Recently, in order to further improve the prevention and management of new coronavirus, and to effectively improve the standardization and homogenization of diagnosis and treatment, the National Health Care Commission and the State Administration of Traditional Chinese Medicine organized experts to revise the "New Coronavirus Pneumonia Treatment Plan (Trial 8th Edition Revised)", resulting in the "New Coronavirus Pneumonia Treatment Plan (Trial 9th Edition)".

In this adjustment, there are further adjustments to the "Discharge Management Criteria" and "Discharge Criteria", from the fourth point of the discharge criteria "two consecutive negative rapid tests for new coronavirus nucleic acid in respiratory specimens (sampling time at least 24 hours apart)." It was changed to "two consecutive novel coronavirus nucleic acid tests with Ct values of N gene and ORF gene ≥ 35 (fluorescent quantitative PCR method with a cut-off value of 40 and a sampling time interval of at least 24 hours), or two consecutive negative novel coronavirus nucleic acid tests (fluorescent quantitative PCR method with a cut-off value below 35 and a sampling time interval of at least 24 hours). "

This provides a clearer and more specific standard for patient care, effectively reducing the phenomenon of false-negative cures, as well as avoiding the risk of transmission caused by hospital discharge repositives.

So, what does it mean to have a Ct value ≥35 for both the N gene and ORF gene in the new rapid nucleic acid test? What is the Ct value of the new rapid nucleic acid test? Next, we explain it in detail.

N gene and ORF gene are the target genes of the current New Coronavirus Nucleic Acid Rapid Test, and they are also the specific fragments of New Coronavirus nucleic acid. New crown nucleic acid rapid test is to extract RNA after taking viral nucleic acid by pharyngeal swab and nasal swab, and then add primers four nucleotides, enzymes and some other reagents to the sample for sequence amplification. If the sample contains virus, the synthesis reaction can continue again and the sequence can be synthesized.

Fluorescence can be excited by the combination of fluorescent dyes, and the fluorescence phenomenon can be seen by the instrument. The Ct value is a reflection of the fluorescent group, when the more fluorescent groups, the higher the surface virus content, the smaller the Ct value, and vice versa. The smaller the Ct value, the more viral content in the sample and the more infectious it is; the larger the Ct value, the less viral content in the sample and the less infectious it is.

So will lowering the Ct value criteria lead to risk?

The adjustment is based on the characteristics of the currently prevalent strain Omicron, which can effectively respond to the transmission characteristics of the Omicron strain. a Ct value of ≥35 is no longer possible to isolate live virus, so this is not a lowering of the standard, but an adjustment based on the reality.