HIV - AIDS
HIV “Human Immunodeficiency Virus”
AIDS “Acquired Immunodeficiency Syndrome”
HIV life cycle:
Attachment: GP120 protein projections binds with CD4 receptors, while also binding with co-receptors called CCR5 or CXCR4 to enter into the cell.
Fusion: Virus unites with cell, viral RNA & viral enzymes unpack contents.
Reverse transcription: viral RNA and viral enzyme (reverse transcriptase) turn into viral DNA & move into nucleus.
Integrate: HIV DNA release integrase (enzyme that can take over cell’s DNA) & integrates into cell’s DNA.
Replicate: HIV DNA makes long chains of virus.
Budding: assembled parts start to grow off cell wall.
Maturity: Pops off cell surface and starts cycle all over.
HIV can turn into AIDS once the body loses enough T cells & its ability to fight off infection & virus.
Transmission of HIV:
Sex without a condom
Pregnancy (birthing process, breastmilk)
Infected injection equipment
blood transfusions
non-sterile tools
HIV can only be transmitted through blood, semen, vaginal fluid, or breastmilk.
HIV Stages:
Acute stage
Can be spread to others
viral load very high in the blood
Signs and symptoms: flu-like (aches, joint pain, fever, fatigue, sore throat, swollen lymph nodes, GI upset, rash)
Begins a couple weeks to months after being infected
Chronic Stage:
may be asymptomatic
can last a decade or more
taking ART (antiretroviral therapy) can keep you here forever and not progress to AIDS
can still transmit to others
low viral load
CD4 count is more than 200 to about 500
no opportunistic infections at this time
When stage ends: viral count increasing, CD4 drops less than 200, signs and symptoms appear, along with opportunistic infections
AIDS
last stage
immune system completely destroyed by virus
without meds, survival is only a few years
Diagnostic Testing for HIV:
Acute stage:
Window period: time when infected to when a test can deliver a positive result (not enough time for virus to get picked up by test)
If the person is suspected to have HIV, they need to abstain from sex until confirmation.
No test can show immediate infection
Combination test - antigen and antibodies of HIV as early as 2 weeks.
Antibody HIV test - not as early as combination test and only tests for the antigen
Nucleic acid test (NAT) - used for high risk exposure patients; can show amount of virus in blood; earliest around 10 days
CD4 count - measure helper T cells
AIDS
CD4 count drops less than 200 cells per millimeter
Opportunistic disease is present
How to avoid opportunistic infections:
Avoid water that is not treated
Do not eat foods that are raw or uncooked
avoid risky sexual activities
Keep up with vaccines
Avoid exposure to animal feces
Need to take ART therapy as prescribed