic.

Studies identified during literature searches are reviewed to identify the most appropriate information to author a CKS topic, ensuring any recommendations are based on the best evidence. We use the principles of the GRADE and PICOT approaches to assess the quality of published research. We use the principles of AGREE II to assess the quality of published guidelines.

Standard exclusions for scoping literature:

• Animal studies
• Original research is not written in English

Possible exclusions for reviewed literature:

• Sample size too small or study underpowered
• Bias evident or promotional literature
• Population not relevant
• Intervention/treatment not relevant
• Outcomes not relevant
• Outcomes have no clear evidence of clinical effectiveness
• Setting not relevant
• Not relevant to UK
• Incorrect study type
• Review article
• Duplicate reference

Organizational, behavioural and financial barriers

Our policy

The CKS literature searches take into consideration the following concepts, which are discussed at the initial scoping of the topic.

• Feasibility
  • Studies are selected depending on whether the intervention under investigation is available in the NHS and can be practically and safely undertaken in primary care.
• Organizational and Financial Impact Analysis
• Studies are selected and evaluated on whether the intervention under investigations may have an impact on local clinical service provision or national impact on cost for the NHS. The principles of clinical budget impact analysis are adhered to, evaluated and recorded by the author. The following factors are considered when making this assessment and analysis.
  • Eligible population
  • Current interventions
  • Likely uptake of new intervention or recommendation
  • Cost of the current or new intervention mix
  • Impact on other costs
  • Condition-related costs
  • In-direct costs and service impacts
  • Time dependencies
• Cost-effectiveness or cost-benefit analysis studies are identified where available. 

We also evaluate and include evidence from NICE accredited sources which provide economic evaluations of recommendations, such as NICE guidelines. When a recommended action may not be possible because of resource constraints, this is explicitly indicated to healthcare professionals by the wording of the CKS recommendation.

Declarations of interest

Our policy

Clarity Informatics requests that all those involved in the writing and reviewing of topics, and those involved in the external review process to declare any competing interests. Signed copies are securely held by Clarity Informatics and are available on request with the permission of the individual. A copy of the declaration of interest form which participants are asked to complete annually is also available on request. A brief outline of the declarations of interest policy is described here and full details of the policy is available on the Clarity Informatics website. Declarations of interests of the authors are not routinely published, however competing interests of all those involved in the topic update or development are listed below. Competing interests include:

• Personal financial interests
• Personal family interest
• Personal non-financial interest
• Non-personal financial gain or benefit

Although particular attention is given to interests that could result in financial gains or losses for the individual, competing interests may also arise from academic competition or for political, personal, religious, and reputational reasons. An individual is not obliged to seek out knowledge of work done for, or on behalf of, the healthcare industry within the departments for which they are responsible if they would not normally expect to be informed.

Who should declare competing interests?

Any individual (or organization) involved in developing, reviewing, or commenting on clinical content, particularly the recommendations should declare competing interests. This includes the authoring team members, expert advisers, external reviewers of draft topics, individuals providing feedback on published topics, and Editorial Steering Group members. Declarations of interest are completed annually for authoring team and editorial steering group members, and are completed at the start of the topic update and development process for external stakeholders.

Competing interests declared for this topic:

None.