HIV transmission Flashcards
What are the 3 modes of HIV transmission?
- Sexual Transmission (95% of new infections)
- Parentral (IV drug use/ iatrogenic- blood prods)
- Mother-to-child
What incr. sexual transmission risk?
- trauma
- anoreceptive sex
- genital ulceration
- concurrent STI
How may a mother transfer inf. to her child?
- IN utero/ trans-placenta
- during DELIVERY
- Breast-feeding
How fatal is HIV in babies?
1 in 3 HIV + bbies DIE before 1st bday if LEFT UNTREATED
- 1 in 4 bbies at risk will be infected
HIV is highly prevalent in what groups?
- MSM (1:7 in London)
- Heterosexuals(15-44)
- black african MEN and WOMEN
- –female partners of BISEXUAL men
- –partners of those LIVING with HIV - IV drug users (1:263)
Whcih group of individuals are most likely to come in LATE with symptoms?
- heterosexual men
When may HIV testing be done???
- only if in Pt’s best interest
- consent from reltive is NOT required
- until pt regains CAPACITY
- obtain support from HIV team if needed
Which markers are used in labs to detect HIV infection?
VIRAL RNA
ANTIGEN
ANTIBODY (IgM and IgG)
What is meant by window period, with HIV testing?
- it takes 4-12 weeks before HIV infection is detectable
- —this time frame is called the WINDOW period !
(avg. 20-25days)
What is the diff. between the 4th and the 3rd gen. HIV test?
Which is BETTER?
3rd Gen HIV test: only checks for Abs
4th Gen HIV test: checks for P24 antigen and Abs —SHORTENS the windor period !- so better (14-28days)
How is HIV tetsting done?
Rapid HIV test (POCT) -fingerprick blood specimen or saliva!
—-results in 20-30 mins
What are the disadvantages of POCT?
- expensive (10£)
- POOR predictive value in LOW prevalence settings
- 12 week window period (earlier not possible)
- —–do blood test (4 week window period) `
What are the advs of POCT?
- simple
- no venepuncture
- no long wait
- reduce follow-up
- good sensitivity
