INTRODUCTION
The late or tertiary stage of syphilis usually occurs after many years and can cause serious conditions, such as heart problems, paralysis and blindness.
The symptoms of syphilis can be difficult to recognise. A simple blood test can usually be used to diagnose syphilis at any stage. It can be treated with antibiotics, usually penicillin injections. When syphilis is treated properly, the later stages can be prevented.
Read more about syphilis.
HIV
HIV is most commonly passed on through unprotected sex. It can also be transmitted by coming into contact with infected blood - for example, sharing needles to inject steroids or drugs.
The HIV virus attacks and weakens the immune system, making it less able to fight infections and disease. There's no cure for HIV but there are treatments that allow most people to live a long and otherwise healthy life.
AIDs is the final stage of an HIV infection, when your body can no longer fight life-threatening infections.
Most people with HIV will look and feel healthy and have no symptoms. When you first develop HIV you may experience a flu-like illness with a fever, sore throat or rash. This is called a seroconversion illness.
A simple blood test is usually used to test for an HIV infection. Some clinics may also offer a rapid test using a finger prick blood test or saliva sample.
Read more about HIV and AIDS and coping with a positive HIV test.
Trichomonas vaginalis
Trichomonas vaginalis (TV) is an STI caused by a tiny parasite. It can be easily passed on through sex and most people are unaware they are infected.
In women, TV can cause a frothy yellow or watery vaginal discharge which has an unpleasant smell, soreness or itching around the vagina, and pain when passing urine.
In men, TV rarely causes symptoms. You may experience pain or burning after passing urine, a whitish discharge, or an inflamed foreskin.
TV can