Enteroviruses are a genus of (+)ssRNA viruses associated with several human and mammalian diseases. Serologic studies have distinguished 66 human enterovirus serotypes on the basis of antibody neutralization tests. Enteroviruses affect millions of people worldwide each year, and are often found in the respiratory secretions (e.g., saliva, sputum, or nasal mucus) and stool of an infected person. VP1 (virion protein 1) along with VP2, VP3 and VP4 form a closed capsid enclosing the viral positive strand RNA genome.