CDC EV-D68 Update & FAQ

States with Confirmed EV-D68 Infections

From August 21 to September 10, 2014, a total of 84 people in Colorado, Illinois, Iowa, Kansas, Kentucky and Missouri have been confirmed to have respiratory illness caused by enterovirus D68 (EV-D68).

 

# 9064

 

Although fewer than 100 cases have been confirmed by the CDC’s testing, anecdotal reports suggest that thousands of kids have been infected by the EV-D68 virus over the past several week, with hospitals from Chicago to Atlanta reporting huge increases in respiratory infections among children – some requiring ICU admission.

 

We started following this story two weeks ago (see Kansas City Outbreak Identified As HEV 68 & Enterovirus D-68 (HEV-D68) Update), and on Monday the CDC held a press briefing.  The audio and transcript for that briefing is available at the following links.

Monday, September 8 at 1:00 pm ET

Transcript | Audio

Today the CDC has updated their Non-Polio Enterovirus D68 webpage with the following Q&A information.

 

 

Q: What is enterovirus D68?

A: Enterovirus D68 (EV-D68) is one of many non-polio enteroviruses. This virus was first identified in California in 1962, but it has not been commonly reported in the United States.

Q: What are the symptoms of EV-D68 infection?

A: EV-D68 can cause mild to severe respiratory illness.

• Mild symptoms may include fever, runny nose, sneezing, cough, body and muscle aches.
• Severe symptoms may include difficulty breathing and wheezing. People with asthma may have a higher risk for severe respiratory illness.

Q: How does the virus spread?

A: Since EV-D68 causes respiratory illness, the virus can be found in respiratory secretions, such as saliva, nasal mucus, or sputum. EV-D68 likely spreads from person to person when an infected person coughs, sneezes, or touches contaminated surfaces.

Q: How many people have been confirmed to have EV-68 infection?

A: As of September 10, 2014, a total of 84 people in six states have been confirmed to have respiratory illness caused by EV-D68.

Q: How common are EV-D68 infections in the United States?

A: EV-D68 infections are thought to occur less commonly than infections with other enteroviruses. However, CDC does not know how many infections and deaths from EV-D68 occur each year in the United States. Healthcare professionals are not required to report this information to health departments. Also, CDC does not have a surveillance system that specifically collects information on EV-D68 infections. Any data that CDC receives about EV-D68 infections or outbreaks are voluntarily provided by labs to CDC’s National Enterovirus Surveillance System (NESS). This system collects limited data, focusing on circulating types of enteroviruses and parechoviruses.

Q: Who is at risk?

A: Like other enteroviruses, anyone can get infected with EV-D68.

Among the recent EV-D68 infections in some states, children with asthma seemed to have a higher risk for severe respiratory illness. However, this is still being investigated.

Q: How is it diagnosed?

A: Many hospitals and doctor’s offices can test for enteroviruses. However, most cannot do testing to determine the specific type of enterovirus, like EV-D68. State health departments and CDC can do this sort of testing.

 

Q: What are the treatments?

A: There is no specific treatment for people with respiratory illness caused by EV-D68.

For mild respiratory illness, you can help relieve symptoms by taking over-the-counter medications for pain and fever. Aspirin should not be given to children.

Some people with severe respiratory illness may need to be hospitalized .

There are no antiviral medications currently available for people who become infected with EV-D68.

Q: How can I protect myself?

A: You can help protect yourself from respiratory illnesses by following these steps:

• Wash hands often with soap and water for 20 seconds, especially after changing diapers.
• Avoid touching eyes, nose and mouth with unwashed hands.
• Avoid kissing, hugging, and sharing cups or eating utensils with people who are sick.
• Disinfect frequently touched surfaces, such as toys and doorknobs, especially if someone is sick.

Since people with asthma are higher risk for respiratory illnesses, they should regularly take medicines and maintain control of their illness during this time. They should also take advantage of influenza vaccine since people with asthma have a difficult time with respiratory illnesses. Asthma can also be controlled by avoiding the triggers that can cause an attack, such as tobacco smoke.

Q: Is there a vaccine?

A: No. There are no vaccines for preventing EV-D68 infections.

Q: What should clinicians do?

A: Healthcare professionals should

• Be aware of EV-D68 as a potential cause of clusters of severe respiratory illness, particularly in young children.
• Consider laboratory testing of respiratory specimens for enteroviruses when the cause of infection in severely ill patients is unclear. Many hospitals can test for enteroviruses, but they are probably not able to perform enterovirus typing. State health departments or CDC can be approached for typing enterovirus.
• Before sending specimens to CDC:
  • contact your state or local health department, and
  • consult with CDC by sending an email to wnix@cdc.gov
• Report cases and clusters of severe respiratory illnesses to state and local health departments for further guidance.

Q: What is CDC doing about EV-D68?

A: CDC is helping states with diagnostic and molecular typing for EV-D68.

CDC is also working with state and local health departments and clinical and state laboratories to

• enhance their capacity to identify and investigate outbreaks, and
• perform diagnostic and molecular typing tests to improve detection of enteroviruses and enhance surveillance.

Enterovirus D-68 (HEV-D68) Update

States reporting suspected or confirmed HEV-D68

 

 

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Although lab confirmation is still awaited in some areas, the outbreak of severe respiratory illness in kids that we saw pop up N.W. Missouri a little over a week ago (see Kansas City Outbreak Identified As HEV 68), and then a few days later in St. Louis (see Missouri Health Alert On Enterovirus 68), has now been reported in at least four more states.

This week we’ve seen media reports of hospitals being slammed with (mostly young) patients with respiratory infections in Ohio, Illinois, Kansas, Missouri, and most recently Colorado.  While test results haven’t come back for all of these locations, local doctors are pointing their fingers at the emerging EV 68 virus.

 

A sampling of some of the media coverage overnight includes:

 

Severe respiratory virus impacting hundreds of kids reaches Colorado

kdvr.com - ‎15 hours ago‎

DENVER — A potentially severe virus that has plagued hundreds of children across a 900-mile stretch in the Midwest in recent weeks has made its way to Colorado.

Colorado children's hospitals see spike in severe respiratory illness

The Denver Post - ‎12 hours ago‎

Children's hospitals in Denver are experiencing an alarming spike in a severe respiratory illness — especially among very young children and those with asthma — that may be caused by an uncommon viral pathogen.

Hospitals across Denver are on alert for a respiratory illness that can leave ...

The Denver Channel - ‎4 hours ago‎

At Rocky Mountain Hospital for Children, physicians report about 10 of the 20 beds in their pediatric intensive care unit are young people battling the virus. "Our pediatric floor is full of patients with pretty severe respiratory distress," said Dr.Raju Meyappan

Denver hospitals see virus spike in kids

9NEWS.com - ‎10 hours ago‎

DENVER - Denver hospitals and pediatricians offices are seeing a spike in a respiratory virus that is hitting kids hard who have histories of asthma and wheezing. ... "It seems to be what's happening with this virus which is more severe than other viruses.".

 

Often called EV 68, this virus is primarily known for producing respiratory symptoms - similar to that seen with rhinoviruses - although in some cases it can be severe enough to require hospitalization. There are reports of a number of children ending up in intensive care, some requiring ventilatory assistance, over the past week.

 

While children are usually the hardest hit, adults are not immune. Co-morbidities – such as asthma – can exacerbate the symptoms.

 

The virus (genus Enterovirus - family Picornaviridae – species HEV-D) –  is just one of 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.

 

HEV-D68  was first indentified in 1962, but until about 5 years ago, had not been often reported. The CDC called attention to its emergence several years ago - (see MMWR: Clusters Of HEV68 Respiratory Infections 2008-2010) – which looked at a half dozen  HEV 68 associated clusters that occurred in Asia, Europe, and the United States during 2008--2010.

 

EV 68’s rarity up until now in North America likely equates to very low levels of community immunity, which probably explains its rapid dissemination over the past couple of weeks, spurred on by the start of the school year.

 

For most kids (and adults) this will likely prove little more than a nasty `cold’ or virus.  But in a small percentage of cases, it can turn severe, and so parents need to pay particular attention this fall.  This virus appears to have `legs’, and so we could see a busy start to the winter respiratory illness season. 

 

While rarely seen in the United States, over the past 10 years we’ve seen this virus on the ascendant in China, The Netherlands, Japan, and the Philippines, sometimes producing significant outbreaks. 

 

A few recent studies include:

 

J Med Microbiol. 2014 Mar;63(Pt 3):408-14. doi: 10.1099/jmm.0.068247-0. Epub 2013 Dec 9.

Detection of enterovirus 68 as one of the commonest types of enterovirus found in patients with acute respiratory tract infection in China.

Lu QB¹, Wo Y, Wang HY, Wei MT, Zhang L, Yang H, Liu EM, Li TY, Zhao ZT, Liu W, Cao WC.

Author information

Abstract

Human enterovirus 68 (HEV-68) is an enterovirus associated with respiratory illness. In China, no information about HEV-68 is available for children yet. This study aimed to investigate the presence of HEV-68 in mainland China between 2009 and 2012 and to explore the migration events of HEV-68 across the world.

Among 1565 samples tested from children, 41 (2.6%) were positive for HEV and 223 (14.3%) for human rhinovirus (HRV). Seven (17.1%) of 41 HEVs were HEV-68. Two HEV-68- and five HRV-positive samples were detected in 585 adult samples. HEV-68 is the predominant type of enterovirus in children with acute respiratory tract infection (ARTI), followed by HEV-71 and coxsackievirus A6. Three HEV-68-infected children presented with severe pneumonia and one presented with a severe asthma attack.

The viruses were attributed to two novel distinct sublineages of HEV-68 based on phylogenetic analysis of partial VP1 gene sequences. Migration events analysis showed that the USA and the Netherlands were possible geographical sources of HEV-68, from where three strains migrated to China.

In conclusion, HEV-68 may play a predominant role among the enteroviruses associated with ARTI in children. Additional surveillance is needed to clarify the reason why HEV-68 causes such a wide spectrum of disease, from asymptomatic to severe respiratory disease and even death.

Virology. 2012 Feb 5;423(1):49-57. doi: 10.1016/j.virol.2011.11.021. Epub 2011 Dec 15.

Emergence and epidemic occurrence of enterovirus 68 respiratory infections in The Netherlands in 2010

Meijer A¹, van der Sanden S, Snijders BE, Jaramillo-Gutierrez G, Bont L, van der Ent CK, Overduin P, Jenny SL, Jusic E, van der Avoort HG, Smith GJ, Donker GA, Koopmans MP.

Author information

Abstract

Following an increase in detection of enterovirus 68 (EV68) in community surveillance of respiratory infections in The Netherlands in 2010, epidemiological and virological analyses were performed to investigate the possible public health impact of EV68 infections.

We retrospectively tested specimens collected from acute respiratory infections surveillance and through three children cohort studies conducted in The Netherlands from 1994 through 2010. A total of 71 of 13,310 (0.5%) specimens were positive for EV68, of which 67 (94%) were from symptomatic persons. Twenty-four (34%) of the EV68 positive specimens were collected during 2010. EV68-positive patients with respiratory symptoms showed significantly more dyspnea, cough and bronchitis than EV68-negative patients with respiratory symptoms. Phylogenetic analysis showed an increased VP1 gene diversity in 2010, suggesting that the increased number of EV68 detections in 2010 reflects a real epidemic.

Clinical laboratories should consider enterovirus diagnostics in the differential diagnosis of patients presenting with respiratory symptoms.

J Clin Virol. 2011 Oct;52(2):103-6. doi: 10.1016/j.jcv.2011.06.019. Epub 2011 Jul 29.

Upsurge of human enterovirus 68 infections in patients with severe respiratory tract infections

Rahamat-Langendoen J¹, Riezebos-Brilman A, Borger R, van der Heide R, Brandenburg A, Schölvinck E, Niesters HG.

 

Abstract

BACKGROUND:

Enterovirus 68 (EV68) belongs to species Human enterovirus D. It is unique among enteroviruses because it shares properties with human rhinoviruses. After the first isolation in 1962 from four children with respiratory illness, reports of (clusters of) EV68 infections have been rare. During the autumn of 2010, we noticed an upsurge of EV68 infections in the Northern part of the Netherlands in patients with severe respiratory illness.

OBJECTIVES:

To give a detailed description of the clinical and virological data of patients with EV68 infection identified in 2010, and compare these with data collected in 2009.

STUDY DESIGN:

We systematically collected clinical data from patients with an EV68 infection detected in 2010. We added four patients with an EV68 infection from 2009. Further characterization of EV68 was performed by partial sequence analysis of the VP1 genomic region.

RESULTS:

In 2010, EV68 was identified as the only cause of respiratory illness in 24 patients, of which 5 had to be admitted to the intensive care unit. Sequence analysis revealed different lineages in the majority of EV68 detected in 2010 as compared to the 2009 isolates.

CONCLUSIONS:

We noticed an increase of EV68 infections and present clinical as well as sequence data, in which two distinct phylogenetic clusters could be identified.

The advice being given this year is pretty standard, but worth repeating:

• Get your flu shot (no, it won’t prevent EV 68, but it could help prevent a dual flu - Enterovirus infection)
• stay home if you are sick & obtain consultation from your health care provider 
• avoid contact with those who are sick
• practice good `flu hygiene’  (cover coughs & sneezes)
• Avoid touching your face, mouth, and eyes with unwashed hands
• and wash your hands often

 

 

Missouri Health Alert On Enterovirus 68

 

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

 

 

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On Friday morning, in Kansas City Outbreak Identified As HEV 68, I wrote at some length about an outbreak of respiratory illness among children in Kansas City, Missouri that had been identified as  Enterovirus 68, and about the recent increases in its detection around the globe.

 

While EV 68 was first identified in the early 1960s, it has only rarely been detected in the United States, although several small clusters were reported (see  MMWR: Clusters Of HEV68 Respiratory Infections 2008-2010) in Arizona, Georgia, and Pennsylvania starting about 5 years ago.

 

Unlike many of the other non-polio enteroviruses, EV 68 is considered primarily a respiratory virus, although the full spectrum of illness it may produce isn’t well understood. Symptoms are generally like those from a `cold’ or rhinovirus, but severe illness can sometimes result, particularly among children with asthma or other respiratory problems.

Over the weekend I began seeing reports that similar cases were showing up in St. Louis, 250 miles to the east.  On Saturday, the Missouri Department of Health and Senior Services issued  the following Health Alert to the medical community:

 

Missouri Department of Health & Senior Services
Health Alert

August 29, 2014
FROM: GAIL VASTERLING DIRECTOR

SUBJECT: Respiratory Illnesses Due to Enterovirus D68 (EV-D68) in Missouri

Current Situation

Recently, a pediatric hospital in Kansas City, Missouri has experienced over 300 cases of respiratory illnesses in their facility. Approximately 15% of those illnesses have resulted in childen being placed in an intensive care unit. Testing of specimens from several cases at a specialized laboratory at the Centers for Disease Control and Prevention (CDC) indicated that 19 of the 22 specimens were positive for Enterovirus D68 (EV-D68). The St. Louis area is also experiencing a recent increase in pediatric respiratory illnesses. Many specimens from those cases have tested positive for enterovirus, and further testing for specific virus type is pending. To date, no deaths have been reported due to EV-68 in Missouri.

Background

Enteroviruses are very common viruses. There are more than 100 types of enteroviruses. It is estimated that 10 to 15 million enterovirus infections occur in the United States each year. Most people infected with enteroviruses have no symptoms or only mild symptoms, but some infections can be serious. Most enterovirus infections in the U.S. occur seasonally during the summer and fall, and outbreaks of tend to occur in several-year cycles.

EV-D68 infections occur less commonly than those with other enteroviruses. EV-D68, like other enteroviruses, appears to spread through close contact with infected people. This virus was first isolated in California in 1962 from four children with bronchiolitis and pneumonia, and has been reported rarely since that time. Unlike the majority of enteroviruses that cause a clinical disease manifesting as a mild upper respiratory illness, febrile rash illness, or neurologic illness (such as aseptic meningitis and encephalitis), EV-D68 has been associated almost exclusively with respiratory disease. EV-D68 usually causes mild to severe respiratory illness; however, the full spectrum of EV-D68 illness is not well-defined.

Clusters of respiratory illness associated with EV-D68 in Asia, Europe, and the U.S. during 2008-2010 have been described previously. EV-D68 infection was associated with respiratory illness ranging from relatively mild illness to severe illness requiring intensive care and mechanical ventilation. These clusters confirmed that EV-D68 is associated with outbreaks of respiratory illness severe enough to require hospitalization, and in some cases, might contribute to patient death. New-onset wheezing or asthma exacerbation were notable symptoms. However, in each cluster, respiratory specimens typically were collected from persons who had sought medical care or were hospitalized, which would have biased these reports toward more severe disease. No data is currently available regarding the overall burden of morbidity or mortality from EV-D68 in the U.S. approved by the Food and Drug Administration for use in clinical settings ( Luminex xTAG RVP, Idaho Technologies FilmArray Respiratory Panel). But, these systems use broadly reactive primers that amplify RNA from either human rhinoviruses (HRVs) or enteroviruses, and results are reported as "entero-rhinovirus" or "human rhinovirus/enterovirus". Most hospitals are not able to perform enterovirus typing to identify specific enterovirus. The gold standard test for EV-D68 detection is partial sequencing of the structural protein genes, VP4-VP2 or VP1.

There is no specific treatment for EV-D68 infections; specifically there are no anti-viral medications currently available for this purpose. Many infections will be mild and self-limited, requiring only symptomatic treatment. Some people with severe respiratory illness caused by EV-D68 may need to be hospitalized and receive intensive supportive therapy.

Vaccines for preventing EV-D68 infections currently are not available.

Guidance for Healthcare Professionals

Clinicians should be aware of EV-D68 as one of many causes of viral respiratory disease, and should report clusters of unexplained respiratory illness to the local public health agency, or to the Missouri Department of Health and Senior Services (DHSS) at 573/751-6113 or 800/392-0272 (24/7).

To help reduce the risk of infection with EV-D68, healthcare professionals should recommend the following:

• Wash hands often with soap and water for 20 seconds, especially after changing diapers;
• Avoid touching eyes, nose, and mouth with unwashed hands;
• Avoid kissing, hugging, and sharing cups or eating utensils with people who are sick;
• Disinfect frequently touched surfaces, such as toys and doorknobs, especially if someone is sick;
• Stay home when feeling sick, and obtain consultation from your health care provider.

Kansas City Outbreak Identified As HEV 68

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 here,  here & 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

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.

Acute Flaccid Paralysis Cases In California

 

 

Credit CDC – Non Polio-Enteroviruses

 

 

# 8325

 

Overnight the news media has been filled with numerous reports of an – as yet, unidentified – polio-like paralytic illness that has stricken a small number of children in California over the past two years.  Crof already has a couple of media reports on his blog (see US: A polio-like illness in California children & US: More on the polio-like illness in California), and ProMed Mail released a summary this morning.

 

The basic facts are recounted in the following excerpt from the Los Angeles Times report, after which I’ll have more:

 

Mysterious polio-like illnesses reported in some California children

By Eryn Brown

February 23, 2014

(excerpt)

The afflicted kids suffer severe weakness or paralysis, which strikes rapidly -- sometimes after a mild respiratory illness. Scans of the patients' spinal cords show patterns of damage similar to that found in polio sufferers, Glaser said. Two of the affected children tested positive for enterovirus-68, a virus that is usually associated with respiratory illness but which has been linked to polio-like illnesses as well.

 

Dr. Keith Van Haren, a pediatric neurologist at Stanford University's Lucile Packard Children's Hospital who has worked with Glaser's team, will present the cases of five of the children at the American Academy of Neurology's upcoming annual meeting in Philadelphia.

 

All five patients had paralysis in one or more arms or legs that reached its full severity within two days, he said. None had recovered limb function after six months.

 

"We know definitively that it isn't polio," Van Haren added, noting that all had been vaccinated against that disease.

(Continue . . . )

 

This report, along with others, suggest that 20 to 25 children in California may have developed Acute Flaccid Paralysis (AFP) following a mild respiratory illness over the past couple of years, and investigators expect that once clinicians know to look for it, they may discover it beyond California.

 

Non-polio AFP is a complex and broad clinical syndrome that can be caused by a wide range of pathogens, including West Nile Virus (and other mosquito-borne encephalopathies), echoviruses, adenoviruses, Campylobacter jejuni (leading cause of Guillain-Barre syndrome), a large group of enteroviruses, along with a variety of toxins and poisons.

 

While the exact cause (or causes) of these California cases remains unknown, a viral infection is strongly suspected, and high on the list of suspects are members of the ubiquitous non-polio enterovirus family of viruses or NPEVs  (which includes Coxsackievirus A, Coxsackievirus B, Echoviruses & numerous other Enteroviruses).

 

According to the CDC, 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. 

 

NPEV infection may also lead to viral conjunctivitis, hand, foot, and mouth disease (HFMD), or viral meningitis and less commonly, a person may develop myocarditis, pericarditis, encephalitis - or in rare cases - even paralysis.

 

The CDC lists the following common Outbreaks of Various Non-Polio Enteroviruses

• Coxsackievirus A16 is the most common cause of hand, foot, and mouth disease (HFMD) in the United States. However, in 2011 and 2012, coxsackievirus A6 was a common cause of HFMD in this country; some of the infected people became severely ill.
• Coxsackievirus A24 and enterovirus 70 have been associated with outbreaks of conjunctivitis.
• Echoviruses 13, 18, and 30 have caused outbreaks of viral meningitis in the United States.
• Enterovirus 71 has caused large outbreaks of HFMD worldwide, especially in children in Asia. Some infections from this virus have been associated with severe neurologic disease, such as brainstem encephalitis.

 

We’ve looked at HFMD outbreaks in the past, most often caused by the Coxsackie A16 virus (and more rarely by Coxsackie A10) here in the United States. In recent years, we’ve also seen the recent emergence of the Coxsackie A6 virus which has been linked to somewhat more severe HFMD cases (see MMWR: Coxsackievirus A6 Notes From The Field).

But it is the Enterovirus 71 that has been most often linked to severe cases of HFMD – particularly across Asia - with serious outbreaks recorded over the past 15 years in places like China, Taiwan, Malaysia, Hong Kong, and two years ago in both Vietnam and Cambodia (see Updating The Cambodian EV71 Story).

 

Last year, in Australia: Acute Flaccid Paralysis & EV71, we looked at a report from the National Enterovirus Reference Laboratory in Australia that described 5 recent cases of acute flaccid paralysis (AFP) in children who tested positive for the EV71 virus.

 

Concerns over the evolution and spread of EV71 have grown in recent years, as detailed in the following 2008 report from The Lancet: Enterovirus 71 infection: a new threat to global public health?  

 

While a potential cause, EV71 is just one of the possible suspects behind these California cases.  Indeed, AFP can be caused by a variety of viral infections, and so there may be more than one etiology involved

 

At least two of the children in California have tested positive for Enterovirus-68, which we looked at in some depth back in 2011 (see MMWR: Clusters Of HEV68 Respiratory Infections 2008-2010).  First detected in California in 1962, but rarely seen since that time, that report summarized six clusters of HEV68 from Asia, Europe, and the United States between 2008-2010.  Those clusters included severe illness, and three fatalities.

 

Although the full spectrum of illness that EV-68 infection can produce has not been well established, it has previously been more commonly associated with respiratory symptoms than with paralysis.

 

So whether EV-68 is actually the cause of these recent California paralysis cases, or simply an incidental finding, is something that will require more research to establish. Despite their outward similarity to NPEV infections, these AFP cases in California may be due to something altogether different.  New viral discoveries are made practically every year.

But most `mystery illnesses’  usually end up being due to previously identified diseases that have either evolved or mutated a bit, or have migrated to a new area.

 

While it is too soon to speculate on the exact cause of these AFP cases, the CDC’s recommendations to prevent NPEV transmission are universally good hygiene suggestions, and are worth following:

 

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.

MMWR: Clusters Of HEV68 Respiratory Infections 2008-2010

 

 

 

# 5871

 

 

There is probably no more nebulous disease description than that of `ILI’ or an influenza-like-illness.  It ranks up there with `malaise’ and `fatigue’ among the most common of human complaints, and is just about as specific.

Nearly all viral (and a fair number of bacterial, parasitic, and fungal) infections present – at least in their prodromal stage – with flu-like symptoms.

The public tends to categorize mild respiratory infections as `colds’ and more severe illnesses as `the flu’, but doctors know there is a whole galaxy of pathogens out there that can mimic influenza.

 

Which is why doctors usually refer to `picking up a virus’, or having an ILI (Influenza-like Illness or sometimes ARI Acute Respiratory Infection), when rendering a diagnosis. 

 

Elaborate testing isn’t usually done because of the costs involved, and because knowing the etiology doesn’t really affect treatment. Bed rest, fever reducers, and plenty of fluids is the usual regimen.

 

Consequently, there are probably still a number of as-yet unidentified respiratory viruses running around out there.

 

All of which serves as prelude to a report in today’s MMWR on the detection of  HEV68 – or Human Enterovirus 68 – that has produced a number of clusters of respiratory illness around the world over the past couple of years.

 

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. 

 

The few excerpts from today’s MMWR report (follow the link to read it in its entirety):

 

Clusters of Acute Respiratory Illness Associated with Human Enterovirus 68 --- Asia, Europe, and United States, 2008--2010

Weekly

September 30, 2011 / 60(38);1301-1304

In the past 2 years, CDC has learned of several clusters of respiratory illness associated with human enterovirus 68 (HEV68), including severe disease. HEV68 is a unique enterovirus that shares epidemiologic and biologic features with human rhinoviruses (HRV) (1).

 

First isolated in California in 1962 from four children with bronchiolitis and pneumonia (2), HEV68 has been reported rarely since that time and the full spectrum of illness that it can cause is unknown. The six clusters of respiratory illness associated with HEV68 described in this report occurred in Asia, Europe, and the United States during 2008--2010.

 

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.

 

CDC learned of clusters of HEV68 from public health agencies requesting consultation or diagnostic assistance and from reports presented at scientific conferences. In each cluster, HEV68 was diagnosed by reverse transcription--polymerase chain reaction (RT-PCR) testing targeting the 5'-nontranslated region, followed by partial sequencing of the structural protein genes, VP4-VP2, VP1, or both, to give definitive, enterovirus type-specific information.

 

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.

(Continue . . . )

 

Occurrence of human enterovirus 68, by month, duration, and geographic location --- Asia, Europe, and United States, 2008—2010

 

In recent years, with advances in microbiology and sequence-independent amplification of viral genomes, the ability of scientists to identify new viruses has improved greatly and so they are adding new names to the `suspect list’.

 

About a decade ago the human metapneumovirus (HMPV) was identified in Dutch children with bronchiolitis.  Since then, it has been found to be ubiquitous around the world, and responsible for a significant percentage of childhood respiratory infections . . . yet until 2001, no one knew it existed.

 

Human Bocavirus-infection (HBoV) wasn’t identified until 2005, when it was detected in 48 (9.1%) of 527 children with gastroenteritis in Spain (cite).  

 

And the list grows longer every year.

 

While discovered 40 years ago, according to this MMWR report, testing for HEV68 remains problematic. So we probably don’t have a good handle on how common it really is. 

 

The summary provided for this release reads:

 

What is already known on this topic?

Human enterovirus 68 (HEV68) is a unique enterovirus that shares epidemiologic and biologic features with human rhinoviruses.

 

What is added by this report?

Although isolated cases of HEV68 have been reported since the virus was described in 1962, clusters of cases have been recognized only recently. The clusters described in this report occurred late in the typical enterovirus season and included severe cases, three of which were fatal.

 

What are the implications for public health practice?

Clinicians should be aware of HEV68 as one of many possible causes of viral respiratory disease. Some diagnostic tests might not detect HEV68 or might misidentify it as a human rhinovirus.

 

For more on the expanding universe of non-influenza respiratory viruses, you might wish to revisit these earlier blogs:

 

BMC Study: A Crowded Viral Field

ILI’s Aren’t Always The Flu