These viruses infect the enteric tract and are transmitted by the fecal–oral route. Poliovirus rarely causes disease in the United States because of the vaccine but remains an important cause of aseptic meningitis and paralysis in developing countries. Of more importance in the United States are Coxsackie viruses, which cause aseptic meningitis, myocarditis, and pleurodynia; and echoviruses, which cause aseptic meningitis. (See Chapter 40.)
These viruses are the most common cause of the common cold. They have a large number of antigenic types, which may account for their ability to cause disease so frequently. (See Chapter 38.)
These viruses possess an unusual genome composed of double-stranded RNA in 11 segments. Rotaviruses are an important cause of viral gastroenteritis in young children. (See Chapter 40.)
This virus is an important cause of hepatitis. It is an enterovirus but is described in this book in conjunction with hepatitis B virus. It is structurally different from hepatitis B virus, which is a DNA enveloped virus. Furthermore, it is epidemiologically distinct (i.e., it primarily affects children, is transmitted by the fecal–oral route, and rarely causes a prolonged carrier state). (See Chapter 41.)
Noroviruses are a common cause of gastroenteritis, especially in adults. They are a well-known cause of outbreaks of vomiting and diarrhea in hospitals, in nursing homes, and on cruise ships (See Chapter 40).
The main human pathogen in the hepevirus family is hepatitis E virus (HEV). It causes hepatitis acquired by fecal–oral transmission similar to hepatitis A virus. HEV is a nonenveloped virus with a positive-polarity single-stranded RNA genome. (See Chapter 41.)