In every corner of California, the Latino population has faced a greater risk of exposure to COVID-19, undergone testing at a lower rate, and suffered more deaths than any other race or ethnicity, according to Stanford-led research.

The effect of the finding is substantial, given that the proportion of Latinos in the Golden State surpassed that of non-Hispanic whites in 2015 — they now make up 39.1% of the population. Whites make up 37.5%; Asians, 14.4% and African Americans, 5.3%. Although Latinos are overrepresented in cumulative cases, Black Californians have died of COVID-19 at a higher rate.

The study, published May 12 in Health Affairs, analyzed testing and case rates by race or ethnicity, at the sub-county level, from March 22 to Oct. 3, 2020. Previous studies of COVID-19 disparities in California have focused on single neighborhoods, specific health-care systems, a single county or the state as a whole.

Grim Death Toll

Using demographic data from the American Community Survey, the researchers estimated community-level risk for exposure and transmission of COVID-19 based on the proportion of people living in households with an essential worker and fewer rooms than household members, a measure of ability to self-isolate at home if exposed. Essential workers are those the government deemed as critical to operations during the pandemic, such as health care and agricultural workers and emergency service personnel. The researchers combined these community-level exposure risk estimates with data on COVID-19 testing, cases, and deaths through a partnership with the California Department of Public Health.

They found that Latinos living in California, who are 8.1 times more likely to live in households facing these higher exposure risks than White Californians (23.6% versus 2.9%), had a COVID-19 case rate more than three times that of whites (3,784 versus 1,112 per 100,000 people). Further, California’s Latino population was tested for COVID-19 at a lower rate than white population (35,635 versus 48,930 per 100,000 people). The Latino population had strikingly worse COVID-19 mortality outcomes as well: The estimated death rate for Latinos (59.2 per 100,000 people) was 1.5 times higher than white residents (38.3 per 100,000 people).

Black populations in California, who also face structural risk factors that put them at high risk of COVID-19 infection and mortality, had the highest death rates (65 per 100,000 people) among the racial/ethnic groups included in the study. During the timeframe of the study, there were 8,635 deaths among Latinos, compared with 5,330 among whites, 2,053 among Asians and 1,295 among African Americans.

“A particularly striking feature was just how concentrated our measure of risk exposure — households with an essential worker and insufficient space at home to self-isolate — was among Latino populations throughout the state, and the strong association between the risk exposure in these communities and the extremely high case rates,” said Jeremy Goldhaber-Fiebert, PhD, the senior author of the study.

“This is an important finding for this pandemic and has relevance for at-risk areas for future respiratory infectious disease pandemics,” added Goldhaber-Fiebert, an associate professor of medicine at Stanford Health Policy.

“The fact that Latinos in California are the majority racial or ethnic group yet have the worst COVID rates highlights that this is not just a small-population issue,” said Marissa Reitsma, a PhD student at Stanford Health Policy and co-lead author of the study with Anneke Claypool, who recently earned her PhD from Stanford in management science and engineering. “Across California, Latinos disproportionately face structural risks that put them at higher risk of exposure to COVID-19, including the housing and occupation risks identified in our study.”

During the coronavirus shutdowns, Reitsma said, essential workers provided many services that allowed other people to shelter in place to avoid the epidemic risks—and many of those essential workers were Latinos who are paid an hourly wage and have no guaranteed paid sick leave.

Role of Racism

The researchers noted that racism could have played a role in the burden the pandemic has placed on California’s Latinos. “Although analyses such as ours provide a powerful tool for understanding the epidemiology of the pandemic and for developing more effective interventions to control it, one limitation of this study and others like it is in understanding the role of racism itself in contributing to disproportionate COIVD-19 burden among racial/ethnic groups,” the researchers wrote. They added: “Just because we did not analyze a definite indicator of exposure to racism in this study does not mean that such an association does not exist.”

The other Stanford co-author of the study was Joshua A. Salomon, PhD, a professor of medicine at Stanford Health Policy and senior fellow at the Freeman Spogli Institute for International Studies.