The first two U.S. cases of swine flu in humans this year are linked to infected pigs at county fairs in Michigan, the U.S. Centers for Disease Control and Prevention confirmed Friday.
The first case involved a Lapeer County child who was an exhibitor at the Oakland County Fair, which took place July 7-16 at Springfield Oaks County Park in Davisburg. The child, who was identified by state health officials only as younger than 18, was exposed to infected pigs within 10 days of developing symptoms.
Preliminary testing showed the child had an A(H3)v strain of the virus, and samples were sent to the CDC for confirmation. The federal agency's confirmatory testing, however, was inconclusive because the respiratory specimen did not contain enough virus. Still, the CDC said the child likely was infected and is counting it as the first U.S. human case of 2023.
The child was treated with flu antiviral drugs, was not hospitalized and has recovered from the illness. No person-to-person spread of this virus has been identified among the child's close contacts, federal health officials said Friday.
The Michigan Department of Agriculture and Rural Development and Department of Health and Human Services notified Oakland County Health Division that several pigs present at the fair tested positive for influenza A virus. The pigs began displaying symptoms on July 14, and the swine barn was closed to the public that evening.
A second case, different strain
The second case involves a Tuscola County resident who had flu-like symptoms after attending the Tuscola County Fair, according to the county health department. The fair took place July 23-29 at the fairgrounds in Caro, in Michigan's Thumb.
That person tested positive for a different strain of swine flu — A H1N1v — and also was treated with influenza antiviral drugs. The person was not hospitalized and is recovering. To date, no person-to-person spread of this strain of the virus has been identified, either, the CDC reported.
The Tuscola County Health Department is asking anyone who developed flu-like symptoms after attending the county fair to call the department at 989-673-8114 or contact their primary care provider.
The health department has alerted local physicians' offices to watch for patients who have respiratory symptoms and also have been exposed to pigs or visited the fair.
How does swine flu spread?
Pigs can be infected with influenza virus strains that are different from human flu viruses, but can sometimes spread them to people. Transmission occurs mainly through droplets when infected pigs cough and sneeze, according to the CDC.
If the droplets land in a person's nose or mouth or if they are inhaled, people can be infected. People cannot get swine influenza from eating properly prepared pork or handling pork products.
Like flu viruses in humans and other animals, the strains that spread among pigs change constantly. Pigs also can be infected by both avian flu and human flu viruses as well as their own flu viruses.
According to the CDC, when flu viruses from birds and humans infect pigs, new strains of the virus can emerge with the ability to spread not only from swine to people, but from person to person. That is what is believed to have occurred in 2009, when a new H1N1 virus with avian, swine and human genes emerged to cause a flu pandemic.
What are the symptoms of swine flu?
Symptoms of swine flu usually appear within three days of exposure but can begin as late as 10 days after exposure and are similar to those of human strains of seasonal flu viruses. They include:
Respiratory symptoms, such as cough and runny nose.
Nausea, vomiting or diarrhea.
Infections with influenza viruses, including swine flu strains, can sometimes cause severe disease, even in healthy people, such as pneumonia, which can lead to hospitalization and, in some cases, death.
People who are at high risk of developing complications if they get a swine flu infection include children younger than 5, people 65 and older, those who are pregnant and those who have health conditions such as asthma, diabetes, heart disease, weakened immune systems and neurological or neurodevelopmental conditions.
Antiviral drugs such as Tamiflu and Relenza, however, are effective in treating swine flu. Early treatment works best and may be especially important for people with a high-risk condition.
How can I avoid getting sick?
Attending swine exhibits at agricultural fairs can increase your risk because pigs from different places come into close contact with each other and with people, the CDC says.
Health officials urge people to take the following precautions in places where pigs are present:
Don't eat or drink in areas with pigs.
Avoid contact with pigs that appear to be sick.
Wash your hands with soap and water often before and after contact with pigs. If soap and water are not available, use an alcohol-based hand sanitizer.
If you're at high risk for developing serious illness from flu or other infections, consider avoiding pigs and swine barns.
Avoid touching your eyes, nose, and mouth.
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.
Do not take toys, pacifiers, cups, baby bottles, strollers, or similar items into pig areas.
If you're at high risk and can't avoid exposure to pigs, the CDC urges you to wear a well-fitting face mask that covers your nose and mouth.
If you develop symptoms after exposure to pigs, seek treatment. Antiviral drugs used to help people recover from human strains of the virus are also effective against swine flu.
Contact Kristen Shamus: firstname.lastname@example.org. Subscribe to the Free Press.
This article originally appeared on Detroit Free Press: First 2 human cases of swine flu in U.S. tied to Michigan county fairs