Avian Influenza (Bird Flu), A World-Wide Concern
Document Number: 309
The race is on with health officials throughout the world to figure out how to ward off a potential global outbreak of deadly Avian Influenza (H5N1 Bird Flu). Avian influenza, which is infectious, is caused by Type A strains of this virus and is commonly found in birds. All birds are thought to be susceptible to infection from the Avian virus and their respective symptoms range from mild illness to a highly contagious fatal disease. The virus was first identified more than 100 years ago in Italy. Bird flu was thought only to infect both wild as well as domestic bird populations. Humans can catch the disease through close contact with live infected birds. One of the more common means of contracting the virus is through inhalation of dried/pulverized fecal matter from an infected bird. Experts continue to remind the public that Avian flu does have a very high fatality rate.
The Avian flu that was once believed to have been mainly confined to Southeast Asia has now spread to Europe and Turkey. Currently, experts cannot predict when the killer flu will strike. The United States is working with China, India, Indonesia, Malaysia and many other countries to improve a global network to detect Bird Flu outbreaks. Within the poultry industry, the highly contagious Avian influenza virus can be easily transmitted from one farm to another by mechanical means including contaminated equipment and vehicles, feed, cages and/or clothing. At this time, there is no evidence that the virus can be transmitted from one human to another human. However, the World Health Organization (WHO) and other experts warn that if that does occur, it could cause a worldwide pandemic. As compared to an annual flu that persons can typically encounter, a pandemic flu occurs three or four times a century and can occur in any season. A pandemic infection rate can affect anywhere from 25-50 percent of the population and is usually associated with more severe illness and high risk of death depending upon the severity of the virus strain.
The WHO advises individuals to avoid contact with chicken farms, duck farms or any other farm where animals have been ill, have been and/or are being slaughtered or are thought to possibly harbor the Avian influenza. For persons whom may have had contact with Avian influenza A (H5N1), the infectious period is seven days after resolution of fever in adults and 21 days after onset of illness in children. The median time between exposure and onset of illness is three days and can range from two to four days. Symptoms are similar to other flu types and include fever, malaise, as well as sore throat and cough. In certain cases, persons can also develop conjunctivitis.
Precautionary control measures for assisting in protecting oneself against the virus include choosing and wearing the appropriate level of personal protective equipment for the potential level of hazard that is present. For example, a health care worker in direct contact with patients that have the virus will require an increased level of protection as compared to another person in an alternative work field who may not be at such a severe risk with contracting the virus. Protective equipment suggested includes gloves, sleeve-apron or gown, cap, overshoes, goggles, shield and respirator. The main intent of the protective equipment is to prevent splash contact from blood, body fluids, excretions and secretions.
Decontamination and isolation techniques are two key components that are currently given top consideration for persons involved in the culling, transporting or disposal of infected birds as well as for those persons in the healthcare industry who may have potential contact with the virus. In addition, experts continue to advise that persons choose and use the appropriate level of personal protective equipment which may include dust- and fluid-resistant protective garments/clothing, gloves, overshoes capable of being disinfected or disposed of, goggles, and respiratory protection. The minimum form of respiratory protection OSHA recommends is an N95, N99 or N100 disposable respirator.
Other general advice for assisting in reducing chance of contracting both human viruses as well as a virus like Avian flu, as with any respiratory-type illness is to wash hands frequently, wear appropriate level of personal protection, be conscious and careful of respiratory secretions like coughing and sneezing when around other persons, especially small children or persons with existing illnesses and seek medical advice if an illness is severe.
At this time, there is not a definitive vaccine proven to protect against the disease caused by the H5N1 virus strain in humans, however, antiviral drugs are currently being produced and stockpiled in hopes to help limit the flu symptoms and potentially reduce chances of the disease from spreading. The WHO and others throughout the world are urgently working with a global network of experts to prevent outbreaks of the pathogenic H5N1 Avian influenza.
Commonly Asked Questions
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What is Bird Flu? |
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Bird Flu is an infection caused by Avian (bird) influenza (flu) viruses. These viruses typically occur naturally among birds. Wild birds throughout the world carry the viruses in their intestines and will usually not get sick from them. Bird Flu, however, is very contagious among birds and can possibly make domesticated birds such as chickens, ducks and turkeys very sick and/or even kill them. |
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What are Bird Flu symptoms? |
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Reported symptoms of avian influenza in humans have ranged from normal influenza-like symptoms (e.g. cough, sore throat, fever and muscle aches) to eye infections, acute respiratory distress, pneumonia, viral pneumonia and other severe and life-threatening complications. |
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How does the Bird Flu spread? |
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Influenza A viruses can be found in many animals, including ducks, chickens, pigs, horses, whales and seals. However, certain subtypes of influenza A virus are specific to certain species, except for birds who are the hosts to all subtypes of influenza A. |
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What is the risk to humans from Bird Flu? |
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Even though avian influenza A viruses do not usually infect humans, several instances of human infections and outbreaks of avian influenza have been reported since 1997. At this time, there is no evidence that the virus can be transmitted from human to another human. However, experts fear that if the Avian flu virus strain combines simultaneously with a human strain of influenza it could then create a new strain of virus that few humans will have a natural immunity to. The new variant of the virus could then potentially be transmitted from person-to-person.
If this occurs, it would be a detrimental risk to the human population due to how easily and quickly the new virus strain could be transmitted from one person to another. Efforts to produce a vaccine that is useful in averting Avian influenza are being hampered due to experts not knowing what form the virus will take if it does indeed mutate as feared. |
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What are the antiviral agents for Bird Flu? |
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Some antiviral drugs which can be used for treatment and prevention, are clinically effective when used for uncomplicated influenza A infection but many have limitations. In addition, these drugs are very expensive and supplies are limited. At this time, the antiviral drug Tamiflu is being stockpiled and indicated as a most effective antiviral agent for Bird Flu, although it is not clear how long people would have to be treated or what doses they will need. However, studies are still underway to prove its effectiveness and/or the effectiveness of a few other possible antiviral agents like Oseltamavir, Zanamavir and Relenza |
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What Personal Protective Equipment is needed? |
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Protective equipment suggested includes gloves, sleeve-apron or gown, cap, overshoes, goggles, shield and respirator. The level of protection required must be decided by the end-user and should be based upon the severity/potential hazard that is present. OSHA advises the use of protective clothing and gloves capable of being disinfected or disposed, goggles, boots or protective foot covers that can be disinfected or disposed and respiratory protection. The minimum form of respiratory protection OSHA recommends is an N95, N99 or N100 disposable respirator. |
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What is used to clean/disinfect surfaces within the healthcare industry that have been exposed to the virus? |
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According to the WHO's interim infection control guidelines for health care facilities, the virus is inactivated by 70 percent alcohol and by chlorine. Therefore, cleaning environmental surfaces with a neutral detergent followed by a disinfectant solution is recommended as per their indicated guidelines. |
Sources for More Information
LSS Pandemic Flu Resource Center
OSHA Guidance for Protecting Employees Against Avian Flu
OSHA Guidance Update on Protecting Employees from Avian Flu (Avian Influenza) Viruses
CDC - Information on Avian Flu
World Health Organizaton - Avian Flu
NIOSH Publication - Protecting Poultry Workers from Avian Influenza