Picornarviridae

It is the oldest viruses which found in ancient Egypt at 1400 B.C. Picornaviruses are also among the most diverse viruses, with over 200 serotypes causing infections such as Polio, Hepatitis A, and the common cold. Foot-and-Mouth Disease Virus (genus: Apthovirus), which causes infections in livestock, was one of the first viruses to be recognized; it was discovered by Loeffler and Frosch in 1898.

• Picornaviruses contain positive sense, single-stranded RNA that is approximately 7-8 kilobases long.


• The viral RNA is infectious and replication takes place in the cytoplasm.


• The virus has an IRES (Internal Ribosomal Entry Site) which distinguishes it from many other RNA viruses.


• The virus is naked with an icosahedral capsid.


• The capsid is one of the smallest of all viruses with a diameter of only 27-30nm.


• Translation and cleavage of viral polypeptides produces eleven distinct proteins.

Picture extracted: http://student.ccbcmd.edu/courses/bio141/lecguide/unit3/viruses/dkpolio.html