Bird Flu (Avian Influenza)
What is bird flu (Avian Influenza)?
It is a viral disease naturally occurring among wild aquatic birds worldwide and can infect domestic poultry and other birds. It is caused by a virus within the "Orthomyxoviridae" family. It is characterized by the occurrence of multiple genetic mutations during the process of viral multiplication, especially in the case of infection caused by two different types of viruses in a single host such as pigs. There are three types of influenza viruses (influenza A, B, and C,); (influenza A) Infects birds, humans and mammals, and there are many strains of the influenza A virus such as H9N2, H7N9, H5N1, H5N8.
How is avian influenza spread from one area to another?
There are many means of international spread of avian influenza:
• International trade in poultry and live birds (both legal and illegal) which is the most common mean.
• Migratory birds.
• Movement of people (when shoes and other clothing are contaminated)
• Contaminated equipment, vehicles and feed..etc.
How is avian influenza transmitted from birds to humans?
Avian influenza virus is primarily a disease of poultry, but there have been cases of human infection of some strains of the virus such as (H5N1 & H7N9) among poultry keepers who raise poultry in their homes or farms.
There are many means of avian influenza transmission from poultry to human:
• Slaughtering birds
• Close contact with birds without wearing appropriate personal protective equipment.
• Plucking feathers
• Chopping birds
• Preparing birds' meat for cooking
Does avian influenza virus transmit from one human to another?
It has not confirmed yet the avian influenza transmission from one person to another.
Avian influenza A viruses transmission from one ill person to another has been reported very rarely, and when it has been reported it has been limited, inefficient and not sustained
Severity of avian influenza virus in humans:
Avian influenza: (H5N1 & H7N9) causes severe disease.
Avian influenza: (H9N2) causes mild disease and patients recovered without receiving treatment.
Avian influenza: (H5N8) no human cases of infection of H5N8 have been yet reported throughout the world.
Is there a vaccine against avian influenza viruses?
Yes, there are many vaccines against avian influenza in poultry. However, the success of the vaccination program against avian influenza depends mainly on the appropriate selection of virus vaccine strain and inversely proportional to the time elapsed since the onset of the outbreak and the speed and accuracy of the diagnosis. An appropriate laboratory method should be available to differentiate between vaccinated and virus-infected birds.
Is there a cure for avian influenza?
Yes, there are Amantadine and rimantadine influenza antiviral drugs that are used in treatment, but they are not effective against all strains of the virus (H5N1).
There are also oseltamivir, known by its brand name Tamiflu, and Zanamivir, known by its brand name Relenza, which should be taken within 48 hours of onset of flu symptoms.
Who is most vulnerable to avian influenza?
Persons who have direct contact with infected poultry and birds in general, such as farm workers, veterinarians, and slaughterhouse workers.
Why avian influenza is given such importance?
bird flu should be given attention due to the following:
• The serious economic implications of the disease, as it cases causes high mortality in poultry and lead to halt all poultry exports in countries where disease cases are reported.
• It is considered one of the most dangerous zoonotic diseases that are transmitted from birds or animals in general to humans and leads to high mortality in humans (H7N9 and H5N1 strains).
• In case a human pandemic occurs before producing vaccines in sufficient quantities, it will cause high death rates in humans.
Are there detected human cases of infection with the current influenza virus (H5N8)?
No human cases of infection with influenza virus (H5N8) have been detected.
Is the influenza virus easily transmitted from birds to humans?
The virus does not spread easily from birds to humans, as (H5N8) has not been yet shown to be transmitted to humans all over the world. However, the virus can spread to people if they regularly come into contact with birds, specially infected birds or birds showing signs of disease, but wearing appropriate personal protective equipment (such as gloves, face masks, etc.) can greatly protect the human health.
Most human cases of infection with influenza virus have been detected in domestic poultry keepers, but not poultry farm owners because whose who raise domestic poultry in home or backyard are not obliged to wear personal protective equipment.
Do migratory birds carry the virus from one country to another?
The virus is naturally occurring among wild aquatic birds worldwide and there are many types of wild and migratory birds that carry the virus, but they show no symptoms due to a partial immunity that protects them against the emergence of symptoms, but contributes to the spread of the disease from one country to another. Wild waterfowl (ducks, geese, and swans) are more likely to carry avian influenza viruses. These birds are spread in many parts of the world except in arid areas.
Are poultry susceptible to infection with avian influenza virus?
Yes, poultry are susceptible to avian influenza viruses including (H5N8).
Is it safe to continue eating chicken?
It is certainly possible to continue eating chicken, as the H5N8 virus has not been shown to be transmitted to humans in all countries of the world so far.
What measures are to be taken to contain the avian influenza virus?
The following measures are to be applied in case disease confirmation
First: Procedures applied at the affected area:
• Hygienic dispose of all birds, eggs, and bedding straw by burying.
• Disinfecting buildings and equipment.
• Closing the farm for a month, then using put sentinel birds to make sure that the farm is free from the virus.
• Don't let employees, vehicles and equipment leave the farm before thoroughly disinfection.
• The same measures are applied in all farms located within a circle of (5) kilometer radius around the affected farm (Infected area).
• Implementing biosecurity measures on the farm and neighboring farms.
Second: Procedures applied to the restricted area:
• Declaring the area surrounding the infected area a restricted area within a circle of (10) kilometer from the end of infected area.
• Conducting a daily check of all farms within the boundaries of that area.
• Prohibiting the bedding straw and forage from exiting the restricted area but allowing forage to enter.
• Prohibiting vehicles and equipment from exiting the restricted area until after the disinfection procedures have been applied.
• Shutting down live birds markets.
• Allowing the birds at the age of slaughter to be slaughtered in the nearest slaughterhouse after declaring them free of the disease.
Third: Procedures applied in the control area:
• Declaring a control area within a circle of 10 kilometer from the end of restricted area from the end of the boundaries of the restricted area.
• Conducting inspections and monitoring on farm located within this area.
• Applying strict preventive security measures on all farms in the region.
What guidelines should a citizen follow for the prevention of bird flu?
1. Don't touch any dead bird or any bird showing disease symptoms.
2. It is preferable to wear personal protective equipment when being in contact with birds (gloves, face masks, plastic shoes, and goggles)
3. Don't smoke, eat or drink when being in contact with birds suspected of bird flu.
4. Wash your hands thoroughly with soap, water and disinfect them after being in contact with birds.
5. Adequately dispose of dead birds remains.
6. Consulting a doctor in case of flu-like symptoms.