What is an HIV viral load?

Image result for What is an HIV viral load? MEDICAL NEWS TODAY

By
Jenna Fletcher   

Reviewed
by Daniel Murrell, MD

Viral
load refers to the amount of HIV in a person’s blood. HIV treatments aim to
reduce the viral load until the virus is no longer detectable, which mean it is
also untransmittable.
In
this article, we discuss what viral load means for people living with HIV and
their partners, the links between viral load and CD4 levels, and how doctors
test and monitor these levels.
What
is HIV viral load?
The
viral load is the amount of HIV in a person’s blood.
Doctors
define the viral load as the number of HIV copies in a milliliter of blood
(copies/ml).
Doctors
initially use the viral load to check the status of HIV after diagnosis, then
to monitor the success of HIV treatments.
When
a person contracts HIV the virus replicates in their blood. The more copies of
the virus there are, the higher a person’s viral load.
If
there is a high number of copies in the blood, this suggests that there is also
a high number in other bodily fluids, such as vaginal fluid and semen.
The
main aim of HIV treatments is to reduce the viral load to the point where there
are so few copies of the virus left that it is undetectable in the blood.
Before treatment: Detectable viral load
When
doctors say a person has detectable levels of HIV in a viral load test, it
means there is a significant amount of HIV in their blood. This level will vary
based on the stage of the condition and the stage of treatment.
On
first diagnosis of HIV, a person’s viral load is typically high. Shortly after
contracting HIV, the viral load will drop as the immune system starts to fight
the virus.
Without
treatment, the viral load will rise again as the virus starts to destroy
specific immune system cells known as CD4 cells.
After treatment: Undetectable viral load
Antiretroviral
therapy aims to reduce a person’s viral load to undetectable levels. This is
known as viral suppression.
After
starting antiretroviral therapy, a person’s HIV viral load tests will come back
with low numbers. When this occurs, the treatment is working, and HIV is no
longer progressing. With a lower viral load, the chances of transmitting the
virus to others become lower.
According
to the United States Centers for Disease Control and Prevention (CDC), an
undetectable viral load means less than 200 copies/ml.
An
undetectable viral load means that a person has effectively zero risk of
sexually transmitting the virus to an HIV-negative partner.
Large-scale research has
shown that when HIV is undetectable, it is virtually untransmittable, even
through condomless sex.
This
concept is known as U=U, which stands for undetectable = untransmittable.
Almost
everyone who starts antiretroviral treatment finds a drug regimen that works
within 6 months. It will take longer to find the right treatment in around
1 in 6 people because of their tolerance or adherence to the regimen.
HIV
is a chronic condition. When the virus becomes undetectable, some copies still
remain in the blood. People must continue to take their HIV medication as
prescribed to keep their viral load undetectable.
When
controlled, people living with HIV can experience the same quality of life as a
person without HIV.
Viral load and CD4 levels
When
someone contracts HIV, the virus begins to take over specific cells in the
immune system, called CD4 cells.
When
the CD4 cells replicate, the HIV cells inside them also replicate. HIV hijacks
the cellular machinery of CD4 cells to reproduce and shed more HIV, which means
the viral load increases.
As
the HIV viral load increases, the number of healthy CD4 cells decreases as they
are destroyed creating HIV copies.
Treatment
aims to produce a low viral load and a high CD4 count. When a person has
achieved this, their HIV is well controlled.
A
low or undetectable viral load means the virus is not progressing. It also
means that HIV is not attacking the immune system as actively. This gives the
immune system the chance to rebuild its healthy cell count. As a result, the
number of CD4 cells in the person’s body will increase as their viral falls.
When should people get a viral load test?
A
doctor can check the viral load by conducting a blood test.
A
doctor will usually test a person’s viral levels when they first diagnose HIV.
Doctors will recommend an HIV test if someone presents symptoms of HIV or if
they may have come into contact with the virus.
People
living with HIV will have repeat viral load tests throughout their lives to
monitor the condition. They should get tested once every 3 to 4
months during treatment.
Additionally,
a person should get tested due to any alteration in their medication or if
their symptoms change.
Low
or undetectable viral counts are strong indicators that the person’s treatment
is working. If a test reveals that the viral load is increasing, a doctor may
need to adjust their treatment.
Viral load test procedure
A
doctor can test the viral load using a simple blood test. No preparation is
needed.
The
doctor or technician will draw a small amount of blood and send the sample to
the labs to test the viral load and CD4 count.
It
often takes a few days for the results to come back. Once they are back, the
doctor will likely call to discuss the results with the individual.
Summary
HIV
viral load refers to the amount of HIV present in a person’s blood. Higher
numbers typically indicate that they have not yet received HIV treatment, or
that their treatment is not effective.
People
living with HIV will also receive tests to check their CD4 count. These checks
measure the number of cells the immune system produces. Higher numbers of CD4
cells indicate that the person’s immune system is stronger and better able to
fight off infections.
When
the viral load reaches less than 200 copies/ml of blood, doctors consider that
HIV is undetectable. Though copies of the virus remain in the blood,
undetectable levels mean that a person cannot transmit the virus to others.
When people achieve this, they can live the same quality of life as those
without HIV.

SOURCE: MEDICAL NEWS TODAY

Kayode Ojo
Kayode Emmanuel Ojo is the Co-Founder and Managing Director at SHEFFA Limited. He is presently studying Computer Science at the National Open University, Victoria Island, Lagos.