HIV Flashcards
(157 cards)
What is the life expectancy for HIV patients on modern ARV therapies?
With the advent of HAART, people living with HIV have an expected lifespan similar to those who are HIV-negative as long as patients receive timely diagnosis, CD4 count at the time of treatment initiation, and access to treatment
What are some populations that may experience lower life expectancies following an HIV diagnosis?
Non-white people
Individuals with history of injection drug use
Individuals who start ARV at low CD4 counts
What are some characteristics of standard screen test for HIV?
Uses 4th generation antibody and antigen
Nearly 100% sensitive and specific for chronic HIV (infection event was more than 15-20 days)
Need to wait a few days to 2 weeks to see results
What are some characteristics of point of care screen test for HIV?
Rapid antibody screen for HIV 1 & 2
Need for confirmatory testing, if result is positive
What are some characteristics of the dried blood spot (DBS) screen test for HIV?
Currently utilized in select projects and communities in Sask.
Blood was collected using a finger prick and placed on the sheet. The sheet is sent away for testing
Better confidentiality
Can test for multiple bloodborne diseases on the same card
What cells does HIV infect?
Human Deficiency Virus targets CD4 lymphocytes (T cells)
T cells infected by HIV are no longer able to coordinate immune responses from macrophages, B cells, and CD8 T lymphocytes
What is AIDS?
Acquired Immunodeficiency Syndrome
End stage of HIV infection
CD4 count of less than 200
Presence of 1 or more AIDS-defining illnesses
Opportunistic Infections (Pneumocystis pneumonia, mycobacterium avium complex, cytomegalovirus)
What is HIV?
HIV is a retrovirus that occurs as two types (HIV-1 and HIV-2)
HIV-1 is the most common (95% of all infections)
HIV-2 is mostly found in West Africa (may affect drug choice)
Review slide 40
What HIV-infected body fluids can spread HIV infections?
The following fluids need to come in contact with mucous membranes(rectum, vagina, penis, mouth) or directly injected into the bloodstream for transmission to occur
- Blood
- Semen
- Vaginal fluid
- Rectal fluid
- Breast milk
What are the modes of HIV transmission?
Sexual
- Unprotected sex with someone with HIV
- Insertive and receptive sex (anal, vaginal)
Blood contact
- Sharing needles (PWID, tattoos, piercing, razors)
- Blood transfusions (prior to 1985 in Canada)
- Occupational exposure (needle-stick injuries)
Vertical transmission
- To fetus/infant in utero, at delivery, or via breastmilk
When is the highest risk for vertical transmission?
Highest risk if:
- Seroconversion occurs during pregnancy due to higher viral load
- Pregnant person is HIV+ but not diagnosed or not on ARV
What are some precautions associated with reducing vertical transmission?
Women taking ARV and maintain a suppressed viral load from conception have less than 1% risk of vertical transmission
Recommendation in resource-rich settings is not to breastfeed as HIV can pass through the milk despite the mother being suppressed
What is the risk of transmission among HIV+ patients on antiretrovirals?
Undetectable=Untransmittable
As long as adherent and viral load is below 200 copies/mL
What are some symptoms associated with a new HIV infection?
Flu-like symptoms within 2-4 weeks after infection
- Fever
- Sore throat
- Enlarged lymph nodes
- Night sweats
- Chills
- Fatigue
What is the relevance of CD4 count in HIV?
It is a marker of immune system health
800-1200 is considered to be normal, and declines rapidly without antiretroviral treatment
Lower values may indicate need to initiate prophylaxis for opportunistic infections
What opportunistic infection is a HIV+ patient at risk for at any CD4 count?
TB
More likely for a latent infection to reactivate
What opportunistic infections is a HIV+ patient at risk for when CD4 count is below 250?
<250: Coccidiomycosis
<200: Pneumocystis
<150: Histoplasmosis and Cryptococcus (rare in SK, more common in southern USA)
<100: Toxoplasmosis (start proph if CD4 count falls below 100)
<50: MAC, CMV, PML (pts become very vulnerable)
What is HIV viral load?
Amount of virus present in the blood
Measured as copies/mL
Less than 50 copies/mL is considered to be suppressed
A patient has an undetected viral load when testing devices are unable to pick up any viral copies
Review slide 54 for typical course of untreated HIV infection
For which patient groups is HIV treatment recommended for?
All individuals with HIV
- To reduce morbidity and mortality
- To prevent transmission to sexual partners and infants
Initiate treatment as soon as possible (well tolerated, and better outcomes with treatment)
Especially important to start treatment for those who have AIDS-defining conditions, acute/recent infection, and pregnant
What are some of the benefits of ARVs?
Allows restoration and preservation of immunologic function
Reduces HIV-related morbidity & mortality
Increases duration and quality of life
Prevents transmission
What is the general MOA of antiretrovirals in HIV?
Antiretrovirals block viral replication within the CD4 cell
Prevents destruction of CD4 cells and allows restoration of immune function
Requires more than one active antiretroviral to achieve and maintain suppression
What is the MOA of nucleoside reverse transcriptase inhibitors (NRTIs) in HIV treatment?
As a part of the HIV life cycle, it highjacks host nucelotides in forming double-strand HIV DNA
NRTIs act as host nucleotide decoys and cause termination of the elongating HIV DNA chain
What is the MOA of non-nuclease reverse transcriptase inhibitors (nNRTIs) in HIV treatment?
nNRTIs bind directly to the HIV reverse transcriptase enzyme and inhibit the function of the enzyme to generate double-strand HIV DNA