The Eclipse Period: When Viruses Go Undetected

The most important difference between bacteria and viruses is the way they multiply. Bacteria have cells and can multiply only by themselves. Viruses, on the other hand, are not cells and cannot multiply on their own. During the period between the time a virus enters a cell and the time it multiplies and emerges from the cell, there is a period when it appears as if the virus does not exist. This period is called the "eclipse" or "incubation period" and lasts from a few hours to a dozen hours, depending on the type of virus and host cell.

What happens during this time is that the parent viral particles are disassembled in the cell and the offspring viral particles are assembled. Therefore, in the case of exposure or infection, no matter how sensitive a gene amplification test (PCR, LAMP, etc.) is the next day, the likelihood of detecting the viral gene is extremely low. Subsequently, the virus becomes detectable only after the proliferating child virus is released from the cells. From this point on, the virus explodes. It is truly the calm before the storm.

References

• 『ウイルスの意味論――生命の定義を超えた存在』山内 一也
• 「コロナ禍」： 収束しても油断は禁物 --- そもそもウイルスとは？