Related Experiment Video
Updated: Jul 27, 2026
Detection of SARS-CoV-2 Neutralizing Antibodies using High-Throughput Fluorescent Imaging of Pseudovirus Infection
Published on: June 5, 2021
Detection of SARS-CoV-2 in conjunctival secretions from patients without ocular symptoms
Xin Li1, Jasper Fuk-Woo Chan2,3,4,5, Kenneth Kai-Wang Li6
1Department of Microbiology, Queen Mary Hospital, Hong Kong Special Administrative Region, China.
Purpose:
To evaluate the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in conjunctival secretions from patients without ocular symptoms.
Methods:
Conjunctival swabs were prospectively collected from laboratory-confirmed Coronavirus disease 2019 (COVID-19) patients without ocular symptoms for reverse transcription-polymerase chain reaction (RT-PCR) and viral culture.
Results:
A total of 158 conjunctival swabs were obtained from 49 laboratory-confirmed COVID-19 patients. The median duration of illness when the first conjunctival swab was obtained was 10 days (range 2-27 days). Four conjunctival swabs from four different 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.
