8.2 HIV Flashcards
What does HIV stand for and what are the 2 types?
Human Immunodeficiency Virus
HIV-1 and HIV-2
What type of virus is HIV and what family does it belong to?
HIV is a retrovirus and belongs to the lentivirus family
What are the 4 main bodily fluids are associated with HIV transmission
1) vaginal and seminal fluids
2) rectal fluid
3) breast milk
4) blood
What are the chances of an HIV positive mother passing on HIV to her child in the UK, if she has received appropriate medical intervention?
Less than 1%
List 5 other factors that increase transmission of HIV
1) A high plasma HIV viral load in the source
2) Breaches in the mucosal barrier (eg. mouth/genital ulcers, trauma following sexual assault or first intercourse, menstruation)
3) STIs enhance transmission and increase HIV shedding from the genital tract.
4) greater if ejaculation occurs
5) Non-circumcision
What does PEP stand for and what is it?
“post-exposure prophylaxis”
PEP is when you are given HIV treatment if you have been exposed/at risk of HIV
It is a 28 day therapy reduces risk of aquiring HIV from incidence
Give an example of when post-exposure prophylaxis (PEP) be recommended?
You have experienced a needle stick injury when taking blood from a person with HIV (or of unknown HIV status)
What does HIV cause and what does this make you more susceptible too?
Progressive damage to the immune system
leads to severe immunodeficency, opprtuntistic infections and death
What is the primary immune dysfunction caused by HIV?
What is the process of HIV infection (4)
Depletion and impaired function of the T helper lymphocytes
1) HIV gains access to cells via CD4 receptor and enters
2) reverse transcriptase makes a DNA copy of the RNA genome and integrates it into host DNA
3) complete virus particles are formed during replication
4) these are released from the infected cells leading to a rapidly reproducing virus
What is the mechanism of impaired function to T-helper cells?
Mechanism is uncertain but probably includes:
- enhanced apoptosis
- inhibition of CD4 lymphocyte growth
What could be measured as a marker of immune function is suspected or infected HIV patients?
Peripheral CD4 cell count
What are the 3 main clinical phases of HIV (3A’s)
1) Acute seroconversion – occurs within a few weeks of initial infection. Marks the period of time when HIV antibodies develop and are detectable. People are extremely infectious at this stage.
2) Asymptomatic – can last years to decades. People can be asymptomatic or have few symptoms. If left untreated, there is steady decline in CD4 T cells.
3) Acquired immunodeficiency syndrome (AIDS) – final stage of HIV infection but does not develop in everyone. Caused by extremely low CD4 count and damage to immune system
Following the period of clinical latency during HIV infection what symptoms may develop and how can these progress?
Iinitially, constitutional symptoms (tiredness, weight loss, fatigue), which can progress to opportunistic, potentially fatal, infections
What is meant by Seroconversion following early Infection of HIV?
What would be seen during this period and what can be said about the “set point” reached?
Serocoversion is the period when the body starts producing detectable levels of HIV antibodies. It is a partial immune response by the body in attempt to fight infection.
During this stage we get a rise in CD4 and a fall of viral load until a set point. The point reached varies from person-person:
If the set point is a high viral load ➞ person is more likely to have a rapid CD4 rate of decline after
If the setpoint is a low viral load ➞ person is more likely to have a slow CD4 rate of decline after
Around how many people experience symptoms shortly after HIV infection and what is this process called?
List 4 possible symptoms of an acute HIV infection
The majority of people (70% to 90%) will experience symptoms shortly after HIV infection during serocoversion
Symptoms include flu-like symptoms:
- sore throat
- fever
- malaise
- myalgia
