This video we're going to talk more details about acute viral infections. And so recall from our previous lesson video that acute infections are viral infections that have a sudden onset of symptoms where the symptoms appear very quickly and over a relatively short period of time, for example, just a few days. Now acute viral infections result in the release of viruses from an infected host cell during apoptosis, and some of the cells of the host cell will die during an acute infection. However, the host or the human itself may still survive the acute viral infection despite the fact that some of its cells will die. This is because the host cell's immune system can gradually eliminate the virus from the body, again, over a relatively short period of time. Examples of acute viral infections include influenza, which is the flu, poliomyelitis or polio, mumps, and COVID-19 itself, which, of course, the COVID-19 pandemic, is associated with acute infections. If we take a look at our image down below, what you'll notice is we're showing you a graph here of an acute infection.

On the x-axis of this graph, we have time, and notice that the time is in units of days. We're talking about an infection that occurs over a short period of time, just a few days. Over here on the y-axis, what we have is the presence of symptoms and the number of virions that are present. The presence of symptoms is indicated by the dark orange area that you see and then the lighter orange area represents the presence of virions, the presence of infectious particles. Upon being infected by a virus that is going to cause an acute infection, the virus will be produced over a relatively short period of days. At its peak is when you'll have the most amount of symptoms, so the individual will have symptoms here. You can see that the virions or the viral particles will be present from the beginning to the end of the infection. The host cell's immune system is able to basically eliminate the virus. Over a relatively short period of time, just again within just a few days, the entire viral infection can be eliminated. The virus is going to be completely eliminated again after just a short period of time of just a few days and that is what characterizes it as being an acute infection. Being able to recognize this graph as an acute infection could be something that you could be tested on.

This here concludes our brief lesson on acute viral infections and we'll be able to get some practice applying these concepts and then we'll talk more about the persistent infection. So I'll see you all in our next video.