HIV Flashcards
how is HIV spread?
Sexual transmission
Injection drug misuse
Blood products
Vertical transmission
Organ transplant
Think of high risk and unknown risk
Can you test an unconscious patient for HIV?
Unconscious patients can be tested if you think it is in the patient’s interest to have the test
Does having had a negative HIV test does affect insurance premiums
Having had a negative HIV test does not affect insurance premiums
what is the immunology of a HIV infection?
HIV infects and destroys cells of the immune system especially the T-Helper cells that are CD4+ (have a CD4 receptor on their surface)
CD4 receptors are not exclusive to lymphocytes - they are also present on the surface of macrophages and monocytes, cells in the brain, skin, and probably many other sites.
what is the natural history of the disease?
Over course of infection:
CD4 count declines & HIV viral load increases
- Increasing risk of developing infections and tumours
- The severity of these illnesses is greater the lower the CD4 count (normal CD4 > 500)
- Most AIDS diagnoses (severe infections) occur at CD4 count <200
what is the classification of a HIV infection?
Original classification was clinical - this was of considerable help in estimating the incidence of disease in the developing world where HIV testing was less readily available.
Pragmatic approach is to consider symptomatic vs asymptomatic disease
Classification no longer based on having certain clinical features but now based on certain laboratory parameters
Used to have certain illnesses to have AIDs
estimate of the timeline:
Opportunistic infections in HIV
Do I have HIV or AIDS?
Certain infections and tumours that develop due to a weakness in the immune system are classified as AIDS illnesses. If you have no symptoms then you have HIV infection only
Virtually everyone with an AIDS illness should recover from it and then be put on antivirals to keep them free from any future illness
what is the presentation of HIV?
earlier you diagnose it, better the _______
prognosis
What is the Natural history?
Acute infection – seroconversion;
Asymptomatic;
HIV related illnesses;
AIDS defining illness;
Death
Acute infection to death in an untreated patient, 10 years 50% of patients will be dead
What is Primary HIV / seroconversion?
Approximately 30 - 60% of patients have a seroconversion illness (when HIV antibodies first develop)
Abrupt onset 2 - 4 weeks post exposure, self limiting 1 - 2 weeks
Symptoms generally non-specific and differential diagnosis includes a range of common conditions
What are the symptoms of Primary HIV / seroconversion?
Flu-like illness
Fever - Fever that last over a couple weeks
Malaise and lethargy
Pharyngitis
Lymphadenopathy
Toxic exanthema
“looks like glandular fever but EBV serology not in keeping”
Patients tend to be ill for over a couple weeks where as other viruses tend to get better in a week
Graph showing Treatment of HIV
is there many different options and effective drugs?
yes many
How has the amoubt of pills patients are required to take changed?
Used to have to take lots of pills with lots of restrictions and many side effects
picture showing where different treatments act
how do they act?
Reverse transcription inhibitors – inhibit viral RNA being transcribed into DNA
Integrase inhibitors – prevent viral DNA being integrated into the host genome
Protease inhibitors – prevent maturation of the virus
Make sure the drugs are working and if the virus is not coming down usually patients ___ taking pills properly or the virus may be _______
not
resistant
(picture showing resistance testing)
Why do treatments fail?
If not taking properly then virus isn’t supressed and the viral can mutate against the low level of antivirals it is exposed to then the antivirals become useless
Used to be more of an issue when not as many drugs available
Gain weight when take medication sometimes and some patients don’t like and then stop taking medication
What is Lipodystrophy and what needs to be done about it?
Change drugs:
- Less likely with newer
- agents
Cosmetic procedures:
- facelift
- liposuction
- fillers
Sometimes offered surgery
Central obesity and loss limb fat
Fat redistribution
Similar to Cushing’s
Distressing side effect
