Quote from RhiaRN75
Is anyone else seeing something similar to this? Pts negative on flu tests but still very ill?
Yes. They were also negative by PCR. But, positive for H1N1 at autopsy...
If you look at some of the cases in our threads on the severe cases this has happened at least a few times.
One of our frequent flyer psych patients was admitted to ICU two days after her last discharge from our unit. She was negative by the rapid test as well as by PCR. The docs suspected flu, and she was indeed positive at autopsy.
Why are the PCR's negative also, I wondered? Maybe the answer lies in the link below. It is an unproven theory at this point, but in light of the recent news reports on viral mutation released today, I am beginning to wonder if this speculation might have some truth to it.
Quote from www.recombinomics.com
These mixtures could be generating false negatives in cases where the level of D225G is high. Virus with D225G would quickly move to the lower respiratory tract and the low levels of wild type in the upper respiratory tract would be cleared by the host's immune response. These patients would be infected and seriously ill, but the reduction or absence of virus in the upper respiratory tract would test negative. The CDC has warned that rapid tests have a sensitivity of 10-70% . Thus, in some circumstances only 10% of H1N1 infected sample test positive. This low sensitivity seems to be somewhat linked to H1N1 samples.
The negative data would lead to more testing for other respiratory viruses, which may explain the data reported for rhinoviruses in the Philadelphia area. No unusual strain has emerged, suggesting that the viruses may simply represent opportunistic infections associated with the H1N1 infection that is testing negative.
The detection of such opportunistic infections is similar to results generated when SARS first emerged. Since there was no direct test for the SARS CoV initially, many additional tests were run, and different labs would find different candidate respiratory viruses. However, after the SARS CoV was discovered and developed into a diagnostic test it was clear that SARS was causeed by SARS CoV and the other viruses were just opportunistic passengers.