COVID-19 is a respiratory illness caused by the SARS-CoV-2 virus. While its primary mode of transmission is well-understood, questions often arise about less obvious pathways for the virus to enter the body.
Understanding COVID-19 Transmission
The SARS-CoV-2 virus primarily spreads when an infected individual expels respiratory droplets and very small particles through activities like breathing, talking, coughing, or sneezing. Other people can then inhale these virus-containing particles, or the particles can land directly on their eyes, nose, or mouth. In addition, touching surfaces or objects contaminated with the virus and then touching one’s own mouth, nose, or eyes can lead to infection, although this is considered a less common mode of spread than direct respiratory exposure.
The Eyes as an Entry Point
The eyes can serve as a portal for the SARS-CoV-2 virus to enter the body. The conjunctiva, which is the mucous membrane covering the front surface of the eye and the inner eyelids, contains receptors that the virus can use to enter cells. Respiratory droplets carrying the virus can directly land on this vulnerable membrane.
Infection is also possible if contaminated hands, after touching surfaces with the virus, then touch the eyes. Some individuals with COVID-19 have developed ocular symptoms, such as conjunctivitis, commonly known as pink eye. The presence of viral particles has been detected in the ocular fluid of infected individuals, suggesting the eye’s susceptibility to the virus.
The Ears as an Entry Point
The external ear canal is not considered a primary or significant entry point for SARS-CoV-2. Unlike the eyes, nose, and mouth, the skin lining the outer ear canal does not contain the mucous membranes that the virus typically uses for entry. This skin barrier, along with earwax, offers protection.
While some studies have detected the SARS-CoV-2 virus in the middle or inner ear structures of deceased COVID-19 patients, this does not indicate external ear canal entry. The main concern for the ears would be indirect transmission, where contaminated hands touch the external ear after being exposed to the virus from the mouth or nose. Overall, the likelihood of direct viral entry through the ear canal is considered very low.
Protecting These Pathways
Protecting the eyes and ears from potential viral exposure involves practical measures. Rigorous hand hygiene is fundamental, as frequent and thorough handwashing with soap and water for at least 20 seconds helps remove the virus from hands. It is also important to avoid touching the face, especially the eyes, nose, and mouth, with unwashed hands. For additional protection in certain settings, eye coverings such as glasses, goggles, or face shields can provide a barrier against respiratory droplets reaching the eyes. Face shields are particularly effective as they cover a larger area of the face.