Question
Can I have sex with someone who is positive and not catch HIV?
16 January 2018. Related: All topics, HIV transmission.
Answer
Yes, there are lots of ways to make sure HIV is not transmitted during sex.
- One of the easiest and most effective ways is just for the HIV positive partner to be on treatment. An undetectable viral load makes HIV untransmittable. (See: The evidence for U=U).
- Another relatively recent option is for the negative partner to use PrEP. This is an oral drug that when taken as prescribed is highly effective. (See: UK guide to PrEP).
- You can use condoms which are an effective barrier against HIV (and other STIs). Condoms need to be used carefully, preferably with plenty of lube. (See: How to use a condom (male and female).
HIV is a much less infectious virus than many other sexually transmitted infections (STI’s).
Even without a condom, the risk from a single exposure is less than, for example, 1 in 300. The actual risk becoming infected varies depending on many factors. These include the type of exposure, whether the other person is HIV positive, how high or low their viral load is, the duration and roughness of the sex etc.
If the partner is HIV positive, then viral load is the most important factor. The PARTNER study reported zero HIV transmissions after 900 couples had sex more than 58,000 times WITHOUT condoms. In this study undetectable viral load was defined as being less than 200 copies/mL.
https://i-base.info/qa-on-the-partner-study
Risk factors for penetrative sex without a condom with someone who has a very high viral load could be as high as 1 in 10 (10% risk). But the risk is effectively zero with someone who is taking treatment and who has an undetectable viral load.
This question was updated in January 2018 and November 2016 from an original answer posted in June 2007. i-Base no longer answers individual questions about HIV transmission and risk. (See: Question 1 at this link).
Hi
There is lots of information about HIV risks and transmission in this guide:
http://i-base.info/guides/testing
There are no tests that show a person’s immune system is strong enough to resist HIV. I don’t understand why a doctor would say this, but until your fiancée has another test in three month to confirm he is still negative, you may want to continue using condoms to protect your own health.
My fiancée told me last night that the girl he was with for almost 10 years, was born HIV positive. A day before he got with me he had unprotected sex with her. He took a test and it came out negative he said the doctor told him that his immune system was so strong that the only way he would be able to contract it was through using needles is that possible?
Hi Bongani,
You can read more about this in our FAQs page. Please let me know if you have any questions after looking at this link.
Hi i need more information about that i want to know, my wife went for a blood test in august 2012 and she was tested positively i also went the results were negative
Hi Jabu,
I’m sorry to hear about your wife’s recent diagnosis. Is she receiving any support right now?
You will have to wait until 3 months after your last unprotected sex to be 100% certain of your test results. It’s possible that you have been lucky and have not been infected. You can read more about testing and sexual transmission in our testing guide.
My wife was diagnosed on 22 May this year HIV + because shes pregnant i went for the blood test results come negetive so im in window period theres any chances that may also infected after three months
The information that you are referring to was purely an estimate because there is a lack of data. There is a high risk of transmission with any unprotected sex with an HIV positive person with a high viral load.
You said that with a high viral load the statistical chances of being infected can range up to 10%; you also mentioned that a high risk encounter grapples around the one percentile (1 out of 100). If I bottomed for an HIV-positive person with a high viral load without him having ejaculated within me, around where would you estimate my chances would be of contracting the virus?
Hi Pepper, because your wife is HIV+ there is always a chance you could still catch HIV if you do not use protection. Using protection will stop you from becoming infected.
My wife was diagnosed on June 14 with HIV+ because she was pregnant. At the begining of our relationship we used protection but after getting married in May 2006 we never used protection.
In June 2007 when we found that she was HIV+ we stopped having sex. Now we always use protection.
In November 2006 I tested negative, and after we found that she was HIV+, I was tested again. My test came back negative again.
My question is ‘What are the chances for me to catch the virus?’