Mycoplasma Genitalium (MGen): Symptoms, Treatment & UK Online Doctor Advice

Mycoplasma genitalium, commonly referred to as MGen, is a bacterium that was first identified in the 1980s. Despite its discovery decades ago, it has only recently gained prominence as a significant sexually transmitted infection (STI) in the UK. It is unique because it lacks a cell wall, making it naturally resistant to many common antibiotics like penicillin that work by attacking the cell wall.

In the United Kingdom, MGen is increasingly recognised as a major cause of non-gonococcal urethritis (NGU) in men and inflammatory conditions of the cervix and pelvis in women. Because the symptoms closely mimic other infections like chlamydia or gonorrhoea, it is often misdiagnosed or overlooked unless specific testing is performed.

Like many STIs, MGen is frequently asymptomatic, meaning a person can carry and spread the infection without knowing. However, when symptoms do occur, they usually manifest within one to three weeks after exposure. The presentation differs slightly between men and women.

Symptoms in Men

• Urethral discharge: A clear or white discharge from the penis.
• Dysuria: A burning or stinging sensation when passing urine.
• Urethritis: Inflammation of the tube that carries urine out of the body, often persisting even after treatment for other STIs.

Symptoms in Women

• Vaginal discharge: An unusual change in the amount, colour, or smell of discharge.
• Post-coital bleeding: Bleeding after sexual intercourse.
• Intermenstrual bleeding: Spotting or bleeding between regular periods.
• Pelvic pain: Discomfort in the lower abdomen, which may indicate the infection has spread to the uterus or fallopian tubes.

Diagnosing MGen is more complex than diagnosing other STIs because the bacteria grow extremely slowly in traditional cultures. Instead, UK health providers use Nucleic Acid Amplification Tests (NAAT), commonly known as PCR tests. These tests look for the genetic material of the bacteria.

For men, the standard test is a 'first-catch' urine sample—the first part of the urine stream passed after not urinating for at least an hour. For women, a clinician-collected or self-collected vaginal swab is preferred as it provides a higher accuracy rate than a urine sample. According to BASHH (British Association for Sexual Health and HIV) guidelines, testing is generally recommended for those with symptoms of urethritis or PID, or those whose partners have tested positive.

Treating MGen has become a significant public health challenge in the UK due to rising antibiotic resistance. The bacteria have become increasingly resistant to azithromycin, which was previously the first-line treatment. If a simple course of azithromycin is prescribed without checking for resistance, the treatment may fail, and the bacteria may become even harder to kill.

Current NICE (National Institute for Health and Care Excellence) and BASHH guidelines suggest a two-stage treatment approach. This often involves an initial course of doxycycline to reduce the bacterial load, followed by a specific antibiotic like azithromycin (if the strain is sensitive) or moxifloxacin. It is vital that patients complete the entire course of medication and avoid sexual contact until both they and their partners have finished treatment and, in some cases, received a 'test of cure'.

If left untreated, MGen can lead to serious reproductive health issues. In women, the most significant risk is Pelvic Inflammatory Disease (PID). PID can cause scarring in the fallopian tubes, which increases the risk of ectopic pregnancy and tubal-factor infertility. There is also emerging evidence suggesting a link between MGen and preterm birth in pregnant women.

In men, untreated MGen can lead to epididymitis, which is the inflammation of the coiled tube at the back of the testicle. This causes pain, swelling, and redness in the scrotum and, while rare, could potentially impact fertility if left managed.

If you are experiencing persistent discharge or pain when urinating, particularly if you have already been treated for chlamydia or gonorrhoea but your symptoms have not improved, you should speak to a GP online in the UK. An online consultation offers a confidential and discreet environment to discuss your symptoms and sexual history.

An online GP can provide advice on the appropriate testing pathway, explain the latest BASHH treatment guidelines, and help you understand how to notify previous partners. Because MGen requires specific antibiotics that are not always available over-the-counter, a professional consultation is necessary to ensure you receive the correct prescription for your specific case.

The most effective way to prevent MGen is the consistent and correct use of condoms during vaginal, anal, and oral sex. While condoms significantly reduce the risk, they do not eliminate it entirely. Regular sexual health screenings are recommended for anyone with new or multiple partners.

If you test positive for MGen, it is your responsibility to inform any sexual partners from the last six months. They need to be tested and treated regardless of whether they have symptoms. This 'partner notification' is a cornerstone of UK sexual health policy to break the chain of infection and prevent reinfection.