I have recently seen and heard people and news outlets quoting numbers showing that the US now has more diagnosed SARS-COV-2 cases than Italy or China. That is actually, factually, correct, but not necessarily accurate.
I am neither an expert on infectious disease nor an epidemiologist, and everything I say needs to be taken with a grain of salt. These are, of course, my own personal lamentations, not official opinions or by any chance or reason guidelines – please listen to your local authorities and healthcare providers regarding the latest guidelines in your area and turn to your disease control website for more information (CDC in the US, ECDC in Europe).
This is a very serious disease! And it’s hitting us bad since we have no immunity to it and for other reasons (urbanization, globalization, etc.). *PLEASE* listen to your local authorities, practice social isolation, respect the needs of others and take care of yourself, your families and communities, stop the spread and make sure the weaker individuals in our society make it through this.
Help healthcare in flattening the curve so that we don’t get overrun and are able to keep taking care of those who will eventually need it.
Everything below does not take away from what I said above.
As far as I can tell, China only tested people that had a fever, then had CT findings (they used CT for screening, not molecular tests), then tested directly those people that had both. Remember that this was the beginning of the plague and tests were less available and only being developed. The US is testing a lot of people without fever and mild symptoms for other reasons (not at hospitals so much but in the outpatient/drive-in settings), so it’s not surprising that numbers are higher.
The US has five times the population of Italy. If you want to compare raw numbers, you should probably compare the US to the EU. Or, just taking the five first countries in that list (Italy, France, Spain, Germany & The UK), using the ECDC numbers from 3/25, the US has 85,991 cases and these combined five have 219,828 cases.
Raw numbers are meaningless, they look nice on maps but they mostly cause panic and sell papers. Benjamin De’Israeli said before:
“There are three kinds of lies: lies, damn lies, and statistics”
Numbers need to be put in context, but that is hard even for the experts in this evolving situation.
We do know this: our goal needs to be to flatten the curve. The important numbers don’t only include the number of people infected, but the rate of infection, the availability of hospital and ICU beds, the availability of healthy healthcare staff, equipment, PPE, etc.
If we take no precautions, the rate of infection will be so high that healthcare will be overrun and when that happens – we get what happened in Italy. And the only way to do that is by practicing social distancing, limiting our contact with other people and objects to slow down the spread. If your job is not absolutely essential or can be done from home, you should stay home. Call your doctor before driving into an ED or UrgentCare as a lot of facilities now have fantastic options for telemedicine and can help you with initial screening over the phone, FaceTime, video chat, etc. If you’re at risk, you should follow more strict social isolation and precautions.
The CDC has a dedicated website for COVID-19. This should be the best source of information. Most importantly, it has guidelines that update daily and are tailored for different populations. Find it here:
https://www.cdc.gov/coronavirus/2019-ncov/index.html
Stay Sane and Healthy! Remember that we’re all in this together.
Image from official CDC web page, accessed 03/27/2020 at 9am. Source: https://www.cdc.gov/coronavirus/2019-ncov/cases-updates/cases-in-us.html
Statistics from ECDC official web page, accessed 03/27/2020 at 9am and are true to 03/25/2020. Source: https://www.ecdc.europa.eu/en/geographical-distribution-2019-ncov-cases
CDC official COVID-19 web site: https://www.cdc.gov/coronavirus/2019-ncov/index.html
ECDC official COVID-19 web site: https://www.ecdc.europa.eu/en/novel-coronavirus-china
McNeil Jr., Donald G. “The U.S. Now Leads the World in Confirmed Coronavirus Cases”. The New York Times. March 26, 2020. Accessed 03/27/2020. https://www.nytimes.com/2020/03/26/health/usa-coronavirus-cases.html
Oded March 28, 2020 at 5:39 AM
Great post!
I saw this analysis – https://aatishb.com/covidtrends/ – where they graph (weekly average of) new cases vs. total cases per country. It’s animated by time so you can think of it as a 3 dimensional graph where the third dimension is time representing time… Anyway, looking at that graph, while your point on US being larger than European countries there for had more cases, still stands, it dies look like US is still on an upwards trajectory while European countries are starting to drop off.
Amnon Berger March 28, 2020 at 9:07 AM
Looking at new over existing cases is an interesting approach. I still think the best estimation here would be a Kaplan-Meyer graph, that takes into account the population at risk and then calculates event rate (e.g. infection, death, survival, etc). It’s hard to generate because you would have to estimate the population at risk – which is tough (unlike with study population where n is small and known).
This is one way of using numbers in context, which is what I was advocating for. And it’s exactly what I was pointing at in my post – it’s the rate we should be worried about. And if you look at other countries, nearly everywhere in the world is progressing at the same rate, which is the nature of this pandemic. Only few places, such as Singapore and South Korea, which took extreme measures – probably owing to their SARS experience – were able to slow the rate down.
And this is exactly why I am pleading everyone to maintain social distancing and listen to local and government authorities. The more we comply as individuals, the rate will go down (hopefully), and the less extreme measures will be needed by governments.
Hadas March 30, 2020 at 11:40 AM
Clear and enlighening