Detection of SARS-CoV-2 in the ocular surface in different phases of COVID-19 patients in Shanghai, China

BACKGROUND: To investigate the temporal pattern of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) presence on ocular surfaces using conjunctival swabs in coronavirus disease 2019 (COVID-19) patients. METHODS: This study included 59 patients (32 newly admitted and 27 hospitalized for ≥2 weeks) with a COVID-19-confirmed diagnosis at the Shanghai Public Health Clinical Center from March 3, 2020, to March 21, 2020. Conjunctival swab samples were collected from both eyes of all the 59 patients and were tested by reverse transcription polymerase chain reaction (RT-PCR) assay. The range of sampling time lies widely between 1 and 50 days since symptom onset. RESULTS: Among the 32 newly admitted patients, positive RT-PCR results for SARS-CoV-2 in conjunctival swab samples were reported in 2 patients (one eye for each) without ocular discomfort, but 1 positive case had conjunctival congestion. The positive results were detected on Day 5 for 1 patient and Day 7 for the other, but repeated tests after 1 week were negative for both patients. All 27 patients who had been hospitalized for ≥2 weeks had negative test results. The mean time from symptom onset to sampling of 2 positive cases was significantly less than that of 57 negative cases (P<0.001). CONCLUSIONS: SARS-CoV-2 on the ocular surface can be detected in the early phase of COVID-19. The risk of ocular transmission remains and might be higher in the early phase.