COVID-19 was identified due to multiple cases of pneumonia of unknown origin arising in the same area. In the couple of months it has been spreading, it’s not been particularly deadly such that I doubt many people would notice at all if it weren’t for the fact that we’ve been able to identify it as a new strain of virus not previously catalogued and we have a test to see if you’re infected with it. This leads to the question of what it would have been like if it had happened in 1980, 1900, 1800, or 1600, or whenever. Certainly the speed of global travel these days has allowed it to spread very quickly compared to previous eras, but it’s not like there was no intercontinental travel in prior eras, and most people seem to fight off the infection just fine such that, especially with laxer hygiene procedures of the past, it wouldn’t be too hard for it to have eventually spread all over the globe.
Given from what I read that it doesn’t really seem much different from other similar diseases other than being slightly more lethal and apparently much easier to transmit, I would imagine that it took a lot of modern understanding of virology to conclude that we had something new and were able to isolate it and develop a test for it such that we could test people all over the world and see just exactly where it had spread. It doesn’t seem like you’d really be able to tell from the excess number of pneumonia deaths all that quickly that you had something new on your hands, and without having the very thorough catalog of viruses that we have today, it seems to me like it could just have been chalked up to whatever other diseases were endemic in the past.
What level of technology has been required to see that this is a new threat and not the same thing that’s always been going around?
They were certainly able to figure that out - and I mean at the time - for the spanish flu.
Here is an article about where the Spanish Flu was first observed and the doctors observing it certainly noticed something new was going on.
Newapaper article about that research, it mentions apart from the aforegoing that the spanish flu was also noticed independently in many other places as a new disease.
A lot of work has been done on the history of influenza pandemics. Records of generalised sicknesses that are not generally fatal but which go through a population quickly and boost death rates can be found through direct records and proxies like burial registers. Usually for pandemic influenza they are first clearly picked up when they hit Russia or the Mediterranean and their progress westwards can be tracked. This transmissable spread was generally recognised without necessarily having much idea about what the causes of this were.
Recognising pandemic influenza as distinct from endemic seasonal influenza happens slowly, but attempts at systematic description start appearing from about the mid-18th century. However, you have to wait almost 150 years before really good epidemiological studies come in around the late 19th century. By the 1918 infectious disease epidemiology was solid science and its public health dimension fairly well understood. That’s why we have such good numbers and almost daily tracking of its emergence and spread (at last in western societies - many places remain epidemiological black holes until very recently). It still took a few decades before the influenza virus was isolated in the mid-1930s.
For the OPs question, I think the effects of coronavirus are similar and general enough to those you’d get from influenza, that until the 1930s it would have been likely to have been mistaken as being another pandemic recurrence of the same thing*. Only when you can get a direct look at the viruses concerned in the 1930s can you determine the difference.
In fact some of these earlier influenza epidemics may have actually been coronaviruses. We simply don’t know.
I went looking for the related question, to see when the “epidemic respiratory syndrome in wuhan” was first identified as a coronavirus, and how it was done, but I don’t know what questions to ask.
Anyone?
Hans Christian Gram developed Gram Staining in 1884. It makes Gram Positive bacteria easier to see, which makes identification easier, and encouraged further development of staining. The idea of a virus was described in 1892, identifiable as ‘not a bacteria’, partly because bacteria were better understood when they were easy to find. The understanding of what a virus does developed from around 1915, with the description of bacteriophages - viruses that infect bacteria. In the 1920’s, we had an understanding that germs caused sickness, and we would have been able to say that the germ causing the novel respiratory syndrome epidemic was not a bacteria, so it would be a virus, and we would be able, in a research laboratory, to separate it and see its effect on cells, but for practical purposes, saying that the flue was “a virus” had no effect on identifying infection.
The status of NCOVID-19 as a “big problem” follows from the development of vaccines (from 1796) and oral antibiotics in the ?? 60’s ???. NCOVID-19 is a big problem because it can’t be treated with antibiotics or an existing vaccine. If, as appears possible, its natural course is to mostly kill old people, it might not have registered as a big problem before the development of vaccines and antibiotics made it special as an “untreatable” respiratory illness.
Identified as a pathogen in the 1880s but noticed as being really odd since it wasn’t filterable. I.e., it was really, really tiny. Finally analyzed in the 1930s when “virus” as a scientifically specific category came to be. (Vs. the vague use of the term before, such as with Spanish flu and such.)
So post-30s for a proper understanding of these diseases. But “good enough to work with” understanding by the late 1800s.
It doesn’t take much technology other than germ theory and the ability to diagnose pneumonia (which I think you can do decently well with a stethoscope) to recognize this.
Electron Microscopes date from about 1940, and the first “coronavirus” was described around 1960, the name coming, I think from an electron microscope image.
I’ve seen a suggestion that NCOCID-19 was sequenced by the Chinese around mid-January, following a November outbreak. SARS (2003) was sequenced around April, in Italy, following a November outbreak in China. Sequencing dates from the 1970’s but was much slower. and more expensive then. I’ve got an idea that SARS was the first epidemic to sequenced while the epidemic was still spreading. (I’m old enough to be really impressed by the quality of both the medical research and the English-language research papers coming out of China this time around.)
So in 1960 we would have been able to identify the new disease agent as “a coronavirus” in a research lab, but it still would have been clinical observation to call it “a new coronavirus”.
I think there’s a misplaced focus on technology in the OP’s thinking. Again, you don’t need the technology to isolate the virus to know that it’s new. A bunch of people all getting sick with the same symptoms in a way they generally didn’t before, and that sickness spreading in a way consistent with an infectious agent is sufficient. People don’t all of a sudden start getting really sick like this from previously extant diseases.
The initial alarms raised in China were due to observed symptoms, not high-tech microbiology.