page_title: Swine influenza
section_title: Diagnosis
hierarchical_section_title: Swine influenza / Diagnosis
caption_attribution_description: English: Arrivals at Singapore airport terminal 3, scanning for fever in response to swine flu.
context_page_description: Swine influenza is an infection caused by any one of several types of swine influenza viruses. Swine influenza virus or swine-origin influenza virus is any strain of the influenza family of viruses that is endemic in pigs. As of 2009, the known SIV strains include influenza C and the subtypes of influenza A known as H1N1, H1N2, H2N1, H3N1, H3N2, and H2N3.
  Swine influenza virus is common throughout pig populations worldwide. Transmission of the virus from pigs to humans is not common and does not always lead to human flu, often resulting only in the production of antibodies in the blood. If transmission does cause human flu, it is called zoonotic swine flu. People with regular exposure to pigs are at increased risk of swine flu infection.
  Around the mid-20th century, identification of influenza subtypes became possible, allowing accurate diagnosis of transmission to humans. Since then, only 50 such transmissions have been confirmed. These strains of swine flu rarely pass from human to human.
context_section_description: The CDC recommends real-time PCR as the method of choice for diagnosing H1N1. The oral or nasal fluid collection and RNA virus-preserving filter-paper card is commercially available. This method allows a specific diagnosis of novel influenza (H1N1) as opposed to seasonal influenza. Near-patient point-of-care tests are in development.
caption: Thermal scanning of passengers arriving at Singapore Changi airport
exif: {"Image Make": "Canon", "Image Model": "Canon DIGITAL IXUS 900Ti", "Image Orientation": "Horizontal (normal)", "Image XResolution": "180", "Image YResolution": "180", "Image ResolutionUnit": "Pixels/Inch", "Image DateTime": "2009:06:19 21:46:59", "Image YCbCrPositioning": "Centered", "Image ExifOffset": "196", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "180", "Thumbnail YResolution": "180", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "5108", "Thumbnail JPEGInterchangeFormatLength": "6560", "EXIF ExposureTime": "1/60", "EXIF FNumber": "14/5", "EXIF ExifVersion": "0220", "EXIF DateTimeOriginal": "2009:06:19 21:46:59", "EXIF DateTimeDigitized": "2009:06:19 21:46:59", "EXIF ComponentsConfiguration": "YCbCr", "EXIF CompressedBitsPerPixel": "5", "EXIF ShutterSpeedValue": "189/32", "EXIF ApertureValue": "95/32", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "95/32", "EXIF MeteringMode": "Pattern", "EXIF Flash": "Flash fired, auto mode, red-eye reduction mode", "EXIF FocalLength": "77/10", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "3648", "EXIF ExifImageLength": "2736", "Interoperability InteroperabilityIndex": "R98", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "Interoperability RelatedImageWidth": "3648", "Interoperability RelatedImageLength": "2736", "EXIF InteroperabilityOffset": "3314", "EXIF FocalPlaneXResolution": "3648000/287", "EXIF FocalPlaneYResolution": "547200/43", "EXIF FocalPlaneResolutionUnit": "2", "EXIF SensingMethod": "One-chip color area", "EXIF FileSource": "Digital Camera", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF DigitalZoomRatio": "1", "EXIF SceneCaptureType": "Standard"}