The count of corona virus has increased to count viruses lumped together. The common cold is a corona virus.
12-20% of colds are caused by a coronavirus. About 40-50% are caused by a rhinovirus. Around 20-30% are not any of the more common ones. In all, there are over 200 different viruses responsible for what we call the common cold.
PCR testing for SARS-CoV-2 detects the presence of SARS-CoV-2’s E gene, which codes for the envelope that surrounds the viral shell, and the gene for the enzyme RNA-dependent RNA polymerase. That’s looking at genes specific to SARS-CoV-2 and not shared with any other known virus. The biggest problem found is that viral proteins linger in a recovered patient’s system for some time (in some cases weeks after recovery). However, the chances of mistaking a different coronavirus for SARS-CoV-2 are pretty small since the things tested for have only ever been observed in SARS-CoV-2 based on the genetic sequencing of it that was done and released to the world back in January.
Not quite. Maybe 5% of common cold due to a corona virus. Most due to rhinoviruses.