COVID-19 in the Navajo Nation
UPDATE: please see updated data here
UPDATED 4/3/20 with additional analysis
My good friend Dr. Sophina Calderon is a fantastic family physician practicing in Tuba City, Arizona, serving the Diné (Navajo) population there. After she mentioned that the National Guard was flown in to her home town of Tuba City to support their response to COVID19, we started talking about putting together some information to better understand the outbreak in her area.
Again using the NY Times publicly available county-level data, Aaron and I graphed cases in the Navajo Counties (green line):
Apache, Arizona
Coconino, Arizona
Navajo, Arizona
Cibola, New Mexico
McKinley, New Mexico
San Juan, New Mexico
San Juan, Utah
And compared them to cases in bordering counties (blue line)
Gila, Arizona
Graham, Arizona
Greenlee, Arizona
Mohave, Arizona
Yavapai, Arizona
Archuleta, Colorado
La Plata, Colorado
Mesa, Colorado
Montezuma, Colorado
Montrose, Colorado
San Miguel, Colorado
Bernalillo, New Mexico
Rio Arriba, New Mexico
Sandoval, New Mexico
Socorro, New Mexico
Valencia, New Mexico
Garfield, Utah
Coronavirus cases in Navajo Counties and surrounding counties over time
These look quite similar until we look at them as cases per population:
Coronavirus cases per 1,000 residents in Navajo Counties and surrounding counties over time
Starting as early as March 20th, the trajectory of local transmission starts to diverge from surrounding counties. This is quite concerning for the impact of the point when cases peak in the affected regions.
We did some comparison with the rise of cases in the Navajo counties to states in the region, along with Seattle and NYC whose experiences have been widely shared and studied. This graph shows the rise in cases per population in the days after the first case was diagnosed in each region:
Cases of coronavirus per population over time, starting from the day the first case was diagnosed in each region.
The NYC experience stands out here, but it is also of note that the rise of cases per population of Navajo counties outpaces that of the surrounding states, as well as Seattle. I have been thinking all along that the outbreak would exacerbate any existing health and socioeconomic disparities — a NY Times article this am reports that location tracker data from cell phones in lower- vs higher-income areas shows a days-long gap in when people started limiting their movements.
From the NY Times: Changes in movement in response to coronavirus in high vs low income areas
We then looked at the Social Vulnerability Index (SVI) for each of the areas that we graphed earlier in the post. This plot shows the SVI for Navajo counties, other counties in the same states, NYC, and Seattle:
Social Vulnerability Index for Navajo counties, other counties in the same region, along with Seattle and NYC
This shows that there are counties in Arizona and NM counties with high SVI scores, meaning high levels of social risk factors, not too far different than the Navajo counties. However, based on the graphs of coronavirus cases per population, the outbreak does not seem to have spread as quickly in the non-Navajo communities as in the Navajo communities, even for non-Navajo communities with high levels of social risk.
A curfew remains in effect for the Navajo Nation from 8pm to 5am and families are encouraged to have only one member of the household do essential shopping.
