Avian Influenza Infopage

World Health Organization Alert Stage:
We are currently in Stage 3

Avian Influenza Links Page

Questions?
If you have questions that are not answered below, click on this link Jeff Sisson and e-mail me the question. I will do my best to provide you with the correct answer and will then post your question and the answer on the "Question and Answer" portion of this site (Individual names will be withheld).

Avian Influenza Viruses
Avian (bird) flu is caused by influenza A viruses that occur naturally among birds. There are different subtypes of these viruses because of changes in certain proteins (hemagglutinin [HA] and neuraminidase [NA]) on the surface of the influenza A virus and the way the proteins combine.

Each combination represents a different subtype. All known subtypes of influenza A viruses can be found in birds. The avian flu currently of concern is the H5N1 subtype.

Avian Influenza in Birds
Wild birds worldwide carry avian influenza viruses in their intestines, but usually do not get sick from them. Avian influenza is very contagious among birds and can make some domesticated birds, including chickens, ducks, and turkeys, very sick and kill them.

Infected birds shed influenza virus in their saliva, nasal secretions, and feces. Domesticated birds may become infected with avian influenza virus through direct contact with infected waterfowl or other infected poultry, or through contact with surfaces (such as dirt or cages) or materials (such as water or feed) that have been contaminated with the virus.

Avian influenza infection in domestic poultry causes two main forms of disease that are distinguished by low and high extremes of virulence. The "low pathogenic" form may go undetected and usually causes only mild symptoms (such as ruffled feathers and a drop in egg production). However, the highly pathogenic form spreads more rapidly through flocks of poultry. This form may cause disease that affects multiple internal organs and has a mortality rate that can reach 90-100%, often within 48 hours. The H5N1 virus is highly pathogenic.

Avian Influenza Pandemic
A pandemic is a global disease outbreak. A flu pandemic occurs when a new influenza virus emerges for which people have little or no immunity, and for which there is no vaccine. The disease spreads easily person-to-person, causes serious illness, and can sweep across the country and around the world in very short time.

It is difficult to predict when the next influenza pandemic will occur or how severe it will be. Wherever and whenever a pandemic starts, everyone around the world is at risk. Countries might, through measures such as border closures and travel restrictions, delay arrival of the virus, but cannot stop it.

Health professionals are concerned that the continued spread of a highly pathogenic avian H5N1 virus across eastern Asia and other countries represents a significant threat to human health. The H5N1 virus has raised concerns about a potential human pandemic because:

  • It is especially virulent
  • It is being spread by migratory birds
  • It can be transmitted from birds to mammals and in some limited circumstances to humans, and
  • Like other influenza viruses, it continues to evolve.

What would be the Impact of a Pandemic?

A pandemic may come and go in waves, each of which can last for six to eight weeks.

An especially severe influenza pandemic could lead to high levels of illness, death, social disruption, and economic loss. Everyday life would be disrupted because so many people in so many places become seriously ill at the same time. Impacts can range from school and business closings to the interruption of basic services such as public transportation and food delivery.

Pandemics Death Toll Since 1900 (as per the CDC)

 

1918-1919
1957-1958
1968-1969

U.S....

675,000+

70,000+

34,000+

Worldwide...

50,000,000+

1-2,000,000

700,000+

A substantial percentage of the world's population will require some form of medical care. Health care facilities can be overwhelmed, creating a shortage of hospital staff, beds, ventilators and other supplies. Surge capacity at non-traditional sites such as schools may need to be created to cope with demand.

The need for vaccine is likely to outstrip supply and the supply of antiviral drugs is also likely to be inadequate early in a pandemic. Difficult decisions will need to be made regarding who gets antiviral drugs and vaccines.

Death rates are determined by four factors: the number of people who become infected, the virulence of the virus, the underlying characteristics and vulnerability of affected populations and the availability and effectiveness of preventive measures.

Questions and Answers

Question:
Can a person become infected with the bird flu through eating under cooked poultry?

Answer:
Yes, in a few instances, cases have been linked to consumption of dishes made of raw contaminated poultry blood. Click on this link to learn more!

Jeff Sisson, Health, Safety, and Risk Management Specialist
Instructional Services Division
518-561-0100 x358