Sunday, July 28, 2019

Deja Flu: Pigs With Swine Influenza At Fowlerville Family Fair (Michigan)




















#14,217


On a Sunday morning almost exactly a year ago (July 29th, 2018) I posted  Michigan: Pigs At Fowlerville Family Fair Test Positive For Swine Flu, an outbreak which would result in at least two human infections (see Michigan DOH: 2 People Test Positive For Influenza After Contact With Infected Swine).
Although the public health threats from swine influenza viruses are believed limited, they are not zero. The concern is that these viruses are constantly evolving, and over time they may gain additional transmissibility and/or virulence.
The CDC's general risk assessment of these swine variant (H1N1v, H1N2v, H3N2v) viruses reads:

CDC Assessment

Sporadic infections and even localized outbreaks among people with variant influenza viruses may occur. All influenza viruses have the capacity to change and it’s possible that variant viruses may change such that they infect people easily and spread easily from person-to-person. The Centers for Disease Control and Prevention (CDC) continues to monitor closely for variant influenza virus infections and will report cases of H3N2v and other variant influenza viruses weekly in FluView and on the case count tables on this website
Late yesterday the Livingston County Health Department announced that pigs once again at the Fowlerville Family Fair have tested positive for swine influenza - and while no human illnesses have been reported - issued the following statement.

FOR IMMEDIATE RELEASE
Swine Flu Confirmed in Pigs at Fowlerville Family Fair
HOWELL, Michigan. – (July 27, 2019) The Michigan Department of Agriculture and Rural Development (MDARD) identified pigs at the Fowlerville Family Fair that tested positive for swine flu.
The Fowlerville Fair Board isolated infected pigs to prevent additional exposure. Infected pigs began showing symptoms in the afternoon of Thursday, July 25 and laboratory results were confirmed late Friday afternoon. 

The fair is scheduled from July 22-July 27. At this time, all pigs have been removed from the fairgrounds and there are no reported human illnesses.
The Livingston County Health Department (LCHD), in coordination with the Fowlerville Fair Board and Michigan State University Extension, are reaching out to exhibitors and their families who participated at the Fowlerville Family Fair that may have been in close contact with the infected pigs. 

The LCHD is also instructing healthcare providers in the area to watch for patients presenting with respiratory symptoms who report exposure to swine or who visited the swine barn. In addition any individuals who attended the fair and were exposed to the pigs who begin to have influenza like symptoms should contact LCHD. 

Swine flu can spread quickly between pigs and while rare, can pass to humans through droplets in the air when sick pigs cough or sneeze. Human symptoms of swine flu are similar to those of seasonal flu and can include fever, cough, runny nose, and sometimes body aches, nausea, vomiting, or diarrhea.

Symptoms usually appear within three days of exposure but can occur up to 10 days. Sometimes swine flu causes severe disease even in healthy people, such as pneumonia, which may require hospitalization.


People who are at high risk of developing complications if they get swine flu include children younger than five years of age, people 65 years of age and older, pregnant women, and people with certain chronic health disease, such as asthma, diabetes, heart disease, weakened immune systems, and neurological conditions.


Currently, there is no vaccine for swine flu and the seasonal flu vaccine will not protect against swine flu; however, antiviral drugs, such as Tamiflu and Relenza, are effective in treating swine flu. These antivirals are only available through prescription by a healthcare professional.
Early treatment works best and may be especially important for people with a high-risk condition. Individuals exposed to the pigs at the fair who begin to show symptoms should see their healthcare provider and inform them of possible exposure.
Below are some steps 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 and wash your hands.
  • Wash your hands often with soap and water. If soap and water are not available, use an alcohol-based hand rub.
  •  Refrain from eating or drinking in livestock barns or show rings.
  • Do not take toys, pacifiers, cups, baby bottles, strollers, or similar items into pig areas.
  • Anyone who is at high risk of serious flu complications and is planning to attend a fair should avoid pigs and swine barns.
  • void 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 seven 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.
  • Get an annual influenza vaccination.
For questions, please contact the LCHD Nurse on Call line at 517-552-6882 and leave your name and phone number and someone will return your call as soon as possible
So far, this summer has been pretty quiet on the swine flu front, with only one other case reported in 2019 (see CDC FluView Week 21: 1 Novel (H1N1v) Flu Infection - Michigan)- reported last May in an adult > 65 years of age (also) from Michigan, who, a bit unusually, reported no recent contact with live pigs.

Earlier this year the CDC released updated Guidance for Human Infections with Swine Flu Viruses so that clinicians would know how to treat, and report, suspected cases.  This update also included an Expert Medscape Commentary.


https://www.medscape.com/viewarticle/912591?src=par_cdc_stm_mscpedt&faf=1


In the fall of 2017, we looked at an EID Journal Dispatch (Transmission Of Swine H3N2 To Humans At Agricultural Exhibits - Michigan & Ohio 2016), that found while widespread illness in pigs was only rarely reported, surveillance revealed an average prevalence of influenza A in fair pigs of  77.5%.  
This study cautioned that this suggests `. .  . that subclinical influenza A infections in pigs remain a threat to public health (3).'
In other words, healthy looking pigs can carry, and transmit swine-variant viruses.  We saw similar findings in a 2012 study (see EID Journal: Flu In Healthy-Looking Pigs).

For more on Swine-variant influenza viruses - both in the United States and around the world - you may wish to revisit the past blogs:

Trop. Med & Inf. Dis.: Mammalian Pathogenicity and Transmissibility of H1 Swine Variant Influenza
BMC Vet.: Novel Reassortant H1N2 & H3N2 Swine Influenza A Viruses - Chile

J. Virology: Pathogenesis & Transmission of H3N2v Viruses Isolated in the United States, 2011-2016

JVI: Divergent Human Origin influenza Viruses Detected In Australian Swine Populations
The `Other' Novel Flu Threat We'll Be Watching This Summer
Emerg. Infect. & Microbes: Novel Triple-Reassortant influenza Viruses In Pigs, Guangxi, China