Since the trend is once again toward increasing case rates, I’ll just put out there a bunch of graphics and tables so you can see what’s happening.
Arizona Zip Code Case Counts
Since I live in Arizona and have followed it more closely than any other state, it might be interesting to see the trends in Arizona. My suspicion is that other states are seeing similar trends. Our first trend turns out to have been relatively low case rates and high deaths due to infections in communities at higher risk, such as our nursing homes and reservations. During this time period the whole state went into lockdown. Case rates were relatively low and constant throughout this lockdown period and a few weeks after. The second AZ trend was the summer outbreak, which I’m quite confident occurred in conjunction with a large outbreak at the same time in Mexico. During this time, we saw cases increase polynomially and mask rules were implemented across the board but did not slow down infections. If you look back in time on this site, you’ll see that the most heavily hit communities during this timeframe were the ones that had significant ties to Mexico (SW Phoenix, S. Tucson, Border Region). Now we’re in the third outbreak and what we’re seeing is the virus sweeping through the communities not touched during the first two outbreaks. Though case rates are increasing, death rates remain relatively low.
In the above two diagrams, note that none of the heavily-infected zip codes from the summer are present. These are generally areas that haven’t been hit hard yet. This makes me suspect that in this wave there is some element of immunity to COVID being expressed by the harder hit zipcodes from the summer. Perhaps this is a normal balancing we should expect.
The above table confirms the above. The top 5 counties all have had lower case rates to date (see their cases per 1000 numbers). You can also see how the death rates range from the high in Apache and Navajo Counties, both of which were hit hard back in the early days of the outbreak when deaths were higher, all the way down to tiny Greenlee County. Maricopa and Pima Counties, which have the large populations, are somewhere in the middle.
Other US States
The above two tables show the states that currently have the highest accelerations of their case and death rates. Acceleration means that the slope of cases (# cases per day) is getting larger or smaller over time. As you can see, North Dakota is in the unfortunate position of having the largest case acceleration (an increase of 0.038 cases per day, every day) and the largest death acceleration (.0035). Interestingly, though South Dakota has tracked right with North Dakota on cases, the death rates are much lower in South Dakota. This makes me suspect that in ND the virus got into a community somewhere that was highly susceptible but in SD it didn’t. Note that ND’s death acceleration is almost 3x the next highest (Iowa). Fortunately, in this latest outbreak, deaths continue to be rare.
Additionally, we can see the Northeastern states creeping back up to the top of the case and death rate lists. In other regions, it seems like when COVID comes back a 2nd or 3rd time the death rates are much smaller, so what’s happening in the Northeast is puzzling. I’d have to look closer at those states (i.e., by zip code) to figure out exactly what is happening.
World Data
I’ve shown the below diagram a few times throughout the COVID outbreak and interestingly, the trend continues that the virus is unusually inactive or unmeasured between about 10 degrees South and 30 degrees north. The below shows the cases and deaths per 1000 since the start of the outbreak by latitude. Other than the growth in 20 to 10 degrees South (Brazil) and 20-30 degrees North (India) not much has changed. Note that despite, India’s large COVID numbers, the overall number of cases and deaths per 1000 people is still much lower than other regions.
And below shows current states for countries + US States sorted by normalized case growth rate (IROC_c_n). We see tiny Andorra at the top of the list, but a number of European countries are moving back up the list. Note that in Belgium (the country in Europe that had the highest death rate), the current death rate (IROC_d_n) is a good bit lower than Czechia, a country that was largely missed by the first round of COVID.
