HSV Antivirals
I spend most of my energy on the STI tag on HPV, since that's the one I know the most about and the one that had the least amount of information when I started this tag. But I found some information on HSV that I thought I ought to share. The part between the horizontal bars below was not written by me, but I did obtain permission to post it.
First of all, some background:
HSV-1 is a strain of herpes that prefers the oral region, but it can reside in either the oral OR the genital region. It's just more commonly found orally.
HSV-2 is a strain of herpes that prefers the genital region, but it can reside in either the oral OR the genital region. It's just more commonaly found genitally.
When we say "prefers", it means that, if a virus comes in contact with the human body, there are some areas that the virus is more likely to attach itself to and some areas that it is not likely to attach itself to. HSV does not like, for example, the backs of your knees. You just don't get HSV on the backs of your knees, even if the backs of your knees are exposed to HSV. So, if HSV-1 comes in contact with your mouth, you have a pretty good chance of it attaching itself there and taking root. If HSV-1 comes in contact with your genitals, it can attach itself to you, but it can also not attach itself to you, to put it simply. The opposite is HSV-2 - it will probably attach itself to your genital region, but there's a good chance it won't attach itself to your oral regions even if it comes in contact - although it can.
You can consider them, for all practical purposes, the same thing, just with different preferences. Both are transmitted through "shedding", which means that they reside in tissue cells that can be transferred by contact and do not require any fluids. So condoms are effective if the area that is shedding the virus is covered by a condom, but not if the area is outside the condom coverage or if affected cells get moved to outside the condom coverage, and condoms are pretty useless to prevent oral-to-oral transmission.
HSV is often passed from older family members to children just by giving them goodnight kisses. As far as I'm concerned, any virus you can catch from your grandma is not an STD. But the reason it can be passed, besides a parent just being careless, is because this virus can be passed through simple touching even when there are no symptoms. It's called asymptomatic shedding.
Touching a person with HSV, even if you touch the affected area, does not automatically mean that you will get HSV, even if you touch them with the HSV's preferred site. In other words, it is possible to kiss someone who has oral HSV-1 and still not get HSV yourself. Whether you get it or not has to do with whether your partner is actively shedding at the time and how well your own body can fight it off for the amount of exposure you have. Lack of symptoms reduces (but does not eliminate) chance of transfer, and antiviral medication that suppresses shedding also reduces significantly (but does not eliminate) chance of transfer. Also, the strength of the viral presence in the infected partner affects how likely you are to catch it, so a partner who has an attenuated viral load is also a much lower chance of transfer.
The following is the results of some research that a layperson did into how likely it was that they would transmit HSV-1 to another partner when the site of their HSV-1 was genital and asymptomatic, meaning they had no symptoms, and whether the antiviral medication used to suppress transmission was effective for asymptomatic genital HSV-1:
You know, I really hate it when doctors just flat out lie to me. It makes me cranky.
I was able to find some of the clinical trials for antivirals used to reduce asymptomatic shedding. The doctor had suggested the studies
were "weak" because there's no way to tell if the antiviral is working. But he was totally full of shit! They can totally tell by doing PCR!
So, back in 1994, they did PCR tests of pregnant women who had HSV-2 but were asymptomatic, and found that they were shedding the virus between 1% to > 75% of the time. In other words the researchers could detect HSV DNA in "genital secretions". That's not to say that the virus would be easily transmissible at this time, but it was present.
Administration of Acyclovir reduced this shedding by a median of 80% as detectable by daily PCR tests. Not bad!
Now keep in mind, this is HSV-2, so you might wonder, as I did, if there are any studies on HSV-1. There are! There was a study for
Famiclovir, which is in the same family as Acyclovir, and as far as I can tell, behaves the same way (they have done studies comparing the two and found no difference). This study is from 2007.
So, there are several interesting bits of information. First of all, the likelihood of asymptomatic genital shedding is much less in HSV-1 vs. HSV-2 given a history of genital symptoms (something the doctor told me which was actually true!). Again, this was tested by PCR. This confirms the common wisdom that HSV-2 "prefers" the genital site.
As in the 1994 study, they showed that the antiviral reduced the incident of asymptomatic shedding in HSV-2, and they also showed
results specifically for genital shedding in patients with a history of genital outbreaks of HSV-1:
"and genital HSV-1 shedding also decreased, from 2.0% of days for participants on placebo to no days for those on famciclovir"
So that's 2% to 0%. Not bad! And note that 2% is very low to begin with. (2% chance of asymptomatic shedding x low chance of transmission with asymptomatic shedding)
As far as oral shedding goes:
"Oral shedding caused by HSV-1 in participants with a clinical history of genital herpes decreased from 4.5% for those on placebo to 1.1% for those on famciclovir, whereas oral shedding decreased slightly in participants without a history, from 3.9% for those on placebo to 3.5% for those on famciclovir"
So if you buy those statistics, that means that the least safe thing a person with genital HSV-1 can do with an HSV- partner is kiss. Though, we're still talking about small percentages (less than 4%).
Obviously, everyone is different and I'm not sure how big their sample set was, so you can't really take these statistics as law, but they are encouraging - both in the base incidence of asymptomatic shedding for a history of genital symptoms for HSV-1, and in the reduction of asymptomatic shedding with an antiviral.
Here's the 1994 study
http://www.ncbi.nlm.nih.gov/pubmed?term=Frequent%20genital%20herpes%20simplex%20virus%202%20shedding%20in%20immunocompetent%20women.%20Effect%20of%20acyclovir%20treatment
2007 study http://depts.washington.edu/herpes/php_uploads/publications/Famciclovir%20Reduces%20Viral%20Mucosal%20Shedding%20in%20HSV-Seropositive%20Persons.pdf
So, this is obviously not an all-comprehensive summary of HSV. But it is important to note that HSV-1 can be found genitally, and HSV-2 can be found orally, although neither really likes those sites. It is also important to note that both types can be transmitted even when there are no symptoms, and that certain types of antivirals do reduce certain transmission rates by a significant margin.
Also, DON'T PANIC. HSV, while a virus and something that no one wants to catch, is not the end of the world. The viruses most likely to kill you are also the ones most easy to avoid, through testing and avoiding fluid transfers. This doesn't mean that HSV is totally harmless so everyone go out and forget about safety, it just means to keep this in perspective - it's a virus like any other virus, and a lot less harmful than some other viruses. Treat it with the caution that is proportional to the effects of the virus, not with the panic that comes from a social stigma.
If you have a partner with HSV or are interested in someone with HSV, you do not have to run away screaming. If you have HSV yourself, you don't have to be afraid that no one will ever want to touch you again, or refrain from all contact out of fear of giving your partner the virus. There are some circumstances which are low risk all on their own without requiring any assistance, there are things that can be done to reduce the risk, and can reduce it by A LOT, and, unless you're severely immunocompromised, even catching HSV can be manageable and something you can live with. In many cases, the misunderstanding and reaction to HSV is a worse inconvenience on a person's life than the virus itself.
First of all, some background:
HSV-1 is a strain of herpes that prefers the oral region, but it can reside in either the oral OR the genital region. It's just more commonly found orally.
HSV-2 is a strain of herpes that prefers the genital region, but it can reside in either the oral OR the genital region. It's just more commonaly found genitally.
When we say "prefers", it means that, if a virus comes in contact with the human body, there are some areas that the virus is more likely to attach itself to and some areas that it is not likely to attach itself to. HSV does not like, for example, the backs of your knees. You just don't get HSV on the backs of your knees, even if the backs of your knees are exposed to HSV. So, if HSV-1 comes in contact with your mouth, you have a pretty good chance of it attaching itself there and taking root. If HSV-1 comes in contact with your genitals, it can attach itself to you, but it can also not attach itself to you, to put it simply. The opposite is HSV-2 - it will probably attach itself to your genital region, but there's a good chance it won't attach itself to your oral regions even if it comes in contact - although it can.
You can consider them, for all practical purposes, the same thing, just with different preferences. Both are transmitted through "shedding", which means that they reside in tissue cells that can be transferred by contact and do not require any fluids. So condoms are effective if the area that is shedding the virus is covered by a condom, but not if the area is outside the condom coverage or if affected cells get moved to outside the condom coverage, and condoms are pretty useless to prevent oral-to-oral transmission.
HSV is often passed from older family members to children just by giving them goodnight kisses. As far as I'm concerned, any virus you can catch from your grandma is not an STD. But the reason it can be passed, besides a parent just being careless, is because this virus can be passed through simple touching even when there are no symptoms. It's called asymptomatic shedding.
Touching a person with HSV, even if you touch the affected area, does not automatically mean that you will get HSV, even if you touch them with the HSV's preferred site. In other words, it is possible to kiss someone who has oral HSV-1 and still not get HSV yourself. Whether you get it or not has to do with whether your partner is actively shedding at the time and how well your own body can fight it off for the amount of exposure you have. Lack of symptoms reduces (but does not eliminate) chance of transfer, and antiviral medication that suppresses shedding also reduces significantly (but does not eliminate) chance of transfer. Also, the strength of the viral presence in the infected partner affects how likely you are to catch it, so a partner who has an attenuated viral load is also a much lower chance of transfer.
The following is the results of some research that a layperson did into how likely it was that they would transmit HSV-1 to another partner when the site of their HSV-1 was genital and asymptomatic, meaning they had no symptoms, and whether the antiviral medication used to suppress transmission was effective for asymptomatic genital HSV-1:
You know, I really hate it when doctors just flat out lie to me. It makes me cranky.
I was able to find some of the clinical trials for antivirals used to reduce asymptomatic shedding. The doctor had suggested the studies
were "weak" because there's no way to tell if the antiviral is working. But he was totally full of shit! They can totally tell by doing PCR!
So, back in 1994, they did PCR tests of pregnant women who had HSV-2 but were asymptomatic, and found that they were shedding the virus between 1% to > 75% of the time. In other words the researchers could detect HSV DNA in "genital secretions". That's not to say that the virus would be easily transmissible at this time, but it was present.
Administration of Acyclovir reduced this shedding by a median of 80% as detectable by daily PCR tests. Not bad!
Now keep in mind, this is HSV-2, so you might wonder, as I did, if there are any studies on HSV-1. There are! There was a study for
Famiclovir, which is in the same family as Acyclovir, and as far as I can tell, behaves the same way (they have done studies comparing the two and found no difference). This study is from 2007.
So, there are several interesting bits of information. First of all, the likelihood of asymptomatic genital shedding is much less in HSV-1 vs. HSV-2 given a history of genital symptoms (something the doctor told me which was actually true!). Again, this was tested by PCR. This confirms the common wisdom that HSV-2 "prefers" the genital site.
As in the 1994 study, they showed that the antiviral reduced the incident of asymptomatic shedding in HSV-2, and they also showed
results specifically for genital shedding in patients with a history of genital outbreaks of HSV-1:
"and genital HSV-1 shedding also decreased, from 2.0% of days for participants on placebo to no days for those on famciclovir"
So that's 2% to 0%. Not bad! And note that 2% is very low to begin with. (2% chance of asymptomatic shedding x low chance of transmission with asymptomatic shedding)
As far as oral shedding goes:
"Oral shedding caused by HSV-1 in participants with a clinical history of genital herpes decreased from 4.5% for those on placebo to 1.1% for those on famciclovir, whereas oral shedding decreased slightly in participants without a history, from 3.9% for those on placebo to 3.5% for those on famciclovir"
So if you buy those statistics, that means that the least safe thing a person with genital HSV-1 can do with an HSV- partner is kiss. Though, we're still talking about small percentages (less than 4%).
Obviously, everyone is different and I'm not sure how big their sample set was, so you can't really take these statistics as law, but they are encouraging - both in the base incidence of asymptomatic shedding for a history of genital symptoms for HSV-1, and in the reduction of asymptomatic shedding with an antiviral.
Here's the 1994 study
http://www.ncbi.nlm.nih.gov/pubmed?term=Frequent%20genital%20herpes%20simplex%20virus%202%20shedding%20in%20immunocompetent%20women.%20Effect%20of%20acyclovir%20treatment
2007 study http://depts.washington.edu/herpes/php_uploads/publications/Famciclovir%20Reduces%20Viral%20Mucosal%20Shedding%20in%20HSV-Seropositive%20Persons.pdf
So, this is obviously not an all-comprehensive summary of HSV. But it is important to note that HSV-1 can be found genitally, and HSV-2 can be found orally, although neither really likes those sites. It is also important to note that both types can be transmitted even when there are no symptoms, and that certain types of antivirals do reduce certain transmission rates by a significant margin.
Also, DON'T PANIC. HSV, while a virus and something that no one wants to catch, is not the end of the world. The viruses most likely to kill you are also the ones most easy to avoid, through testing and avoiding fluid transfers. This doesn't mean that HSV is totally harmless so everyone go out and forget about safety, it just means to keep this in perspective - it's a virus like any other virus, and a lot less harmful than some other viruses. Treat it with the caution that is proportional to the effects of the virus, not with the panic that comes from a social stigma.
If you have a partner with HSV or are interested in someone with HSV, you do not have to run away screaming. If you have HSV yourself, you don't have to be afraid that no one will ever want to touch you again, or refrain from all contact out of fear of giving your partner the virus. There are some circumstances which are low risk all on their own without requiring any assistance, there are things that can be done to reduce the risk, and can reduce it by A LOT, and, unless you're severely immunocompromised, even catching HSV can be manageable and something you can live with. In many cases, the misunderstanding and reaction to HSV is a worse inconvenience on a person's life than the virus itself.