According to scientific research, viruses like avian influenza—commonly known as "bird flu"—are older than most living organisms on the planet. They are also very different from other organisms; in fact, many experts define viruses as organic structures rather than living things. Like seeds, viruses require additional help to become active. Left to themselves, they remain dormant and replicate only when introduced into a living organism—your body, for example.
A bird flu virus' main goal is survival; therefore, viruses mutate constantly. As a result, they indirectly ensure that their potential hosts' immune systems remain open to new infection. Less severe strains, as well as strains confined to one particular species, are capable of evolving into much more serious threats in a relatively short period of time. The original bird flu virus, H5N1, has developed considerably since its discovery; numerous variants are capable of jumping species quite efficiently.
However, the latest bird flu threat is not attributable to the H5N1 virus or to any of its variants. Instead, a new strain—H7N9—has been causing considerable concern, particularly in mainland China. H7N9 bird flu symptoms and the virus' resulting pneumonic complications have proven lethal in a high percentage of cases. According to the China Academy of Agricultural Sciences (CAAS), the subtype, which was originally discovered in eastern China in February 2013, may have several different viral origins.
The results of a genetic analysis on samples taken from poultry revealed that six of the genes in the new virus came from another type of avian flu: H9N2. The source, or sources, of the virus' other components remained unclear at the time of the April 2013 CAAS statement. A collaborative study conducted by the World Health Organization (WHO) and the Influenza Virus Research Center—a part of Japan's National Institute of Infectious Diseases—apparently confirmed the virus's increasing acclimatization to human hosts.
Shortly after the CAAS statement, the WHO reported that, although approximately half of the reported victims of H7N9 in China had not been directly exposed to poultry, evidence of human-to-human transmission of the virus had not been confirmed. However, WHO experts conceded that their understanding of the "unusually dangerous" bird flu virus was still in its early stages. Representatives also said that the H7N9 virus' ability to jump species from birds to humans appeared to be more advanced than the similar ability found in its 2006 predecessor, the H1N1 virus.
Meanwhile, a fifty-three-year-old Taiwanese man who started displaying bird flu symptoms after returning to Taiwan from China was confirmed as the first H7N9 victim outside the Chinese mainland. The man maintained that he had not been in contact with birds or bird products while in China. Chinese authorities continued to investigate reports of human-to-human infection. By April 24, 2013, twenty-two of the 109 reported victims of H7N9 in China had succumbed to the disease. Elsewhere, the Center for Disease Control (CDC) continued its efforts to produce a vaccine for the strain. Sources agree that a pandemic, while possible, is far from inevitable.
The origins of bird flu are, as you might expect, found in the bird population, specifically, in Asian poultry. According to scientists, human cases of bird flu are largely caused by direct bird-to-human contact, and cases of H7N9 virus transmission between humans are apparently still unproven. Nevertheless, various health organizations have continued to explore the virus; the CDC in particular is making progress on a vaccine for the bird flu strain. As a healthcare professional, you may wish to remain updated about the status of H7N9 to ensure that you and your team are ready to tackle the disease if and when it becomes an international concern.
(Photo courtesy of Freedigitalphotos.net)
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