Protecting Swine Workers from H1N1 Influenza

In April 2009, a new influenza virus emerged in humans in the United States. Initially misnamed as “swine flu,” the virus contains components of human, swine, and avian influenza viruses, and is very different from influenza viruses found in North American pigs.1


Nearly all infections with novel influenza H1N1 have occurred in humans. However, limited outbreaks of novel influenza A (H1N1) in pigs have occurred, most notably in Canada and Australia.2,3 As of October 8, 2009, there have been no pigs diagnosed with novel influenza A (H1N1) in the United States.


People with swine contact can transmit the novel H1N1 virus to pigs2,3 and pigs can most likely transmit the virus to people. The Centers for Disease Control and Prevention (CDC) has developed minimum precautions that aim to protect people exposed to pigs known or suspected to have influenza on premises not used for commercial production (e.g. small backyard or hobby farms, zoo settings including petting zoos, homes with pet pigs) AND for protecting pigs from people with influenza.4 Although these guidelines are not intended to apply to commercial pork producers, they contain valuable information that can help producers develop a H1N1 influenza prevention plan.


(Taken from “CDC Interim Guidance for People who have Close Contact with Pigs in Non-commercial Settings: Preventing the Spread of Influenza A Viruses, Including the Novel Influenza A (H1N1) Virus”)


Recognizing the Signs of Flu in Pigs


Flu viruses are thought to spread from infected people and pigs to other people and pigs mostly through coughing or sneezing, and through contact with surfaces contaminated by flu viruses. To prevent flu viruses from spreading between people and pigs, it is important for people working with pigs to recognize the signs of flu in pigs. Typically a combination of signs will occur together in infected pigs. Signs of flu in pigs can include any of the following:

  • sudden onset of fever
  • lethargy, lack of alertness
  • going off feed (poor appetite)
  • coughing (barking)
  • discharge from the nose or eyes, eye redness or inflammation
  • sneezing
  • breathing difficulties

If a pig is showing these signs, even mildly, you should call your veterinarian. Do not allow sick pigs to enter your farm or facility and do not move sick pigs off your property.


Recognizing the Signs of Flu in People


To prevent spread of flu viruses from people to pigs, you should also be aware of the signs of flu in people. Flu-like symptoms in people can include any of the following:

  • fever
  • cough
  • sore throat
  • runny or stuffy nose
  • body aches
  • headache
  • chills
  • fatigue
  • possibly vomiting or diarrhea


Preventing Spread of Flu Viruses from Pigs to People


If possible, people should avoid getting close (within 6 feet) to pigs known or suspected to be infected and/or their environment. However, if you must come in contact with pigs known or suspected to be infected, or their environment, you should use appropriate protective measures and practice good personal hygiene.


When entering barns or areas where sick pigs are present, wear protective clothing. This can include disposable coveralls or barn clothes that are laundered after each use and shoes or boots that can be disinfected. This will limit your chances of getting flu from the pigs and from spreading flu virus to other people or pigs. Barn clothes should ideally be laundered at the barn. If clothes must be taken home they should be placed in a plastic bag and laundered separately from nonwork family clothing. When working around sick pigs, you should avoid touching or rubbing your eyes, nose, and mouth. Ideally, you should wear goggles and a disposable NIOSH-certified N-95 (or greater) filtering facepiece respirator. Disposable gloves or gloves that can be disinfected after use should be worn. Disposable gloves should be taken off by turning them inside out over the hand and placed in the trash after use.


Hands should be washed after contact with animals or their environments, equipment and surfaces that are possibly contaminated, and after removing gloves and/or contaminated clothing. Hands should be washed thoroughly for 20 seconds with soap and running water after gloves are removed. Use alcohol-based gel hand cleaners* if soap and water are not available.


Commonly used disinfectants, such as quaternary ammonium compounds and 10% bleach solutions, will kill flu viruses. Equipment and surfaces that have been in contact with sick pigs should be thoroughly cleaned and disinfected with products registered for use against flu viruses. More information on disinfectant use can be found at: http://www.epa. gov/oppad001/influenza-disinfectants.html.


Steps to Take if You Develop Flu-Like Symptoms


If you become ill with flu-like symptoms you should take the following steps:

  • Seek medical care or advice. Your healthcare provider will decide if testing or treatment is needed. Be sure to tell your healthcare provider if you were in contact with pigs.
  • Keep away from others as much as possible. This is to keep from making others sick.
  • Stay home for at least 24 hours after your fever is gone except to get medical care or for other necessities. (Your fever should be gone without the use of a fever-reducing medicine).
  • Practice good personal hygiene, such as covering your nose and mouth with a tissue when you cough or sneeze. If tissues are not available, cough or sneeze into your upper sleeve. Wash your hands often with soap and warm water. Alcohol-based gel hand cleaners are also effective*.


Persons at Higher Risk for Complications from Flu


Certain groups of people are at increased risk of becoming severely ill with influenza. These groups include children younger than 5 years, persons 65 years and older, and pregnant women. Also included are persons of any age who have certain medical conditions (including those immunosuppressed because of medications or HIV). Individuals in these groups may choose to avoid direct animal contact. Persons at increased risk for having severe illness from influenza and household contacts of these persons should get seasonal flu vaccine every year (see http://www.cdc.gov/flu/protect/vaccine/index.htm).


Preventing Spread of Flu Virus from People to Pigs


Influenza is occasionally transmitted from people to pigs. If you have been diagnosed with flu or if you develop flu-like symptoms, take the steps listed above: seek medical care, limit your contact with others, and practice good personal hygiene. In addition to limiting your contact with people, you should avoid contact with pigs. You should also contact your veterinarian if you note signs of flu in a pig. Notify your veterinarian if the pig became ill two weeks before or after contacting a person with flu-like symptoms.


1 http://www.cdc.gov/h1n1flu/qa.htm
2 http://www.usda.gov/wps/portal/?contentidonly=true&contentid=2009/04/0131.xml
3 http://www.outbreak.gov.au/pests_diseases/pests_diseases_animals/swine-flu/index.htm
4 http://www.cdc.gov/H1N1flu/guidelines_pig_workers.htm