Flashcards in Diagnosis of HIV pts Deck (96)
How long can HIV-1 RNA be detected before the detection of HIV ab?
Do HIV antibodies assays detect HIV-1 or HIV 2?
True or false: HIV antibody/antigen testing, if positive, needs to be followed up by a second test.
What is the gold standard for diagnosing HIV?
ELISA (99.7% sensitive, 99.9% specific)
How sensitive/specific are the rapid tests for HIV?
Very, both above 99.5%
What is the confirmatory tests for HIV?
If the reactive HIV ag/ab test is positive, and the multispot confirmatory test is negative, what is the next step in diagnosis?
HIV-1 nucleic acid testing
What is the sequence of HIV testing?
-HIV ab/ag screen
-HIV1 nucleic acid testing if multispot is negative
What is the role of HIV screening?
-Offered to all pregnant women
Where, geographically, is HIV-1 found more often? HIV-2?
HIV-1 = US
HIV-2 = Africa
How does HIV-2 compare to HIV-1 in terms of virulence and transmissibility?
HIV-2 is less virulent, and less easily transmittable
What are the two receptors on CD4 cells for HIV? Which is more common, and which progresses more rapidly?
-CCR5 or CXCR4
-CCR5 = major one that is transmittable
-CXCR5 = more rapid progression
What is the role of gp120?
Antigen that varies--determines tropism
What happens to the pathogenicity of an HIV virus if the tropism changes from CCR5 to CXCR4?
What is the role of delta 32 deletion in humans (hetero and homozygous)?
If have homozygous, then less susceptible to HIV virus
If heterozygous, then slower progression
What is the ligand for CCR5 on cells?
What is the treatment for kids born to HIV+ mothers? (3)
-Have mom on HIV antiretrovirals
-Do not breastfeed
-Give baby post-exposure prophylaxis
True or false: the placenta is a good barrier for the prevention of HIV positive infants
What is the most common route of transmission of HIV from mother to fetus?
During vaginal delivery
What is the viral load goal for mother's who are HIV+? Can they deliver vaginally if they meet this requirement?
-Less than 100
-Vaginal delivery okay if this is met
Can breast milk transmit HIV?
What is the normal CD4 count?
More than 750
True or false: syphilis occurs at any CD4 count
True or false: syphilis occurs mostly in women
True or false: syphilis usually spares the eyes
True or false: syphilis rarely involved the oral mucosa
What are the ssx of secondary shyphilis?
Patchy rashes--condyloma lata
How infectious are the condyloma lata of syphilis?
In what risk group is syphilis incidence rising?