Testing the Sensitivity of Conjunctival Swabs from Confirmed COVID-19 Patients

• Main Authors: Hadrawi M, Malak M, Almahmoudi F, Mogharbel A, Rozy O, Hanafi S, Ali B, Nabeel S, Faqieha F, Alzahrani K
• Format: Article
• Language: English
• Published: Dove Medical Press 2021-06-01
• Series: Clinical Ophthalmology
• Subjects: covid-19; conjunctival swab; sensitivity; specificity; rna
• Online Access: https://www.dovepress.com/testing-the-sensitivity-of-conjunctival-swabs-from-confirmed-covid-19--peer-reviewed-fulltext-article-OPTH

Manal Hadrawi,1 Mohammad Malak,1 Faeeqah Almahmoudi,1 Ahmed Mogharbel,2 Omar Rozy,1 Somaya Hanafi,1 Batool Ali,3 Sanaa Nabeel,3 Fatimah Faqieha,4 khaled Alzahrani1 1Department of Ophthalmology, King Fahad Armed Forces Hospital, Jeddah, Saudi Arabia; 2Faculty of Medicine, King Abdulalziz University, Jeddah, Saudi Arabia; 3Department of Infectious Diseases, East Jeddah Hospital, Ministry of Health, Jeddah, Saudi Arabia; 4Department of Public Health, Ministry of Health, Jeddah, Saudi ArabiaCorrespondence: khaled Alzahrani; Ahmed MogharbelDepartment of Ophthalmology, Faculty of Medicine, King Fahad Armed Forces Hospital King Abdulaziz University, Jeddah, Saudi ArabiaEmail [e-mail]; [e-mail]: To investigate the incidence of COVID-19 viral RNA in the conjunctiva of patients priorly confirmed to have COVID-19, using a conjunctival swab and to determine swab sensitivity.Methods: This cross-sectional study enrolled patients who tested positive for COVID-19 with PCR via nasopharyngeal swabs. Conjunctival swabs were collected for each patient and subjected to RT-PCR assay. Demographic data and clinical history of patients were investigated and analysed.Results: In this study, 4.9% of the patients tested positive with conjunctival swabs for COVID-19; 29.9%, 28.7%, 20.1%, and 12.2% of the patients had fever, shortness of breath, cough, and red eye, respectively. Among all patients, 18.9% and 73.2% had a history of traveling and contact with positive COVID-19 cases, respectively. There were significant correlations between the conjunctival results and diabetes (P=0.049) and hypertension (P=0.002). Traveling was a risk factor for positive conjunctival swab testing (P=0.016). The sensitivity of the conjunctival swab was 4.8%.Conclusion: Among all positive cases of COVID-19, a small percentage had positive results when tested using a conjunctival swab. Conjunctival swabs have very low sensitivity for the detection of COVID-19. However, tears could still be a mode of disease transmission, especially from patients to eye care specialists.Keywords: COVID-19, conjunctival swab, sensitivity, specificity, RNA