The Body: The Complete HIV/AIDS Resource
Follow Us Follow Us on Facebook Follow Us on Twitter Download Our App 
Professionals >> Visit The Body PROThe Body en Espanol
Ask the Experts About

Safe Sex and HIV PreventionSafe Sex and HIV Prevention
Rollover images to visit our other forums!
Recent AnswersAsk a Question
  • Email Email
  • Glossary Glossary

causes false positive elisa

Oct 27, 2007

Hi Dr. Frascino,

I tested positive on an ELISA test three weeks ago about October 4th. It was a routine check up not really concerned because I don't do IV drugs, or any other drugs for that matter. All my sexual encounters were protected, no condom break at all. I've had sex with 8 guys in the past 3 years. 4 came inside of me WITH a condom. 4 of them used a condom but came OUTSIDE of me. That's why I refused to believe that I'm HIV positive even though I tested positive in the ELISA test. I had to call back in two weeks to make an appointment and hear the results of my confirmatory test. I DIDN'T: partly because I was afraid but also because I've never had unprotected sex, and had no real reason to believe that I was at risk. Well sometimes ignorance is bliss... so I'm kind of just having faith that the confirmatory test was negative but I'm too nervous to find out. I even threw away the id number they gave me (I tested anonymously) because I was so confused, frustrated and afraid.

I was doing some research about possible causes for false positive results on the ELISA test and I came up with a website that had a list of possible things that may cause false positive readings. Here is my situation.

I'm a nursing student. The last time I got tested was 3 years ago and it was negative. But exactly three years ago I started clinicals in different sites exposing myself to different patients. I know there could be some cross reactivity of antibodies on the ELISA test.

1. could my body have produced different antibodies based on my exposure to sick patients for the past 3 years (no needle stick incidence) and this may have caused a cross reactivity?

2. I had my hep B series done 4 years ago. Two months ago I had to get a hep b titer test which came back positive meaning I'm immune to the Hep B virus. Now my question is: I tested negative on my first ELISA test 3 years ago. But that was 1 year after I had finished my Hep B series. Can the hep b vaccination still cause false positive results on an ELISA 4 years after?

3. On the day of the exam I had not been sleeping well for the past week so I had a bit of a cough or upper respiratory infection which is also listed as a cause for false positive on ELISA test.

4. Back to immunizations I had my last MUMPS shot about 6 months ago. AND I had a TDaP (tetanus, diptheria and pertussis) vaccination 4 months ago. Tetanus is also on the list of things that may cause false positive on ELISA. Could this also be a possibility?

5. Also after going through the whole crying and rationalizing I remembered that the counselor (not a nurse or physician) but a counselor had pricked my finger WITHOUT cleaning the skin with an alcohol swab. Could the bacteria on my finger have affected the results because the blood was contaminated?

Thank you so much,

Your response would be greatly appreciated.

Response from Dr. Frascino


You're a nursing student??? From the way you are behaving I would strongly suggest you hand in your white shoes and find a different career. You'll never become an effective nurse based on the way you are handling this situation!

To answer your specific questions:

1. No, absolutely not. That is not how the immune system works.

2. No, absolutely not.

3. A cough and URI are not causes for a false ELISA test.

4. Extremely unlikely at best.

5. No, absolutely not.

If indeed you've had essentially no HIV risk, then I agree your chances of being HIV positive are essentially nonexistent. This would suggest your positive screening ELISA was indeed a false positive. However, your decision not to call back for your confirmatory and follow-up tests, because you were afraid to hear the results, doesn't make any sense whatsoever. "Just having faith the confirmatory test was negative" is equally illogical. Ignorance is not bliss! Just look at Dubya. You just can't get any more ignorant than that ignoramus. And his impressive lack of smarts has caused anything but bliss! You report being confused, frustrated and afraid. You've been spending time reviewing causes for false positive ELISAs on the Web and now you're writing into HIV information Web sites. It doesn't sound to me like your life is blissful in the least.

I absolutely agree with you that your screening ELISA may well have been a false positive, but you won't know that for certain until you get retested. Trying to ignore that result or merely having faith the confirmatory test would be negative won't cut it dearie. Stop behaving like a ninny and go get tested. There really is no other option. If you don't, you'll continue to dwell on this and drive yourself into the locked psych ward. You should also learn from this entire experience, if indeed you do become a health care worker. Understanding how irrational fears can cause patients to make irrational health care decisions is an important lesson. However, as mentioned above, I tend to doubt nursing is the correct career option for you.

Dr. Bob

Masturbation using a plastic baggy

  • Email Email
  • Glossary Glossary

 Get Email Notifications When This Forum Updates or Subscribe With RSS



This forum is designed for educational purposes only, and experts are not rendering medical, mental health, legal or other professional advice or services. If you have or suspect you may have a medical, mental health, legal or other problem that requires advice, consult your own caregiver, attorney or other qualified professional.

Experts appearing on this page are independent and are solely responsible for editing and fact-checking their material. Neither nor any advertiser is the publisher or speaker of posted visitors' questions or the experts' material.

Review our complete terms of use and copyright notice.

Powered by ExpertViewpoint