Bird Flu
        and You

                                     
                                                   How Bird Flu affects birds

 

There are many different types of the bird flu viruses.  The infamous bird virus H5N1 is at the forefront of the current bird flu saga.  The H5N1 is the recent deadly bird virus that has been striking poultry in Asia and Eastern Europe for the past couple of years.  It is entrenching itself into the domestic population of poultry in Asia and is steadily moving into the flocks of Eastern Europe.  As of December 2005, the virus had killed 65 people and infected 130.  Since the H5N1 was first discovered in 1997, there has been millions of poultry infected and millions of birds slaughtered to prevent the spread of the disease.  The flu viruses are normally found in wild birds worldwide.  It can be found in their intestines, but a majority of the birds do not get sick from it.  It is very contagious among birds and once domesticate birds are infected they get sick and die.

The theory is that wild birds migrate from Asia to Europe carrying H5N1 within their intestines.  Once at their destination the infected birds release their virus via nasal or saliva secretions or feces into water.  The water may be frequented by domestic poultry or other water birds.  The water birds get infected and in turn infect domestic fowl.  There are two levels of the disease caused by contracting the bird flu virus.  There is the “low pathogenic” form; this form can go undetected and is manifested only by mild symptoms.  The signs of infection by this form is ruffled feather, a drop in egg production and mild effects on the birds respiratory system.  The “High Pathogenic” form spreads rapidly among flocks of domesticated fowl and causes the death of the bird within 48 hours.  In this form, the virus attacks the respiratory tract and also infects multiple organs and tissues.  As the virus replicates in the birds cells it causes massive internal bleeding or hemorrhaging; earning a nickname as the Chicken Ebola.  The highly pathogenic outbreaks have been attributed to the H5 and H7 virus subtypes.  However it is interesting to note that not all H5and H7 subtypes are lethal. 

The bird flu virus spreads rapidly from farm to farm through the movement of live birds and people, vehicles, cages and equipment.  H5N1 can survive outside the body if the temperatures are right, allowing for its easy spread.  Once the poultry are infected culling is the first line of defense.  Restrict the movement of birds between farms and countries can also impact the spread of the disease.  In more rural areas where the poultry roam free it is harder to contain the spread of the virus.  In these domestic situations where the birds enter the houses, scavenge for food in the wild, effectively mingling with wild birds and humans.  These rural populations rely on their poultry for their livelihood and not willing to report if they have an outbreak as they would have to slaughter them to prevent the spread of the disease.  They are not compensated for the loss of their flock or livelihoods.