By Cara Murez
FRIDAY December 11, 2020 (HealthDay News) – A self-collected saliva sample is as effective at detecting COVID-19 as a nasal swab administered by a Health care worker – without exposing medical personnel to the virus when collecting the sample.
“The flow pandemic put significant pressure on the supply chain, from swabs to personal protective equipment [PPE] Healthcare workers must safely collect samples, ”said lead researcher Esther Babady, director of clinical microbiology at Memorial Sloan Kettering Cancer Center in New York. and reduce the need for specialized collection devices, such as swabs and viral transport media. “
Saliva tests detected the genetic material of the virus in saliva samples at rates similar to swabs that collected material through the mouth or nose. They are also stable for up to 24 hours when stored with ice packs or at room temperature.
Researchers at Memorial Sloan Kettering collected samples from 285 employees between April 4 and May 11, atop New York City. epidemic. The participants had symptoms of the virus or had been exposed to it.
Each of the participants provided a pair of samples. Some were asked to take a nasopharyngeal swab through the nose and a saliva sample. Some provided an oropharyngeal swab through the mouth and saliva. Others provided the nasopharyngeal swab and a sample from a mouthwash, another method of collection that was being tested.
The researchers found that the concordance between saliva and the oral swab was 93% and the sensitivity was 96.7%. The swab administered through the nose and saliva had a concordant result of 97.7%, with a sensitivity of 94.1%. Oral rinsing was only 63% effective in detecting the virus. The concordance between the nasal swab and the mouthwash was 85.7%.
Nasal swabs and saliva with a range of viral loads were stored both at room temperature and in a cooler. The researchers did not detect any difference in concentration when the sample was taken, eight hours later or 24 hours later.
The study was published online recently in The Journal of Molecular Diagnostics.
The results hold great promise for broad testing strategies that would mitigate the risk of infection for healthcare workers while preserving PPE, Babady said.
“The current public health ‘test, track and trace’ approach to surveillance relies heavily on diagnostic and surveillance testing,” she said in a press release.
“The use of self-collected saliva offers a less expensive and less invasive option for viable sample collection. It is certainly easier to to spit in a cup twice a week than having to undergo frequent nasopharyngeal swabs, “Babady said.” This can improve patient compliance and satisfaction, especially with surveillance tests, which require frequent sample collection. Since we have also shown that the virus is stable at room temperature for at least 24 hours, the saliva collection can be used at home. “
US Centers for Disease Control and Prevention offers more on test for COVID-19.
SOURCE: The Journal of Molecular Diagnostics, press release, December 2020