Influenza is a kind of flu like illness. It mostly affects respiratory tract. It is a kind of contagious respiratory disease, caused by influenza virus, which infects nose, throat and lungs of a person. Image Source - uploaded by author How influenza spreads? It spreads through droplets, from cough or sneeze of influenza infected patient. When you touch those surfaces, where these droplets of influenza infected patient are present, and then touch your mouth, nose and eyes, you also get infected. When do influenza infected person, most infectious? That means, at what stage of influenza, patient’s droplet are most infectious ? Patient is most infectious (contagious) during the first 3 days of illness. If a patient is presently not showing symptoms of influenza , but infected with influenza virus, still that patient can infect another healthy person. That means, influenza virus infected asymptomatic patient, can infect another healthy person. It is...