Health care workers might not be that different from the general population in the factors that determine their risk of getting COVID-19, researchers at Cedars-Sinai Medical Center said Wednesday.
A study led by Cedars-Sinai shows that health care workers are more likely to have antibodies to COVID-19 in their blood if they are Black or Latino or have hypertension.
But it suggests that the community — rather than the workplace — is the more common source of coronavirus exposure.
The research, published online in the peer-reviewed journal BMJ Open, was based on blood tests and a survey of more than 6,000 employees in the Cedars-Sinai Health System starting last May.
During that first wave of the pandemic, about 4% of the employees were found to have antibodies to the SARS-CoV-2 virus in their blood, indicating they had been exposed to COVID-19.
“Our study shows that we started out last summer with a relatively low exposure rate to SARS-CoV-2,” said Dr. Susan Cheng, associate professor of cardiology at the hospital and director of the Institute for Research on Healthy Aging in the Department of Cardiology at the Smidt Heart Institute. “This fact means the vast majority of our communities have remained vulnerable to infection, and therefore vaccination and continued vigilance are critical.”
Across the board, regardless of whether they had been diagnosed with COVID-19, blood tests showed that health care workers were significantly more likely to have antibodies to the SARS-CoV-2 virus if they were Black or Latino rather than of other racial or ethnic groups.
“These disparities underscore the ongoing, urgent need for us to understand why certain demographics and communities remain at higher risk in the pandemic than others,” said Kimia Sobhani, medical director of the clinical core laboratories and associate professor of pathology and laboratory medicine at Cedars-Sinai. “The reasons may well include structural and societal factors that we were unable to capture.”
Another significant finding was that having antibodies to the virus was related more to having had community-based exposure, including a household member previously diagnosed with COVID-19, than to workplace exposure.
“Our data show that public health measures work,” said study co-author Dr. Peggy Miles, medical director of Employee Health Services at Cedars-Sinai. “Our workers are taking care of the sickest people, including high-risk patients, and yet we see very little transmission of coronavirus in the hospital.”
The study also found:
— Not all workers with antibodies to SARS-CoV-2 reported experiencing symptoms, but among those who did, the most common symptom was loss of smell.
— The degree of antibody response to the virus was related not only to the magnitude of exposure and severity of illness but also to the presence of hypertension, or high blood pressure, for reasons that are not yet clear.
— Asthma patients had lower antibody levels that were less often above the threshold of detection used in the study. The reason was unclear.