HIV Flashcards
Etiologic agent of Acquired Immunodeficiency
Syndrome
Human Immunodeficiency Virus (HIV)
HIV can lead to what disease if left untreated
Acquired immunodeficiency syndrome (AIDS)
when was HIV-1 discovered and where was it discovered
1983-1984
France and the US
HIV 1 group that is Most common worldwide;
includes 9 subtypes (A-K)
M (Major)
HIV 1 group that is most widespread globally
Subtype C
HIV 1 group that is common in the U.S., Europe, and Australia
Subtype B
HIV 1 group that is Rare, mainly in West Africa
Group N, O, P
HIV 1 group that is created by genetic mixing of subtypes
Recombinant Forms (CRFS)
when was hiv2 discovered and where
1986, West Africa
Less transmissible and less harmful than
HIV-1 but can still cause AIDS
HIV-2
surface of the viral envelope and is responsible for binding to the CD4 receptor on the surface of host cells
gp120
allows the viral envelope to fuse with the host
cell membrane
gp41
- Shell that surrounds the viral RNA and enzymes
- Uncoats, releasing the viral RNA into the cytoplasm
Capsid Protein (p24)
- Two single-stranded RNA molecules
- Genetic material of the virus
RNA Genome
- HIV uses to convert its RNA genome into DNA once
inside the host cell
Reverse Transcriptase Enzyme
integrating the newly reversetranscribed viral DNA into the host cell’s genome
Integrase
involved in processing the viral proteins. Cleaves these polyproteins into smaller functional units that are necessary for the assembly of new viral particles
Protease
Not MOT’s of HIV
- Kissing
- Hugging
- Sharing Food
- Insect Bites
- Sharing Toilet seats
- Bathing
- Sneezes and Coughs
- Sweat
mot of hiv
- Unprotected sexual intercourse with an infected
partner - Vertical transmission (From mother to child)
o In utero (Antenatal)
o During delivery (Intranatal)
o Breastmilk (Postnatal) - Injection drug use
o Rare: infected blood/blood products
day 3-7 symptom
fever
day 7-14 symptoms
fever +
fatigue
body pain
join pain
skin rash
day 14-28 symptoms
previous 5+
mouth sore
enlarged lymph nodes
day 29 to 20years
lymph nodes are enlarged and all other sypmtoms get resolved
early neurological symptoms
forgetfulness
poor concentration
apathy
late neurological symptoms
dementia
seizures
gait disburbances
Flu-like symptoms that occur within first 2-4 weeks of
contracting HIV infection
Acute Infection
Symptoms in Children
- Failure to thrive, recurrent infections, and
developmental delays - Influenced by immune maturity, viral dose, and
infection route
Occurs when CD4 cell count falls below 200cells/mm3 and vulnerable to opportunistic infections
Acquired Immunodeficiency Syndrome
Chronic HIV infection after acute infection stage, can
last for decades
Clinical latency
Risk Factors of HIV
Unprotected Sex
Multiple Sexual Partners
Intravenous Drug Use
Occupational Exposure
Treatment of HIV
Antiretroviral Therapy (ART)
Viral Suppression
PrEP (Pre-Exposure Prophylaxis)
Challenges in HIV Management
Drug Resistance
Adherence
Mental Health
Cure research
HIV Vaccine Development
Long-Acting Antiretroviral
Global Health Initiatives
Prevention Strategies of HIV
Condom Use
Needle Exchange Programs
Mother-to-Child Transmission Prevention
HIV Testing and Counseling
Impacts of HIV/AIDS on Global Health
Orphaned Children
Healthcare System Strain
Economic Impact
- A confirmatory test to identify specific HIV proteins
- Known as Golden Standard for testing
Western Blot
A Screening test that detects HIV antibodies
Enzyme-Linked Immunosorbent Assay (ELISA)
- Quantifies the amount of HIV in the blood and helps
determine the viral load
HIV-RNA PCR Tests
- Detects HIV antibodies in minutes, offering a quick
alternative to ELISA
Rapid Tests
negative test
result is reported if either no bands are present or if none of the bands present correspond to the molecular weights of any of the known viral proteins
positive
at least two of the following three bands are present
measures state of a person’s immune function
CD4 Count
CD4 T-cell counts to classify patients into various stages of HIV infection, with those whose counts are below 200/uL being classified as having AIDS
CD4 T-Cell Enumeration
The gold standard for enumerating CD4 T
cells is
immunophenotyping
Detect the amount of virus present
Monitors effectiveness of Antiretroviral Therapy
Used during acute infection to detect virus
HIV Lab testing – Viral Load
Methods in viral load
o PCR
o Branched chain DNA
o Nucleic acid sequence-based amplification
- Attachment to the surface of host cell (CD4+T cell)
- gp120 protein binds to the CD4 receptor on the
host cell’s surface - gp120 undergoes a conformational change, allowing
it to also bind to a coreceptor (either CCR5 or
CXCR4) on the host cell
Binding
- Viral gp41 protein undergoes a conformational
change, which causes the viral envelope to fuse with
the host cell’s membrane - Allows the viral RNA, enzymes, and other essential
components to enter the host cell’s cytoplasm
Fusion
- Viral RNA genome is released into the cytoplasm
- Reverse transcriptase begins the process of
reverse transcription, converting the singlestranded viral RNA into double-stranded DNA - Allows the viral genetic material to be integrated into
the host’s DNA
Reverse Transcription
- Newly formed viral DNA is transported into the
nucleus of the host cell - Enzyme integrase facilitates the integration of the
viral DNA into the host cell’s genome (PROVIRUS)
Integration
- Transcribe he proviral DNA into mRNA
- mRNA is then translated into viral proteins in the host cell’s ribosomes
Replication
- newly produced viral proteins and viral RNA are
assembled into new viral particles in the cytoplasm
of the host cell - viral capsid proteins (p24) form the protective hell
around the viral RNA, while other proteins like gp120
and gp41 are embedded in the viral membrane
Assembly
Viral particles are transported to the surface of the
host cell, where they bud off from the host cell’s
membrane.
Budding
what viral protein undergoes conformational change
gp41
coreceptor of binding
ccr5 or cxcr4
where is the viral dna trasnported during integration
nucleus
in replication dna is transcribed into
mrna
during replication mRNA is then translated into viral proteins in the host cell’s
ribosomes
during assembly, newly produced viral proteins and viral RNA are assembled into new viral particles
cytoplasm
