Infected people generate larger droplets and aerosols which can infect over longer distances A poster outlining precautions for<unk>  in healthcare settings. It is intended to be posted outside rooms of patients with an infection that can spread through<unk> . Video explainer on reducing<unk>  pathogen<unk>  indoors<unk>  or aerosol<unk>  is<unk>  of an infectious disease through small particles suspended in the air. Infectious diseases capable of<unk>  include many of considerable importance both in human and veterinary medicine. The relevant infectious agent may be viruses, bacteria, or fungi, and they may be spread through breathing, talking, coughing, sneezing, raising of dust, spraying of liquids, flushing toilets, or any activities which generate aerosol particles or droplets. This is the<unk>  of diseases via<unk>  of an infectious agent, and does not include diseases caused by air pollution.<unk>  traditionally has been considered distinct from<unk>  by droplets, but this distinction is no longer used. Respiratory droplets were thought to rapidly fall to the ground after emission. Individuals generate aerosols and droplets across a wide range of sizes and concentrations, and the amount produced varies widely by person and activity. Larger droplets greater than 100 μm usually settle within 2 m. Smaller particles can carry<unk>  pathogens for extended periods of time. While the concentration of<unk>  pathogens is greater within 2m, they can travel farther and concentrate in a room. The traditional size cutoff of 5 μm between<unk>  and respiratory droplets has been discarded, as exhaled particles form a continuum of sizes whose fates depend on environmental conditions in addition to their initial sizes. This error has informed hospital based<unk>  based precautions for decades. Indoor respiratory secretion transfer data suggest that droplets/aerosols in the 20 μm size range initially travel with the air flow from cough jets and air conditioning like aerosols, but fall out gravitationally at a greater distance as "jet riders". As this size range is most efficiently filtered out in the nasal mucosa, the primordial infection site in COVID-19, aerosols/droplets in this size range may contribute to driving the COVID-19 pandemic.
Airborne transmission
Vertical transmission
Horizontal transmission
Human-to-human transmission
Intentional contagion of infection
Natural reservoir
Animal bite
Fecal–oral route