I have tested reactive on a rapid test and then indeterminate on Western Blot test. This was exactly a month after my exposure. The STD clinic told me to return in 12 weeks to repeat the Western Blot test to confirm my HIV status.
I would like to start with my risk assessment:
Unprotected vaginal/oral sex with a male partner, lost my virginity to him. Partner tested negative right after being informed about my inconclusive test results. I believe I was not exposed to non-sexual ways to contract HIV such as needle sharing, blood transfusions, getting tattoos or piercings.
My questions are:
1. If I test indeterminate for the 2nd time would this be conclusive? Should I take PCR RNA test then?
2. Could common cold virus throw off Western Blot test results?
3. Could having HPV throw off Western Blot results?
Thanks in advance for any input.
Hi there, thanks for contacting the AIDS Vancouver helpline with your HIV related questions/concerns. We're happy to help!

This is a very tricky situation, and I'm sorry that you're experiencing this! I hope that my answer will provide some reassurance and clarify some things for you though!

So just to start off, it's important to note that tests such as the rapid test, the 4th generation test, etc are HIV sensitive, This means that they react with HIV, but they could potentially also react with other things in your body that are similar (such as very similar cross-reactive antibodies, or a similar protein for the P24 antigen). Further, the rapid test is actually just a screening test, meaning it can produce false positive results if it cross-reacts with something similar in the body. In contrast, the Western Blot test is HIV Specific. This means that it will ONLY react with HIV specific antibodies.

To summarize this concept, this information from the BC CDC puts it nicely:
Sensitivity of a test is to try to identify those that do have HIV, it is the probability that the test will produce a positive result when the person is actually positive. The specificity is the ability of the test to correctly identify those that do not have HIV. it is the probability that a test will produce a negative result when the person is actually negative. So, this is why the western blot is always used a confirmatory test for positive results, to make sure that the result is indeed correct!!

1) Yes, if you take another western blot at 12 weeks and it is indeterminate, then these results are conclusive. PCR tests are also considered HIV specific, so this is a great option of a test to take in the meantime, while you're waiting for that 12 week western blot test to confirm your status. A negative PCR test would be a great sign.

2) No, the common cold would have no effect on your Western Blot test results!

3) No, again having HPV wouldn't affect these results.

So overall, your best bet is to wait it out till 12 weeks time (and you can take a PCR test in the meantime) to determine your actual status.

I hope this helped! Please call our helpline if you would like further information.



AIDS Vancouver Helpline/Online

Monday-Friday 9am-5pm (PST)

1 844 INFO-HIV (Toll free Canada & U.S.)

Private & Confidential**



Charitable Registration #
10668 9896 RR0001

© 2019
Privacy Policy


1101 Seymour Street
Suite 235, 2nd Floor
Vancouver, BC V6B 0R1


Main Phone: 604-893-2201
Fax: 604-893-2205