key: cord-0826030-rpjehijd
authors: Azzi, Lorenzo; Carcano, Giulio; Dalla Gasperina, Daniella; Sessa, Fausto; Maurino, Vittorio; Baj, Andreina
title: Two cases of COVID‐19 with positive salivary and negative pharyngeal or respiratory swabs at hospital discharge: A rising concern
date: 2020-05-11
journal: Oral Dis
DOI: 10.1111/odi.13368
sha: 2845127982be14827a7c145fa85bb5ab4d4999ae
doc_id: 826030
cord_uid: rpjehijd

We report two cases of COVID‐19 showing negative respiratory swabs but positive salivary samples at the same time. These findings rise the concern about how to manage these patients before hospital discharging, thus avoiding contagion among their family members or a second coronavirus wave once the lockdown is over.

A 71-year-old man with a history of dyslipidemia, mild obesity, OSAS, and turbinate hypertrophy presented at our hospital with fever, dyspnea, and cough on March 9. His nasopharyngeal swab was positive on admission. The course of the disease was severe, but the patient did not require intensive care or endotracheal intubation. After 10 days, a salivary sample was collected through the drooling technique. This technique allows to collect only oral fluids, thus excluding mucous secretions from oropharynx or lower respiratory tract. A RT-qPCR analysis was performed. The specimen was resuspended in 2 ml of PBS; 140 μl were subjected to RNA extraction by QIAamp Viral RNA Mini Kit (Qiagen) and eluted in 60 μl. One-step rRT-PCR was performed using Luna Universal During the two following days, two bronchoalveolar swabs were found to be negative for SARS-CoV-2, but on March 27, a second salivary sample confirmed the presence of the virus in the mouth.

RT-qPCR analysis on pharyngeal or respiratory tract swabs is considered the gold standard for the detection of SARS-CoV-2 infection.

Nevertheless, several reports showed the existence of false-negative results or the persistence of the virus in the body after the pharyngeal swab conversion (Li et al., 2020) .

CoV-2 is an issue that has been recently raised (Khurshid, Asiri, & Al Wadaani, 2020) .

During our research, we found two patients out of 25 subjects (i.e., 8%) affected by COVID-19 with different degrees of severity, who showed positive salivary results on the same days when their pharyngeal or bronchoalveolar swabs proved to be negative . These findings, together with those reported by the F I G U R E 1 The temporal line of the clinical course in the two patients shows how their salivary samples tested positive, while the pharyngeal or bronchoalveolar swabs were negative on the same day (Patient 1 on March 19) or during the interval between two consecutive salivary swabs (Patient 2, March 23-28) Chinese colleagues on sputum, rise the concern about how to manage these patients before hospital discharging.

As an example, in our department we will carry out a salivary analysis after that two consecutive pharyngeal swabs prove negative and wait until the same results are registered also in saliva.

However, if patients are discharged without a salivary control, it should be advisable that they resort to social isolation for at least 14 days, avoiding contagion among their family members or a second coronavirus wave once the lockdown in Italy is over.

None. 

https://orcid.org/0000-0003-2532-7651

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Two cases of COVID-19 with positive salivary and negative pharyngeal or respiratory swabs at hospital discharge: A rising concern