Serial simultaneously self-swabbed samples from multiple sites show similarly decreasing SARS-CoV-2 loads in COVID-19 cases of differing clinical severity

Abstract

Serial simultaneously self-swabbed samples from multiple sites show similarly decreasing SARS-CoV-2 loads in COVID-19 cases of differing clinical severity Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is essential for diagnosis of Coronavirus disease (COVID-19). Nasopharyngeal swabs (NPS) are recommended by the World Health Organisation (WHO) as the current standard method to detect SARS-CoV-2 in suspected patients. 1 However, collection of an NPS or oropharyngeal swab (OPS) can be technically difficult, uncomfortable for patients, may induce sneezing or coughing, and expose those nearby to aerosolised SARS-CoV-2). 2 We postulate that alternative easier-to-sample swabs such as those from the nose (NS) or cheek (CS) may be equally sensitive in acute COVID-19 cases, and can be effectively taken by patients themselves. In addition, longitudinal analysis of serial samples collected contemporaneously from multiple upper respiratory tract (URT) sites, from the same patient, has not been well described. Here, we performed a prospective longitudinal analysis of three healthcare worker volunteers with differing clinical severities of acute COVID-19. Shortly after a confirmed diagnosis of COVID-19 using the local diagnostic AusDiagnostics (Ausdiagnostics UK Ltd., Chesham, England) SARS-CoV-2 PCR test, 3 each participant volunteered to provide serial self-collected swabs from the nasopharynx (NPS, 1 swab), just inside the soft part of the nose (NS, 1 swab), the oropharynx (OPS, 1 swab), inside the cheek (CS, 1 swab). In addition, we also decided to check for the presence of SARS-CoV-2 in the conjunctiva (CJS, 1 swab for both eyes). All of these swabs were taken at the same time-point, on a daily basis-or as frequently as was practical and tolerable-until all the SARS-CoV-2 viral loads became undetectable. Thus, each patient collected up to 5 separate swabs on a daily basis for this study. All three participants (hereafter referred to individually as 'Patient' 1, 2, or 3) became symptomatic with confirmed COVID-19 during the week of 12th April 2020. Patient 1 had mild COVID-19, complaining of a 7-day history of anosmia only; Patient 2 had moderate COVID-19, with a 5-day history of fevers, shivers, dry cough and myalgia; Patient 3 had severe COVID-19, presenting with a 2-week history of fevers, shivers and a productive cough that required supplemental oxygen therapy, and eventual admission to the intensive care unit (ICU) during the second week, after which no further swabs were taken. Final follow-up swabs were performed by the participants on 5th May 2020, two weeks after symptom onset for all participants. From 17th April to 5th May 2020, a total of 105 swabs were collected from three participants (Fig. 1). Patient 1 (mild COVID-19) provided a total of four days of swabs (20 swabs) from Day 8 days post-symptom onset; Patient 2 (moderate COVID-19) provided a total of 11 days of swabs (55 swabs) from Day 1 post-symptom on

Evaluation of RT-qPCR of mouthwash and buccal swabs for detection of SARS-CoV-2 in children and adults

“…However, critically ill adults or children are often unable to spontaneously produce sufficient amounts of saliva or sputum [10]. Findings of previous studies concerned with detection of SARS-CoV-2 in saliva specimens were limited by small sample size and diverse methodology [11][12][13][14]. Whether PCR from saliva mouthwash is an accurate method to detect SARS-CoV-2 in symptomatic patients remains, therefore, yet to be determined.…”

Nasopharyngeal versus nasal swabs for detection of SARS-CoV-2: a systematic review

“…Another study, which we could not include into our systematic review due to a limited number of examined patients, was conducted by Pan et al and investigated the diagnostic performance of self-collected OPS, nares, cheek, and conjunctiva swabs in three patients with different severities of COVID-19. They found that a self-obtained nares swab as well as self-collected conjunctiva, cheek, or OPS samples were able to detect SARS-CoV-2 in the early stage of disease and showed that Ct values increased over time (56) .…”