Human enteroviruses consist of at least 72 serotypes, which include poliovirus types 1–3, coxsackieviruses A types 1–24, coxsackieviruses B types 1–6, echoviruses types 1–34, and entero-viruses 68–71. Originally hepatitis A virus (enterovirus 72) was included in this group but has been reclassified as a hepatovi-rus in the genus Hepatovirus.
The capsids of the enteroviruses are very resistant to environmental conditions and the conditions in the gastro-intestinal tracts. They can remain viable for several weeks in feces at room temperature. They also remain viable for a year at 220 to 270°C and for months at 4°C. The virus may sur-vive heat at 60°C in food stuffs and also holder method of pasteurization. The enteroviruses are also rapidly inactivated by 0.3% formaldehyde, 0.1 M hydrochloric acid, drying, or ultraviolet light. The enteroviruses are readily killed by moist heat at 50–55°C, and they are also inactivated on exposure to ether, chloroform, and deoxycholate. A higher concentration of chlorine is necessary in water to inactivate the virus in the presence of organic matter, because the latter diminishes the activities of residual chlorine.
Most enteroviruses are host specific; they infect only one or a few related species.