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Detection of SARS-CoV-2 in conjunctival secretion and tears in patients with COVID-19 in a tertiary care centre, South India


Nayak, Rajesh et al. (2022), Detection of SARS-CoV-2 in conjunctival secretion and tears in patients with COVID-19 in a tertiary care centre, South India, Dryad, Dataset,


Aims and objectives: The purpose of this study is to detect the presence of SAR-CoV-2 viral RNA in conjunctival secretions of COVID-19 patients and to compare the RT-PCR positivity rate for SARS-CoV-2 in conjunctival and nasopharyngeal swabs.

Materials and method: Eighty hospitalised COVID-19 patients whose nasopharyngeal swab tested positive for SARS-CoV-2 by RT-PCR were included in the study. Conjunctival swab was collected from the eyes of these patients and sent for detection of SARS-CoV-2 by RT-PCR method.

Results: Among the eighty patients, 51 (63.7%) were males and 29 (36.3%) were females. The mean age of the patients was 55.93 ± 16.59. Six patients had ocular manifestations. Eleven (13.75%) patients tested positive on conjunctival swab for SARS-CoV-2 viral RNA, and only one of them had ocular manifestations out of the eleven.

Conclusion: In our study, the presence of SARS-CoV-2 in conjunctival secretions of COVID-19 patients was detected and this was not dependent on the presence of ocular manifestations or duration of disease. Though the conjunctival positivity is lower compared to the nasopharyngeal swab sampling, ocular surface and secretions can be a potential route of viral transmission.


Study participants: Patients admitted with a positive nasopharyngeal swab for SARS-CoV-2 within a duration of 1 week, and age of more than 18 years. Patients with COVID-19-like symptoms but whose RT-PCR was negative for COVID-19 were excluded. Critically ill patients who couldn’t give consent were also excluded.

Patients presenting complaints were noted along with any ocular complaints. The patient’s co-morbidities were recorded and clinical parameters on presentation like body temperature and oxygen saturation (SpO2) were also taken from the patient’s medical record. The day of nasopharyngeal swab collection was recorded, and days between the nasopharyngeal swab collection and conjunctival swab collection were calculated for every patient. Written informed consent was obtained from patients before sample collection.

Sample collection: A bedside ophthalmologist examination was done, and the patient’s eyelids, adnexa, conjunctiva, and cornea were examined before collection of samples. The sample was collected under aseptic conditions by the same ophthalmologist who donned personal protective equipment. Samples were collected by using nylon-flocked swabs by sweeping movement over the inferior fornix from the medial to the lateral direction. Sample from both eyes was collected for each patient using separate swab sticks without the use of any topical anaesthetic drops. Both swab sticks were then dipped into a single viral transport medium and transferred to the institutional microbiology lab, maintaining a proper cold chain at all times. The  RTPCR was performed on the samples using the kit protocol and the results were recorded .

Statistical analysis: All the data was entered into an Excel sheet and analyzed using IBM SPSS version 25. The continuous and categorical variables have been represented as mean ± standard deviation and frequency percentages respectively. The association between conjunctival swab positivity and variables like the severity of COVID, presence of symptoms such as fever, breathlessness, cough, fatigue, myalgia, diarrhea, and ocular symptoms was analyzed using the chi-square test. Correlation between the duration of days after which the conjunctival swab tested positive from the day of nasopharyngeal swab positivity, and oxygen saturation was done using Pearson’s correlation and p <0.05 was considered significant.

Usage Notes

Excel and README files