What is Viral Load?
Viral Load is the amount of HIV present in a milliliter (mL) of blood. Viral load testing is a regular part of health check-ups for people who are HIV-positive.
Undetectable refers to a viral load that is below levels that can be detected on current HIV viral load tests. This does not mean the virus is gone. In Ontario, this means that there is less than 40 copies of the HIV virus per mL of blood.
In addition to a better, longer, and healthier quality of life, achieving an undetectable viral load means that people who are HIV positive cannot pass the virus on sexually. Many people have started to use the symbol “U+” as a shorthand for HIV positive and undetectable on dating and cruising sites.
Viral Load and HIV Transmission
When someone becomes HIV-positive, the virus replicates quickly in their body. During this stage, viral load is high, and the risk of HIV transmission to a partner is also higher. Approximately half of all new HIV infections involve a newly HIV-positive person, who often does not know they have HIV, during the first few months of their infection1.
As time goes on, their viral load will drop to a steady level, and the use of HIV medication can lower viral load even further to undetectable levels. This is good news for the person achieving better health and for HIV prevention.
While the threshold for undetectable viral load in Ontario is generally 40 copies of HIV per mL of blood, in other countries this number may be higher. For example, up to 200 copies per mL is considered ‘undetectable’ in areas of Europe where the PARTNER study was conducted2. (Note: the PARTNER study was a landmark study, in which no HIV-negative participant became HIV-positive when their sexual partners were undetectable and when no condom was used. In this study, undetectable was 200 copies and below.)
The idea of “undetectable” is also relevant when considering criminal charges and disclosure. While Ontario defines undetectable as 40 copies of HIV per mL of blood, the Canadian legal system may define “low” viral load as 1,500 copies/mL, as it applies to laws around disclosure. Note: Having a viral load below 1,500 copies or an undetectable viral load does not absolve the legal responsibility to disclose HIV status. Courts have attached further conditions to not disclosing. If you are interested in this topic, please seek out specific resources on our disclosure page and from the Canadian HIV Legal Network or the HIV & AIDS Legal Clinic Ontario (HALCO). Note this is usually termed “HIV criminalization” or “HIV Criminal Law” on legal websites addressing this complex issue.
Achieving Undetectable Viral Load
New research shows that starting treatment as soon as possible makes it easier for HIV-positive people to get to undetectable more quickly, as well as live longer, healthier lives.
For some people, it can take a long time to get to undetectable, and some folks aren’t ever able to get there. For poz folks who have detectable viral loads, other prevention strategies, like using condoms, having sex with other HIV-positive people, or choosing HIV-negative partners that take PrEP, can reduce anxiety and help sex feel even better.
Just because the research promotes early treatment, that doesn’t mean everyone is ready for it. Some people who are HIV-positive may feel pressure to go on meds to achieve an undetectable viral load. Community services like ACT, peers, and medical professionals can help as you are working through this decision.
Things to keep in mind…
Access to treatments should not be taken for granted. It can be hard to understand the various drug coverage systems, especially as the science, policies and processes are constantly changing. It will be harder for some people to obtain medications than it will be for others. Talk to others you know who have coverage, as well as professionals and community organizations for help.
HIV stigma is real. Some people with HIV are beginning to wonder if their viral load will determine if they are desirable. Will less fear of transmission mean less stigma for people living with HIV? What about people who cannot achieve an undetectable viral load?
An Important Note on Breastfeeding/Chestfeeding and Injecting:
A low viral load, although good for the parent’s health, does not necessarily reduce the risk for HIV transmission in the context of breast feeding/chestfeeding. It is important to understand that viral load in the blood does not necessarily match viral load in the breast milk.
We do not currently have enough data to know if undetectable viral load provides protection from HIV transmission from shared injection drug gear.
1 Wilton J. Recently infected individuals: A priority for HIV prevention. CATIE. Retrieved June 8, 2017 from: http://www.catie.ca/en/pif/fall-2011/recently- infected-individuals- priority-hiv- prevention#footnoteref1_x2k0hto
2 Q and A for PARTNER Studies. PARTNER pg 9. Retrieved June 8, 2017 from: http://www.chip.dk/Portals/0/files/PARTNER/ press/PARTNER_QA%20__2016JUL12_3.pdf