A total of 31 distinct echovirus serotypes are known to infect humans. Although
the majority of infections are asymptomatic, disease when it does occur depends
on the age, gender and immune status of the host, as well as the subgroup and serotype
of the infecting strain.
Non-polio enteroviruses, which include all Coxsackieviruses and Echoviruses, constitute
a major subgroup of small RNA viruses (picornaviruses) that readily infect and are
shed from the lower digestive tract. Initially it was believed that these agents
primarily caused mild acute aseptic meningitis syndromes, pleurodynia, exanthems,
pericarditis, non-specific febrile illness and occasional fulminant encephalomyocarditis
of the newborn. It is now apparent that their spectrum of disease is much broader;
there may be permanent sequelae and some infections may trigger chronic active disease
Although echoviruses, like all other enteroviruses, are predominantly organisms
of the gastrointestinal tract with transmission by the faecal oral route. Where
hygiene standards are adequate to prevent this, limited transmission can still take
place via the respiratory route.
Surveillance in Scotland
Regional virus labs report confirmed cases to HPS. While the numbers of cases reported
via this route will be a gross underestimate of the levels of infection, it remains
a useful means of monitoring the predominant types of Echovirus in circulation,
as well as identifying outbreaks.
Trends in Scotland (1995-2000)
Numbers of echovirus reports to HPS have been at low levels (200 or less per year)
since 1990 when there were a large number of reports. A shift in the predominant
types is apparent for 2000, with types 13, 18 and 30 accounting for most infections
compared with types 4, 9 and 11 throughout the 1990's.
Incidence and Risk
Since the vast majority of echovirus infections are asymptomatic, it is difficult
to determine what the true incidence of infection might be. A common cause of summer
respiratory infections in children, they occur with a higher prevalence in summer
and autumn months.
The predominantly mild symptoms and the ubiquitous nature of these infections, means
that preventative measures are not usually necessary or recommended.