Friday, August 29, 2014

Kansas City Outbreak Identified As HEV 68

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Credit CDC – Non Polio-Enteroviruses

 

See Update Sept 6th:  Enterovirus D-68 (HEV-D68) Update

 

# 9016

 

Local media reports (see Unusual respiratory virus strikes metro kids) from Kansas City, Mo. indicate that a rarely seen – and not yet well understood – respiratory virus called HEV 68 (Human Enterovirus 68) has sickened hundreds of kids in the region this week, and that the local Children’s Hospital is unusually at full census in late August.


Without specifying the pathogen, Children’s Mercy Hospital posted the following notice yesterday on their website: Viruses in the Community Prompt Inpatient Visiting Restrictions.

 

I’ve checked the local and state Health departments but can find no official statement regarding this respiratory outbreak.  Hopefully we’ll get some official confirmation soon, but assuming local media reports are correct . . .

 

Enteroviruses encompass a large family of small RNA viruses that include the three Polioviruses, along with myriad non-polio serotypes of Human Rhinovirus, Coxsackievirus, echovirus, and human, porcine, and simian enteroviruses.  We’ve looked at EV-71 and the Coxsackieviruses on numerous occasions in regards to AFP (Acute Flaccid Paralysis) and HFMD (see herehere & here).

 

According to the CDC  Non-Polio Enteroviruses (NPEVs) cause 10 to 15 million – mostly mild and often asymptomatic – infections in the United States each year, primarily among infants, children, and teenagers. Fever, runny nose, sneezing, coughing, a skin rash or mouth blisters, and body and muscle aches are the most commonly reported symptoms.

 

First isolated in 1962, EV 68 (genus Enterovirus - family Picornaviridae – species HEV-D) has only rarely been identified over the years.  In 2011 – in MMWR: Clusters Of HEV68 Respiratory Infections 2008-2010 – we looked at a half dozen  HV 68 associated clusters which occurred in Asia, Europe, and the United States during 2008--2010.


A few excerpts from that report:

 

HEV68 infection was associated with respiratory illness ranging from relatively mild illness that did not require hospitalization to severe illness requiring intensive care and mechanical ventilation. Three cases, two in the Philippines and one in Japan, were fatal. In these six clusters, HEV68 disproportionately occurred among children.

<SNIP>

This report highlights HEV68 as an increasingly recognized cause of respiratory illness. Clinicians should be aware of HEV68 as one of many causes of viral respiratory disease and should report clusters of unexplained respiratory illness to the appropriate public health agency.

<SNIP>

The spectrum of illness caused by HEV68 remains unclear. HEV68, like other enteroviruses, has been associated with central nervous system disease (9). Further investigation could help clarify the epidemiology and spectrum of disease caused by HEV68. Some diagnostic tests might not detect HEV68 or might misidentify it as an HRV

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Unlike influenza, classic enteroviruses tend to break out in summer-to-fall, although EV 68 has been observed to occur well into the winter season. The largest outbreak characterized by this MMWR report involved 28 children and adolescents from Pennsylvania in the fall of 2009. 


Since the vast majority of  mild-to-moderate respiratory infections are never tested, the actual incidence of this viral infection isn’t well understood, but it tends to be among the least commonly identified enteroviruses.

 

In recent years, with advances in microbiology and sequence-independent amplification of viral genomes, the ability of laboratories to identify new or rarely seen viruses has steadily improved, and so it is hard to know whether these recent clusters indicate that the incidence of EV 68 is increasing, or they are a result of better surveillance and testing.

 

Unlike other enteroviruses which can produce a wide spectrum of respiratory, gastrointestinal, and neurological symptoms – EV 68 is mainly associated with respiratory symptoms – although it was tentatively linked to two of five children (see Acute Flaccid Paralysis Cases In California) who developed a rare polio-like syndrome last winter.

 

Whether EV-68 was actually the cause of these paralysis cases, or simply an incidental finding, is something that will require more research to establish.

 

Although there is no vaccine and no specific treatment for this virus, there are things that can be done to protect yourself.  In addition to the standard `flu’ etiquette urged every year (hand washing, covering coughs, sneezes, staying home when sick), the CDC’s recommendations to prevent NPEV transmission include:

 

You can help protect yourself and others from non-polio enterovirus infections by—

  • Washing your hands often with soap and water, especially after using the toilet and changing diapers,
  • Avoiding close contact, such as touching and shaking hands, with people who are sick, and
  • Cleaning and disinfecting frequently touched surfaces.

According to Dr. Mary Anne Jackson, an infectious disease specialist interviewed yesterday by local media, roughly 10%-15% of the children currently affected in Kansas City are experiencing serious illness, and that it is hitting kids with asthma particularly hard.

 

With schools just letting in for the fall, we’ll want to keep a close eye on this outbreak to see how it progresses, and if it spreads to other areas of the country.