Which transmission route is most common for respiratory infections?

Respiratory droplets are the most common transmission route for respiratory infections because these droplets are expelled when an infected person coughs, sneezes, talks, or breathes. When these respiratory droplets are inhaled by someone nearby, the pathogens can be effectively transmitted, leading to infections. This mode of transmission is particularly significant for viruses such as influenza, the common cold, and more recently, SARS-CoV-2, which causes COVID-19.

Direct contact with infected individuals, while also a possible route of transmission, is less common for respiratory infections specifically. It typically involves close physical contact and may not efficiently transmit pathogens that are primarily spread through droplets. Contaminated surfaces can serve as reservoirs for pathogens but are not the predominant method for spreading respiratory infections, compared to droplet transmission. Vector-borne transmission usually involves insects that carry diseases from one host to another, which is not applicable to most respiratory pathogens. Therefore, the primary and most effective means of spreading respiratory infections remains through respiratory droplets.