Friday, June 03, 2016

ECDC CDTR Assessment - Enterovirus Outbreak in Catalonia


Twelve days ago, in Catalonia: Enterovirus Outbreak Hospitalizes 29 Children we looked at early reports of an outbreak of severe enterovirus in Catalonia - in the Northeast of Spain.

While not explicitly stated, my assumption at the time was that the culprit was likely EV-71, which the ECDC confirms in today's report. 

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 illness, and that primarily affect children under the age of 10 - usually in the form of HFMD.

EV-71 is also somewhat notorious for occasionally causing serious - even fatal - neuroinvasive disease in some small percentage of cases. 

First, the ECDC assessment, followed by a fresh media report that increases the number of hospitalized children to 82, and some additional background.

New! Outbreak of Enterovirus

Opening date: 30 May 2016
A71 - Catalonia, Spain - 2016
Latest update: 3 June 2016

Epidemiological summary

An outbreak of enterovirus with neurological complications caused by enterovirus A71 has been ongoing in Catalonia since mid-April 2016 affecting children. As of 31 May, 73 cases of enterovirus infection with neurological complications have been reported, most of which have evolved favourably. The cases are widespread in Catalonia. No cases have been identified from other areas in Spain so far.

Web sources: Department of Health, Catalonia |Media

ECDC assessment

Enterovirus A71 (EV-A71) is a major cause of hand, foot and mouth disease (HFMD) and is particularly prevalent in parts of Southeast Asia, affecting thousands of children and infants each year. EV- A71 infection is transmitted from person to person by direct contact with nose and throat discharges, saliva, fluid from blisters, or the stool of infected persons.
The illness is contagious during the acute stage and perhaps longer, as faecal shedding of the virus can continue for several weeks. Incubation period ranges from 3 to 7 days.
It is the most neuropathogenic nonpolio enterovirus in humans, causing a variety of neurological diseases including aseptic meningitis, encephalitis and poliomyelitis-like paralysis.
Large outbreaks have been reported in Malaysia, Taiwan, Mainland China, Singapore, Australia. In Europe, EV-A71 commonly causes asymptomatic infection and is only occasionally associated with severe neuroinfection.
The last epidemics of EV-A71 infection in Europe occurred during 1975 in Bulgaria with over 705 cases, of which 149 cases developed paralysis, and 44 deaths. Hungary  experienced an outbreak of EV-A71 in 1978 with 323 cases (13 poliomyelitis-like paralysis, 145 encephalitis, 161 aseptic meningitis, 4 hand, foot and mouth disease).

This week's CDTR also includes updates on West Nile, MCR-1, Yellow Fever and Zika virus around the world.

The most recent media report (dated today) raises the number of children affected to 82.

Six children with enterovirus are in the ICU and those affected rises to 82

Updated 06/03/2016 at 17:13


Six children affected by enterovirus with neurological disorders are admitted to the intensive care unit ( ICU ), two more than last Monday, and the total affected has risen Friday to 82 children, most of whom have the type A71 associated with the rhombencephalitis. 

Speaking to the media after meeting in follow - up committee, deputy director of the Catalan Health Service (CatSalut), Josep Maria Argimon; Secretary of Public Health, Joan Guix; the Chief of Pediatrics Hospital Vall d'Hebron in Barcelona, ​​Carlos Rodrigo, and the head of Microbiology Department of Vall d'Hebron, Tom├ás Pumarola have updated the number of cases and specified distribution. 

According Argimon in health region of Camp de Tarragona have detected 32 cases a "superior number expected" ; in Barcelona and its metropolitan region they have registered 35 cases ; in Girona , five affected; Central Catalonia four cases; in Lleida other four , and Terres de l'Ebre two cases

While it has been nearly 40 years since Europe has seen very  large outbreaks of EV-71, we continue to see large epidemics in China, Taiwan, Cambodia and Vietnam nearly every summer, often involving thousands of children and dozens of deaths.

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).

Among the challenges of controlling EV71 outbreaks are:

For now, control and prevention are limited to promoting good hygiene, and removing children with signs of the disease from child care or school environments.

We've been fortunate that HFMD outbreaks in Europe and North America have been largely confined to the milder A16, A10 and (the somewhat more serious) A6 coxsackieviruses (see EID Journal: HFMD Cluster Due To CVA6), and not the more dangerous EV-71. 

But as we saw two summers ago in EID Journal: New Introductions Of EV-71 Subtype C4 To France – 2012, and now with this outbreak in Catalonia, there is little reason to believe that EV-71 will forever remain only a problem in Asia and the Western Pacific.