Virus causing COVID-19: transmission routes and infection prevention

The World Health Organization (WHO) has issued a scientific brief detailing the transmission modes of the virus causing COVID-19 and the implications for infection prevention recommendations. The report clarifies that the virus primarily spreads between people through respiratory droplets and contact.

Droplet transmission occurs when individuals are exposed to respiratory secretions, such as from coughing or sneezing, in close proximity (within 1 meter), potentially exposing mucous membranes. Transmission can also occur through indirect contact with contaminated surfaces or objects in the infected person's environment.

Airborne transmission, involving smaller particles that can remain in the air for extended periods and travel over distances, is considered possible only in specific circumstances and settings involving aerosol-generating procedures. While some preliminary studies have detected the virus in air samples under controlled laboratory conditions, the WHO stresses the need for careful interpretation and further research to confirm airborne transmission in real-world clinical settings.

Based on the available evidence, the WHO continues to recommend droplet and contact precautions for the care of COVID-19 patients. Airborne precautions are advised for situations involving aerosol-generating procedures, based on risk assessment. The organization reiterates the importance of proper use of all personal protective equipment, hand hygiene, respiratory etiquette, environmental cleaning, and maintaining physical distancing.