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.

Keywords: COVID-19; Coronavirus; SARS-CoV-2; Saliva; nCoV-2019.

Fig. 1

Scatter plot of LDH (a) or usCRP (c) values on the rRT-PCR cycle threshold values. Women and men are indicated by red and blue points; the blue line represents the regression result and the light blue area is its 95% confidence intervals. Panels (b) and (d) showed the same plots using age- and sex-adjusted residuals of LDH and usCRP levels, respectively, instead of their measured values, and the regression result from age- and sex-adjusted analysis (Table 2). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)