There was a significant discrepancy between the results of virus culture and RT-PCR testing in our study, with many more frequent positive results from RT-PCR. Possible explanations for this finding include virus degradation from breaks in the cold chain during sample collection, storage, and shipping; the greater sensitivity of RT-PCR relative to culture; and, in the case of the saliva specimens, possible virus inactivation by salivary enzymes. The less-than-ideal storage conditions of the specimens in the isolation ward immediately after acquisition and the fact that even the nasal blood from 1 patient was culture negative suggest that some virus degradation indeed occurred. Nevertheless, we cannot exclude the possibility of a true absence of viable virus in the original samples. We hope to be able to repeat this study in the future with better maintenance of the cold chain to resolve this question.
It appears the cold chain was not maintained, thus the breakdown of virus in at least some of the samples is anticipated.
Bottom line, where results are positive, they are positive, where negative, they are inconclusive because the samples were not handled properly.
I would be reluctant to stake my life on any negative results obtained by the study.
I agree. I think there are other factors that the authors specifically did not study like human susceptibility. We basically don’t know the pathways and virus load needed to contract the disease.