Three weeks ago, in Catalonia: Enterovirus Outbreak Hospitalizes 29 Children, we looked at an unusually large, ongoing outbreak of EV-71 in the Northeast of Spain (followed up here).
Human Enterovirus 71 (EV-71) – which is most commonly reported in Asia and the Western Pacific region - is one of more than 60 non-polio enteroviruses (NPEVs) known to cause cause human illnesses.
NPEVs generally produce mild illness, or are asymptomatic infections that occur primarily in children under the age of 10. Symptomatic cases can range from a mild fever or a runny nose - to HFMD (Hand Foot Mouth Disease) - or very rarely, may escalate to viral meningitis or encephalitis, or even Acute Flaccid Paralysis.
EV-71 is one of several NPEVs known to cause serious - sometimes even fatal - neuroinvasive disease in a small percentage of cases.
In 2014, we saw a different NPEV - EV-D68 - spread rapidly across the United States and into parts of Europe, causing scores of cases of polio-like paralysis (see Eurosurveillance: Acute Flaccid Paralysis Following EV-D68 Infection – France).
Due to its reputation for heightened virulence, over the years we've followed both the spread, and the evolution, of EV-71.
- In 2009 China reported 1,155,525 HFMD cases, including 13,810 severe cases and 353 deaths. Among laboratory confirmed cases, EV71 was responsible for 41% of cases, 82% of severe cases, and 93% of the deaths (cite WHO HFMD Guide Pg.6).
- In 2012, we saw an outbreak of EV-71 in Cambodia that claimed the lives of dozens of children (see Updating The Cambodian EV71 Story).
- In 2013 in Australia: Acute Flaccid Paralysis & EV71, we looked at a report that described 5 cases of acute flaccid paralysis (AFP) in children who tested positive for the EV71 virus.
- And two years ago, in EID Journal: New Introductions Of EV-71 Subtype C4 To France – 2012, we saw evidence of multiple introductions of the more aggressive C4 genotype – which first appeared in China in 1998 - into Europe.
Large outbreaks of EV-71 still occur every year in Asia and the Western Pacific - and as stated often in the past - there's no good reason to believe outbreaks won't eventually become more common in Europe or the Americas.
All of which brings us to a RRA published by the ECDC today on the the EV-A71 outbreak in Catalonia, Spain which is the largest seen in Europe in decades. The report warns:
`There is evidence to suggest that the epidemiological pattern of EV-A71 in Europe is going through a change, both due to virus molecular evolution, as well as an increasing likelihood of importation of new virus strains from outside the EU.'
You'll find the press release below. But you'll also want to download, and read, the full report.
Outbreak of enterovirus A71 in Catalonia, Spain – rapid risk assessment
16 Jun 2016
ECDC has published a rapid risk assessment due to a localised outbreak of neurological symptoms associated with enterovirus A71 (EV-A71) in Catalonia, Spain.
Most EV infections, including EV-A71, result in asymptomatic infection. Most symptomatic EV-A71 infections manifest as a self-limiting hand, foot and mouth disease and only a very small proportion of patients develop severe and life-threatening disease. The current outbreak is notable in terms of its magnitude and the severity of symptoms of the reported cases.
The outbreak with neurological complications caused by enterovirus has been ongoing in Catalonia since mid-April 2016, affecting children up to ten years of age. As of 7 June, 87 cases of enterovirus infection with neurological complications have been reported, most of which have evolved favourably, but 22 of the cases remain in hospital, including seven in intensive care units. According to the information received from regional authorities, there are no deaths related to this outbreak. The cases are widespread in Catalonia.
Other EU Member States have not reported concomitant enterovirus outbreaks and ECDC is not aware of signals of other unusual enterovirus outbreaks in the EU.
There is evidence to suggest that the epidemiological pattern of EV-A71 in Europe is going through a change, both due to virus molecular evolution, as well as an increasing likelihood of importation of new virus strains from outside the EU. The full characterisation of the isolates from the Spanish outbreak, and comparison of these to virus sequences from other countries and continents, should contribute to a better understanding of the changing pattern of EV-A71 epidemiology in Europe.
This outbreak of EV-A71 together with the previously reported clusters of EV-D68 reinforces the need for vigilance for enterovirus infections presenting with hand, foot and mouth disease and more severe clinical syndromes. Paediatricians should be encouraged to obtain specimens for enterovirus detection and characterisation from all patients presenting with symptoms suggestive of meningitis, encephalitis or acute flaccid paralysis (AFP), as well as hand, foot and mouth disease. In addition to non-polio enterovirus laboratory surveillance, AFP surveillance for purposes of polio surveillance or surveillance of meningoencephalitis are likely to be the most sensitive clinical surveillance systems to pick up such signals.
As a general precaution, children residing in or travelling to Catalonia should avoid contact with symptomatically ill children and follow strict hygiene in personal contacts.
Most EV infections, including EV-A71, result in asymptomatic infection. Most symptomatic EV-A71 infections manifest as a self-limiting hand, foot and mouth disease and only a very small proportion of patients develop severe and life-threatening disease