HIV Flashcards
Explain the virus structure of HIV?
- RNA retrovirus
- uses reverse transcription
How quick is HIV replication?
- very quick in early and late infection
- new generation every 6-12yhours
Explain the stages of HIV virus entry into the body?
- binding to the CD4+ cell
- fusion into the cell
- reverse transcriptase
- integration into the cell
- transcription
- translation
- formation of new viral proteins
- new generation every 6-12hrs
What cells do HIV virus primarily target?
- CD4+ T cells
T helper cells
Explain what happens to an infected CD4+ Cell?
- CD4+ Cell infection
- transported to regional lymph nodes
- infection established within 3 days (72hrs)
- dissemination of virus?
Affects on cell levels in HIV?
- Reduced circulating CD4+ Cells
- reduced proliferation of CD4+ cells
- reduced CD8 Cells (initially higher)
- chronic immune activation
What is the normal and abnormal levels of CD4+ Cells?
- normal > 500
- bad < 200
What is an opportunistic infection?
- infection caused by a pathogen that does not normally produce a disease in a healthy individual
What are the 3 stages of HIV infection?
- primary infection
- asymptomatic infection
- symptomatic
What are the symptoms often displayed in the primary infection phase of HIV?
- Non-specific symptoms
- rash, fever, myalgia, headache
What is PCP?
- Pneumocystic pneumonia
- Opportunistic infection
- CD4 <200
- Insidious onset, SOB, Dry cough
Investigations of PCP?
- CXR = Interstital infiltrates
- Exercise oxygen desaturation
- bronchoalveolar lavage -> PCR
Treatment of PCP?
- Co - trimoxazole
Symptoms of cerebral toxoplasmosis?
- CD4 < 150
- Headache, fever, focal neurology
- cerebral oedema
How does cerebral toxoplasmosis appear on CT?
- Ring enhancing lesions on brain CT
Symptoms of cytomegalovirus?
- CD4 < 50
- Reduced visual acuity
- floaters
- abdo pain
- diarrhoea
Symptoms of HIV associated neurocognitive impairment?
- reduced short term memory
- +/- motor dysfunction
Name some opportunistic infections associated with HIV?
- Pneumocystic pneumonia
- TB
- Cerebral toxoplasmosis
- cytomegalovirus
- HIV associated neurocognitive impairment
- progressive multifocal leukoencephalopathy
Skin infections associated in hIV?
- Herpes zoster
- herpes simples
- HPV
Cancers associated with HIV?
- Kaposis sarcoma
- non-hodgkin lymphoma
- cervical cancer
Symptoms of HIV - non-AIDS?
- Mucosal candidiasis
- seborrhoeic dermatitis
- diarrhoea
- fatigue
- lymphadenopathy
Haematological manifestations of HIV?
- Lymphopenia
- thrombocytopenia
Modes of transmission of HIV?
- Sexual transmission
- Parenteral transmission
- Mother-to-child
What might increase the transmission of HIV sexually?
- unreceptive sex
- trauma
- genital ulcerations
- concurrent STI
When might mother-to-child spread of HIV occur?
- in utero
- delivery
- breast feeding
Testing strategies for HIV?
- Universal screening
- opt-out during certain procedures
- screening at risk groups
- testing on clinical grounds
Who are considered high risk groups for HIV?
- MSM
- Black Africans
- Prisoner’s
- Trans women
- PWID
- Partner’s of people living with HIV
What 3 factors can be tested for in HIV?
- Viral RNA (First to become positive)
- Antigen
- Antibody (can take 3 months to become positive)
What testing is done in Tayside for HIV and what is the window period?
- 4th generation testing (combining antibody and antigen)
- window period = test may be falsely negative in first 45 days
What is the anti-retroviral therapy treatment?
- high active antiretroviral therapy (HAART)
- 2 X nucleoside reverse transcriptase inhibitor
- 1 x another
Name different HIV (Anti-retroviral) drug classes?
- Nucleoside reverse transcriptase inhibitor
- integrase inhibitor
- non-nucleoside reverse transcriptase inhibitor
- protease inhibitor
- integrase inhibitor
Explain PrEP?
- Pre-exposure prophylaxis
- 2 tablets either daily or before risk
- tenofovir
- emtricitabine
Explain Post-exposure prophylaxis?
- within 72hrs of risk
- 3 drugs taken for 4 weeks
- raltegravir
- tenofovir
- emtricitabine
What prevents mother-to-child HIV transmission
- undetectable load = natural delivery
- detectable load = caesarean
- formula feeding
- 2/4 weeks of PEP for neonate
Best preventions for HIV?
- Testing
- condoms
- opioid substitution
- raising awareness
