Self-collected saliva and deep nasal swabs collected by healthcare providers are equally effective for detecting SARS-CoV-2, the virus that causes COVID-19, according to a new study conducted by ARUP Laboratories and University of Utah (UofU) Health.
The study, published in the Journal of Clinical Microbiology, represents one of the largest prospective specimen type comparisons to date, said Dr. Julio Delgado, ARUP chief medical officer. Other studies, including one from the Yale School of Public Health, have reached similar conclusions but with markedly fewer patients and specimens.
The results have important implications for patients and providers. The collection process for saliva and anterior nasal specimens is less invasive than the deep nasal, or nasopharyngeal, swab. In addition, both specimen types can be self-collected, reducing the risk of exposure for healthcare workers who collect nasopharyngeal specimens, said Dr. Kimberly Hanson, section chief of clinical microbiology at ARUP and the primary author of the study.
ARUP and UofU Health anticipate being able to start offering testing on saliva in some UofU Health clinical settings in early September. They already are using anterior nasal swabs in combination with throat swabs to test some asymptomatic individuals.
Hanson and her colleagues analyzed more than 1,100 specimens from 368 volunteers at the UofU Health Redwood Health Center drive-through testing site from late May through June. Volunteers self-collected saliva that they spit into a tube and swabbed from the front of both nostrils to produce specimens for testing. The study showed that SARS-CoV-2 was detected in at least two specimen types in 90 percent of the patients who tested positive for the virus.