> Less likely is an emerging infectious disease. The most concerning possibility is something novel or highly unexpected.
What's the difference between an emerging and novel disease?
What's the difference between an emerging and novel disease?
Novel is new. Never before seen. SARS-Cov-2 was a novel virus.
Emerging means identified but changing [1]. The Covid variants were EIDs. So are antibiotic-resistant strains.
[1] https://en.wikipedia.org/wiki/Emerging_infectious_disease#Cl...
SARS-CoV-2 response could be as rapid as it was in no small part because two decades of research on SARS-CoV more or less was applicable, and looking at genetic similarity alone contemporary variants of SARS-CoV-2 are now more different from the original strain isolated in Wuhan than that strain is different from SARS-CoV.
So was the threat from pathogenic Coronaviruses really novel? To a degree, and depending on what aspects one chooses to emphasize maybe.
Also, I'd say the pathogen itself doesn't necessarily need to do the changing in the context of emerging diseases. I'd take it to mean they have potential to become more prevalent or have a more significant impact, but that could easily also be due to changes in conditions, including human behavior.
Are you saying this as an epidimeologist? (I'm not an epidimeologist. I've only studied the math.)
> looking at genetic similarity alone
Epidimeology is the study of disease in a population. You can't look at the virus alone.
The dividing line between emerging and novel is brighter than between emerging and existing. It has to do with whether the population has pre-existing immunity. SARS-CoV infection conferred no immunity to SARS-CoV-2. Getting infected with the Alpha variant, on the other hand, conferred immunity to Omega.
> I'd say the pathogen itself doesn't necessarily need to do the changing in the context of emerging diseases. I'd take it to mean they have potential to become more prevalent or have a more significant impact, but that could easily also be due to changes in conditions, including human behavior
Literally in the Wikipedia. "EIDs may also result from spread of an existing disease to a new population in a different geographic region, as occurs with West Nile fever outbreaks."