6 STEPS
TO AVOID
BIRD FLU!
 Avian Influenza
in Azerbaijan newsletter,
May 2007
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Frequently Asked Questions about Avian Influenza
What is avian influenza (Bird flu)?
Avian influenza, or "bird flu", is an infection caused by viruses that normally infect only birds (avian) and, less commonly, pigs. Wild birds worldwide carry the viruses in their intestines, but usually do not get sick from them. However, bird flu is very contagious among birds and some domesticated birds, including chickens, ducks, and turkeys are especially vulnerable to infections that can rapidly reach epidemic proportions.
The disease in birds has two forms. The first causes mild illness, sometimes expressed only as ruffled feathers or reduced egg production. Of greater concern is the second form, known as "highly pathogenic avian influenza". This form, which was first recognized in Italy in 1878, is extremely contagious in birds and rapidly fatal, with a mortality approaching 100%. Birds can die on the same day that symptoms first appear.
Do bird flu viruses infect humans?
Bird flu viruses do not usually infect humans, but several cases of human infection with bird flu viruses have occurred. The first documented human infections with the H5N1 avian strain occurred in Hong Kong in 1997. In that first outbreak, 18 persons were hospitalized and 6 of them died. The source of infection in all cases was traced to contact with diseased birds on farms (1 case) and in live poultry markets (17 cases). The human cases coincided with outbreaks of highly pathogenic H5N1 avian influenza in poultry.
Which are the stages of a pandemic?
Phase 1 and Phase 2: are inter-pandemic phases during which no new Influenza A virus subtypes have been detected in humans but a circulating animal Influenza A virus subtype has been identified which poses a substantial risk of human disease.
Phase 3: human infection with a new Influenza A virus subtype has been identified but there is no spread of the virus from human to human (or most rare instances of spread, and only to a close contact). We are currently in Phase 3.
Phase 4: small cluster(s) are identified with limited human to human transmission, but spread is highly localized suggesting that the virus is not well adapted to humans yet.
Phase 5: large cluster(s) are identified but human to human spread is stiil localized. This suggests that the virus is increasingly better adapted to humans but not yet fully, transmissible. Risk for a pandemic is substantial at this stage.
Phase 6: increased and sustained viral transmission is seen in the general population.
What are the symptoms of bird flu in humans?
Symptoms of bird flu in humans have ranged from typical flu-like symptoms (fever, cough, sore throat and muscle aches) to eye infections, pneumonia, severe respiratory diseases (such as acute respiratory distress), and other severe and life-threatening complications. The symptoms of bird flu may depend on which virus caused the infection.
How does bird flu spread?
Infected birds shed flu virus in their saliva, nasal secretions, and feces. Susceptible birds become infected when they have contact with contaminated excretions or surfaces that are contaminated with excretions. It is believed that most cases of bird flu infection in humans have resulted from contact with infected poultry or contaminated surfaces.
What are the control measures in birds?
The most important control measures are rapid destruction ("culling" or "stamping out") of all infected or exposed birds, proper disposal of carcasses, and the quarantining and rigorous disinfection of farms.
The virus is killed by heat (56 degrees C for 3 hours or 60 degrees C for 30 minutes) and common disinfectants, such as fomalin and iodine compounds. The virus can survive, at cool temperatures, in contaminated manure for at least three months. In water, the virus can survive for up to four days at 22 degrees C and more than 30 days at 0 degrees C. For the highly pathogenic form, studies have shown that a single gram of contaminated manure can contain enough viruses to infect 1 million birds.
Restrictions on the movement of live poultry, both within and between countries, are another important control measure.
How is bird flu in humans treated?
Flu viruses can become resistant to drugs, so medications may not always work. Two classes of drugs are available. These are the M2 inhibitors (amantadine and rimantadine) and the neuraminidase inhibitors (oseltamivir and zanimivir). These drugs have been licensed for the prevention and treatment of human influenza in some countries.
Initial analysis of viruses isolated from the recently fatal cases in Viet Nam indicates that the viruses are invariably resistant to the M2 inhibitors. Further testing is under way to confirm the resistance of amantadine. Network laboratories are also conducting studies to confirm the effectiveness of neuraminidase inhibitors against the current H5N1 strains.
At present the antiviral medication called oseltamivir (better known as Tamiflu) is thought to be effective, as long as treatment is started within 48 hours since onset of the symptoms.
Is there a vaccine effective against H5N1 in humans?
No. Currently available vaccines will not protect against disease caused by the H5N1 strain in humans. WHO is urgently working together with laboratories in the WHO Global Influenza Surveillance Network to develop a prototype H5N1 virus for use by leading vaccine manufacturers.
An available vaccine prototype virus, developed using the 2003 strain of H5N1 (which caused the two human cases in Hong Kong), cannot be used to expedite vaccine development. Initial analysis of the 2004 virus, conducted by laboratories in the WHO network, indicates that the virus has mutated significantly.
Are presently available vaccines useful in averting an influenza pandemic?
Yes, potentially but in a precisely targeted way. Current vaccines, when administered to high-risk groups, such as poultry cullers, protect against circulating human strains and thus reduce the risk that humans at high risk of exposure to the bird virus might become infected with human and avian viruses at the same time. Such dual infections give the avian and human viruses an opportunity to exchange genes, possibly resulting in a new influenza virus subtype with pandemic potential.
WHO has issued guidelines for the vaccination, using the current trivalent influenza vaccine, of groups considered at high risk of exposure in countries experiencing outbreaks of highly pathogenic H5N1 avian influenza in poultry.
The UN response
The Secretary-General has appointed Dr. David Nabarro as Senior United Nations System Coordinator for Avian and Human Influenza, to ensure that the United Nations system makes an effective and coordinated contribution to the global effort to control the epidemic of avian influenza. The coordinated United Nations system-wide effort against a flu epidemic would tap into the technical guidance provided through the Organization's specialized agencies responsible for animal and human health - WHO and the Food and Agricultural Organization (FAO). That effort would also envelop the World Bank; the World Organization for Animal Health, an intergovernmental agency that was not part of the United Nations system; development banks; and non-governmental organizations such as the International Federation of Red Cross and Red Crescent Societies. The United Nations effort would also work with national, regional and local Government officials, who would play a key part in the effort.
The first pillar of the programme should focus on preventative efforts to control the spread of avian flu. That effort involves Government officials at all levels, farmers and corporations involved in chicken farming, as well as communities where people lived in close proximity to their poultry. The second pillar focuses on the preparedness of officials, agencies and communities in case the avian flu virus were to cross over into humans. The third pillar focuses on the responses of the United Nations system and other agencies and health officials. Officials want to minimize the effect of a pandemic on people's health, as well as on trade, travel and the economy.
A Partners meeting on avian Influenza and human pandemic influenza is planned to take place on 7-9 November 2005 at WHO headquarters, Geneva. The meeting will include members of the cosponsoring organizations, country representatives, donor partners, and regional organizations involved in the influenza issue will enable an examination of integrated national plans to deal with the issue, focusing on affected countries and countries at risk.
Unicef is closely working at the global level in support of the UN's preparedness and response including UN Medical Services Staff Contingency Plan guidelines for an influenza pandemic. Further guidance on the implications of possible pandemic for Unicef programmes for children will be sent.
Public health implications
The spread of H5N1 to poultry in new areas is of concern as it increases opportunities for further human cases to occur. However, all evidence to date indicates that the H5N1 virus does not spread easily from birds to infect humans. WHO advises countries experiencing outbreaks in poultry to follow certain precautions, particularly during culling operations, and to monitor persons with a possible exposure history for fever or respiratory symptoms. The early symptoms of H5N1 infection mimic those of many other common respiratory illnesses, meaning that false alarms are likely.
The WHO level of pandemic alert remains unchanged at phase 3: a virus new to humans is causing infections, but does not spread easily from one person to another.
Countries located along migratory routes need to be vigilant for signs of disease in wild and domestic birds. Recent events make it likely that some migratory birds are now implicated in the direct spread of the H5N1 virus in its highly pathogenic form.
Here are web pages on avian and pandemic influenza with links that are updated regularly:
UN: http://extranet.unsystem.org/avianflu/
WHO: http://www.who.int/csr/disease/avian influenza/en/index.html
Centers for Disease Control and Prevention:
http://www.cdc.gov/flu/avian/index.htm
World Organization for Animal Health:
http://www.oie.int/enq/en index.htm
Information on this section is taken from various websites by UNICEF Azerbaijan.
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