Wellbeing / 25 May, 2020

The importance of detecting STIs

Dr Goh Lit Ching

What are STIs and how do they spread?

Sexually transmitted infections (STIs) are infections acquired through sexual intercourse or close contact with another person who is infected with an STI.

Modes of transmission can be through intimate skin to skin contact, transfer of body fluids and from mother to child during pregnancy or delivery.

Common types of STIs can be divided into three main categories – bacteria, viruses, and parasites and protozoa.

Bacteria

STIs associated with bacteria include:

  • Chlamydia – Caused by Chlamydia trachomatis
  • Gonorrhea – Caused by Neisseria gonorrhoeae
  • Syphilis – Caused by Treponema pallidum

Common signs and symptoms of these infections include:

  • Genital rash
  • Itchiness
  • Pain or burning during urination
  • Penile discharge
  • Unusual or odd-smelling vaginal discharge
  • Unusual vaginal bleeding
  • Pain during sex

Syphilis infections can also cause a rash on other parts of the body.

In some people, these infections may not cause any symptoms but will still be infectious to any sexual partners.

Bacterial infections are usually treated through antibiotics. If you test positively for a STI, sexual partners should be contacted and told to also seek treatment. Testing post-treatment is important to prevent re-infection.

Long term consequences of untreated bacteria STIs can include the development of chronic pelvic inflammatory diseases (PID), fertility issues, and in severe cases of syphilis, neurological consequences.

Viruses

STIs associated with viruses include:

  • Genital Herpes – caused by Herpes Simplex Virus (HSV)
  • Genital Warts – caused by Human Papilloma Virus (HPV)
  • HIV and AIDS – caused by Human immunodeficiency virus (HIV)

Virus infections don’t always show symptoms, however common signs and symptoms include:

  • Genital rash,
  • Ulcers
  • Lesions
  • Painful or burning urination
  • Painful intercourse
  • Unusual or odd-smelling vaginal discharge

HIV infections can be latent for many years without symptoms before presenting as AIDS infection at later stages.

Treatment for Genital Herpes includes the use of antiviral medications once you begin to show symptoms. However, HSV infection usually turns into a chronic infection in the body which flares up when your immunity is low.

Treatment for Genital Warts include removal of the wart if deemed suitable.

HIV infection will need a specific treatment regimen and follow up with Infectious Diseases (ID) specialists.

Viral STIs will usually result in chronic infections in the body, which can go unnoticed or cause flare up episodes and symptoms from time to time. HPV infections caused by high risk virus strains can potentially lead to cervical cancer, anal cancer and penile cancer; while HIV infection can lead to AIDS which can potentially be life-threatening.

Parasites and protozoa

STIs associated with parasites and protozoa include:

  • Scabies – Caused by Sarcoptes scabiei
  • Pubic lice – Caused by Pediculosis pubic
  • Trichomoniasis – Caused by Trichomonas vaginalis

Commons signs and symptoms of these infections include:

  • Intense itch on the genitalia
  • Rash
  • Scratch mark
  • Pain or burning during urination
  • Unusually coloured or odd-smelling vaginal discharge

Scabies and pubic lice can be treated with anti-parasitic agents while trichomoniasis can be treated with antibiotics.

Sexual partner is also advisable to go for treatment if symptomatic. There is usually no long-term consequences provided treatment is rendered appropriately. Some patients can experience scarring or change in skin colour on the area previously infected due to extensive scratching or hyperpigmentation of the skin post infection.

If your sexual partner also experiences symptoms, they should be told to seek treatment. There are generally no long-term consequences provided treatment is provided promptly and appropriately. You may experience scarring or a change in skin colour on the area previously infected due to extensive scratching or hyperpigmentation of the skin following the infection.

Screening and diagnosis

STIs can be diagnosed through lab tests, such as sample collections from the affected area (vagina or penis), urine samples and blood samples. Various methods are used to detect whether an infection is present including culture tests, antibody tests or direct microscopy tests on the samples collected.

Screening for STIs is very important, as you may be infectious without showing any symptoms. This can result in transmission to another person or to many different sexual partners unknowingly. Some of these infections can also be transmitted non-sexually, such as from mother to infant during pregnancy or childbirth, resulting in infection of the newborn baby.

It is important to note that different STIs have different incubation periods and some may have window periods before they are detectable. For example, HIV can potentially have a window period of three months before being shown as positive on the lab test. This is why it is crucial to declare your sexual history while being screened for STIs.

How often should you get screened for STIs?

There is no right or wrong answer for this. As soon as you suspect that you may have been exposed to someone with a STI, you should come forward and receive STI screening immediately. Screening can be done as part of contact tracing, or conducted on anyone who begins to show symptoms following sexual activity. For people who are planning to get into a new relationship with a new sexual partner, screening is also recommended.

If you test positively for any STIs, depending on the type, your doctor will then recommend an appropriate interval for follow up and subsequent testing.

Can STIs be prevented?

The primary method of STI prevention is the barrier method of contraception, such as condoms. Condoms are effective at preventing STIs that transmit through body fluid exchange. However, birth control methods such as oral contraceptives, injections or IUDs do not prevent STI transmission. Condoms are not fully effective against infections acquired through skin-to-skin contact like genital herpes.

To assist in preventing STIs you should not engage in high risk behaviours such as having casual sexual activities or multiple sexual partners.

Human Papillomavirus (HPV) can also be prevented through vaccination. Vaccination is most effective in individuals who have never been exposed to the HPV strain before.

It is important to be aware of the various types of STIs and their prevention and treatment. Ensuring that STIs are detected early through screening can help reduce your risk of any long term consequences.

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