Prevent techniques include disease-specific immunization, wearing a respirator and limiting time spent in the presence of infected individuals. Wearing a face mask can lower the risk of transmission, as it slows the air flow between individuals. The type of mask that is effective against<unk>  is dependent on the size of the particles, whilst fluid-resistant surgical masks prevent droplet inhalation, smaller particles which form aerosols require a higher level of protection with filtration masks rated at N95 (US) or FFP3 (EU) required. Use of FFP3 masks by staff managing patients with COVID-19 reduced acquisition of COVID-19 by staff members. Personal protective equipment (PPE) is lower down the hierarchy of control than engineering solutions which aim to control or eliminate the exposure. In this context effective ventilation and high frequency air changes, or air filtration through high efficiency particulate filters, reduce detectable levels of virus and other bioaerosols. Portable air filters, such as those tested in Conway Morris A et al present a readily deployable solution when existing ventilation is inadequate, for instance in repurposed COVID-19 hospital facilities. Exposure does not guarantee infections, as infection is dependent on host immune system competency plus the quantity of infectious particles ingested. Antibiotics may be used in dealing with<unk>  bacterial primary infections, such as pneumonic plague. The United States Centers for Disease Control and Prevention (CDC) advises the public about vaccination and following careful hygiene and sanitation protocols for<unk>  disease prevention. Many public health specialists recommend physical distancing (also known as social distancing) to reduce transmission. A 2011 study concluded that vuvuzelas (a type of air horn popular e.g. with fans at football games) presented a particularly high risk of<unk> , as they were spreading a much higher number of aerosol particles than e.g., the act of shouting.
Airborne transmission
Vertical transmission
Horizontal transmission
Human-to-human transmission
Intentional contagion of infection
Natural reservoir
Animal bite
Fecal–oral route