If you know you had H1N1,then you can't get it twice in the same season. However most of our office kits are not specific for H1N1 but for influenza A/B. therefore, unless your son had the seasonal flu mist and was tested within two weeks, he may have had two different flu strains. Testing too close to the mist gives a false positive.
Wayne Yankus, MD, FAAP
expert panelist: pediatrics