Question
What is an undetectable viral load?
27 March 2012. Related: All topics, CD4 and viral load.
What is an undetectable viral load? I had thought it was less than 50 but when I got my results today mine was 42 (down from 82 last time). Can labs measure almost any level of virus these days?
Answer
An undetectable viral load means that the level of HIV in your blood is below the threshold needed for detection by this test.
A viral load test is a measurement of the amount of HIV in your body. The measurement is given in the number of copies in milliliter (copies/mL).
If you are on treatment, then your viral load should go down to undetectable level (less than 50 copies/mL). Once your viral load goes down, then slowly your CD4 count will increase, although not to the level before infection.
Since your viral load has reduced from 82 to 42, this is a good indication that your treatment is working for you. It is also possible for your viral load can go down further too.
Viral load technology has progressed during the last 30 years of HIV history. The tests have been greatly improved and tests used for research are even more sensitive – down to 5 or even 1 copy/mL.
All hospitals in the UK now routinely use viral load tests that measure down to 20, 40 or 50 copies/mL.
Am HIV negative on pep after my partner failed to disclosed his status and has been on medication for long. My worry is, I again had unprotected sex with him while on pep. Will I be positive by the time I test again?
If your partner is on medication for a long time, you are not at risk. In the UK, this would not be a reason to take PEP.
my viral load has been ‘lower than detectable limit’ for 6years now. but now it reads 31 copies. should I be worried about this especially coz I am still breastfeeding my 14 month baby who tested negative on her 6weeks HIV test
Hi Ruby,
HIV is passed from mother to child, not from the father. If you are HIV negative then your baby will also be negative. It’s important that you get tested to make sure you haven’t been infected. You may also want to think about using condoms for extra protection during your pregnancy as there is still a very small risk of infection even though your partner is undetectable. You can read about this in our transmission guide.
I am a woman and my partner has a undetectable viral load. I am now 4 weeks pregnant. Is there a risk that the baby could have contracted HIV?
The term “undetectable” is an anachronism. Clinically it means below the quanitificaton limit of the assay used. An assay may return “detected,” meaning the target was detected but the number of copies was to quantify. Somewhat confusingly, this is still considered clinically “undetectable.” Even if the result is “undetected” with a modern clinical clinical assay, a team of research scientists could likely quantify a single-digit number of copies. The clinical significance of such low levels of virus is unclear, but the lower the better certainly.
Hi JJ,
It’s not clear from your email if you are male or female which makes it harder to answer your question. While being undetectable means you are unlikely to pass the infection to your partner it is important for HIV positive women to be monitored during pregnancy to prevent passing the infection to their unborn child. Please follow this link for more information about HIV, pregnancy and women’s health.
Please let me know if you have any questions after looking over the guide and I’ll be happy to help!
Hi
I am part of hetero couple and I am the only one with HIV. I have been undetectable for nearly 3 months. We were thinking of trying for a baby naturally. Is there any risk to my partner or the baby? Many thanks
Hi Chris,
Sorry if the original reply to you question was unclear. The term ‘undetectable’ applies to any viral load count of under 50. This is because this is the lowest reading that many of the viral load tests will pick up. Some of the newer tests, including many tests used in research, can read lower than this. Hospitals in the UK now regularly use tests that read as low as 20 or 40 counts. So if your viral load has come back at a number under 50 you would still be considered ‘undetectable’.
Thanks, but what I really meant was that you often see the term “undetectable viral load” in research papers and articles. For instance your own guide to HIV and pregnancy has phrases like “So, as with treatment for anyone with HIV, one important goal of therapy is to reach an undetectable viral load.”
Is that term generally assumed to refer to a VL under 50? If so then I’ve probably reached it (from initially over a million) after 9 months’ treatment. If not, then because my reading was a number, then I’m not “undetectable”.