Isolating ourselves when acutely ill prevents community spread—and also protects us from acquiring a second acute illness during the course of the acute illness. More than one illness can spread in a community at the same time, such as chlamydia, influenza, whooping cough, RSV, etc. Acquiring two acute illnesses at the same time, i.e. combination of bacterial, viral, and/or parasitic diseases, increases the risk of developing a more serious acute illness and of developing chronic disease.
When a person has a chronic disease and develops an acute illness, the acute illness can worsen the underlying chronic disease. Influenza-like illnesses can trigger a stroke, for 15-60 days after the illness, and the risk of stroke increases if the patient was hospitalized for an acute “influenza-like illness” and with each decade of age.
Isolating ourselves is a good policy whenever we are acutely ill—not just for coronavirus.
Boehme A, et al. 2018. Influenza-Like Illness as a Trigger for Ischemic Stroke. Ann Clin and Transl Neurology. Apr 2018. 5(4): 456-463. Doi: 10.1002/acn3.545.