Study: Self-Collected Saliva, Nasal Swabs Effective at Diagnosing COVID-19

Self-collected saliva and deep nasal swabs are equally effective at detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as those collected by health care providers, according to a new study published in the Journal of Clinical Microbiology.

SARS-CoV-2 is the virus that causes coronavirus disease 2019 (COVID-19). The COVID-19 pandemic has caused more than 800,000 deaths worldwide and there has been over 23.3 million confirmed cases, according to the World Health Organization. Finding a quick and effective test has been a high priority and is seen as crucial to controlling the disease.

The study included more than 1100 specimens collected from 368 volunteers at the University of Utah Health Redwood Health Center drive-through testing site from late May through June. Participants collected their own saliva by spitting into a tube and swabbed the front of both of their nostrils for testing. Results were then compared with samples collected from nasopharyngeal swabs by health care professionals from the same individuals.

The SARS-CoV-2 virus was detected in at least 2 specimen types in 90% of the patients who tested positive for the virus, according to the study. Positive rates for saliva specimens were nearly the same as those for nasopharyngeal specimens.

Self-collected navel swabs when used alone were found to miss nearly 15% of infections. The study authors found that combing them with throat swabs could improve accuracy to 98%.

"Saliva and nasal swab self-collection can resolve many of the resource and safety issues involved in SARS-CoV-2 diagnostic testing," ARUP Laboratories Chief Medical Officer Julio Delgado, MD, MS, said in the press release.

The study is the largest of its kind, according to the press release. Smaller studies, such as an ongoing one from the Yale School of Public Health, have reached similar conclusions with a smaller sample size.

Reference:

Self-collected saliva and deep nasal swabs are equally effective for diagnosing COVID-19 (Press Release) Salt Lake City, Utah, August 20, 2020, EurekAlert! Accessed August 24, 2020