False negatives on blood tests, how common are they?

Hi everyone! I was diagnosed with herpes month and a half ago. I had 2 small sores and the doctor said it was herpes. After that I got a blood test, thinking it'd show already, but it was just 2 weeks after exposure, so it came out negative. Then I went to a gynecologist who seemed pretty skeptical about it being herpes after I told her the symptoms I had (by then the symptoms had disappeared). She sent me to have another blood test, this time 2 months after exposure, she said it was enough time. They came out negative. I don't know what to think. I had 2 sores in my genital area, what else could have it been? So I don't want to celebrate quiet yet. I wonder if some of you guys had false negatives or if you know how common they are. Thanks!

After 12 weeks, the rate of false negatives for HSV1 with an IgG test is 30%, and the rate of false negatives for HSV2 is 5%.

Visual diagnosis is incorrect about 20% of the time, so you are right to want actual testing.

In my opinion, if the doctor didn't swab you during that first visit, one option is to wait until the 12 week mark to test again, or get swabbed if you ever have symptoms again. If you get another negative result at 12 weeks and don't get symptoms again, you can either assume you are negative or follow-up with a more sensitive Western Blot if you feel a need to know with greater certainty.

After 12 weeks, the rate of false negatives for HSV1 with an IgG test is 30%, and the rate of false negatives for HSV2 is 5%.

 

Visual diagnosis is incorrect about 20% of the time, so you are right to want actual testing.

 

In my opinion, if the doctor didn't swab you during that first visit, one option is to wait until the 12 week mark to test again, or get swabbed if you ever have symptoms again. If you get another negative result at 12 weeks and don't get symptoms again, you can either assume you are negative or follow-up with a more sensitive Western Blot if you feel a need to know with greater certainty.

Thank you Optimist, that information was helpful

After 12 weeks, the rate of false negatives for HSV1 with an IgG test is 30%, and the rate of false negatives for HSV2 is 5%.

 

Visual diagnosis is incorrect about 20% of the time, so you are right to want actual testing.

 

In my opinion, if the doctor didn't swab you during that first visit, one option is to wait until the 12 week mark to test again, or get swabbed if you ever have symptoms again. If you get another negative result at 12 weeks and don't get symptoms again, you can either assume you are negative or follow-up with a more sensitive Western Blot if you feel a need to know with greater certainty.

I gotta ask something else. I had both the IgG and IgM tests done. Are those 2 different tests or 2 parts of the same? I wonder because if they are different tests and they both came out negative maybe I actually don't have herpes after all.

They’re different tests. Although the IgMs are commonly used still, experts say they are notoriously unreliable and those results should be ignored. Don’t base any conclusion from the IgM. Insist on an IgG.

They’re different tests. Although the IgMs are commonly used still, experts say they are notoriously unreliable and those results should be ignored. Don’t base any conclusion from the IgM. Insist on an IgG.

Thanks Hiking girl :) May I ask something else? I was told by my doctor that to get the test I have to wait a certain amount of time from the time I had my first OB, but I thought it was from the time of exposure. Do you know about that? (sorry if the question is not understandable, I'm not from an EN speaking country)

It’s from the time of exposure (not outbreak). Some people will develop enough antibodies to test positive in less than two weeks post exposure, but it’s not until nearly the 16 week mark that virtually everyone with the virus would test positive on a blood test for it.

It’s from the time of exposure (not outbreak). Some people will develop enough antibodies to test positive in less than two weeks post exposure, but it’s not until nearly the 16 week mark that virtually everyone with the virus would test positive on a blood test for it.

Thanks for the info!