Respiratory infections can be transmitted through droplets of different sizes: when the droplet particles are >5-10 μm in diameter they are referred to as respiratory droplets, and when then are <5μm in diameter, they are referred to as droplet nuclei.1
Droplet transmission occurs when a person is in in close contact (within 1 m) with someone who has respiratory symptoms (e.g., coughing or sneezing) and is therefore at risk of having his/her mucosae (mouth and nose) or conjunctiva (eyes) exposed to potentially infective respiratory droplets.
6
传播也可能通过被感染者周围直接环境中的污染物发生8。
Transmission may also occur through fomites in the immediate environment around the infected person.8
Airborne transmission is different from droplet transmission as it refers to the presence of microbes within droplet nuclei, which are generally considered to be particles <5μm in diameter, can remain in the air for long periods of time and be transmitted to others over distances greater than 1 m.
In the context of COVID-19, airborne transmission may be possible in specific circumstances and settings in which procedures or support treatments that generate aerosols are performed; i.e., endotracheal intubation, bronchoscopy, open suctioning, administration of nebulized treatment, manual ventilation before intubation, turning the patient to the prone position, disconnecting the patient from the ventilator, non-invasive positive-pressure ventilation, tracheostomy, and cardiopulmonary resuscitation.
9
有证据表明COVID-19感染有可能导致肠道感染并出现在粪便中。
There is some evidence that COVID-19 infection may lead to intestinal infection and be present in faeces.
10
然而，迄今为止，只有一项研究从一个粪便样本中培养出了COVID-19病毒9。
However, to date only one study has cultured the COVID-19 virus from a single stool specimen.9