“My 7-year old daughter recently tested negative for the flu. Her friend, with identical symptoms on a daily basis, tested positive. What is the accuracy of the nasal swab flu test?” Syracuse
It's about 94-percent accurate. A pediatrician we called says it's possible that your daughter's friend got a better nasal swab. If you just stick the swab in front, and not far back into the nasal cavity you don't get as good of a sample for the flu test. It's also possible that the negative result may take time to become positive, usually in 24-hours or so - so you may want to have your daughter re-tested. If the symptoms still don't confirm flu, it may not be the flu, but a similar illness.