by: Dr. Tara Nath Gaire
MS Veterinary Medicine, student
Institute of Agriculture and Animal Science (IAAS), Rampur, Chitwan, Nepal
Index of Bird Diseases … Symptoms and Potential Causes … Bird Species and Diseases They are Most Susceptible to
Avian influenza or bird flu viruses are highly infectious micro-organisms that primarily affect birds. Nevertheless, they have also been isolated from a number of mammals, including humans.
Avian influenza virus can cause large economic losses to the poultry industry because of its high mortality. Although there are pathogenic variants with a low virulence and which generally cause only mild, if any, clinical symptoms, the subtypes H5 and H7 can mutate from a low to a highly virulent (pathogenic) virus and should be taken into consideration in eradication strategies.
The primary source of infection for commercial poultry is direct and indirect contact with wild birds, with waterfowl forming a natural reservoir of the virus. Live-poultry markets, exotic birds, and ostriches also play a significant role in the epidemiology of avian influenza.
The secondary transmission (i.e., between poultry farms) of avian influenza virus is attributed primarily to fomites and people.
Airborne transmission is also important, and the virus can be spread by aerosol in humans.
Diagnostic tests detect viral proteins and genes. Virus-specific antibodies can be traced by serological tests, with virus isolation and identification being complementary procedures.
Importance of Control
The number of outbreaks of avian influenza seems to be increasing – over the last 5 years outbreaks have been reported in Italy, Hong Kong, Chile, the Netherlands, South Korea, Vietnam, Japan, Thailand, Cambodia, Indonesia, Laos, China, Pakistan, United States of America, Canada, South Africa, Malaysia and Nepal.
Moreover, a growing number of human cases of avian influenza, in some cases fatal, have paralleled the outbreaks in commercial poultry. There is great concern about the possibility that a new virus subtype with pandemic potential could emerge from these outbreaks.
From the perspective of human health, it is essential to eradicate the virus from poultry; however, the large number of small-holdings with poultry, the lack of control experience and resources, and the international scale of transmission and infection make rapid control and long-term prevention of recurrence extremely difficult.
In the Western world, the renewed interest in free-range housing carries a threat for future outbreaks. The growing ethical objections to the large scale culling of birds require a different approach to the eradication of avian influenza.
Multiple outbreak of avian influenza in various part of Nepal causes huge losses of economy as the same time increasing the risk of disease transmission.
To prevent the birdflu in our context, there should be maintaining the biosecurity, development of contingency plan, logistic support for inspection, early conformation and declaration of disease.
Proper cooking of eggs and meat, washing of hand with soap after handling of bird are some common precaution against of disease.
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Information contained on this website is provided as general reference only. For application to specific circumstances, professional advice should be sought.