Chance of HSV2 igg false positive after previous negative

[Nervouscurious]

Hello

I have previously gotten tested for HSV2 3 times as part of full STD panels, when starting a new relationship, etc.

I have always gotten negative <.02

I recently read about false positives particularly between 1.1-3.5 and also read that this may be caused by having a protein in the blood of similar weight that trips the test.

This scares me as I really don’t want a false positive. So my questions

1. If I have gotten <.02 negatives more than once, does this mean I don’t have the false positive protein and will never get a false positive ?

2. If I was someone who is prone to false positives, would I have seen that on previous testing ? Or is each time a separate 5% chance of false positive based solely on imperfect testing ?

3. I live in FL, if I did ever get a False positive, could I use AnyLabTest now or a general physician to send my blood for a WB?

Thank you so much
I don’t want to stop my practice of full panel testing when starting a new relationship, but also don’t want to risk 3-5% false positive everytime I test

[Terri Warren]

1. Correct. Your value is negative – you don’t have a positive, false OR real. But that doesn’t mean you would never get a false posiive.
2. Yes, I think you would have seen a low positive in the past.
3. yes, most certainly, I could order that for you to be drawn in Florida, if you ever get a positive value that falls between 1.1 and 3.5

Terri

[Nervouscurious]

Thank you for the reply, as a follow up:

1. What is the percentage of people who get indertiminate WB results?

2. So you think if I’ve had all negatives up to this point, I’m biologically less likely to get a false positive in the future ?

[Nervouscurious]

To further clarify follow up question 1:
I am trying to find the likelihood of someone getting a false positive ELISA And then getting repeated permanent indeterminate WB results?

Basically, I’m trying to see if it’s likely that current testing could ever leave me in permanent HSV status limbo, because then I maybe won’t even pursue testing

Thank you

[Terri Warren]

1. In my experience, almost all of the false positives that I see (perhaps 7% of all who test) are in people who have low positive index values – whatever is tripping the IgG test is also showing up as a single protein in the western blot.
2. Yes
I’m confused by this question – as you report, you don’t have a positive ELISA
The University of Washington guidance about indeterminates is if you have one and have not had sex in a year, you should consider yourself NEGATIVE. And if you have two indeterminates within 3 months of each other you should consider yourself NEGATIVE. So we definitely have ways of dealing with indeterminates to get a final answer.

This is your final post on this subscription. If you have more questions, feel free to renew

Terri

• This reply was modified 4 years ago by Terri Warren.

[Nervouscurious]

Hello Terri I purchased more questions so I could clarify

1. What I was trying to ask in one of my previous questions is:
Of the people who get a low positive ELISA, how many of those people get indeterminate WB? I read 20%… so 1/5 people can’t get a false positive rules out by WB?

2. I will clarify my situation so you can possibly give me a recommendation:

I I have gotten 3 herpes ELISA test in my life, as part of routine testing or start of a new relationship…all fame back <.02 negative.

My most recent and third test was a month ago after a possible exposure. But I started reading online and realized I had gotten it 6 weeks too early.
So now I want to go back and get retested at 12 weeks post exposure….

The reason I’m now worried is because u didn’t ever know about false positives and inaccurate testing until I started reading online last month

Should I get tested 12 weeks post exposure ?
Or is it too risky? I don’t want to go through the emotional distress of getting a positive, waiting for a WB, etc

Overall I’m just not sure if I should be testing after a possible exposure with no symptoms

Any thoughts?

Thank you for your time.

[Terri Warren]

I do not think it is too risky to test, no. In my practice about 8% of testing results in an indeterminate – most in low positives.
You could just skip testing if you can relax about the negative IgG – it only misses 8% of HSV 2 infection compared to the western blot. Can you do that?

Terri

[Nervouscurious]

Hello Terri

I am asking about percent of Indeterminate Western Blot

Are you saying the Western Blot has a 8% indeterminate rate?

————————

Also
I do trust the iGG test. But I need to retake it because it wasn’t long enough after exposure.
Even after 4 months,are you saying that the ELISA misses 8%? I’ve read numbers of 96%+ sensitivity ?

So just to summarize

1. You are saying the Western Blot has an 8% indeterminate rate?

2. You are saying at 4 months the ELISA IGG has an 92% sensitivity and will miss 8% of true positives ?

This isn’t in line with what I’ve read so I just wanted to clarify I was talking about Western Blot in the first question. And ELISA IGG At 4 months for the second question .

Thank you! I think I misrepresented my previous question so I hope this clears it up, because now I’m confused about the numbers

Thank you!

[Nervouscurious]

I’ll use my final question to make sure I’m explaining my question right because I think we are saying different things:

What I thought:

ELISA iGG At 4 months is about 96% sensitive and will only miss 4% of positives

About 6-8% of ELISA IGG are positives, with about half being false positives

Of the people who get a low positive and then take the Western Blot, about 20% of those people will get indeterminate Western Blot

———————-

What I think you are saying:

ELISA IGG is 92% sensitive at 4 months

8% of Western blots come back indeterminate

Please let me know what is correct in the above !
Thank you very much for your time
If that’s cleared up that’s my final question !

[Terri Warren]

Yes, I would say that about 8% of the time when people take the western blot, they obtain an indeterminate result for either HSV 1 or HSV 2. That might be a little high – it’s not a statistical thing I have analyzed specifically. This almost always happens in people who have low positive results on the IgG test. I rarely see an indeterminate in someone who has tested negative on the IgG
yes, compared to the western blot, the IgG test misses 8% of HSV 2 and 30% of HSV 1.
If you have questions about these numbers, I will refer you to a article that we published in 2017 on PubMed.

This is your final post on this subscription. If you have more questions, feel free to renew

Terri

[Nervouscurious]

Hello Terri
Thanks so much for clearing that up!

I purchased more questions as there are a few things I want to clarify

I have read so much conflicting information on this. From Medhelp (Drs Hook and Handsfield) and this forum…but the topic is prior HSV1 and how much it delays HSV2 seroconversion. I really hope you can clarify because it’s stressful to decide when to get my final test…

All questions below pertain to ELISA IGG

1. If you have prior HSV1, how long is HSV2 seroconversion delayed with ELISA IGG? I trust whatever you say, but I’d love to see any studies because I’ve read everything from “not at all” to up to a month …

2. How accurate is ELISA IGG HSV2 At 12 weeks WITH PRIOR HSV1?

3. How accurate is ELISA IGG HSV2 At 16 weeks WITH PRIOR HSV1?

4. How likely is it that prior HSV1 delays HSV2 seroconversion past 16 weeks?

5. Why are there so many discrepancies and conflicting information regarding prior HSV1 and seroconversion ?

6. Is there really any realistic difference between 14,15,16 weeks (with prior HSV1)? I hate waiting

7. The reason I am asking all this and why I am suffering is: I am at the 10 week point after 2 unprotected exposures. I am trying to figure out if it’s worth it to wait till 12 or 16 weeks… again, I have no symptoms . I’d like to test at 12 weeks and be done AND MENTALLY FREE…but I will wait 16 weeks if needed
I just want to know how long (with prior HSV1) I have to wait to test to be conclusively done with this ?

So:
-2 unprotected exposures with known HSV2 partner
-no symptoms
-I have prior HSV1

Thanks again so much for your time
In a few weeks this will be over for me! But I just need to know when to test

[Nervouscurious]

Adding one more
8. Should I wait LONGER than 16 weeks due to prior HSV1 ? I Didn’t address that above

Also, if your answer above is to wait the full 16 weeks. Can you please tell me the difference in accuracy at 12vs16 weeks WITH PRIOR HSV1? So I can make the decision if it’s worth it to wait an extra month

Thanks again!

[Terri Warren]

No, 16 weeks is fine.
I think you will not get greater clarity at 16 weeks

1. If you have prior HSV1, how long is HSV2 seroconversion delayed with ELISA IGG? I trust whatever you say, but I’d love to see any studies because I’ve read everything from “not at all” to up to a month …

This has only been studied a little so the answer is not clear but I would say perhaps a couple of weeks.

2. How accurate is ELISA IGG HSV2 At 12 weeks WITH PRIOR HSV1?

3. How accurate is ELISA IGG HSV2 At 16 weeks WITH PRIOR HSV1?
I would say the answer to both compared to the blot is 92%

4. How likely is it that prior HSV1 delays HSV2 seroconversion past 16 weeks?

Extremely unlikely

5. Why are there so many discrepancies and conflicting information regarding prior HSV1 and seroconversion ?

Because it has not been studied well

6. Is there really any realistic difference between 14,15,16 weeks (with prior HSV1)? I hate waiting

I don’t see a reason to wait

7. The reason I am asking all this and why I am suffering is: I am at the 10 week point after 2 unprotected exposures. I am trying to figure out if it’s worth it to wait till 12 or 16 weeks… again, I have no symptoms . I’d like to test at 12 weeks and be done AND MENTALLY FREE…but I will wait 16 weeks if needed
I just want to know how long (with prior HSV1) I have to wait to test to be conclusively done with this ?

If you would feel more secure testing at 16 weeks, then do that.

Terri

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