Fair Biosecurity & H3N2 In North Dakota Show Pigs

 

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County and State Fair season is underway in the northern states and will continue across the nation well into fall. One of the highlights for many visitors are the agricultural exhibits, including livestock exhibitions.  While educational, entertaining, and financially lucrative, there are admittedly some downsides.

Bringing together animals from farms all over the region provides unique opportunities to swap pathogens amongst themselves, and potentially spread them to handlers and the public.

 

In years past, the concern has centered primarily on swine flu, but the recent emergence of two new swine coronaviruses – PEDV & PDCoV  (see SECD: Another Emerging Coronavirus Threat) have complicated matters as well.  Unlike the swine influenzas, however, SECDs - or Swine Enteric Coronavirus Diseases – are not known to transmit to humans.

 

While they generally cause mild symptoms in adult pigs, among piglets, the mortality rate can run close to 100%. 

 

In some regions, fair administrators have implemented a terminal show policy – where pigs exhibited at the fair must be sent to market at the show’s end, rather than back home (or worse, to another fair) to prevent the potential spread of porcine diseases. 

 

This report (and video) from a local Wisconsin TV station.

Terminal show policy in place to control swine virus

The PED virus has had a significant impact on pig populations in the United States in the last two years

Author: Dave Delozier, ddelozier@wisctv.com

Published On: Jul 25 2014 05:44:58 PM CDT

PORTAGE, Wis. -

While most pig exhibitors attend county fairs with the expectation their animal will be sold to market, it is now becoming a certainty.  Because of concerns about the spread of a deadly virus, Porcine Epidemic Diarrhea or PED, county fairs have adopted a terminal show policy.  That means a pig shown at a county fair must be sold to market at the shows end and cannot be taken back to a farm.

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Beyond the opportunities for porcine diseases to spread between pigs, fairs also provide lots of human-animal contact, which can lead to the spread of infections from humans-to-pigs, and from pigs-to-humans. 

 

Illustrating the two-way nature of disease sharing - shortly after the 2009 H1N1 virus emerged in the human population - it began showing up in pig herds around the world (see Study: Reassortants of H1N1pdm & Swine H1 & H3 Viruses in Japan)

 

With the emergence of several swine variant influenza viruses in the past few years (H1N1v, H1N2v, H3N2v) – all able to jump to humans (albeit, not able to transmit efficiently) -  we are seeing a greater emphasis on fair biosecurity than ever before (see CDC: Measures to Minimize Influenza Transmission at Swine Exhibitions, 2014).

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Last week, in EID Journal: H3N2v Swine To Human Transmission At Agricultural Fairs – 2012, we looked at what was the most active year for swine variant transmission to humans, where the authors cautioned:

 

Swine-to-human transmission and human-to-swine transmission of influenza A virus are known to occur at fairs (28), highlighting the fact that swine in this setting are potentially exposed to multiple lineages of influenza A viruses simultaneously, making fairs ideal locations for genomic reassortment and novel virus formation.

 

Swine are highly susceptible to a variety of flu viruses (human, swine, avian) - and are viewed as excellent `mixing vessels’, allowing viruses to reassort into new hybrid strains.  This is how the 2009 H1N1 pandemic virus was created, after bouncing around swine herds for a decade or more.

 

State & local  fairs have instituted inspections for any signs of illness in livestock – but as we’ve discussed previously (see Asymptomatic Pigs: Revisited) - pigs can sometimes carry these viruses without showing any outward signs of infection.

 

While we’ve not seen any reports of human infection with swine variant influenza this summer, fair officials and health departments are understandably on heightened alert, and are taking steps to try to prevent that from happening.  All of which serves as prelude to this announcement (yesterday) by North Dakota’s Department of Health.

 

Influenza A H3N2 Variant Viruses (H3N2v)

Influenza A H3N2v is a non-human influenza virus that normally circulates in pigs. In 2011, a small number of humans were found to be infected with this virus. From 2011 to 2013, a total of 340 cases of H3N2v was identified in 13 states, resulting in 17 hospitalizations and one death. Most of these cases occured in the summer months, and most reported contact with pigs. Symptoms and severity of H3N2v infections in humans resemble that of seasonal influenza, and include fever, cough, sore throat, body aches, and headache. No cases have been identified at this time for 2014, and no cases in North Dakota have ever been reported.

On July 31, 2014 it was reported that three pigs at the 2014 North Dakota State Fair had been removed for illness and had tested positive for an H3N2 virus. The North Dakota Department of Agriculture put out the following news release:

North Dakota Department of Agriculture
July 31, 2014

For immediate release

Precautions advised regarding influenza

BISMARCK – The North Dakota Department of Agriculture (NDDA) and North Dakota Department of Health (NDDoH) received results from the National Veterinary Services Laboratory confirming that three pigs exhibited at the state fair in Minot have tested positive for an influenza A H3N2 virus strain. Although influenza can be passed from swine to people, there is no evidence at this time that any people have become ill as a result of exposure to these pigs.

 
NDDA animal health division staff inspects all animals displayed at the North Dakota State Fair. The pigs appeared healthy when they arrived at the fair and became ill thereafter. After being tested, they were removed from the fairgrounds by their owners at the recommendation of veterinarians. This is the first time that an influenza virus has been confirmed in swine at a fair in North Dakota.

“Fairs and exhibits are an excellent way to showcase livestock and expose the public to animal agriculture production,” said Agriculture Commissioner Doug Goehring. “When appropriate precautions are taken, there is minimal risk of spreading disease to the public.”

 
However, some influenza viruses can spread from pigs to people and from people to pigs. Spread from infected pigs to humans is thought to happen in the same way that seasonal influenza viruses spread between people; mainly through infected respiratory droplets created when an infected pig coughs. Swine influenza has not been shown to be transmissible to people through eating properly handled and prepared pork or other products derived from pigs.

According to the NDDoH, appropriate precautions to prevent the spread of influenza from pigs to people include the same types of measures used to prevent the spread of influenza between people; frequent hand washing and avoiding contact with those that are ill. Other precautions include not eating or drinking around animals and avoiding contact with material, such as bedding material, which has been in contact with pigs. Any exhibitor or visitor at high risk of serious flu complications, who is planning to attend a fair where pigs will be present, should consider avoiding pigs and swine barns. The NDDoH also encourages those who work with pigs to take precautions to avoid the spread of illness. Use masks and gloves when you work with ill animals to protect yourself against transfer of the virus.

“Washing hands prior to working with or handling animals and likewise after working with animals is a good practice,” State Veterinarian, Dr. Susan Keller said. “Swine producers should contact their veterinarians if they have any questions about influenza-like illnesses in their pigs. Vaccines are available that may prevent illness.”

According to the NDDoH, if you experience symptoms of influenza (fever, cough, sore throat, body aches, headache) after contact with animals, report that contact to your primary health care provider. Conversely, if you have influenza, avoid contact with pigs during your illness and for another week after symptoms have disappeared.

For more information about influenza, including the H3N2v flu, visit the health department’s influenza website at www.ndflu.com or call the North Dakota Department of Health at 701-328-2378. For recommendations for swine producers, visit the NDDA website at www.nd.gov/ndda/disease/h3n2-influenza or call the State Veterinarian’s office at 701-328-2655.

 

 

Although only 19 swine variant flu infections were reported last year,  in 2012 more that 300 cases were reported, with nearly all linked to fairgoers, mostly in Indiana & Ohio.  Given the limits of surveillance, and the likelihood that some number of mild or asymptomatic cases went undetected, both numbers probably under represent the true incidence of the disease.

Nevertheless, these swine variant viruses do no yet appear ready for prime time, as they have yet to show signs of sustained and efficient transmission in the community.  

 

They do, however, bear watching as research has shown only limited community immunity to these variant strains (see CIDRAP: Children & Middle-Aged Most Susceptible To H3N2v).

CDC: Measures to Minimize Influenza Transmission at Swine Exhibitions, 2014

Credit Wikipedia

 

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A little over three weeks ago, in Keeping Our Eyes On The Prize Pig, I wrote about the upcoming county & state fair season, and concerns that we could see a resurgence in Swine Variant Influenza infections in fairgoers this year.  Although only 19 such cases were identified in 2013, the previous year more that 300 cases were reported.

 

The CDC describes Swine Variant viruses in their Key Facts FAQ.

What is a variant influenza virus?

When an influenza virus that normally circulates in swine (but not people) is detected in a person, it is called a “variant influenza virus.” For example, if a swine origin influenza A H3N2 virus is detected in a person, that virus will be called an “H3N2 variant” virus or “H3N2v” virus.

 

Swine are highly susceptible to a variety of flu viruses (human, swine, avian) - and are viewed as excellent `mixing vessels’, allowing viruses to reassort into new hybrid strains.

Here in North America we’ve been watching the evolution of several swine variant viruses (H1N1v, H1N2v, H3N2v) over the past few years, all of which have reassorted with - and picked up the M gene segment from – the 2009 H1N1 virus.  We’ve also seen similar reassortant viruses emerge in other parts of the world (see J. Virol: Continued Reassortment Of Swine Flu Viruses With Genes From pH1N1 In China).

While most reassortant viruses are evolutionary failures, the concern is that over time another swine variant virus might emerge – as did the 2009 H1N1 virus – and start another human epidemic or pandemic.

 

One strategy to try to prevent that from happening is limiting the number of humans that are exposed to these variant viruses, depriving the virus of opportunities to adapt to human physiology.  To that end, the CDC has issued the following advice for those planning to visit the fair:

 

 

For the past two years the CDC has also provided extended advice to exhibitors of swine, and those in charge of the venues, on their Guidance Associated with Fairs website.

Yesterday the CDC published a 6-page PDF file of Measures to Minimize Influenza Transmission at Swine Exhibitions, 2014, as prepared by the National Assembly of State Animal Health Officials (NASAHO) and the National Association of State Public Health Veterinarians (NASPHV).

 

Follow the link to download and read  the entire file.

 

National Assembly of State Animal Health Officials (NASAHO)
National Association of State Public Health Veterinarians (NASPHV)

Measures to Minimize Influenza Transmission at Swine Exhibitions, 2014

It is estimated that 150 million people visit agricultural fairs each year in North America.  Agricultural exhibitions provide valuable educational venues for the public. Equally important, livestock shows are an important learning opportunity for thousands of 4-H and FFA youth across the United States. For these youth, exhibiting at their county or state fair is the culmination of many months of work dedicated to the care and training of their animal.

Pigs can be infected with human, swine and avian origin influenza A viruses.  While rare, influenza A viruses can spread from pigs to people and from people to pigs. Transmission usually requires close contact between pigs and people.  This has happened in different settings, including livestock shows. When people are infected with swine origin influenza A viruses, it is termed as a variant virus infection and denoted with a “v” after the subtype (e.g. H3N2v).

In the past 5 years, cases of influenza A H1N1v, H1N2v and H3N2v have been associated with swine exhibitions.  Between 2011 and 2013, 340 human cases infected with H3N2v were reported from 13 states.  The largest outbreak occurred in 2012 when a total of 309 human cases of H3N2v flu were identified.

 
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Although the Public Health risk from these swine variant viruses is considered low at this time, the CDC takes these emerging swine flu viruses seriously, as evidenced by their most recent assessment.

 

CDC Assessment

It's possible that sporadic infections and even localized outbreaks among people with this virus will continue to occur. While there is no evidence at this time that sustained human-to-human transmission is occurring, all influenza viruses have the capacity to change and it's possible that this virus may become widespread. Illness associated with H3N2v infection so far has been mostly mild with symptoms similar to those of seasonal flu. Like seasonal flu, however, serious illness, resulting in hospitalization and death is possible. In 2012, for example, 309 infections with H3N2v were detected. Of these cases, 16 people were hospitalized and one of these people died. Most of the people who were hospitalized and the person who died had one or more health or age factor that put them at high risk of serious flu-related complications.

People at high risk of serious complications from seasonal influenza and H3N2v include children younger than 5, people with certain chronic conditions like asthma, diabetes, heart disease, weakened immune systems, pregnant women and people 65 years and older. CDC has issued guidance for people attending fairs where swine might be present this fair season, including additional precautions for people who are at high risk of serious flu complications. Limited serologic studies indicate that adults may have some pre-existing immunity to this virus while children do not. Most cases of H3N2v infection have occurred in children who have little immunity against this virus.

Keeping Our Eyes On The Prize Pig

Credit Wikipedia

 

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To give you an idea of how rapidly things change in the world of emerging infectious diseases, two summers ago (June 2012), no one had ever heard of the MERS coronavirus, the H7N9 avian flu virus was still 8 months away from breaking out in China, and avian H5N8, H10N8, H6N1 and H5N6 weren’t on anyone’s radar screen.

 

Aside from the perennial concerns over change in transmissibility of H5N1 virus, our primary emerging disease concerns that summer lay in a major outbreak of West Nile Virus (see DVBID: 2012 Record Number Of West Nile Fatalities), and an outbreak of human infection with variant influenza  contracted from show pigs displayed at county and state fairs. 

 

The CDC describes Swine Variant viruses in their Key Facts FAQ.

What is a variant influenza virus?

When an influenza virus that normally circulates in swine (but not people) is detected in a person, it is called a “variant influenza virus.” For example, if a swine origin influenza A H3N2 virus is detected in a person, that virus will be called an “H3N2 variant” virus or “H3N2v” virus.

Although the actual number of human variant flu infections that occur each year is unknown, the CDC has reported 1 or 2 cases each year since 2005. In 2010, that number jumped to 8, and in 2011, to 12. During the summer of 2012 more than 300 cases were recorded across the United States, and nearly all were linked to contract with pigs displayed at county and state fairs that summer.

 

Last year we only saw a handful of cases, but with state and county fair season once again upon us (it runs June-November around the nation) the potential exists for seeing cases again this summer and fall. 

 

While fairs have instituted inspections for any signs of illness in livestock – as we’ve discussed previously (see Asymptomatic Pigs: Revisited) - pigs can carry this virus without showing any outward signs of infection.

 

Swine are highly susceptible to a variety of flu viruses (human, swine, avian) - and can serve as `mixing vessels’, allowing viruses to reassort into new hybrid strains, a topic well covered by Helen Branswell a few years ago in a SciAm article called called Flu Factories.

 

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Some of my earlier blogs on swine variant influenza include: H3N2v: When Pigs Flu , You Say You Want An Evolution? & The (Swine) Influenza Reassortment Puzzle.

 

These swine variant strains are – like the 2009 H1N1 pandemic virus – reassortants, that continue to circulate (and evolve) in swine herds.  Starting in 2011, the H1N1v virus was found to have acquired the M (matrix) gene from the 2009 H1N1 pandemic virus. Since then, this M gene has been showing up regularly in all three swine variant viruses (H1N1v, H1N2v, H3N2v).

 

The CDC has speculated that `This M gene may confer increased transmissibility to and among humans, compared to other variant influenza viruses.’

 

The concern with these variant swine flu infections, as it is with any animal flu that jumps to humans, is that it gives the virus another opportunity to better adapt to human physiology. While humans have a long history of exposure to seasonal H3N2 flu viruses, research has shown only limited community immunity to these variant strains (see CIDRAP: Children & Middle-Aged Most Susceptible To H3N2v).

 

The good news is that while some limited community transmission of these variant flu strains appears to have occurred during the summer of 2101, sustained and efficient human-to-human transmission did not, and for the most part, the virus only caused mild to moderate illness.

 

But as we’ve seen so often in the past, things can change quickly in the world of infectious diseases.

 

So while Chikungunya, West Nile Virus and MERS will be getting the bulk of the headlines this summer,  public health officials will also be on the lookout for any new swine variant infections - and more importantly - for any signs that the behavior of the virus has changed.

 

In the meantime, the CDC offers this advice for those planning to visit the fair this year:

 

Exhibitors of swine, and those in charge of the venue, will want to consult  Guidance Associated with Fairs.

Michigan Reports 1st H3N2v Case Of 2013

 

Credit CDC

 

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Compared to last year, when more than 300 cases of H3N2v were reported across the country (mostly associated with livestock exposure at county & state fairs),  2013 has seen relatively few cases of swine variant influenza reported.

 

Prior to today, just 16 cases have been reported to the CDC over the summer.  Nevertheless, the CDC and local public health departments remain on alert for new cases, and it is likely that some cases go unidentified.

 

Last weekend, in CDC Updates H3N2v County & State Fair Advice, we looked at the latest guidance from the CDC for fairgoers and exhibitors.

 

On July 5th, the CDC released a HAN Advisory On H3N2v, alerting doctors to the possibility that more cases could turn up this summer.

 

Also in July the CDC also released two new interim guidance documents on H3N2v for local public health agencies; one on case definitions, and the other on surveillance and specimen collection.

 

The CDC’s most recent assessment of the risk of H3N2v reads:

 

CDC Assessment

It's possible that sporadic infections and even localized outbreaks among people with this virus will continue to occur. While there is no evidence at this time that sustained human-to-human transmission is occurring, all influenza viruses have the capacity to change and it's possible that this virus may become widespread. Illness associated with H3N2v infection so far has been mostly mild with symptoms similar to those of seasonal flu. Like seasonal flu, however, serious illness, resulting in hospitalization and death is possible. In 2012, for example, 309 infections with H3N2v were detected. Of these cases, 16 people were hospitalized and one of these people died. Most of the people who were hospitalized and the person who died had one or more health or age factor that put them at high risk of serious flu-related complications.

People at high risk of serious complications from seasonal influenza and H3N2v include children younger than 5, people with certain chronic conditions like asthma, diabetes, heart disease, weakened immune systems, pregnant women and people 65 years and older.

CDC has issued guidance for people attending fairs where swine might be present this fair season, including additional precautions for people who are at high risk of serious flu complications. Limited serologic studies indicate that adults may have some pre-existing immunity to this virus while children do not. Most cases of H3N2v infection have occurred in children who have little immunity against this virus.

 

Today Michigan reports their first detection of a swine variant flu infection this year, that of a child who was exposed to an infected pig at the Berrien County Youth Fair, which ran from August 12th to the 17th.

 

 

Here is a link to the Berrien County Health Department’s announcement of today’s case.

 

 

First Case of Influenza A H3N2 Variant Detected for 2013

FOR IMMEDIATE RELEASE: August 29, 2013

LANSING – Today, August 29, 2013, the Michigan Departments of Community Health (MDCH), and Agriculture and Rural Development (MDARD), along with the Berrien County Health Department (BCHD) have identified one case of an H3N2 variant (H3N2v) in a child who was a swine exhibitor at the recent Berrien County Youth Fair, which took place August 12-17, 2013.

 

The child, who was not hospitalized, is reported to have contracted H3N2v after exposure to swine at the fair. In addition, a sick pig from the fair tested positive for Influenza A H3N2 at the National Veterinary Services Laboratories in Ames, Iowa. MDCH, MDARD, and BCHD are working with the Berrien County Youth Fair (BCYF) board to reach out to swine exhibitors who attended the fair to identify additional illnesses. As a precaution, Michigan public health agencies have conducted an extensive multi-state outreach to meat processing plants that were identified as being in receipt of live swine from the fair. These facilities have been made aware of the potential exposure to their employees, symptoms of illness, and given instruction on seeking care and testing. MDARD has notified managers at eight additional fairs scheduled to take place in the coming weeks, and asked them to reach out to swine exhibitors and the fair veterinarians about the H3N2v case and to use proper safety measures to prevent spreading illnesses.

 

“Influenza is common to swine and is not a food safety concern,” said Dr. James Averill, MDARD Animal Industry Division Director and State Veterinarian. “Berrien County Youth Fair had hand washing stations, posters, and good biosecurity practices in place, and it’s important that all fairs continue these practices.”

 

Symptoms of H3N2v infection in people are similar to those of seasonal flu viruses and can include fever and respiratory symptoms, such as cough and runny nose, and possibly other symptoms, such as body aches, nausea, vomiting, or diarrhea. Infections with influenza viruses (including variant viruses like H3N2v) can sometimes cause severe disease, even in healthy people. This can include complications, such as pneumonia, which may require hospitalization, and sometimes results in death. People who are at high risk of developing complications if they get influenza include children younger than 5 years of age, people 65 years of age and older, pregnant women, and people with certain long-term health conditions, such as asthma, diabetes, heart disease, weakened immune systems, and neurological or neurodevelopmental conditions.

 

“While this variant flu virus has rarely been shown to spread from person to person, we remain on the look-out for such secondary cases. In addition, any individual with flu-like-symptoms at this time, prior to the traditional flu season, should contact their medical provider and local health department,” said Dr. Rick Johansen, Medical Director of the BCHD.

 

The incubation period (the time it takes from exposure to illness) for this influenza, like the usual seasonal influenza, is 1 to 7 days; and most commonly 2 days. Therefore, it is unlikely that there will be new cases from direct exposure at the recent Berrien County Youth Fair. Early treatment works best and may be especially important for people with a high risk condition. Currently there is no vaccine for H3N2v and the seasonal flu vaccine will not protect against H3N2v.

 

"While Michigan did see a handful of H3N2v cases in 2012, this first case for 2013 should serve as an important reminder of the simple steps that can be taken to protect our health as we would with any flu season," said Dr. Matthew Davis, Chief Medical Executive with the MDCH. "Washing your hands, covering your nose and mouth when you sneeze or cough, and staying home when you feel sick are some of the best ways to protect yourself and others from becoming ill. This serves as a good reminder for Michigan residents that everyone 6 months and older should get a seasonal flu vaccine each year."

Below are some steps that you can take to protect yourself and prevent the spread of any illness:

• Avoid close contact with sick people.
• Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
• Wash your hands often with soap and water. If soap and water are not available, use an alcohol-based hand rub.
• Do not eat or drink in livestock barns or show rings.
• Avoid touching your eyes, nose and mouth. Germs spread this way.
• If you are sick, stay home from work or school until your illness is over.
• Avoid contact with pigs if you have flu-like symptoms. Wait 7 days after your illness started or until you have been without fever for 24 hours without the use of fever-reducing medications, whichever is longer. If you must have contact with pigs while you are sick, take the protective actions listed above.
• Get an annual influenza vaccination.

For more information about H3N2v, visit www.cdc.gov/flu/swineflu/h3n2v-basics.htm.

CDC Updates H3N2v County & State Fair Advice

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After last year’s sudden jump in the number of human swine-variant flu infections linked to exposure to pigs at state and county fairs - from a dozen in 2011 to 300+ in 2012 -  authorities this year have been braced for a repeat performance.

 

This year, we’ve yet to see a repeat of last year’s mini-epidemic. Friday’s FluView report summarizes this year’s activity:

 

Novel Influenza A Viruses:

No additional infections with influenza A (H3N2) variant (H3N2v) virus were reported to CDC during week 33. A total of 16 H3N2v cases have been reported this summer (Illinois [1], Indiana [14], and Ohio [1]).

 

So far during 2013, one person has been hospitalized as a result of H3N2v illness; no deaths have occurred. At this time no ongoing human-to-human transmission has been identified and all 16 cases have reported close contact with swine in the week prior to illness onset.

 

Nonetheless, fair season runs through late fall, and there remain ample opportunities for variant flu transmission to humans.  On Thursday The CDC updated their advice on preventing the spread of flu at the fair, and for people exhibiting pigs at fairs this year on their

 

• UPDATED: Take Action to Prevent the Spread of Flu Between People and Pigs at Fairs PDF  Thursday, August 22, 2013 5:06:00 PM

 

 

 

• UPDATED: Key Facts for People Exhibiting Pigs at Fairs PDF  Thursday, August 22, 2013 5:02:00 PM

 

On Thursday, Minnesota Public Radio carried the following report on how that state is working to prevent flu transmission at their state fair, which runs through September 2nd (Labor Day).

 

 

State Fair watching closely for signs of swine flu

by Lorna Benson, Minnesota Public Radio

August 22, 2013

ST. PAUL, Minn. — Hundreds of thousands of visitors will wander through the animal barns at the Minnesota State Fair over the next 12 days to view some of the state's top farm animals.

 

Whenever people and animals are in close proximity there's always a chance that a disease can pass between them.

 

A strain of swine influenza swept through fairs last summer sickening 309 people in a dozen states, including Minnesota. One person died from the new virus. This year 16 people have contracted influenza from pigs after visiting fairs in Indiana, Illinois and Ohio. So far, Minnesota hasn't had any cases.

(Continue . . .)

 

 

Although it is likely (see CID Journal: Estimates Of Human Infection From H3N2v (Jul 2011-Apr 2012)) that the number of confirmed cases (this year, and in previous years) under-represents the total number of infections that occur each year - for now, the threat to the public from these swine variant viruses appears low.

 

The CDC, in a statement on June 28th of 2013, offered this assessment:

 

CDC will continue to watch this virus closely to make sure there are no changes in the epidemiology of related human infections. That means watching for any changes in the severity of illness caused by infection with this virus and any signs that the virus is becoming more adept at spreading from person-to-person. Like all influenza viruses, it’s possible that mutations could occur that would allow this virus to become more severe or to spread more easily between people.

 

The risk of this virus triggering a full-blown pandemic is considered relatively low, however, because serology studies have suggested that significant numbers of adults have some existing immunity against this virus. Children younger than about 10 years old, however, have little to no immunity against H3N2v virus. Given this, a more likely scenario if H3N2v were to become more transmissible among people would be localized outbreaks in pockets of the population that do not have immunity against this virus, for example, in day care or school settings.

Indiana Reports 4 H3N2v Infections

Credit Wikipedia

 

 

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Last Sunday in A Variant Swine Flu Review I wrote about the upcoming county and state fair season (which started in mid-June) and the possibility of seeing a repeat of last year’s  swine variant influenza infections among fair goers.

 

During the summer and early fall of 2013, more than 300 people – mostly linked to county and state fairs in the Mid-West - were diagnosed with one of three swine variant flu strains (H1N1v, H1N2v, and H3N2v).

 

Today, we’ve the first report of 2013 of the H3N2v influenza detected in 4 fairgoers who recently attended the Grant County fair in Indiana. First the Press Release from the Indiana Department of Health, and then I’ll return with a bit more.

 

Health Officials Encourage Hoosiers to Protect Themselves From Swine Flu

 

INDIANAPOLIS—State health officials are encouraging Hoosiers to take steps to protect themselves at county and 4H fairs around the state this summer following detection of four cases of variant influenza A (H3N2v). All individuals visited the Grant County Agricultural Fair, June 16-22, prior to illness, and at least two had contact with swine. Variant influenza A H3N2v was identified in Indiana last year, with a total of 138 cases in 2012.

 

The Indiana State Department of Health and the Grant County Health Department continue to investigate these cases. Human infections with H3N2v are rare but have most commonly occurred after close proximity to live infected pigs, such as working with them in barns and livestock exhibits at fairs. Influenza viruses are not transmitted by eating pork and pork products.

 

According to the State Board of Animal Health, thirteen pigs at the fair tested positive for H3N2. It is not uncommon for pigs to be infected with swine influenza viruses but not show any signs of illness. If ill with influenza they typically recover.

 

“Fairs are a great way to get outdoors, have some fun and learn about agriculture,” said State Health Commissioner William VanNess, M.D. “If you plan to attend a fair this summer, just be sure to wash your hands frequently and avoid taking food into areas where animals are kept.”

 

Symptoms of variant influenza A include: fever, cough, sore throat, chills, headache and muscle aches. Diarrhea and nausea may occur in children. Symptoms can begin approximately one to four days after being exposed to the illness and last from two to seven days.

 

As several county fairs will open in the next few weeks, State health officials are increasing surveillance for influenza-like illness.

 

“We are increasing our surveillance so we can learn more about this virus and because antiviral treatment is most effective if given within 48 hours,” said Dr. VanNess. “It’s important to contact your health care provider if you begin experiencing flu-like symptoms.”

 

And if you have visited a fair or been around animals, let your health care provider know. Influenza antiviral drugs can treat infection with H3N2v and quick treatment is especially important for people who are at high risk of serious flu complications, including the very young, the elderly, people with chronic health conditions like asthma, diabetes and heart disease and pregnant women.

 

Visiting animal exhibits is fun and educational, and Hoosiers are reminded to follow some simple safety steps to prevent illness. Wash hands with soap and water before and after petting or touching any animal. Never eat, drink or put anything in your mouth when visiting animal areas and avoid face-to-face contact with animals. People at high risk for flu complications should avoid close contact with swine in the fair setting particularly.

 

While influenza is not an uncommon diagnosis in pigs, the State Board of Animal Health encourages swine owners to contact a veterinarian if their animals show signs consistent with flu, including coughing, respiratory illness, off-feed and fever. Most county fairs have a private veterinary practitioner on call for on-site assistance.

 

Since there is no vaccine available for people to protect against this H3N2v virus, the best way to prevent infection with variant influenza is to avoid sources of exposure to the virus. As always good hygiene and other everyday preventive actions are important to take as well. Wash your hands frequently. Cough or sneeze into your sleeve or elbow. Avoid contact with people or animals that are ill. Stay home if you develop influenza symptoms and contact your health care provider.

 

In 2012, the Centers for Disease Control and Prevention (CDC) reported 309 infections with H3N2v in the United States. According to the CDC, most of these infections resulted in mild illness, though 16 people were hospitalized and one person died. Most of the people who were hospitalized and the person who died had one or more high risk conditions.

 

For more information about variant influenza A, visit www.StateHealth.in.gov or follow the Indiana State Department of Health on Twitter at @StateHealthIN and on Facebook at www.facebook.com/isdh1.

 

The CDC’s Assessment of the risks from these swine variant flu strains reads:

 

CDC Assessment

It's possible that sporadic infections and even localized outbreaks among people with this virus will continue to occur. While there is no evidence at this time that sustained human-to-human transmission is occurring, all influenza viruses have the capacity to change and it's possible that this virus may become widespread.

So far, Illness associated with H3N2v infection so far has been mostly mild with symptoms similar to those of seasonal flu. Like seasonal flu, however, serious illness, resulting in hospitalization and death is possible.

People at high risk of serious complications from H3N2v include children younger than 5, people with certain chronic conditions like asthma, diabetes, heart disease, weakened immune systems, pregnant women and people 65 years and older. Limited serologic studies indicate that adults may have some pre-existing immunity to this virus while children do not. Most cases of H3N2v infection have occurred in children who have little immunity against this virus.

 

While fairs have instituted inspections for any signs of illness in livestock – as we discussed last October (see Asymptomatic Pigs: Revisited) – tests indicate that pigs can carry these viruses without showing any outward signs of infection.

 

The CDC maintains an H3N2v and You FAQ page, and offers the following advice for fairgoers and exhibitors.

 

Preventive Actions

CDC Recommendations For People At High Risk:

• If you are at high risk of serious flu complications and are going to a fair where pigs will be present, avoid pigs and swine barns at the fair this year. This includes children younger than 5 years, people 65 years and older, pregnant women, and people with certain long-term health conditions (like asthma, diabetes, heart disease, weakened immune systems, and neurological or neurodevelopmental conditions).

If you are not at high risk, take these precautions:

• Don’t take food or drink into pig areas; don’t eat, drink or put anything in your mouth in pig areas.
• Don’t take toys, pacifiers, cups, baby bottles, strollers, or similar items into pig areas.
• Wash your hands often with soap and running water before and after exposure to pigs. If soap and water are not available, use an alcohol-based hand rub.
• Avoid close contact with pigs that look or act ill.
• Take protective measures if you must come in contact with pigs that are known or suspected to be sick. This includes minimizing contact with pigs and wearing personal protective equipment like protective clothing, gloves and masks that cover your mouth and nose when contact is required.
• To further reduce the risk of infection, minimize contact with pigs and swine barns.

 

For a more complete overview of these swine variant viruses, you may wish to revisit:

 

A Variant Swine Flu Review