HIV Flashcards
(30 cards)
How can HIV spread?
SEXUAL TRANSMISSION
IVDU (rarer nowadays)
Blood products
(very rare due to careful screening)
Vertical transmission
(mothers screened)
Organ transplant
When can you test for HIV?
What permission do you need?
Must have permission from patient to test
Can test unconscious patients if it is in the patients best interest for treatment of current condition
-E.g. toxoplasmosis brain abcess
How does negative HIV testing effect a patient in terms of insurance premiums and jobs etc?
If negative absolutely no effect for patient.
Insurance or work will not care
Give very general overviews in basic terms of the 4 clinical stages of HIV
Clinical stage 1:
-Asymptomatic
Clinical stage 2:
- Weight loss under 10%
- Minor infections that anyone can get, just that they are more common (URTI, Herpes zoster)
Clinical stage 3:
- Weight loss >10%
- More rare infections that usually require immunosuppression (oral candidiasis or oral hairy leukoplakia, TB, severe bacterial infections)
Stage 4:
- Rarer diseases/ rare causes of disease or prolongued disease
- Classical scary AIDS complications
What is the difference between HIV and AIDS?
Certain infections and tumours that develop due to a weakness in the immune system are classified as AIDS illness.
If you have no symptoms then you have HIV infection only
Virtually anyone with an AIDS illness should recover from it and then be put on antivirals to keep them free from any future illness
What does HIV do to the immune system?
What cells does it effect?
HIV infects and destroys cells of the immune system especially the T-helper cells that are CD4+ (have a CD4+ receptor on their surface)
Where are CD4+ receptors found?
what cells?
Not exclusive to lymphocytes
Also present on the surface of macrophages and monocytes, cells in the brain, skin, and probably many other sites
How does HIV infection progress?
Why do the infections get worse and what happens to the HIV virus?
Over the course of infection CD4+ count declines and HIV viral load increases
Increasing risk of developing infections and tumours
The severity of these illnesses is greater the lower the CD4 count
At what CD4+ count do most AIDS diagnoses occur?
What do we call the pathogens which take advantage of HIV patients?
Opportunistic pathogens
Capable of causing infection only when the host defences are compromised
What two types of opportunistic infections may occur in HIV?
Think really basically
New infections
- Pneumocystis jiroveci (carinii) pneumonia (PCP)
- Cryptosporidiosis
- Candidiasis
- Mycobacterium avium complex
Re-activation of existing infection
- Cerebral toxoplasmosis
- Tuberculosis
- CMV disease
How does the natural history of HIV progress?
Acute infection - seroconversion
Asymptomatic
HIV related illness
AIDS defining illness
Death
How many patients have a seroconversion illness when HIV antibodies first develop?
30-60%
Describe the duration/ progression of the seroconversion (Primary HIV) illness in HIV.
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
Describe the symptoms in seroconversion (Primary HIV)
Flu like illness Fever Malaise and lethargy Pharyngitis Lymphadenopathy Toxic exanthema (rash)
Looks like glandular fever but EBV serology not in keeping
How do you pinpoint when someone first started to have HIV?
If seroconversion illness then that is when first infected.
If no illness then most accurate way is to test stored samples of blood (if available)
Failing that, consider when you were most at risk
How can you monitor HIV infection?
3 ways
CD4+ lymphocyte count
HIV viral load
Clinical features
What do we mean by combination antiretroviral therapy (cART)?
At least 3 drugs from at least 2 groups
How important is complience in HIV medication?
Adherence needs to be over 90% to be effective
Where do HIV treatments act?
Reverse Transcriptase Inhibitors
-Reverse transcription
Integrase inhibitor
-Integration of viral DNA
Protease Inhibitors
-Release of virus from cell
(also some peripheral targets like entry inhibitors)
When should you consider starting ART?
Consider starting all patients at diagnosis regardless of CD4
When should you encourage ART to patients?
If CD4
When do you need to start ART ASAP?
CD4
When should treatment adjustment of 3 drug therapy be considered?
If VL not adequately suppressed after 4-6 weeks of therapy
