Co-infection is the word used to describe when you have HIV as well as other infections or diseases. There are some infections that many people living with HIV get, and these are called opportunistic infections (OIs) as they are diseases that take the opportunity to attack your body when your immune system has been weakened by HIV. OIs are caused by different bacteria, viruses or funguses. Common infections include tuberculosis (TB), pneumonia, meningitis, thrush, hepatitis and herpes. It is easy to get sexually transmitted infections (STIs) when you have HIV, and certain cancers are also common. All of these infections can be tested for and treated, which it why it is important to visit the clinic regularly, especially if you have any unusual symptoms.