Coronavirus:Clues

These posts contain frequent reference to the idea that there is no one single factor that accounts for the wide disparity in coronavirus impacts between various places. This is not to say however, that there may not be dominant factors. and it natural to ponder what these factors might be.

Arapahoe and Douglas counties are adjacent political subdivisions in Colorado. Arapahoe County has a population of about 650,000 and Douglas County has about 350,000 residents. Douglas County has a higher average household income. Being adjacent areas in the Denver suburbs, the two counties have very similar appearances; one is usually unaware of passing over the county line from one to the other. The City of Aurora has portions in both counties. The counties share the same board of health. Each county has three hospitals, one from each of the same three large hospital systems. The same physicians take care of patients in both counties.

As of 4/30/20, Arapahoe County had 2,472 COVID cases and 141 deaths, and Douglas County had 478 cases with 22 deaths. What might be the dominant factor accounting for this discrepancy? Why is the per capita case rate in Arapahoe County 2.7 times higher than in the adjacent county, and the per capita death rate 3.45 times higher?

The answer may be contained in an observation from the Kaiser Family Foundation: "27 percent of the deaths in the 23 states that report fatalities publicly have occurred in nursing homes and long term care facilities. In six of those states - Delaware, Massachusetts, Oregon, Pennsylvania, Colorado and Utah- the percentage of coronavirus deaths in nursing homes was over 50 percent of the total deaths..."

The Colorado department of Health provides outbreak data, listing individual outbreaks, the affected county and the number of cases. There were 38 discrete outbreaks in Arapahoe County as of 4/30/20. Over the same period there were 5 in Douglas County. This suggests that the cases in Arapahoe County are occurring among populations more likely to die from it, and this would at least in part account for the discrepancy in death rates. But it also suggests that having a nidus of outbreak increases the rate of infection in the vicinity. Nursing Homes and long term care facilities cannot be completely isolated from the surrounding community. Workers must go in and out, trash must be collected, supplies must be delivered, residents are admitted and discharged, etc. A nursing home may act like a corona virus factory that makes containment challenging in the immediate vicinity.

It is quite possible that the most effective coronavirus mitigation strategy would have been more effective isolation of nursing homes and long term care facilities, not simply because the residents were most vulnerable, but because they created the most efficient reservoirs for infecting teh broader community.