Chlamydia and gonorrhoea are common sexually transmitted infections (STIs) that can affect both men and women, often without causing noticeable symptoms, yet they can still be transmitted. Left untreated, both infections can lead to serious complications, including reduced fertility. Chlamydia can infect the urethra, cervix, rectum, anus, throat, and eyes, while gonorrhoea commonly affects the genitals, rectum, and throat, particularly in young adults aged 15–24.

Syphilis is a bacterial infection usually spread by sexual contact. The disease starts as a painless sore — typically on your genitals, rectum or mouth. Syphilis spreads from person to person via skin or mucous membrane contact with these sores.

Hepatitis may be caused by infection, viruses, chemicals, alcohol, drug use and other factors. Chronic hepatitis means ongoing inflammation of the liver, irrespective of the underlying cause. There are various forms of viral hepatitis which include: - Anyone can be infected if they come in direct contact with the hepatitis A virus through food, drinks or objects contaminated by the faeces of an infected person. - Hepatitis B virus is spread when blood, semen, vaginal secretions or other body fluids from someone infected with hepatitis B enter the bloodstream of someone who is not infected with hepatitis B. - Hepatitis C is a blood-borne virus that is spread when blood from a person with hepatitis C enters another person’s bloodstream. In Australia, the most common way it is transmitted is through sharing unsterile injecting drug equipment.