can you differentiate between hsv1 and hsv2 with a test

[Missy386]

Hi,

Can a test reliably distinguish between hsv 1 mouth cold sores and hsv 2, genital sores? Since they are so closely related? I keep telling my friend that from my research, I don't see how they can distinuish the two, and she is very upset, her doctors says they can and so she has done a test for that. I remembe from a virology project that the dna of the two is 50% the same, so have they come up with a way to differentiate the two via the use of a novel testing device?

Thank you,

Missy

[Mistakeguy789]

Ah.  Okay my mistake in not understanding.  

I would agree with you on the in the absence of symptoms it is best to believe that it is oral and not genital.  

Please forgive my statement and misunderstanding of your statement.

[petal130]

I know the math. Yes, 97% plus 3% equals 100%.

I don't think you read it correctly. My point is, if a person tests via an IgG positive for HSV1, AND they get RECURRING cold sores - then it is a logical deduction that it's oral HSV1 going on. The 99.999% remark is more so the odds that it's HSV1, based on what I just stated.

I do agree that in the absence of SYMPTOMS, but with a positive blood test for HSV1, that in fact you'd need a swab of potential to symptoms to verify location. But even then, in the absence of ANY symptoms, statistically it would be an oral infection (and were HSV2 IgG blood test positive but no symptoms, genital) - I believe both grace and Terri have stated the same.

[Mistakeguy789]

Just to add corrective response to this.  

Petal states that my statement of "can't determine without a PCR culture" is somewhat true please allow me to clarify my response to both the orginal poster and response to petal.

My statement was in regards to a "DNA" testing. PCR testing is not looking for the virus to be alive but the actual DNA makeup of the virus itself to distingush the virus.  As this was my understanding of the question.  While I am sure culture does the same thing the point to the questioners question was do they have a device/test that can tell between the two.  The answer is yes.  Since he was stating that the DNA is 50% alike in the two strains (if I remember it maybe a little higher but I am not 100% on that and will differ that to later research).  

I would disagree that saying its 99.999 percent chance it is HSV when there is about 3% of people with HSV-2 cold sore infection.  I would say its 97% chance that its HSV-1.  Given that the total of all coldsores would be related to HSV is 100%.  

Not trying to argue just clarify my position on the question.  Nothing more.

[petal130]

Only 3% of oral herpes is HSV2. If you're having recurring cold sores, it's probably safe to say that it's about 99.999 percent chance that it's HSV1, as HSV2 is very uncommon, and almost never recurs.

So while mistakeguy states you "can't determine without a PCR culture", well that's somewhat true, but in your case logical deduction of having cold sores and testing positive via a blood test would be enough to know it's oral HSV1 that's going on.

[Mistakeguy789]

To answer your question yes it can be done.

PCR is one test that when done with a swab will tell the difference in the DNA/RNA of Herpes virus to tell what type it is.  You can look into more on PCR with a good google search.

Now you can also tell the difference in testing by the IgG protein found in the persons body who has HSV.  gG-1 is for HSV-1 and gG-2 is found in HSV-2 patients.  These two anitbodies are detecable and can tell the difference between the virus.

Going into that you can't tell which site of the body has the infection without a culture or PCR of the lesision.  HSV-1 can be genital and oral as can HSV-2.