COVID-19 detected in saliva of infected patients
Traces of COVID-19 were detected in the saliva of 11 of 12 patients infected with the virus, suggesting that saliva may be a “promising, noninvasive specimen” for the diagnosis, monitoring and infection control of the virus, according to a study published in Clinical Infectious Diseases.
“Saliva specimens can be provided easily by asking patients to spit into a sterile bottle. Since no invasive procedures are required, the collection of saliva can greatly minimize the chance of exposing healthcare workers to 2019-nCoV,” Kelvin Kai-Wang To, clinical associate professor at the University of Hong Kong’s department of microbiology, and colleagues wrote. “We have tested 2019-nCoV in saliva from patients with suspected 2019-nCoV infection based on clinical and epidemiological criteria as outlined by the Centre for Health Protection of Hong Kong. Here, we report the results of the saliva testing.”
To and colleagues collected saliva a median of 2 days (range, 0-7 days) after hospitalization from 12 patients in Hong Kong with lab-confirmed COVID-19. Samples were collected by asking patients to cough out saliva from their throat into a sterile container, with 2 mL of a viral transport medium added to the sample. They conducted a viral culture of each sample. Virus-induced cytopathic effects were then studied daily for up to 7 days.
Patients examined were aged from 37 to 75 years, with a median age of 62.5 years. There were five female and seven male patients.
COVID-19 was detected in the saliva of 11 of 12 (91.7%) of the patients, and viral loads were highest in the earliest specimens for five (83.3%) of the patients.
“The presence of 2019-nCoV in patients’ saliva suggests the possibility of salivary gland infection,” the researchers wrote. “However, it should be noted that saliva specimens not only contain saliva secreted from major or minor salivary glands but also contain secretions coming down from the nasopharynx or coming up from the lung via the action of cilia lining the airway. Further studies are required to delineate the sources of 2019-nCoV in saliva.” – by Eamon Dreisbach
Disclosures: The authors report no relevant financial disclosures.