Construction workers have highest asymptomatic COVID positivity rates, Curative study finds

Written by Amy Ta, produced by Rosalie Atkinson

One reason why COVID-19 spreads so quickly is because a lot of people who have it never show symptoms — between 20-40% of all cases. A new report finds that certain professions seem to have higher rates of asymptomatic infection than others. Construction workers, who are deemed essential, top that list. 

The report comes from Curative, a health company processing more than 1 million COVID tests a week. They also have testing sites all over LA.

Dr. Jeffrey Klausner, Curative’s medical director and a professor at UCLA’s School of Public Health. He says their data covered 730,000 tests from August to October, and among those who tested positive, 42% had no symptoms. 

He adds that by far, the highest proportion of people infected reported that they were Hispanic. “[The] Hispanic population had about [a] sixfold increase rate of infection compared to non-Hispanics. And that's an important finding because that can help us direct our prevention interventions in our messaging to different Hispanic populations around Los Angeles.” 

Klausner says within the Hispanic population, people self-reported whether they worked in construction, delivery services, health care, media, education, food services, manufacturing, etc. 

“I was surprised that the occupation with the highest positivity were construction workers, followed by retail or manufacturing workers. And then thirdly, followed by disability care providers.”

He points out that construction workers spend time both indoors and outdoors, and people who drive by sites can see these workers wearing masks. However, he adds, “We don't really know what they're doing indoors, we don't really know the ability of people to distance indoors. … Perhaps the masking and the distancing … is not as effective as it could be. And that's why we really need to make sure that they have access to frequent testing.”

Klausner says the California Division of Occupational Safety and Health (Cal/OSHA) has been at the forefront of assuring safe work conditions. 

“Cal/OSHA has, in my opinion, not been as aggressive as it could be monitoring workplaces. They do issue recommendations. But monitoring of those recommendations and enforcement of those recommendations is actually quite limited. And I think it takes the worker advocacy groups, and it takes employers’ responsibility to protect the safety of their essential staff,” he says. 

Klausner says the Coronavirus Aid, Relief, and Economic Security (CARES) Act covers essential workers for testing, so construction workers who have health insurance can get tested with no out-of-pocket cost. 

He adds, “One of the challenges that people who are undocumented or maybe uninsured — someone has to pay for the test. So many counties and some large cities provide backup for those uninsured or undocumented individuals. The CARES Act will provide reimbursement for testing to the laboratory if someone is not insured. But if someone's undocumented, the city or county or the employer has to cover that cost.” 



  • Jeffrey Klausner - professor at UCLA’s School of Public Health, Curative's medical director