|  | Public Health Safety | Medical Research

Difference Between Swine & Bird Flu

The CDC website calls the 1918 bird flu pandemic--which infected roughly one-third of the world population and killed between 50 million and 100 million people--the "mother of all pandemics," and states that all pandemics since 1918 have been caused by "descendants" of that virus, including the 2009 swine flu pandemic. But a new and deadly bird flu introduced in the beginning of the third millennium differs from swine flu in several ways.

  1. Risk of Contagion

    • Comparing the two kinds of flu viruses, swine flu appears to scientists to be much more contagious or likely to infect many more people than bird flu because it spreads easily via human-to-human contact (such as by coughing without covering the face or by shaking unwashed hands). Avian or 'bird' flu does not spread so easily. Also, avian flu reportedly infects only the people who have had direct contact with the birds carrying the virus.

    Geographic Location

    • Although the 2009 swine flu pandemic spread across the entire globe, it originated in Mexico and spread first through North America. Conversely, the turn-of-the-century bird flu reportedly originated in Asia and had not--as of April 2010--spread further than Eastern Europe and Africa. It was not significantly present in Western Europe or the Americas.

    Genetic Structures

    • Swine flu and bird flu differ in their genetic structure. Hemagglutinin, which causes red blood cells to cling to each other, and neuraminidase, an enzyme, are commonly found in flu viruses. Swine flu, designated H1N1 by scientists, and bird flu, called H5H1, differ from each other in the kinds of hemagglutinin and neuraminidase that make up their gene structures, according to Testcountry.org.

    Not Quite Swine Flu

    • According to the Flu.Gov website, the swine flu virus that emerged in 2009 in Mexico and became a world-wide pandemic later that year actually represented a "quadruple reassortant" virus. "Although each separate gene segment of the virus has been found in pigs previously, the individual gene segments of the virus originated from humans, birds, North American pigs and Eurasian pigs."

    More Dangerous

    • Although considered by scientists to be more dangerous than swine flu and watched for signs that it might become a pandemic, bird flu does not usually infect people. However, more than half of all recorded infections have been lethal. In comparison, the 2009 swine flu strain became contagious and dangerous but not highly lethal. The Flu.Gov website notes that two-thirds of the people hospitalized with it had other medical conditions that put them particularly at risk for complications.

Medical Research - Related Articles