The COVID-19 epidemic appears to have become chronic, endemic phase with occasional cluster outbreaks.

It is getting harder to define the course of the COVID-19 pandemic in the United States. Statements about different states and cities define rates of infection that seem to vary greatly between different sources. Therefore once a week I’m going to try and look at several sources of information and gather epidemiological data to get an understanding of exactly where the pandemic is heading. 

United States’ Numbers of new infections, deaths and tests.

The numbers from Johns Hopkins school of public health have been fairly consistent for the past week. Overall, the United States has seen a decrease in the number of cases that appears to be greater than the decrease in testing (that’s been blamed for the overall reduction). The percentage of tests that are positive has fluctuated and is trending upward in a number of cities in the US. It is not clear whether this suggests another resurgence of infections or is more in line with variations, seen in places like Michigan and Ohio, where the overall numbers have fluctuated but no trend has occurred. 

Nationally, deaths continue at approximately 1,000 to 1,500 per day. No clear reason for this consistency exists at the present time, especially given the fluctuations in infections. This is disconcerting.

New infections, death and testing in Texas. These daily numbers show the inconsistency of state data. The number of new deaths and tests appears to not be accurately or consistently captured.

There appeared to be overall drops in the number of infections in some of the southern states, like Texas and Arizona, that were most affected by recent outbreaks. I present the Texas numbers above to document another concern. In many states, the number of new cases, testing, and the number of new deaths have not been consistently reported on daily intervals, so it is difficult to identify trends. I am especially concerned that as more testing is available in the private sector these numbers won’t be captured. That will make testing numbers artificially low.

Rt values suggest COVID-19 infection is persistent, with 20 states having values <1.0, suggesting a contracting of infection spread, and 20 having numbers greater than 1.2, suggesting widening spread.  

Rt data for August 6, 2020. (from

If I can come to any conclusion, we have entered what appears to be a more chronic phase of the pandemic, with widespread infection and persistent outbreaks of infection clusters mainly associated with large-scale events. This can be viewed as either concerning or expected, but the most important message is that we need states to provide more consistent and complete information so we can better monitor the illness and make knowledgeable public health decisions. 

Published by jbakerjrblog

Immunologist, former Army MD, former head of allergy and clinical immunology at University of Michigan, vaccine developer and opinionated guy.

2 thoughts on “The COVID-19 epidemic appears to have become chronic, endemic phase with occasional cluster outbreaks.

    1. A good question. We have sort of backed into the “herd immunity” approach. I would feel better if there was a concerted, prospective effort on this that managed the process, but given the way people think and act about these issues that just may not have been possible. I think the end point will likely be the same, potentially with more deaths but otherwise the timeline and outcome will be similar. I guess that it is not pessimism as much as fatalism.

      By the way, spent a couple of days in NJ on business this past week (flew in right after the hurricane, another story). Was astounded that on the streets of downtown Somerville less than half the folks were wearing masks! It is actually the law there right now!


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