HIV Flashcards
Which cells express CD4? (4)
Th cells
Macrophages
Monocytes
Macroglia
Normal range of CD4+ Th cells
500-1600 cells/mm3
What range of CD4+ predisposes to opportunistic infections?
When are HIV replication rates highest?
Very early and very late infection
Outline how a person becomes infected with HIV (5)
Exposure to virus in mucosal surface Mucosal CD4 cells become infected Migrate to regional lymph nodes Virus replicates Infection is disseminated
The four main stages of HIV infection
- Seroconversion illness
- Asymptomatic illness
- Symptomatic infection
- AIDS
How long after infection does the initial seroconversion illness manifest?
About 2-4 weeks
What are the symptoms of seroconversion?
glandular fever-like illness- rash, fever, myalgia, pharyngitis, headache
What are the manifestations of symptomatic infection prior to AIDS? (2)
General systemic symptoms
Minor opportunistic infections
What is the definition of an opportunistic infection?
Infection caused by a pathogen which does not normally cause disease in a healthy individual
Hamatological manifestations of HIV/AIDS (2)
Anaemia
Thrombocytopenia
Causative organism of pneomocystis pneumonia
Pneomocystic jiroveci
Examples pulmonary OIs (4)
TB
Bacterial pneumonia
Pneumocystic pneumonia
Mycobacterium avium
What is miliary TB?
Disseminated TB characterized by tiny lesions
OI which causes multiple cerebral abscesses
Toxoplasmosis (toxoplasma gondii)
OI which causes reduced visual acuity and floaters
CMV
Types of meningitis seen in AIDS (3)
Viral
Aseptic
Cryptococcal
Caused by the John Cunningham virus
Progressive multifocal leukoencephalopathy
Symptoms of HIV-associated encephalopathy (2)
Reduced short term memory, motor problems
Cancers associated with AIDS (3)
Kaposi sarcoma
Non-Hodgkins lymphoma
Cervical cancer
What is Slim’s disease and what is thought to cause it?
HIV-associated wasting
Chronic immune activation; anorexia; malabsorption; hypogonadism
What causes Kaposi sarcoma?
Human herpes virus 8
Where are Kaposi sarcoma seen? (3)
Skin
Mucuous membranes e.g. mouth
Visceral e.g. lungs, gut
Hamatological manifestations of HIV/AIDS (2)
Anaemia
Thrombocytopenia
Commonest mode of transmission of HIV
Sexual transmission
Factors which increase the risk of sexual transmission (4)
Anoreceptive sex
Genital ulceration
Trauma
Concurrent STI
Means of parenteral transmission (3)
“Works” sharing
Infected blood products
Iatrogenic
What are the chances of at-risk children contracting HIV?
1/4
How can HIV be transferred mother to child? (3)
Transplacenta
Trauma during delivery
Breastfeeding
Why is the prevalence of HIV increasing while the incidence falls?
More people living with HIV- fewer people progressing early to AIDS/death
In which groups is the prevalence of HIV highest?
Men who have sex with men (MSM) and Black African men and women
Which group are most likely to be undiagnosed/present late?
Heterosexual men
Four general scenarios where testing is recommended
In high prevalence areas (inc Tayside)
In particular services (e.g. GUM, TOP, drug dependency clinics)
High risk groups (MSM and their female partners, IVDU)
Where HIV falls into the differential
Prophylaxis of PCP
Co-trimoxazole 480mg daily
What is highly active anti-retroviral therapy?
Combination of three drugs from at least two anti-viral classes
In what two ways are the chances of preventing resistance enhancced?
Multi drug treatment
Ensuring adherence
Three strategies for partner notification
Patient referral
Provider referral
Conditional referral
Strategies to prevent onward transmission (5)
Condom use HAART to suppress viral load partner disclosure scale up testing programmes PEP/ PrEP
Fertility options for serodiscordant couples (3)
Sperm washing with IUI/IVF
Timed sex with HAART +/- PrEP
Self-insemination
How should the baby be delivered to prevent MTCT? (2)
Vaginal delivery if undetectable viral load
C-section if detectable
Length of PEP for neonates?
4 weeks
What did the HPTN-52 trial show?
Early HAART reduced sexual transmission in serodiscondart couples by 95% compared to untreated
