Nevada: HFMD Coxsackievirus A6 Outbreak

 

 

Credit - Washoe County Health Department

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HFMD (Hand Foot & Mouth Disease) is a very common – generally mild - viral infection, that usually peaks in late summer or early fall, and is mainly seen among children under the age of 10 (although adults may be vulnerable as well).

 

HFMD may be caused by a number of the non-polio enteroviruses. 

 

While this virus classification may be unfamiliar to a lot of people, the 60+ viruses that fall into this category are among the most prevalent viral infections in the world, probably only second to the myriad and ubiquitous variants of Rhinovirus (`common cold’) that circulate every year.

 

The two most common causes of HFMD have been the Coxsackie A16 virus, and (particularly in Asia)  Enterovirus-71 (EV-71), and rarely, the Coxsackie A10 virus.

 

Late last year, however, coxsackievirus A6 was reported in the United States (Alabama, California, Connecticut & Nevada (see MMWR: Coxsackievirus A6 Notes From The Field). First detected in Finland in 2008, this virus has since been seen popping up around the world, including in Taiwan and Japan.

 

Unlike Coxsackievirus A16, A6 produces a more robust infection, and and can occasionally lead to serious illness.  According to the MMWR report mentioned above, 20% of the cases in the United States last year required hospitalization. The good news is no deaths were reported.

 

Barely a week before the start of the fall school session, the Washoe County, Nevada Health Department has issued a warning to parents of an ongoing outbreak of this atypical A6 HFMD strain in their community.

 

The local school district has asked parents to keep kids home if they are contagious (see media report).

 

Excerpts from the Health Department Release follow:

 

A rare strain of hand, foot, and mouth disease (HFMD) has made its way to the Truckee Meadows. Over four hundred self-reported cases of HFMD have been received by WCHD in 2012.  Typical HFMD, most commonly caused by either Coxsackievirus A16 (CVA16) or Enterovirus 71 (EV 71) is a common illness of infants and children ≤ 5 yrs. 

What is Atypical HFMD caused by Coxsackie A6 (CVA6)?

This specific virus (CVA6) has been identified as, an
emerging disease (new to the U.S. in 2012), causing
outbreaks of HFMD. The disease presentation associated with CVA6 differs from the more commonly seen forms of HFMD (e.g. CVA16 and EV 71) in that: 

1. Transmission from children to adults is more common with CVA6, 
2. The sores associated with CVA6 can be impressive and painful, appearing not only on the hands, feet and mouth but also on the buttocks, groin, face and extremities
3. Some cases report nail shedding or peeling
   (onychomadesis) weeks after initial onset, and
4. This strain is not confined to just the summer months as with other viruses causing HFMD

   (Continue . . .)

 

The local health department is offering the following advice to parents to help control the spread of this virus:

 

How is HFMD caused by CVA6 prevented and controlled?
Interrupting person-to-person and surface-to-person
transmission controls the spread of HFMD. If people
practice good personal hygiene after going to the
bathroom and before eating it may limit the spread of the disease.  

Protect Yourself and Prevent the Spread of HFMD.
• Wash hands with soap and water carefully and frequently, especially after going to the bathroom, after changing diapers, and before preparing and/or consuming foods or beverages.
• Disinfect surfaces and items, including toys. First wash the items with soap and water; then disinfect them with a solution of 2 tablespoons of bleach to 4 cups of water.
• Avoid close contact such as kissing, hugging, or sharing eating utensils or cups with infected people.
• Remain at home until all three following criteria are met:

1. fever free for 24 hours without the use of a fever reducer
2. all lesions have dried or are scabbed over
3. no new lesions have appeared for two days.

 

For many years HFMD has been a mild childhood disease in this country, rarely producing serious illness.  For that reason, many parents may not be aware of this more serious, atypical form of the disease.

 

The CDC maintains a large website on HFMD, where you’ll find audio podcasts by a CDC pediatrician on the illness, and links to other resources.

 

The good news is that most cases of HFMD in this country are apt to be due to the milder Coxsackie A16 virus, and serious complications are rare.

 

Like all emerging viruses, we’ll simply have to watch to see how well this upstart coxsackievirus A6 manages to adapt and spread in the human population. 

Stay tuned.

MMWR: Coxsackievirus A6 Notes From The Field

Vesicular eruptions in A) hand, B) foot, and C) mouth of a 6.5-year-old boy from Turku, Finland, with coxsackievirus (CV) A6 infection.  Credit - CDC EID Journal

 

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As a follow up to a blog I wrote in February (see HFMD: An Old Illness With A New Cause), today we’ve a field report that appears in the current MMWR on an emerging coxsackievirus (CVA6) that has recently been reported in the United States.

 

HFMD (Hand Foot & Mouth Disease) is a very common viral infection, usually peaking late summer or early fall, and mainly seen among children under the age of 10 (although adults may be vulnerable as well).

 

It is caused by several of the non-polio enteroviruses.

 

The two most common causes of HFMD have been the Coxsackie A16 virus, and the Enterovirus-71 (EV-71), and rarely, the Coxsackie A10 virus.

 

The disease in the United States is commonly caused by the Coxsackie A16 virus and is generally mild. Outbreaks are not uncommon in schools and childcare facilities.

 

In 2008, the CDC’s EID Journal carried a dispatch describing an outbreak of HFMD in Finland due to an unusual, and apparently emerging, viral cause; the Coxsackie A6 (CVA6) virus.

 

Since then, we’ve seen a growing number of reports of HFMD outbreaks around the world due to this particular coxsackievirus, but until this winter, never in the United States.

 

Today’s MMWR brings us details of the spread and severity of these cases.

 

As they note: The age ranges of patients, severity of illness, seasonality of disease, and identification of CVA6 in these cases were unusual for HFMD in the United States.

 

The good news is - while more severe than typical HFMD, and resulting in the hospitalization of nearly 20% of the cases - no deaths from the emerging CVA6 strain were reported.

 

Notes from the Field: Severe Hand, Foot, and Mouth Disease Associated with Coxsackievirus A6 — Alabama, Connecticut, California, and Nevada, November 2011–February 2012

Weekly

March 30, 2012 / 61(12);213-214

Hand, foot, and mouth disease (HFMD) is a common viral illness caused by enteroviruses that predominantly affects children aged <5 years. In the United States, outbreaks of HFMD typically occur during summer and autumn months. The most common cause of HFMD in the United States has been enterovirus serotype coxsackievirus A16. Most infections are asymptomatic; persons with signs and symptoms typically have a mild febrile illness with rash on the palms of the hands and soles of the feet, and sores in the mouth. HFMD also has been associated, often weeks after initial symptom onset, with nail dystrophies (e.g., Beau's lines or nail shedding).

 

From November 7, 2011, to February 29, 2012, CDC received reports of 63 persons with signs and symptoms of HFMD or with fever and atypical rash in Alabama (38 cases), California (seven), Connecticut (one), and Nevada (17). HFMD is not a reportable disease in the United States; the cases were identified as unusual by health-care providers or by a department of health that contacted CDC for diagnostic assistance. Clinical specimens were collected from patients in 34 of the 63 cases. Coxsackievirus A6 (CVA6) was detected in 25 (74%) of those 34 patients by reverse transcriptase–polymerase chain reaction and partial sequencing of the VP1 gene at CDC or at the California Department of Public Health. No enteroviruses were detected in the other nine patients.

 

Of the 63 patients, 40 (63%) were aged <2 years, and 15 (24%) were adults aged ≥18 years; 44 (70%) of the patients had exposure to a child care facility or school, and eight (53%) of the 15 adults had contact with children in child care where cases of HFMD were reported, or provided medical care or were related to a child with HFMD. Rash and fever were more severe, and hospitalization was more common than with typical HFMD. Signs of HFMD included fever (48 patients [76%]); rash on the hands or feet, or in the mouth (42 [67%]); and rash on the arms or legs (29 [46%]), face (26 [41%]), buttocks (22 [35%]), and trunk (12 [19%]). Of 46 patients with rash variables reported, the rash typically was maculopapular; vesicles were reported in 32 (70%) patients and scabs in 30 (65%) patients. Shedding of nails occurred after initial infection in two (4%) patients. Of the 63 patients, 51 (81%) sought care from a clinician, and 12 (19%) were hospitalized. Reasons for hospitalization varied and included dehydration and/or severe pain. No deaths were reported.

 

The age ranges of patients, severity of illness, seasonality of disease, and identification of CVA6 in these cases were unusual for HFMD in the United States. CVA6 has been associated with more severe and extensive rash than HFMD caused by other enteroviruses (1). Since 2008, international outbreaks of CVA6 HFMD in children and adults have been described (1–4), but no outbreaks had been reported in the United States previously. Although all 25 of the CVA6 strains identified in the U.S. cases were genetically closely related (based on partial VP1 gene sequences) to CVA6 strains identified in recent international outbreaks, no epidemiologic evidence (e.g., travel history) has directly linked any of the U.S. cases to importation.

 

HFMD is spread from person to person by contact with saliva, respiratory secretions, fluid in vesicles, and feces. Transmission of HFMD can be reduced by maintaining good hygiene, including handwashing and disinfection of surfaces in child care settings (5). CDC continues to receive reports of CVA6-associated HFMD. Persons who suspect a severe case of HFMD should contact their health-care provider. Local or state health departments may contact CDC for assistance with enterovirus laboratory diagnosis.

 

 

For more on HFMD, including the more severe Enterovirus-71 (EV-71) version found mostly in southeast Asia, you may wish to revisit the following blogs:

 

Vietnam’s HFMD Outbreak

China: A Recombinant EV-71

HFMD Rising In China

China Sounds Alert Over EV-71 Virus

HFMD: An Old Illness With A New Cause

 

 

 

Vesicular eruptions in A) hand, B) foot, and C) mouth of a 6.5-year-old boy from Turku, Finland, with coxsackievirus (CV) A6 infection.  Credit - CDC EID Journal 

 

# 6138

 

Since late in January the newshounds on FluTrackers  have been following a story out of Alabama, where public health authorities have been dealing with an offseason outbreak of Hand Foot and Mouth Disease (HFMD).

 

Hand Foot and Mouth Disease is often confused by the public with Foot and Mouth Disease (FMD) seen in cattle, swine, and sheep.  Despite the similar name, the diseases are in no way related.

 

HFMD is a very common viral infection, usually peaking late summer or early fall, and mainly seen among children under the age of 10 (although adults may be vulnerable as well).

 

It is caused by several of the non-polio enteroviruses.

 

While this virus classification may be unfamiliar to a lot of people, the 60+ viruses that fall into this category are among the most prevalent viral infections in the world, probably only second to the myriad and ubiquitous variants of Rhinovirus (`common cold’) that circulate every year.

 

 

The two most common causes of HFMD have been the Coxsackie A16 virus, and the Enterovirus-71 (EV-71), and rarely, the Coxsackie A10 virus.

 

The disease in the United States is commonly caused by the Coxsackie A16 virus and is generally mild. Outbreaks are not uncommon in schools and childcare facilities.

 

Over the past decade we've seen outbreaks - particularly in the Far East  - caused by the more pathogenic EV-71 virus, and this version of the HFMD can occasionally be quite serious.

 

Last year, Vietnam reported more than 90,000 cases of HFMD and reported more than 150 deaths, mostly among young children.

 

And two years ago , the Virology Journal, published an analysis of an EV-71 HFMD virus that caused a major disease outbreak in Fuyang City, China in 2008 that showed it was due to an emerging recombinant virus (see China: A Recombinant EV-71).

 

In 2008, the CDC’s EID Journal carried a dispatch describing an outbreak of HFMD in Finland due to an unusual, and apparently emerging, viral cause; the Coxsackie A6 virus.

 

Dispatch

Coxsackievirus A6 and Hand, Foot, and Mouth Disease, Finland

Riikka Österback, Tytti Vuorinen, Mervi Linna, Petri Susi, Timo Hyypiä, and Matti Waris

Abstract

During fall 2008, an outbreak of hand, foot, and mouth disease (HFMD) with onychomadesis (nail shedding) as a common feature occurred in Finland. We identified an unusual enterovirus type, coxsackievirus A6 (CVA6), as the causative agent. CVA6 infections may be emerging as a new and major cause of epidemic HFMD.

 

This dispatch describe a prolonged nationwide outbreak of HFMD starting in 2008, in Finland:

 

During fall 2008, a nationwide outbreak of HFMD occurred in daycare centers and schools in Finland, starting in August and continuing at least until the end of the year and possibly into the following year. From vesicle fluid specimens of hospitalized children, we identified the etiologic agent as coxsackievirus A6.

 

Since then, we’ve seen a growing number of reports of HFMD outbreaks around the world due to this particular coxsackievirus, including:

 

 

An outbreak of coxsackievirus A6 hand, foot, and mouth disease associated with onychomadesis in Taiwan, 2010

Sung-Hsi Wei, Yuan-Pin Huang, Ming-Chih Liu, Tsung-Pei Tsou, Hui-Chen Lin, Tsuey-Li Lin, Chen-Yen Tsai, Yen-Nan Chao, Luan-Yin Chang and Chun-Ming Hsu

BMC Infectious Diseases 2011, 11:346 doi:10.1186/1471-2334-11-346

Published: 14 December 2011

Hand, Foot, and Mouth Disease Caused by Coxsackievirus A6, Japan, 2011

Fujimoto T, Iizuka S, Enomoto M, Abe K, Yamashita K, Hanaoka N, et al.

Emerg Infect Dis [serial on the Internet]. 2012 Feb

 

 

Until now, this A6 virus has not been associated with HFMD outbreaks in the United States. This from the Alabama Health Department’s website:

 

 

Alabama Department of Public Health monitors new cases of hand, foot and mouth disease

FOR IMMEDIATE RELEASE 
CONTACT:  Mary McIntyre, M.D.
(334) 206-5325

The Alabama Department of Public Health asks the public to be aware that cases of the contagious viral illness called hand, foot and mouth disease are more numerous and severe than normal in Alabama this winter. No known deaths have resulted from the virus, although there have been hospitalizations and there can be some rare, severe complications.

 

As of Feb. 10, the ADPH has interviewed patients and collected and submitted specimens to the Centers for Disease Control and Prevention for individuals with febrile illnesses and rash. Based on the results of testing done by the CDC, the Coxsackie A6 virus has been identified.

 

This  specific type of virus has been identified in other countries but has not previously been
associated with an outbreak in the U.S. There is no specific treatment for hand, foot and mouth
disease.

 

“As this is a new virus for our population, we can expect more cases and are monitoring for any change in the clinical presentation,” Dr. Donald Williamson, state health officer, said. “We will continue statewide surveillance on severe cases of this emerging disease and ask physicians and infection control specialists to make notifications to us.”

The public should not be unduly alarmed at this time; however, individuals diagnosed with hand, foot and mouth disease need to follow the recommendations of their health care provider to remain at home until they have no fever, all lesions have scabbed over, and no lesions have appeared for two days.  

The viral disease affects the hands, feet and mouth and usually infects infants and children younger than 5 years old in summer and early autumn. There is no vaccine to protect against it, but learning about the disease and following these recommendations can reduce the risk of illness.

Hand, foot and mouth disease spreads: 

• Person-to-person: Direct contact with saliva, sputum or nasal mucus from the infected person’s nose and throat or with fluid in blisters, or with stool.
• Surface-to-person: Touching objects and surfaces touched by infected persons.
• Infected persons are most contagious during the first week of the illness, but can still pass the virus for weeks after symptoms have gone away.

These are the symptoms:

 

• Fever, rash, sores, poor appetite, a vague feeling of illness and sore throat.
• Painful sores in the mouth may blister and become ulcers.
• Skin rash, flat or raised red spots, develops over 1 to 2 days.
• Rash usually on the palms of the hands and soles of the feet and may appear on the knees, elbows, bottom or genital area.
• Dehydration may occur because of painful mouth sores.

 

Recommendations to protect yourself and prevent its spread:

• Wash hands with soap and water carefully and frequently, especially after going to the bathroom, after changing diapers, and before preparing foods or beverages.
• Disinfect surfaces and items, including toys. First wash the items with soap and water; then disinfect them with a solution of 1 tablespoon of bleach and 4 cups of water.
• Avoid close contact such as kissing, hugging or sharing eating utensils or cups with infected people.

Health care providers are being asked to notify the Alabama Department of Public Health if higher than normal numbers of cases are being hospitalized with hand, foot and mouth disease symptoms. Please call (800) 338-8374 immediately for hospitalized cases.

     -30-

2/10/12

 

 

While apparently a bit more serious than the garden variety of HFMD we are used to seeing in the United States, this A6 virus doesn’t appear to be as pathogenic as the EV-71 virus seen in Asia.

 

But its arrival in the United States serves as a reminder that well adapted emerging viruses are very good at spreading, and that with today’s highly mobile society, oceans and borders provide little in the way of protection.