Condoms protect women but not men from HSV2?

[JohnB5000]

This condom study shows that women in discordant couples were HIGHLY protected from HSV2 acquisition when condoms were used 25% of the time or more, but men were not statistically significantly protected. Is this accurate and/or widely known? The study says this is likely due to anatomy differences and virus pathology - specifically that condoms cover the riskiest area of virus shedding from a man, but women shed virus from a larger area, including higher risk areas that may make contact with the skin of a man not covered by a condom.

Is there a reason why condom use is not stressed more when people give risk reduction advice for a HSV2+ male in a discordant relationship with a HSV2- woman? According to this study, the risk of discordant women acquiring HSV2 is reduced 90% by condom use (compare to the 48% risk reduction for valacyclovir suppression therapy).

Why do people say condoms are 40-50% risk reduction, and not mention the gender specific risk reduction? According to this study, it seems like condoms actually provide a 90% risk reduction for women and very little risk reduction for men in discordant heterosexual relationships . . . can someone help to explain this please?

Is the 40-50% that people quote for condom risk reduction just the average (women 90%, men 0%, so average = ~45% risk reduction. . . I really hope that's not where that number comes from, because that could be a bit misleading).

From the study (link below):
"Our data allow us to estimate how many cases of HSV-2 could be averted with consistent condom use in discordant couples. In the United States, an estimated 500,000 persons acquire HSV-2 infection each year, of whom an estimated 350,000 are women. Assuming a relative risk for HSV-2 infection of 10 for women who use condoms 25% of the time or less, more consistent condom use may avert up to 315,000 new cases of HSV-2 infection among women. Unfortunately, condom use remains infrequent in the general population."

https://depts.washington.edu/herpes/php_uploads/publications/Effect%20of%20condoms.pdf

Thanks in advance.

[JohnB5000]

Can anyone suggest other studies that support the effectiveness of condoms for reducing transmission risk from a HSV2+ male to HSV2- female - the data in the study linked above suggests 90% risk reduction on average . . . are there results from other studies that show different numbers?

The average for condoms reducing risk of transmission in couples overall appears to be much lower than 90%, because it is not very effective at all at reducing female HSV2+ to male HSV2- risk of transmission (due to anatomical difference).

Can anyone link to another study about this?

Thanks

[JohnB5000]

Interesting, thank you. It seems that asymptomatic shedding can be anywhere - but the easiest way for the virus to shed is from areas with thin skin, in particular mucus membrane. This would support the idea that a condom would be very effective in covering this "most risky" part of the man (perhaps regardless of the site of original infection, excluding an ob) - but much less effective for preventing transmission from women to men, since contact of female skin prone to shedding can occur frequently to a male below the area of coverage of the condom (it suggests this risk is asymmetric - much less likely for this contact to transmit male to female, then female to male) .

It is true that "skin to skin" contact is all that is needed to have risk, but "mucus membrane to mucus membrane" or "mucus membrane to abraded skin" seems to be by far the most risky transmission vector . . .

It is encouraging that an HSV2+ man could reduce transmission risk by 90% by wearing a condom (not every man perhaps, but the study was interpreting the risk data at a population level - so it would appear to imply 90% for the average man - maybe 100% for some and less for others, but 90% is pretty good)

[Fleetwood20]

For some men, I imagine condoms give 100% protection to partners. This would only occur if that person only shed from the nerve endings covered by a condom or didn't shed at all. There are indeed people who fall in this category.

You'd also imagine the opposite is true. That is if a make contracted HSV2 while using protection the the nerve endings shedding most are likely to be outside the condom area.

Equally some can shed anywhere, a lot do.

Hence it is possible that condom use could provide 0% additional protection, 100% and proportionate if shedding in multiple places.

The average, which never applies to a particular individual has been estimated in the range of 60% to 90%. Is it changing though as more people are using protection such that primary infection sites are moving away from the penis shaft?

[JohnB5000]

Terri Warren, ARNP is listed on the heading as a contributing researcher on this study . . . It's from 2001 . . . seems pretty solid

Can anyone confirm the implication from the study that condoms reduce transmission risk from HSV2+ male to HSV2- female by up to 90%?

Is there anything more recent to back that up?

Thanks

[JohnB5000]

Can anyone comment on the effectiveness of condoms on transmission risk by gender in discordant couples? I am not sure what the recommendations are, beyond the idea that everyone should use them . . . the data suggests condoms are highly protective for women in discordant relationships, but not significant for men . . . is this known/verified to be true?

If it is indeed true, it affects transmission risk significantly and should be useful information for discordant couples to be aware of . . .