2 Virology HIV
Virology 4.03.12 ®
Dr. Angela Stanic
Management of HIV Infection
HIV Basics
HIV= human immunodeficiency virus causes AIDS
Attacks the immune system and causes depletion of the CD4 (white blood cells) cells
With time, a person progresses to AIDS
Testing is available
Rapid tests are confirmed by more accurate antibody tests
No cure
But we have long term therapies available
HIV Laboratory Parameters
HIV Viral Load (HIV RNA)
Number of HIV copies/mL measured in a person’s blood
This test tells you how many copies/mL a person’s blood is infected with the HIV virus
We will check this at baseline, after someone is tested positive and before starting therapy.
Typically two sets of HIV viral labs are necessary.
We cannot make a decision based on just one set of HIV viral labs
Absolute CD4 Cell Count
Calculated measure by looking at the overall number of T-lymhocytes and the percentage of T-lymphocytes
This test is done in a lab and used as a guide to predict how someone’s immune system is working.
If the number is low, the person may be immuno-compromised and may need therapy sooner
If the number if lower, they may be immunosuppressed and it may be due to HIV
CD4 Percentage
Percentage of total lymphocytes that are T-lymphocytes
This number is also correlated to how well a person’s immune system is doing
By looking at the ABSOLUTE CD4 CELL COUNT and the CD4 PERCENTAGE, we can get an idea how the person’s immune system is doing (the persons AIDS progression) and we can decide what treatment option to use.
Less than 14% (CD4 percentage) suggests disease progression
The more a person’s number falls, the more sick that person is.
Uninfected individual has CD4 % of about 40.
Routes of HIV Transmission
Main source of infection is through body fluids of an infected person and transmission of these body fluids through different pathways.
Transmission routes
UNPROTECTED Sexual intercourse with an infected person
Sharing needles and syringes with an infected person
Exposure to
Dr. Angela Stanic
Management of HIV Infection
HIV Basics
HIV= human immunodeficiency virus causes AIDS
Attacks the immune system and causes depletion of the CD4 (white blood cells) cells
With time, a person progresses to AIDS
Testing is available
Rapid tests are confirmed by more accurate antibody tests
No cure
But we have long term therapies available
HIV Laboratory Parameters
HIV Viral Load (HIV RNA)
Number of HIV copies/mL measured in a person’s blood
This test tells you how many copies/mL a person’s blood is infected with the HIV virus
We will check this at baseline, after someone is tested positive and before starting therapy.
Typically two sets of HIV viral labs are necessary.
We cannot make a decision based on just one set of HIV viral labs
Absolute CD4 Cell Count
Calculated measure by looking at the overall number of T-lymhocytes and the percentage of T-lymphocytes
This test is done in a lab and used as a guide to predict how someone’s immune system is working.
If the number is low, the person may be immuno-compromised and may need therapy sooner
If the number if lower, they may be immunosuppressed and it may be due to HIV
CD4 Percentage
Percentage of total lymphocytes that are T-lymphocytes
This number is also correlated to how well a person’s immune system is doing
By looking at the ABSOLUTE CD4 CELL COUNT and the CD4 PERCENTAGE, we can get an idea how the person’s immune system is doing (the persons AIDS progression) and we can decide what treatment option to use.
Less than 14% (CD4 percentage) suggests disease progression
The more a person’s number falls, the more sick that person is.
Uninfected individual has CD4 % of about 40.
Routes of HIV Transmission
Main source of infection is through body fluids of an infected person and transmission of these body fluids through different pathways.
Transmission routes
UNPROTECTED Sexual intercourse with an infected person
Sharing needles and syringes with an infected person
Exposure to