Re: HIV-2 ..how easy to pass on?
HIV-2 is about 60-70% similar to HIV-1. The Pathogenesis of HIV-2 is different with people Infected with HIV-2 maintaining higher CD4 counts longer. I thought that HIV-2 was as infectious as HIV-1 but after some research it isn't as infectious, that's not to say the risk is only there if your partner has outbreaks of cold sores or other symptoms because that's false.
After a little research. The differences between HIV-2 transmissibility and pathology compared to HIV-1 are not clear but several features offer an explanation.
Features of HIV-2 infection that could explain it's less pathogenic nature compared to HIV-1.
-Lower viral load in blood and genital fluids(sometimes up to 100x less)
-Replication to lower titers in infected cells.
-Lack of modulation on CDA protein on the cell surface.
-Reduced immune activation
-Reduced T cell apoptosis
-Reduced affinity of the envelope gp105(vs gp120) for cell surface receptors.
- Increased B-chemokine induced by the HIV-2 envelope, with subsequent down modulation of the CCR5 receptor.
-Autologous neutralizing antibodies found more frequently than with HIV infection.
-HIV-2 specific T helper cells more preserved and functional.
-Enhanced CD8+ cell noncytotoxic immune response.
- CD8+ cells have a more diverse T cell receptor repertoire.
-Strong CD8+ cell noncytotoxic antiviral response.
A bit off topic but there has been some speculation that certain subtype in the M group of HIV-1 are easier transmitted through vaginal penile intercourse versus the predominant HIV-1 strain in the US which is thought to be easier transmitted through Anal sex(sub type B). Albeit a large portion(if not all) of the reason why anal sex is a higher risk is because of the trauma(which most often causes microscopic bleeding) and micro tears to the anus.
You're best bet for all HIV-1 subtypes or strains and HIV-2 is to assume the risk is 1/1000 for receptive vaginal intercourse and for insertive vaginal intercourse it's 1/2000 if your circumcised or 1/1000 if you aren't. Again there are lot's of factors like if ejaculation took place, the viral load of the HIV + person, if there are any active STD infections(chlamydia, herpses), if there is blood involved from trauma or menstruation.
This guy did mislead you even if it's somewhat less infectious I still wouldn't put myself at risk. Let me repeat he is wrong saying that he is only infectious when he has a cold sore or something else. While yes it may be like 25-50% less infectious than HIV-1(just a guess) the risk is still ALWAYS there.
Last edited by missingyou; 09-20-2010 at 12:05 AM.