Trichomoniasis: Symptoms, Causes, and Effective Treatment in the UK

Trichomoniasis, often referred to as 'Trich', is a sexually transmitted infection (STI) caused by a microscopic unicellular parasite called Trichomonas vaginalis. While it is less commonly discussed than chlamydia or gonorrhoea in the UK, it remains a significant cause of vaginal and urethral discomfort. Unlike many other STIs which are bacterial or viral, Trichomoniasis is a protozoal infection.

The parasite is primarily spread through unprotected vaginal sex. It can also be passed via skin-to-skin contact in the genital area or by sharing sex toys. It does not typically infect the anus, mouth, or throat. According to the NHS and NICE guidelines, Trichomoniasis is highly treatable, but because it often presents with no symptoms, many individuals carry the infection unknowingly.

Statistics suggest that up to 70% of people with Trichomoniasis do not have any signs or symptoms. When symptoms do occur, they can range from mild irritation to severe inflammation. Symptoms usually appear between 5 to 28 days after exposure.

Symptoms in Women

• Vaginal Discharge: This is often the most noticeable sign. The discharge may be thin, frothy, or thick, and is frequently yellow-green in colour. It often has a distinct, unpleasant 'fishy' odour.
• Soreness and Itching: The vulva and vagina may feel itchy, sore, or inflamed.
• Dysuria: Pain or discomfort when urinating.
• Dyspareunia: Discomfort or pain during sexual intercourse.
• Lower Abdominal Pain: Occasional dull aching in the pelvic region.

Symptoms in Men

• Urethral Discharge: A thin, white discharge from the penis.
• Irritation: Itching or irritation inside the penis (the urethra).
• Burning Sensations: A burning sensation after urination or ejaculation.
• Frequency: Needing to urinate more often than usual.

Trichomoniasis is caused by the Trichomonas vaginalis parasite. It is transmitted during sexual activity through the exchange of bodily fluids or contact between the vagina and the penis. It can also be passed from a vagina to another vagina. The parasite cannot survive for long outside the human body, so you cannot catch it from toilet seats, swimming pools, or casual contact like hugging or sharing cutlery.

Factors that increase the risk of infection include having multiple sexual partners, a history of other STIs, and not using barrier contraception such as condoms. Using condoms consistently and correctly significantly reduces the risk of transmission, though it does not eliminate it entirely as the parasite can live on skin not covered by the condom.

If you suspect you have an STI or are experiencing unusual discharge, it is important to get tested. Trichomoniasis can be difficult to diagnose based on symptoms alone because they mimic other conditions like Bacterial Vaginosis (BV) or Thrush. In the UK, testing is available through NHS sexual health clinics (GUM clinics), some GP surgeries, and private online providers.

The diagnostic process usually involves:

• A physical examination: A healthcare professional may look for signs of inflammation or 'strawberry cervix' (tiny red spots on the cervix).
• Swab tests: In women, a swab is taken from the vaginal wall. In men, a swab may be taken from the urethra, or a urine sample may be requested.
• Lab Analysis: The samples are examined under a microscope or sent for a Nucleic Acid Amplification Test (NAAT), which is the most accurate method for detecting the parasite's DNA.

The standard treatment for Trichomoniasis in the UK, following NICE guidelines, is a course of the antibiotic Metronidazole. This is highly effective at killing the parasite. Treatment is typically administered in one of two ways:

• A single large dose: Taking 2g of Metronidazole in one go.
• A seven-day course: Taking 400mg or 500mg twice daily for seven days.

It is crucial to finish the entire course of antibiotics, even if symptoms disappear quickly. Important: You must avoid drinking alcohol while taking Metronidazole and for at least 48 to 72 hours after the final dose. Mixing the two can cause severe nausea, vomiting, and a rapid heartbeat (the disulfiram-like reaction).

Sexual partners must also be treated simultaneously, regardless of whether they have symptoms. This prevents 'ping-pong' infections where the parasite is passed back and forth between partners. You should avoid any sexual contact until both you and your partner have completed the treatment and symptoms have resolved.

If you are experiencing any changes in your urinary or sexual health, seeking professional advice is the safest course of action. An online GP can provide a confidential consultation to discuss your symptoms and help differentiate between Trichomoniasis, thrush, or a UTI.

You should consult an online GP if:

• You have noticed a change in the colour or smell of your vaginal or penile discharge.
• You experience pain during urination that doesn't resolve.
• A recent sexual partner has informed you they have tested positive for an STI.
• You require a prescription for Metronidazole after a positive test result.
• You need advice on sexual health screening and how to access home testing kits.