Enterovirus: biology, diseases, transmission and public health significance

Structure and genome

Enteroviruses are non-enveloped, icosahedral particles that contain a single-stranded, positive-sense RNA genome of roughly 7,000–8,000 nucleotides. The genome is translated as a single polyprotein that is subsequently cleaved into structural and nonstructural proteins needed for replication. Their stability outside a host and the small genome size are characteristic features that influence how they spread and persist in populations; for technical background on their RNA biology see molecular descriptions.

Transmission and life cycle

Most enteroviruses spread by the fecal–oral route, although some may transmit via respiratory secretions or close contact. Following entry (often via the gut or upper respiratory tract) they replicate in local tissues and may circulate in the blood to reach other organs. Seasonality is common in temperate climates, with more cases in summer and early autumn. Viral shedding in stool can continue for weeks after symptoms resolve.

Clinical manifestations and notable types

Clinical outcomes vary widely by virus type and host factors. Common illnesses include:

• Hand, foot, and mouth disease and herpangina (often caused by coxsackie A and enterovirus A types).
• Aseptic (viral) meningitis – an important cause of meningitis in children and adults.
• Myocarditis and neonatal sepsis-like illness can occur with certain types.
• Poliovirus historically caused paralytic poliomyelitis; vaccination has greatly reduced its incidence worldwide (poliovirus resources).
• Recent attention has focused on respiratory-associated outbreaks and rare neurological complications such as acute flaccid myelitis linked to some nonpolio enteroviruses.

For concise clinical notes on meningitis caused by this group, see meningitis references.

Diagnosis, treatment and prevention

Diagnosis relies on nucleic acid detection (PCR) from stool, throat swabs or cerebrospinal fluid, and on virus isolation in specialized laboratories. Treatment is mainly supportive; no broadly effective antiviral drugs are widely used for enterovirus infections, although research is ongoing. Prevention emphasizes hand hygiene, sanitation and, where available, vaccination — most notably the inactivated and live attenuated vaccines that control poliovirus. Public-health measures focus on surveillance and outbreak control.

History and public health importance

Enteroviruses have been known to medical science for over a century, with poliovirus and the clinical syndromes it causes being central to the development of modern virology and immunization campaigns. Nonpolio enteroviruses continue to cause seasonal epidemics of mild and occasionally severe disease, and they remain a cause of hospitalizations for meningitis, neonatal illness and respiratory disease. Ongoing surveillance, laboratory capacity and vaccination programs are the primary tools for reducing their health impact.