South Dakota has reported a case of swine flu in a human, a 19-year-old South Dakota State University student. The individual was ill five weeks ago and a specimen was collected December 4, 2008. The state Public Health Laboratory identified the A/H1 portion of the virus and just this week, the Centers for Disease Control and Prevention (CDC) influenza lab identified the swine components of the virus.
"Swine flu in humans is rare but it does occur," said Dr. Lon Kightlinger, State Epidemiologist for the department. "Most often, the cases occur in people with direct exposure to pigs, such as swine farm workers. Human to human transmission is very rare."
Nationally, the CDC typically receives about one report of swine flu virus in a human each year. The South Dakota case is believed to be the state’s first case. Kightlinger said the department is on enhanced surveillance for additional cases and is working closely with CDC and the U.S. Department of Agriculture on the case investigation.
The symptoms of swine flu in people are the same as those of seasonal human flu. They include a fever with a cough, sore throat, body aches, and tiredness. It is also possible to be infected and have no symptoms. There is a swine flu vaccine for pigs but because people seldom become infected with the virus, there is no human vaccine. Seasonal flu activity is low in Brookings and in the state this year.
Dr. Sam Holland, State Veterinarian, noted that swine viruses are often observed in routine poultry disease surveillance, due to the ever-present and circulating nature of influenza viruses. "We also know that the strains of flu viruses circulating in pigs do contain genes common to influenza viruses in humans. Influenza viruses are constantly circulating and mutating among birds, animals, and people so the occasional finding of a bird or swine virus in people or vice versa is not a surprise," said Dr. Holland.
More information about swine flu is available from the Centers for Disease Control and Prevention at http://www.cdc.gov/flu/swine/pdf/facts.pdf or from the Iowa Department of Health at http://www.idph.state.ia.us/adper/common/pdf/epifacts/swine_influenza.pdf