i was just reading some information on yellow fever virus , and it says that yellow fever virus is an acute viral disease. i dont quite understand what the "acute" in there means. can some one plz explain to me in simple terms?
Generally, acute means it’s "sudden", i.e. first you don’t have it, and after the exposure to the virus you do. Acute also means it’s more or less temporary. Although if you don’t manage to get rid of the virus, the infection may become chronic – that is, long lasting.
Examples of an acute viral infection: influenza, Ebola ( 🙂 )
Examples of a chronic infection: herpes simplex infection (in the central nervous system, after an initial acute phase). HIV infection is also chronic (similarly after an acute phase).
Yes, in a similar manner. E.g tuberculosis can often be a chronic infection lasting for decades (although if the infection causes no visible symptoms, it is often called subclinical). A bacterial pneumonia, on the other hand, is a usually a typical acute infection: a quick onset with clear symptoms and lasts for a limited time (if not treated by antibiotics it either goes away eventually or kills the patient, but rarely becomes a chronic infection).
I don’t think there are universal criteria to determine when exactly an infection is acute and when cronic, but you could think it this way: if you fall and hurt your knee the pain is acute. If you have a poor back and it has been aching for months of years, the the pain is chronic. With infections it’s pretty much the same 🙂