Is A Negative IgM Result At 18 Days Post Sexual Exposure Accurate?

Posted on Sun, 25 Mar 2018

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Sun, 25 Mar 2018 Answered on

Tue, 9 May 2023 Last reviewed on

Question : hello. I had a sexual event with a women March 1st. I had blood work done on match 19th to determine if I had herpes. I currently have no lesions that I believe to be herpes and I've seen many doctors who have said the same thing. I'm going to get retested on Monday because of the results. I got negative for hsv1 and 2 on the igm report ( which I was told is for recent infections ) however I got equivocal of 1.02 on the igg test. my doctor told me since my sexual relation was 18 days before the test and that since my igm was negative for hsv2 it's likely that I don't have it even with the equivocal result. what do you think? I heard a western blot test is the best way to determine for sure

Answered by Dr. Dr. Monika Dede (2 hours later)

Brief Answer:
I suggest to do a second test HSV 2 IgG after 3 months.

Detailed Answer:

Hello,

It is a good news that you don't have lesions as usually the presence of them can definitely define the diagnosis.

You should know that having an equivocal result of HSV2 IgG doesn't mean that you are positive specially after 18 days from exposure. I suggest to do a second test HSV 2 IgG after 3 months.

It is rare for a second test to be equivocal again. If it is, then you should follow-up with a western blot test, which is more sensitive and the gold standard.

I hope my answer helps you. Let me know if I can assist you further.

Regards,
Dr. Monika Dede
Infectious Diseases Specialist

Above answer was peer-reviewed by : Dr. Raju A.T

Follow up: Dr. Dr. Monika Dede (39 minutes later)

ok do you think going Monday march 26th is too soon? I'm very anxious about this. in your opinion since the igm was negative and igg was equivocal, logically speaking shouldn't it make sense I don't have it ? Because igm tests for recent infection and I had the encounter March 1st. my last encounter before that was in December so if I got it then my igg would be positive.

Answered by Dr. Dr. Monika Dede (22 hours later)

Brief Answer:
If you have a negative IgG after 3 months means you are not infected.

Detailed Answer:

Hello,

Having a negative result of IgM means that you don't have a recent infection from this exposure (march encounter)but usually we don't use it.

Usually, according the recommendations, we use HSV 2 IgG test after 3 months from exposure to define the presence of infection.
So, if you have a negative IgG result tomorrow, 3 months from exposure (from december encounter) means that you are not infected from this exposure.

I hope my answer helps you. Let me know if I can assist you further.

Regards,
Dr. Monika Dede
Infectious Diseases Specialist

Above answer was peer-reviewed by : Dr. Raju A.T

Follow up: Dr. Dr. Monika Dede (42 minutes later)

well im more concerned about the one in march. the igm was negative for this , do you think going a month after the encounter is too soon? I don't think I can wait 3 months the anxiety is killing me

Answered by Dr. Dr. Monika Dede (23 hours later)

Brief Answer:
Please don't worry!

Detailed Answer:

Hello,

As I said above, I think that having a negative result of IgM is a good news but just to be calm it is better to do HSV 2 IgG after 3 months from this exposure (march) as a conclusive test.

I hope my answer helps you.

Regards,
Dr. Monika Dede
Infectious Diseases Specialist

Note: Consult a Sexual Diseases Specialist online for further follow up- Click here.

Above answer was peer-reviewed by : Dr. Raju A.T