What are enteroviral infections?
Enteroviral infections cover a wide range of illnesses that are caused by a group of viruses called enteroviruses (EVs). They are members of the Picornaviridae family which are small, icosahedral, single-stranded, positive-sense RNA viruses.
The most well known of the enteroviruses is the Poliovirus (PV) but this has largely been eradicated. Other enteroviruses are the coxsackie A and B viruses (CVA and CVB) and the echoviruses (Es).
How are enteroviruses classified?
Enteroviruses have been classified into 5 groups based on their molecular properties:
|Enterovirus (EV)||Enteroviral illness|
|Human EV A (HEV-A)
|Human EV B (HEV-B)
|Human EV C (HEV-C)
|Human EV D (HEV-D)
Enteroviruses are the cause of many illnesses including the common cold. Some of the coxsackieviruses, echoviruses and EV71 cause a number of skin diseases. Many of the enteroviruses cause exanthems (skin rash or skin eruption as a symptom of a more general disease) or enanthems (rash on the mucous membranes).
Who gets enteroviral infections and how is it spread?
Enteroviral infections are very common and it is estimated that more than one billion people worldwide are affected annually. It appears that people in lower socio-economic groups are more susceptible. In the United States 30,000 to 50,000 hospitalisations each year are due to enteroviral infections.
Enteroviral infections are highly contagious. Enteroviruses spread from person-to-person via oral-oral routes, for example viruses are carried in respiratory droplets when someone sneezes. Other routes are oral-faecal and through direct contact with fluid from skin lesions.
The incubation period for enteroviruses is usually 2-5 days. Once someone is infected the enterovirus implant and replicate in the alimentary tract.
If the infection remains local there is usually no symptoms. However, if the virus passes into the lymphatic system, generalised symptoms of un-wellness may develop. If the virus spreads into the bloodstream then more severe symptoms are experienced.
Enteroviral infections that cause skin reactions
Many enteroviruses cause diseases that have associated skin or mucous membrane reactions. The cutaneous features of some of these diseases are shown in the table below.
|Enteroviral infection||Cutaneous features|
|Boston exanthem disease||
Below is a list of other cutaneous features that have been associated with the following enteroviruses.
|Cutaneous feature/eruption||Causative enterovirus|
|Pustular stomatitis with erythema multiforme||CVB5|
|Widespread vesicular eruption (blisters)||CVA4|
|Infantile papular acrodermatitis (Gianotti-Crosti)||CVA16|
|Rubelliform eruption (see rubella)||E2|
|Morbilliform eruption (see measles)||E6, E11, E25|
|Petechiae (tiny purple spots or purpura)||E11, E19|
|Punctate macular eruption (tiny flat spots)||E19|
|Vesicular eruption (blisters)||E11|
What is the treatment of enteroviral infections?
Most enteroviral infections heal spontaneously within 7-10 days. Less than 1% of enteroviral infections result in serious symptomatic illness. Cutaneous lesions heal by themselves without scarring.
Treatment is limited to supportive therapy.
- Hydration with plenty of fluids
- Antipyretics such as paracetamol for fever
- Mouth rinses with topical anaesthetics to relieve mouth pain.
Occasionally enteroviruses can causes severe heart and nervous system complications such as myocarditis, aseptic meningitis, meningoencephalitis and paralysis. The antiviral drug pleconaril has shown to be effective treatment in some severe enteroviral infections. This is not yet available in New Zealand (August 2008).