Enteroviruses infect an estimated 50 million people each year in the US and possibly a billion or more worldwide. While ninety percent of enteroviral infections are asymptomatic or result in a mild illness, counting up the fraction of those with serious illness adds up to a large number of people.
Enteroviruses are small, very contagious viruses made of ribonucleic acid (RNA) and protein. The most well known are polioviruses -- the cause of paralytic poliomyelitis, commonly known as polio. While paralytic poliomyelitis is targeted for global eradication through vaccination, the nonpolio enteroviruses continue to be responsible for a wide spectrum of diseases. Infants and young children are hit hardest, however adults are affected as well. (Goldman, 2008).
The unsettling fact about enteroviruses is that they can spread to various organs and persist in the body for years -- potentially causing disease long after the initial infection.
Enteroviruses are associated with at least 26 different syndromes and diseases, including coronary heart disease, type 1 diabetes, hand-foot-and-mouth disease, chronic fatigue syndrome/myalgic encephalomyelitis, encephalitis, herpangia, myocarditis, pleurodynia, ADHD, and central nervous system infections such as polio, meningitis, encephalitis, chronic meningoencephalitis, and acute flaccid paralysis. It is possible for an enteroviral infection to result in a multi-organ illness or a series of illnesses in different organs spanning several years.
Enteroviruses are small, nonenveloped, positive-stranded RNA viruses that are directly or indirectly transmitted from person to person, initially infecting the enteric or intestinal tract. Fifty to eighty percent of enterovirus infections are completely asymptomatic. They cause a wide variety of clinical syndromes, most benign and self-limiting; however, the same viruses can cause severe and life threatening diseases.
Enteroviruses are very contagious. They are typically spread by fecal-oral route (this only takes microscopic amounts and is why hand washing is important), and can also be spread by respiratory routes and from mother to infant in the peripartum period.
Enteroviruses are acid stable and able to survive exposure to the tough environment of the gastrointestinal tract. They can also survive chlorine, freezing, and can live on surfaces for several days, long enough to allow for transmission by fomites such as door handles, pillowcases, and dust. The virus can be killed with standard disinfectant and heat. The average incubation period is 3-10 days.
Enteroviral infections are common during infancy. The majority of children have experienced at least one enteroviral infection by one year of age. Infection is also very common in family members and those who work with young children. Adults are less likely to get acute infections due to built up immunity and better hygiene; however, poor conditions can result in more infections in this group. The immuno-compromised also have a high risk for acute infection.
Although it is clear that enteroviruses can persist in the body after the initial infection is over, there is currently no explanation as to why, or what groups are at a greater risk.
There currently is no approved treatment for enteroviral infections. Hand washing is the most effective way to reduce the spread of infection. Please see the US Centers for Disease Control and Prevention site for effective preventative measures. http://www.cdc.gov/ounceofprevention/