Human-to-human transmission occurs mainly through respiratory droplets, but other routes are under investigation, because SARS-CoV-2 has been detected in several body fluids.
With regard to COVID-19, unprotected ocular exposure was thought to be responsible for infections that occurred in the Wuhan Fever Clinic in January 2020; in addition, SARS-CoV-2 RNA was detected in conjunctival secretions collected from the only patient with conjunctivitis out of 30 patients with COVID-19 from a hospital in China. However, further studies were needed to evaluate the infectious potential of the SARS-CoV-2 RNA detected in the ocular specimens and to determine whether transmission may occur through ocular secretions.
In this way, researchers from the Imi Spallanzani in Rome (Italy) have isolated the new coronavirus in the tears of a patient, proving that the virus is also active and potentially infectious in the ocular secretions of people affected by COVID-19, including when respiratory samples are negative.
In the study published in the Annals of Internal Medicine, the experts used an eye swab three days after hospitalization of a patient infected with COVID-19 and who also suffered from bilateral conjunctivitis. Later, the experts managed to isolate the virus, which shows that the new coronavirus is capable of replicating in the conjunctiva.
However, further studies will be needed to verify how long the virus remains active and potentially infectious in tears ―molecular analysis detects only the presence of viral RNA in the sample and only the isolation of the virus in a cell culture can demonstrate its infectious capacity―.
This finding has already been reported to the World Health Organization (WHO) before being published in the scientific journal.
Link to the paper: https://doi.org/10.7326/M20-1176
Editorial Disclaimer: information published during the 2020 COVID-19 pandemic may be updated frequently to reflect the dynamic nature of current understanding.