Basics of STIs

Chlamydia is the most common STI in Australia and many other countries.

Many people with chlamydia infection have few or no symptoms. However, chlamydia can cause abnormal genital discharge, burning while peeing, or rectal discharge (from your bum) and bleeding.

The most common and serious complications for chlamydia happen in people with a uterus. These can include pelvic inflammatory disease, ectopic pregnancy, and trouble getting pregnant (infertility).

People with a penis may have urinary symptoms (hurts to pee), or no symptoms at all.

Chlamydia infection, like all bacterial STIs, can be treated with antibiotics.

Gonorrhoea can cause an abnormal discharge from the vagina, penis, or rectum. It also causes painful or difficult urination or bowel movements.

The most common and serious complications happen in people with a uterus. These include pelvic inflammatory disease, ectopic pregnancy, and trouble getting pregnant (infertility).

People with a penis may have urinary symptoms (hurts to pee), an abnormal discharge from the penis, or no symptoms at all.

Gonorrhoea infections, like all bacterial STIs, can be treated with antibiotics.

The first symptom of syphilis is often a painless open sore, seen on or around the sexual organs, including the penis, vagina, anus or rectum, or even in the mouth.

Untreated syphilis can last for years and may go on to more advanced stages. This includes a rash. Over time, the heart and central nervous system may be seriously affected. Untreated syphilis during pregnancy can cause serious illness for the baby, birth defects, or miscarriage.

Syphilis infections, like all bacterial STIs, can be treated with antibiotics.

Most people with trichomoniasis don't show any symptoms. However, symptoms can develop over time. People with a vagina may experience foul-smelling discharge, itching and burning around the genitals, genital redness, painful urination, pain during sexual intercourse, or discomfort around the pelvis and lower belly.

People with a penis may experience penile discharge, itching or burning inside the penis, painful urination, or burning after ejaculation.

Trichomoniasis can be treated with antibiotics.

Scabies is caused by a tiny, microscopic mite, which burrows into the skin and lays eggs. This can lead to intense itching and rash around the affected areas. It's caused by skin-to-skin contact, including sexual contact.

Scabies can be treated through creams from the pharmacist, or prescription oral medication.

Pubic lice is also commonly known as crabs. These are tiny insects which can be found in the genital region. Pubic lice is a different type of lice from head lice or body lice. Bites from these lice can cause severe itching around your genitals, and without treatment, the lice can spread to other parts with coarse body hair, including your legs, chest, armpits, or even facial hair.

Pubic lice can be treated with creams and lotions from a pharmacist.

HIV, the virus that causes AIDS, is a blood-borne virus that destroys the body's ability to fight off infection. HIV is spread when the sexual fluids (specifically semen, vaginal fluids, or blood) of a person with HIV directly enters the bloodstream of a person who doesn't have HIV.

This means that HIV can be spread through unprotected penetrative sex (penis-in-vagina or anal sex), or by sharing sharps, such as razors or injecting equipment.

The best way to prevent HIV transmission is to use condoms when having penetrative sex, or to access specific medications. These medications are known as either PrEP (to be used before sex) or PEP (to be used after sex), which you can use to reduce the likelihood of transmission.

There is no vaccine for HIV, and there is no known cure for HIV. Treatment involves using antiretroviral medication taken daily, which is highly effective at preventing symptoms and illness.

HPV, or human papillomavirus, is a common STI that can cause genital warts. These warts can appear on the inside or outside parts of the genitals and rectum. They may spread to the skin of a sex partner. Some types of HPV can cause more common warts in other body parts such as the hands (though these don't generally cause health problems).

HPV infection doesn't always cause warts, so you may not always know you are infected. A majority of HPV infections (about 9 in 10) are cleared by the body within 24 months. However, because HPV is so common, it's possible to catch it again and get infected again.

It's important to know that HPV can cause cervical cancer and other types of cancer. All people with a cervix need regular cervical screening tests, which can also help to diagnose HPV infection, as well as detect any abnormal cervical cells.

A HPV vaccine is available to prevent cervical cancer and genital warts. In Australia, most young people receive the HPV vaccine at ages 12-13 (in year 7). There is also treatment for genital warts.

HSV, or the herpes simplex virus, is the virus that can cause genital herpes. Symptoms may include painful blisters or open sores in the genital or rectal area, which may begin with a tingling or burning feeling in the area.

While the herpes sores often go away in a few weeks, the virus stays in the body for life, and the sores may come back from time to time. The virus is most likely to be spread when the sores are visible.

There is no vaccine for HSV, and there is no known cure for HSV. However, there are antiviral medicines that can shorten an outbreak and reduce symptoms.

Viral hepatitis refers to the different viruses that can cause liver problems. There are many types of viral hepatitis, but the ones that can be sexually-transmitted are hep A and hep B, and possibly hep C.

• Hep A is caused by oral contact with infected faecal matter, or more simply, from getting infected poo in your mouth. In most cases around the world, this is because of contaminated drinking water or contaminated food products. Another way you can get hep A is by rimming, when hep A from an infected person enters the mouth of an uninfected person.

Hep A is extremely rare in Australia. In most cases, a person with hep A will clear the infection on their own within 6 months. You can also get supportive treatment for the illness, if needed. There is also a vaccine for hep A.

• Hep B is transmitted through blood and sexual fluids, and can be transmitted from unprotected penetrative sex (penis-in-vagina or anal sex), between an infected and an uninfected person.

There is a vaccine for hep B, and most people who were born in Australia will have received it. Some people who get hep B can clear the infection by themselves. However, for those who don’t clear it, there is treatment available.

• Hep C is caused by blood-to-blood contact from an infected person to an uninfected person. In most cases, hep C is passed on from sharing injecting equipment, sharps such as razors, or shared tattoo and piercing equipment. However, sexual activities that involve blood-to-blood contact are also known ways that hep C can be passed on.

There is no vaccine for hep C. However, there are treatments, including antiviral medications that can clear hep C for some people completely.