Saliva is a reliable tool to detect SARS-CoV-2

Abstract

Objectives: This study analyzed salivary samples of COVID-19 patients and compared the results with their clinical and laboratory data. Methods: Salivary samples of 25 COVID-19 patients were analyzed by rRT-PCR. The following data were collected: age, sex, comorbidities, drugs. Lactate dehydrogenase (LDH) and ultrasensitive reactive C protein (usRCP) values were registered on the same day when a salivary swab was collected. Prevalence of positivity in saliva and association between clinical data and the cycle threshold as a semiquantitative indicator of viral load were considered. Results: Twenty-five subjects were recruited into this study, 17 males and 8 females. The mean age was 61.5 + / − 11.2 years. Cardiovascular and/or dysmetabolic disorders were observed in 65.22% of cases. All the samples tested positive for the presence of SARS-CoV-2, while there was an inverse association between LDH and Ct values. Two patients showed positive salivary results on the same days when their pharyngeal or respiratory swabs showed conversion. Conclusions: Saliva is a reliable tool to detect SARS-CoV-2. The role of saliva in COVID-19 diagnosis could not be limited to a qualitative detection of the virus, but it may also provide information about the clinical evolution of the disease.

Dentistry during the COVID-19 Epidemic: An Italian Workflow for the Management of Dental Practice

“…This could explain the occasional lack of symptoms in infected subjects. Moreover, the positive rate of COVID-19 in patients' saliva can reach up to 100%, and saliva samples can also cultivate the live virus [21,26], thus the potential infectivity of saliva should be strongly considered.…”

Saliva—Friend and Foe in the COVID-19 Outbreak

“…The incubation period in susceptible COVID-19 patients is 1-14 days, with an average of 3-7 days [18]. From the existing data, the SARS-CoV-2 virus can be detected in multiple sources, including gastrointestinal tissue [26], tears [27], stool [28], blood [29], and saliva [30][31][32][33] of COVID-19 patients.…”

“…However, only 15% of patients hospitalised with pneumonia had detectable SARS-CoV-2 RNA in serum [48], and 55% of patients showed positive SARS-CoV-2 RNA in fecal samples [49]. Conversely, in saliva samples, it was reported from different clinical studies that 87%, 91.6%, and 100% of COVID-19 patients were identified as being viral positive, respectively [30,31,33], suggesting that saliva is a powerful specimen source for the diagnosis of the SARS-CoV-2 virus.…”

“…SARS-CoV-2 was detected in self-collected saliva (by asking the patients to expectorate saliva) in 11 out of 12 confirmed cases [31]. Another recent study found that 100% of COVID-19 patients (n = 25) were detected as viral positive in drooling saliva samples [33]. Further, in a cohort of COVID-19 positive patients, it has been demonstrated that 87% of posterior oropharyngeal (deep throat) saliva samples were detected viral positive (n = 23), and serial respiratory viral load of SARS-CoV-2 was detected from week 1 and up to 25 days after symptom onset, while serum (n = 16) samples showed positive RT-qPCR detection only 14 days after symptom onset [30].…”

“…Further investigations are required to explore the potential role of saliva for COVID-19 detection in both symptomatic and asymptomatic patients. [33] In summary, the current gold standard diagnostic test is RT-qPCR to detect SARS-CoV-2 RNA which takes approximately 48 h to obtain the test results. More new tests with higher sensitivity and specificity need to be appropriately validated before being implemented into the current routine diagnosis.…”