In a large case series comprising 1099 confirmed COVID-19 cases in China, only 0

In a large case series comprising 1099 confirmed COVID-19 cases in China, only 0.8% presented with conjunctival congestion [5]. patients (4/49, 8.2%) were positive for SARS-CoV-2 RNA by RT-PCR. The Ct values ranged from 32.7 to 37.7 (mean 35.4). Viral cultures were negative for all four RT-PCR-positive conjunctival swabs. Conclusion Conjunctival secretions of a minority of COVID-19 patients without ocular symptoms may contain relatively low levels of SARS-CoV-2 RNA, but their infectiousness remains undetermined. Appropriate infection control measures should be implemented during ophthalmological assessment of COVID-19 patients to prevent potential nosocomial transmission of SARS-CoV-2. and Indobufen subgenus [2]. It is phylogenetically closely related to SARS-related coronaviruses in bats [3]. Within 6?months, SARS-CoV-2 has evolved into a global pandemic with more than 8 million laboratory-confirmed cases and over 0.4 million deaths [4]. The clinical manifestations of SARS-CoV-2 infection, or Coronavirus disease 2019 (COVID-19), Indobufen range from asymptomatic or subclinical infections, to acute viral pneumonitis with respiratory failure and/or multi-organ dysfunction [5C7]. Case reports and small retrospective cohorts of conjunctivitis as a presenting feature of SARS-CoV-2 infection emerged since the early phase of the pandemic. But the prevalence of ocular symptoms was reported to be 1% in larger case series [5]. SARS-CoV-2 has been detected in different bodily fluids, including respiratory secretions, blood, and feces [8, 9]. SARS-CoV-2 RNA has been detected by reverse transcription-polymerase chain reaction (RT-PCR) in the conjunctival secretions in a number of Indobufen patients, and by viral culture in one patient in Rome [10C21]. Conjunctival secretions may, therefore, be a potential source of transmission of SARS-CoV-2. However, the rate of asymptomatic shedding of SARS-CoV-2 in conjunctival secretions remains unknown. Objective In the present study, we investigated the presence of SARS-CoV-2 in conjunctival swabs of laboratory-confirmed COVID-19 patients without ocular symptoms. Study design Subjects and clinical specimens This multi-center prospective study was conducted at four public hospitals in Hong Kong. Adult (?18?years old) patients confirmed with COVID-19 by RT-PCR of nasopharyngeal specimens Indobufen and admitted to four regional hospitals (Queen Mary Hospital, United Christian Hospital, Pamela Youde Nethersole Hospital, and Ruttonjee Hospital) from February to March 2020 in Hong Kong Special Administrative Region, China were recruited. This study was approved by the Institutional Review Board of the University of Hong Kong/Hospital Authority. Written consents were obtained from all recruited patients. Forty one of the 49 recruited patients were enrolled in an open-label, randomized, phase-2 trial on triple combination of interferon -1b, lopinavirCritonavir, and ribavirin for treatment of patients hospitalized with COVID-19 [22], and the remaining 8 patients were enrolled in a case series on returnees from a cruise ship [23]. Conjunctival swabs were prospectively collected from recruited patients during hospitalization using transport swabs (Copan Italia, Brescia, Italy) following standardized protocol for conjunctival sampling. Informed consent was obtained from each patient before each procedure. Adequate conjunctival tissue was obtained by sweeping the lower fornix of each eye with the swab for 3 times. The swabs were Bmpr2 immediately placed into 2? mL viral transport medium as described previously [24]. The specimens were sent to the laboratory of the Department of Microbiology in Queen Mary Hospital for testing. Nucleic acid extraction TNA extraction was performed using NucliSENS easyMAG extraction system (BioMerieux, Marcy-ltoile, France) according to manufacturers instructions and as previously described [9, 25, 26]. Briefly, 250?L of each conjunctival swab was subjected to extraction with an elution volume of 55?L. The extracts were stored at ? 80?C until use. SARS-CoV-2 RNA detection by real-time reverse transcription-polymerase chain reaction (RT-PCR) assay SARS-CoV-2 RNA in the conjunctival swabs was detected by RdRp/Hel RT-PCR assay using QuantiNova Probe RT-PCR Kit (QIAGEN, Hilden, Germany) on LightCycler 480 II Real-Time PCR System (Roche, Basel, Switzerland) as described previously [8]. Briefly, each 20?L reaction mixture contained 10 L of 2??QuantiNova Probe RT-PCR Master Mix, 0.2 L of QN Probe RT-Mix, 1.6 L of each 10?M forward and reverse primers, 0.4 L of 10?M probe, 1.2 L of nuclease-free water and 5 L of TNA as the template. The thermal cycling condition was 45?C for.