[Question #6003] HSV Test Results

17 months ago

Hello. Thank you for taking the time to review and answer my questions. 

Approximately one year ago my 7 yr old daughter was hospitalized with a severe case of what turned out to be HSV 1 (Oral). Subsequently, I noticed sores on my lips that were similar to the early stages of the sores that my daughter had on her lips - although mine never turn into blisters like hers do. I had a swab done of the sores on my lips and the HSV results came back negative. I had my daughter's similar sores swabbed and the result for the HSV and her results came back negative too.

Because my daughter had a confirmed case of HSV 1, and I had sores on my lips similar to hers, my doctor prescribed to me  an antiviral for treatment of the suspected HSV 1 outbreak. However, despite daily doses of the prescription for 6 months, my lips sores persist. Similarly, my daughter has to take daily antiviral to manage her symptoms, if she stops she'll have a full outbreak (blisters on lips).

At the request of my doctor, I had a blood draw for HSV 1 & 2. The HSV Type 1/2 DNA PCR (whole blood) test came back negative. However, the HSV 1 IgG Type Specific AB test came back as positive with a score of 42.10, the HSV2 IgG Type Specific AB test was negative.

Questions:

1) Would a daily antiviral result in a false negative for  the HSV Type 1/2 DNA  PCR?

2) Would a daily antiviral result in a false positive for the HSV 1 IgG Type Specific AB test?

3) What does it mean that the HSV 1 IgG Type Specific AB test value is so high (42.10)?

4) I've been told that the HSV Type 1/2 DNA PCR test is the gold standard for HSV testing and can be used on different body fluids, including a blood draw. IS that correct?

5) Given the conflicting results, which one is accurate?

Thanks!

Terri Warren, RN, Nurse Practitioner
Terri Warren, RN, Nurse Practitioner
17 months ago
Of course the DNA PCR from blood is negative - HSV is almost never in blood and that test should not have been ordered.  The PCR for herpes should be done as a swab test, not a blood test.  So you have HSV 1, no question, given the IgG level but that doesn't mean the symptoms that you are having are due to herpes.  Daily antiviral therapy would not influence (and has not influenced) these results.  Your index value for HSV 1 simply indicates that you've had HSV 1 for some time - it is not new.  Your IgG test is accurate BUT again, that doesn't mean these continuing symptoms are due to HSV 1.  And that is consistent with a negative swab test on your lips.

Terri
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17 months ago
Terri,
Thank you for your response. Very good information about the PCR test. 
To your comment about the HSV 1 IgG score indicating that the infection is not new. I have 2 follow-up questions. 

1) What time frame would you guess when you say "not new"?  Weeks, months, years?
2) Could the high value correlate to the virility of the HSV virus and not indicate whether it is old or new? 

Thanks!
Terri Warren, RN, Nurse Practitioner
Terri Warren, RN, Nurse Practitioner
17 months ago
1.  It could be years.  Or anything less, but not, for example, a month
2.  No.  The index value has nothing to do with infectivity of the virus nor transmission risk.

Terri
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