HIV Transmission Basics
HIV Transmission Basics
Charles Farthing (Chief of Medicine, AIDS Healthcare Foundation) gives expert video advice on: How is HIV transmitted?; What bodily fluids do not transmit HIV?; What are the odds that I will contract HIV if I engage in a high-risk activity? and more...
How is HIV transmitted?
The principle human activity that causes HIV is unprotected vaginal or anal intercourse. Wearing a condom is incredibly important in preventing it. If a condom was worn on all episodes of anal and vaginal sex, I guess HIV would almost stop transmitting, certainly on the continent of Africa, where it's largely sexually transmitted. In countries where there is a lot of intravenous drug use of course, you have to use clean needles as well to prevent HIV transmission.
What bodily fluids do not transmit HIV?
It's probably very hard to get the HIV virus from saliva or from urine or from faeces. It's really blood and genital secretions that transmit HIV.
What are the odds that I will contract HIV if I engage in a high-risk activity?
One episode of unprotected sex is a small chance of contracting HIV: maybe one in several hundred, one in a thousand. But repeated episodes increase your risk of contracting HIV. And of course, you could be unlucky on the first episode of unprotected anal or vaginal sex, and contract HIV. But persistent unprotected anal or vaginal sex, and you run a high risk of catching HIV.
If I am on HIV therapy, can I still transmit the virus?
If you're on therapy for HIV with any retroviral drugs, the level of virus in your blood and the level of your virus in the semen, if the treatment is appropriate and properly taken, will go to undetectable levels, so you will be much less infectious, possibly non-infectious, which is really great, and so people who are on HIV treatment are much less likely to transmit the HIV virus. But you have to be careful because if someone's not taking the HIV treatment properly or the HIV treatment's not working properly, the HIV virus has become resistant, then you could transmit the virus when you're on HIV therapy.
Why is HIV still being contracted in the US?
HIV is still being contracted in America, unfortunately a lot because of our success. People aren't dying from HIV, and for example, young gay men do not see terribly ill friends and friends dying with Kaposi Sarcoma on their face and wasting away and looking like pitiful concentration camp victims like people saw in the 80's. They are not seeing that and they realise that HIV is treatable and essentially fully suppressible, so they don't care and many don't care. There are many infections in young gay men because they are not wearing condoms and also because of that, we are seeing epidemics of gonorrhoea and syphilis which twenty years ago were very rare diseases and they are now very common. So, we are a bit of a victim of our own success and it is very, very hard to change this new practice of unsafe sex.
What can we do to prevent the transmission of HIV in the US?
We should be doing a lot more to prevent the transmission of HIV in the United States. But what can we do? We can have more media campaigns for the need for safe sex. If you look at what happened to smoking cessation, we have achieved great things in the United States but we had tremendous media advertising to do that. We had sick people smoking through tracheostomies on television and many, many advertisements. We do not see that for HIV and yet many young people are getting infected because of the lack of awareness. We should be pushing condoms. We should be advertising condoms and we should also be promoting HIV testing. The CDC is trying to do this but who distributes HIV infections? infected people. So a good way to prevent it is to find all the HIV positive people and educate them about being at risk and concentrate prevention efforts on these infected people. If we don't test routinely we don't find out who's HIV positive so we can't work with them to prevent them spreading it. There is much more that can and should be done in this country to prevent spread of HIV, many young people are contracting it because they are not taking precautions.