Overview

Sexually transmitted infections (STIs) are infections that are spread through sexual contact. There are many different types of STIs. Each exhibits different symptoms, and treatment is often dependent on the type of STI. Chlamydia is the number one, most common STI in the UK. It is thought that young adults aged between 15 to 24 account for around 60% of reported chlamydia cases.¹

Read on to find out more about symptoms and treatment for chlamydia, as well as how this compares to other STIs.

Chlamydia

Chlamydia is an infection caused by a bacteria called Chlamydia trachomatis, which is spread through contact with infected genital fluids.² Find out more about what chlamydia is here.

What are the symptoms of chlamydia?

Chlamydia is often asymptomatic – meaning that it doesn’t always present with symptoms. Asymptomatic cases are as common as 50% in people assigned male at birth (PAMAB), and 70% in people assigned female at birth (PAFAB). Without clear symptoms, it can be difficult to know if a person has chlamydia. This makes it easy for chlamydia to be unknowingly transmitted to other people.¹

When symptoms are present, typical signs include pain when passing urine, abdominal pain, and white, cloudy discharge. PAMAB may also experience pain in the testicles, while PAFAB may see bleeding in between periods or bleeding after sex.^1,3

How is chlamydia treated?

As a bacterial infection, uncomplicated chlamydia can be treated with a short course of antibiotics. Examples of antibiotic treatment regimens for chlamydia include:²

• Doxycycline 100mg twice daily, for seven days
• Azithromycin 1g once daily for one day, then 500mg once daily for two days
• Erythromycin 500mg twice daily, for fourteen days

Individuals taking treatment for chlamydia should refrain from having sex of any sort, until their treatment is complete or for seven days after taking azithromycin. As doxycycline is unsuitable in those who are pregnant or breastfeeding, azithromycin or erythromycin may be considered in these cases instead.^1,2

Gonorrhoea

Gonorrhoea is another bacterial infection. The causative bacteria is called Neisseria gonorrhoeae. 

What are the symptoms of gonorrhoea?

Similarly to chlamydia, common symptoms with gonorrhoea include white, yellow or green discharge, and pain in passing urine. PAMAB may also have inflamed foreskin, while PAFAB may experience bleeding in between periods.^3,4

How is gonorrhoea treated?

Like chlamydia, treatment for gonorrhoea without complications uses antibiotic treatment, albeit different antibiotics are used. Examples include ciprofloxacin 500mg as a single oral dose, or ceftriaxone 1g as a single injection. For pregnant or breastfeeding people, ceftriaxone is the safer option. As with chlamydia treatment, sex should be avoided until seven days after treatment has been completed.^2,4

If other symptoms point to a more serious case of gonorrhoea, then further follow-up may be required.

Trichomoniasis

Unlike chlamydia, trichomoniasis is a protozoal infection caused by Trichomonas vaginalis. Protozoa and bacteria are both microorganisms, but their differences lie in their size and structure. Protozoa are bigger and have a structure that is more similar to plant and animal cells than bacteria. This makes them similar to parasites.⁵

Find out more about what trichomoniasis is here.

What are the symptoms of trichomoniasis?

Trichomoniasis is an STI that can cause a characteristic abnormal discharge. 

In PAFAB, the discharge may be thick, thin or frothy and yellow-green. The discharge may have an unpleasant fishy smell, and itchiness or soreness around the vulva is common.

In PAMAB, the discharge is thin and white, while the penis or foreskin may be sore and red. 

Both PAFAB and PAMAB may experience pain while urinating and sex.^3,5

How is trichomoniasis treated?

Although trichomoniasis is caused by protozoa, it can still be treated with antibiotics. The antibiotic metronidazole is used. Metronidazole may be dosed at either 2g as a single dose or at 400-500mg twice daily for five to seven days. 

The latter regimen is safer for pregnant or breastfeeding people. Alcohol should also be avoided while completing metronidazole treatment and for 48 hours afterwards. This is because the alcohol can make the individual feel very sick while taking metronidazole.

 It is best to avoid sex for at least one week after completing treatment.^2,5

Genital herpes

Genital herpes is an STI caused by a virus called Herpes simplex.

What are the symptoms of genital herpes?

Symptoms may not appear immediately. This is because the Herpes simplex virus can stay dormant inside the body, where it will not be infectious and will not cause signs or symptoms. Once activated, a tingling sensation is normally felt around the infected area, followed by the emergence of small, fluid-filled blisters. These blisters burst to reveal sores.⁶

How is genital herpes treated?

There’s no cure for genital herpes. Treatment can help to clear symptoms, but the virus can be reactivated again in the future. Although chlamydia treatment uses antibiotics, treatment for genital herpes uses antiviral medication, such as aciclovir. This is dosed at 200mg five times daily for five days and should be started as soon as the tingling sensation is felt. Creams may also be used to ease pain and discomfort by numbing the area.^2,6

Genital warts

Genital warts are small lumps on the skin that appear around the genital area, caused by the Human papillomavirus (HPV).

Find out more about what genital warts are here.

What are the symptoms of genital warts?

Genital warts may be smooth and flat, or large and cauliflower-like. Genital warts are usually painless but can be itchy.⁷

How are genital warts treated?

Unlike chlamydia, treatment may not be necessary for genital warts, as one-third of cases disappear spontaneously on their own. Treatment options include creams and ointments that are specially made for genital warts, although these are not recommended in pregnancy. Genital warts may also be surgically removed by a trained professional.⁷

Screening for STIs

It is important to get tested and treated as soon as possible if chlamydia or another STI is suspected. Chlamydia does not often cause symptoms, but it can lead to serious long-term health problems if left untreated.

Most tests and treatments can be accessed at the GP, sexual health clinic, or genitourinary medicine (GUM) clinic. The National Chlamydia Screening Programme offers annual screening for all sexually active people younger than 25 years of age.

If an individual has an STI, it can be important to test and treat their current and recent sexual partners to help reduce the spread of STIs. Contact tracing is a service that is often offered alongside treatment. The service can be used to notify partners anonymously, advising them to seek their own STI test and treatment.

Preventing STIs

Many STIs are passed on through skin-to-skin contact with the infected areas (i.e. vaginal, anal or oral sex), or sharing sex toys with an infected person. The chances of passing on and contracting STIs can be reduced by:

• Regular STI testing — especially if with a new partner, or with multiple partners
• Using a condom every time during sex
• Avoiding sharing sex toys without washing or putting a condom on the toy

Summary

Different STIs present with different symptoms, which can include unusual discharge, itchiness or sores around the genital area – the vagina, penis or anus. STI tests can be used to determine the type of STI, and thus the treatment that is required. Different STIs will require different treatments. STI tests and treatments are available from the GP, sexual health clinic or GUM clinic. Condoms are the best protection against STIs when used correctly.