HIV Flashcards
HIV refers to
Human Immunodeficiency Virus
HIV is an
RNA retrovirus that causes acquired immunodeficiency syndrome (AIDS)
HIV primarily targets the
CD4+ T cells, a type of cell known as T helper cells and uses them to replicate itself
What cells does the virus use as a host to replicate
T helper cells
Most common HIV
HIV 1
what does the virus do to the CD4 T-helper cells
enters and destroys them
how does the HIV first present
an initial seroconversion flu-like illness occurs within a few weeks of infection
after the seroconversion flu what happens
The infection is then asymptomatic until the condition progresses to immunodeficiency.
immunodeficiency causes
AIDS- defining illnesses and opportunistic infections. This progression occurs potentially years after the initial infection.
Transmission
Unprotected anal, vaginal or ora; sexual activities
Vertical transmission - Mother to child at any stage of pregnancy, birth or breast feeding
Mucous membrane, blood or open wound exposure to infected blood or bodily fluids
Name 4 Aids defining illnesses
Kaposi’s sarcoma
PCP
Lymphomas
Tuberculosis
Why do AIDs defining illnesses occur
The CD4 count has dropped to a level that allows unusual opportunistic infections and malignancies to appear
Is HIV treatable
Yes, most patients are fit and healthy after treatment
How long does it take to develop antibodies for the virus
up to three months
Testing 3 ways
Antibody testing is the typical screening test for HIV = simple blood test.
p24 antigen test = checks directly for the specific HIV antigen in the blood. This can give a positive result earlier in the infection.
PCR testing for the HIV RNA levels = tests directly for the number of viral copies in the blood, giving the viral load
What needs monitoring
CD4 count and Viral load
What is the CD4 count
the number of CD4 cells in the blood. These are the cells destroyed by the virus. The lower the count, the higher the risk of opportunistic infection.
CD4 count for:
Normal range and end stage HIV
500-1200 cells/mm3 is the normal range
< 200 cells/mm3 is considered end-stage HIV (aids) (high risk infection)
What is the viral load
the number of copies of HIV RNA per ml of blood
Undetectable refers to a viral load below the labs recordable range, what is this range?
usually 50 - 100 copies/ml
What does treatment involve
a combination of antiretroviral therapy (ART) medications.
What do the BHIVA guidelines (2015) suggest
starting regime f two NRTIs (tenofovir and emtricitbine) plus a third agent
What can specialist blood tests establish
the resistance of each HIV strain to different medications and help tailor treatment.
What do some treatment regimes involve
a single combination tablet taken once daily, with the potential to suppress the virus completely
What are the treatment aims:
achieve a normal CD4 count
Undetectable viral load
What other medication can be used
Highly Active Anti-Retrovirus Therapy (HAART)
Management: what medication is given to patients with a CD4 under 200/mm3 and why
Prophylactic co-trimoxazole (Septrin) to protect against pneumocystis jirovecii pneumonia PCP
Management: increased risk of which chronic diseases
cardiovascular disease
human papillomaviruss (HPV)
Cervical cancer
What vaccines should patients avoid
Live vaccines
What vaccines should they have
influenza, pneumococcal, hep A and B, tetanus, diphtheria and polio vaccines
Preventing vertical transmission: viral load determine mode of delivery, what are the they
vaginal birth < 50 copies / ml
Caesarean section > 50 copies / ml and in all woman with > 400 copies / ml
IV zidovudine should be given during caesarean if the viral load is unknown or there are > 10000 copies / ml
What can be used straight away after exposure to HIV
Post-exposure prophylaxis (PEP) within 72hrs
