The main routes of transmission are through blood or body fluids:
- Sex is the most common route of transmission
- Blood and blood products like sharing needles, blood transfusions in some countries
- Mother to child- through childbirth and breast feeding
For HIV to be transmitted there must be contact with blood or body fluid from a person who is infected with HIV and has a detectable viral load (HIV is not controlled with medication).
The HIV virus survives for only a few minutes long outside the body, but can last much longer within needles
Treatment with HAART means that the person does not transmit HIV through sex, and the risk via the other routes is significantly decreased.
HIV negative people who are at ongoing risk of acquiring HIV can protect themselves by taking Pre-Exposure Prophylaxis (PREP) medication, enrolling in opioid agonist therapy (substitution programme) and using Post Exposure Prophylaxis (PEP) medication as necessary.
Sexual Risk
The risk of HIV transmission via sexual contact is highest through unprotected (without condom) anal intercourse followed by vaginal intercourse – BUT ONLY from a contact whose HIV virus is detectable.
Oral sexual intercourse (fellatio and cunnilingus) have very low risk of HIV transmission.
Blood and blood products
Sharing needles for injecting recreational drugs is a small but important avenue for HIV transmission. The use of HAART and having an undetectable viral load decreases the risk of HIV transmission, but it is unclear by how much. Which is the reason that needle exchange programmes are so important in protecting the injecting community, not only for providing clean needles and a safe injecting space, but also the support for those who would like to stop injecting.
Mother to Child
With modern HIV management by the use of HAART, the risk of mother to child transmission is less than 1%. HAART is easy to take, with minimal side effects for the mother and baby. The mother can have a normal vaginal delivery (so long as there are no obstetric reasons for a Caesarean section). The information around the risks and benefits of breast-feeding is complex and needs to be discussed with the HIV Specialist Doctor.