“Influenza is a contagious respiratory disease transmitted from person to person primarily via virus-laden droplets. Viral shedding starts 24 to 48 hours after infection, and typically 24 hours before the onset of symptoms. Shedding normally persists less than 5 days but can be longer in children and in those who are immuno-compromised.  Respiratory syncytial virus, or RSV, is a respiratory virus that infects the lungs and breathing passages. Like influenza, RSV is transmitted via virus-laden droplets. People infected with RSV are usually contagious for 3 to 8 days, although some infants or immunocompromised people can be contagious for several weeks.”

OHSU (OHSU.ed)