The viral RNA obtained from a patient with influenza symptoms was analyzed and the results for a real-time PCR were negative for the influenza A virus and positive for the AH1NI virus.
The positive and negative control were fine.
Basicly it is imposible , I recomend you to repeat the test and make a double check of the negative and positive control. what about other cases?
In logical terms, it is indeed impossible because A/H1N1 is an influenza A virus. If all the assay controls are OK (and this includes being sure that the primers used for "influenza A virus" and "AH1N1" are still good) then it's most likely telling you that the virus the patient was infected with has changed so that one of the primers used for "influenza A virus" no longer binds to the viral RNA. In the multiplex diagnostic screen I used to use, the generic flu primers were chosen to match conserved regions of segment 7, which changes more slowly than some other parts of the viral genome, but it can happen. If you see this again with other samples then it might well be telling you that the assay needs to be updated.
Paul
PS - sorry for all the multiple posts - the RG forum code seems to be struggling...
Thanks for your suggestions :)
@Paul Digard, probably you are right about the virus changed because it happened with two more patients. Anyway, the sequencing will have the answer.
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