Non-Polio enterovirus infections overview

# Overview
Enteroviruses are a genus of positive-sense single-stranded RNA viruses associated with several human and mammalian diseases. Serologic studies have distinguished 66 human enterovirus serotypes on the basis of antibody neutralization tests. Additional antigenic variants have been defined within several of the serotypes on the basis of reduced or nonreciprocal cross-neutralization between variant strains.

# Classification
On the basis of their pathogenesis in humans and animals, the enteroviruses were originally classified into four groups, polioviruses, Coxsackie A viruses (CA), Coxsackie B viruses (CB), and echoviruses, but it was quickly realized that there were significant overlaps in the biological properties of viruses in the different groups. Enteroviruses isolated more recently are named with a system of consecutive numbers: EV68, EV69, EV70, and EV71, etc..

# Pathophysiology
Enteroviruses can be found in respiratory secretions (e.g., saliva, sputum, or nasal mucus) and stool of an infected person. Other persons may become infected by direct contact with secretions or stool from an infected person or by contact with contaminated surfaces or objects, such as a drinking glass or telephone. Parents, teachers, and child care center workers may also become infected by contamination of the hands with stool from an infected infant or toddler during diaper changes.

# Causes
Non-polio enterovirus infections are caused by enteroviruses. Enteroviruses are a genus of positive-sense single-stranded RNA viruses associated with several human and mammalian diseases. Enteroviruses are made of ribonucleic acid (RNA) and protein. This group includes the polioviruses, coxsackieviruses, echoviruses, and other enteroviruses. In addition to the three different polioviruses, there are over 60 types of non-polio enteroviruses that can cause disease in humans. Non-polio enteroviruses are very common. They are second only to the "common cold" viruses, the rhinoviruses, as the most common viral infectious agents in humans.

# Epidemiology and Demographics
Non-polio enteroviruses are very common. They are second only to the "common cold" viruses, the rhinoviruses, as the most common viral infectious agents in humans. The enteroviruses cause an estimated 10-15 million or more symptomatic infections a year in the United States. However, all three types of polioviruses have been eliminated from the Western Hemisphere, as well as Western Pacific and European regions, by the widespread use of vaccines.
Parents, teachers, and child care center workers may be prone to non-polio enterovirus infections as they can become infected by contamination of the hands with stool from an infected infant or toddler during diaper changes.

# Risk Factors
Although everyone is at risk of infection, factors such as age and season can increase the chance of an individual getting infected by non-polio enteroviruses.

# Diagnosis

## History and Symptoms
Most people who are infected with a non-polio enterovirus have no disease at all. Infected persons who become ill usually develop either mild upper respiratory symptoms (a "summer cold"), a flu-like illness with fever and muscle aches, or an illness with rash.