key: cord-354612-7f91l0n9
authors: Villar, Livia Melo; da Costa, Vanessa Duarte; Marques, Bianca Leires; da Silva, Lucas Lima; Santos, Alanna Calheiros; da Fonseca Mendonça, Ana Carolina; Marques, Vanessa Alves; do Nascimento, Giselle Prado; Lewis-Ximenez, Lia Laura; de Paula, Vanessa Salete
title: USEFULNESS OF SALIVA SAMPLES FOR DETECTING SARS-CoV-2 RNA AMONG LIVER DISEASE PATIENTS
date: 2020-07-23
journal: J Infect
DOI: 10.1016/j.jinf.2020.07.017
sha: 
doc_id: 354612
cord_uid: 7f91l0n9

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First, we evaluated extraction method and limit of detection of artificially spiked SARS-CoV-2 saliva samples (estimated viral load: 10 3 , 10 2 , 10 1 , 10 0 copies/mL). Saliva were collected using Salivette Device as previous described (3) Both methods were feasible to extract SARS-CoV-2 RNA saliva, however using M1 the detection limit was 10 copies/mL and M2 the limit of detection was 1 copy/mL. M2 was applied to extract RNA from saliva and NPS from 13 volunteers (5 hepatitis cases and 8 non hepatitis cases).

Volunteers gave saliva samples using Salivette device after signing informed consent. A total of four individuals (two hepatitis cases and two without liver disease) were negative to SARS CoV-2 in NPS and saliva (100% of specificity). The overall positivity was 9/13 (69.2%) lower than observed in saliva from ambulatory patients without liver disease (84.6%) (5). A total of 11/13 (84.6%) had concordant results in saliva and NPS samples what is lower than observed by Azzi and coleagues (1) and

probably is the reflex of severity of disease among both studies. Positive concordant results in NPS and saliva were observed in seven individuals (two hepatitis cases and 5 without liver disease) until 7 days after onset of symptoms (100% of sensitivity). After 7 days of onset of symptoms, RNA was detected in NPS but it was not observed in paired saliva samples. This is the first report of SARS CoV-2 detection in saliva samples among liver disease patients showing best results until 7 days of beginning of symptoms. There is an urgency for alternative methods for SARS-CoV-2 RNA detection to overcome swab availability and increase the access of diagnosis. Saliva samples have been evaluated for SARS CoV-2 RNA detection in severe cases or hospitalized patients, but there is a lack of data about theses samples in mild cases or a standard protocol for sample collection and viral detection. In addition, there is no information regarding the usefulness of saliva for detecting SARS CoV-2 RNA in individuals presenting comorbidities, such as liver disease. The present study gives new information regarding the presence of SARS CoV-2 in saliva of liver disease patients. Since saliva can be collected easily, SARS CoV-2 RNA detection in saliva can be useful strategy to increase the access of sample collection for the diagnosis of COVID-19 in patients with liver disease.

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

Utility of oral fluid samples for hepatitis B antibody detection in real life conditions

Comparison of oral fluid collection methods for the molecular detection of hepatitis B virus

Centers for Disease Control and Prevention (CDC). CDC 2019-Novel Coronavirus (2019-nCoV) Real-Time RT-PCR Diagnostic Panel

Saliva as a noninvasive specimen for detection of SARS-CoV-2

Figure 1. Box Plot Graph of cycle threshold (Ct) values in nasopharyngeal swabs and saliva specimens of positive samples for SARS CoV-2. Vertical lines indicate range of values, and the median Ct value is represented as black horizontal line within the box plot