It seemed that history will repeat itself if we don’t act now. Influenza or flu, for short, comes and go yearly. Different strains of virus due to mutation come and go. The flu shot every year is crucial and no one is immune. The most devastating among the flu outbreaks that inflicted the world was the Spanish flu of 1918 that killed 50 million healthy people, young and old. Now another type of flu has disturbed the world, the Avian flu, most commonly known as bird flu has resurfaced once again. The bird flu is recorded to have been around since 2000 B.C. This type of flu naturally infects only animals and mostly migratory birds. Wild birds are usually the carriers of the influenza A virus. Today, domesticated animals and livestocks get infected through contaminated feces. Naturally, humans do not get sick from this type of flu however; since the 1997 event, this changed.
Mode of transmission
The World Health Organization (WHO) reported in 2003 that there were 160 diagnosed and confirmed cases of human infection. Now, health scientists and researchers are motivated around the world to learn more how the avian flu virus will adapt to human that will cause pandemic disease. The spread and transmission of the disease to human is not well understood. However, studies have shown that the influenza type A that is shed in birds’ feces can remain dormant for about 30 days. If any bird will have direct contact with contaminated feces, the virus will reactivate once absorbed by another host.
Studies from the University of Erasmus Medical Center in Rotterdam, Netherlands headed by Thijs Kuiken, DVM, PhD and his colleagues have shown that in domesticated animals (cats) and mammals, the virus replicates in the lungs, intestines, and in other body parts that gives more perspective on how it can be transmitted to humans. According to Kuiken, humans become infected when the person is exposed to infected chicken or through eating poultry products from infected fowl. Humans also get infected through direct contact with the mucous membranes, contaminated feces, or infectious secretions from birds. This is especially common with people who are in the culling operations. During the culling process, the person gets infected through the lungs and the eyes. Some animals are the “mixing vessel” for the virus—a place where the virus stays, transforms, and mutates into a new form of the virus. The virus undergoes antigenic shift, which occurs continuously, thus making it easy for the virus to be transmitted to humans. Because of this notable feature of the influenza type A virus, vaccine cannot be produced easily and that is why there is the potential for it to become a pandemic disease.
The virulent Influenza Type A H5N1
Studies have shown that there are 2 major classes, Type A and B. Influenza A is usually found in the intestine of migratory birds. Through oral-fecal contamination, other animals like pigs get infected thus, passing the infection on to animals and subsequently to humans. Like any influenza virus A, the specific strain of virus was identified by 2-layers cholesterol and 2-protein coats, called the hemagglutinin (H) and the neuraminidase (N) that are used as markers in identifying the virus. Today, there are 16 different H and 9 different N antigens that are identified and 4 are associated with the flu infecting humans (H1N1, H2N2, H3N2, and H5N1) and H5N1 virus has been the focus of Centers for Disease Control (CDC). What makes this flu so different from the other types of flu virus, H5N1 can remain dormant, reactivate, and replicate when a suitable host comes along. Then, the infected host will have multi - organ systems failure that can lead to death. Now is the time to be aggressive in finding the cure or treatment. Early detection and containment is the key.
To learn more about avian flu, visit the following off- site links:
Pandemic INfluenza Information for Healthcare Professionals
Unless we act now, bird flu may win
Outbreak Notice on Human infection with Avian Influenza A (H5N1) Virus.
Should health care staff worry about avian flu?
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