First, it is important to know how people become infected.  As of yet, there is no person-to-person transmission of the disease, so the only way of catching the bird flu is from the birds themselves.  This can include direct contact with infected birds, or coming in contact with surfaces or objects that have been contaminated by their feces.  This most often occurs in areas where chickens and other poultry are raised as food sources and come in close proximity with their human caregivers.  People who are involved with the slaughter, removal of feathers, butchering, or food preparation of bird for cooking are at the most risk.

The first line of defense against the bird flu is the destruction of the infected birds.  Hundreds of millions of sick or potentially exposed birds have been destroyed worldwide since the first human case in 1997.  Farms that have been affected by the disease were also quarantined.  While the methods sometimes used to destroy the infected birds are often controversial, and may include being burned or buried alive in some areas, the Worldwide Health Organization (WHO) feels that this widespread destruction may have prevented a potential pandemic of the disease, and it is still considered the first line of defense.

Some countries have taken a stricter stance on the surveillance of poultry farms and markets.  This includes stricter vaccination programs, steps to prevent the smuggling of birds, quarantine programs for new birds, and  procedures for equipment that has come in contact with birds.

Other countries have taken an even stricter stance and banned or restricted the importation of birds and hatching eggs entirely from regions that have been affected by the bird flu.  For example, in 2004 the United States CDC banned the importation of poultry from the majority of the Asian countries.

If you are a traveler, there are things that you can do to protect yourself as well, particularly if you must travel in a region with confirmed bird flu outbreaks.  Avoidance of domesticated birds is highly recommended, including avoidance of rural areas, farms, and open-air markets.  Wash your hands frequently.  While this may sound like basic common sense, it is the simplest way to prevent all types of infections, including the bird flu.  If soap and clean water are not always going to be available, consider carrying an alcohol-based hand sanitizer that does not require water to work.  These are often better than the use of soap and water, as they kill more infectious organisms and are less damaging to the skin than frequent hand washing.  Ensure that kids wash their hands frequently as well, as they are more likely to put their hands in their mouths and less likely to wash frequently.  Avoid products that use raw eggs in the preparation, including mayonnaise and ice cream.  Also consider getting a flu shot before you go to reduce the risk of simultaneous infection of the bird flu and regular flu virus.

While no cases of human bird flu have been linked to eating poultry, the virus has been known to survive even on frozen meat.  Carefully wash cutting boards, utensils, and other surfaces that come in contact with poultry.  Chicken should always be cooked thoroughly, which is when the juices run clear and the meat has an internal temperature of 180 degrees Fahrenheit.

Taking the proper precautions will help to protect you from contracting the bird flu, as well as help stop its spread should it become possible to spread it from person to person.

The term “avian flu” literally means “flu from viruses adapted to birds”.  However, it is also often incorrectly used to refer to other flu types and the viruses that caused them, or the virus itself.  All of the current known avian flu viruses are of the species Influenza A virus, of which all of the subtypes are adapted to birds.  The majority of them may be transferred to other species, but the new carrier does not actually get the disease, and so does not get the “flu”.

In current lingo, however, the bird flu has become the layman’s term for the H5N1 virus – a form of avian flu that has been known to infect humans.  For an unknown reason, this strain of the virus has evolved into a strain that is particularly infectious one.  In humans, approximately 50% of those who were infected with the virus died from it, making it a very real scare.  Currently, this particular strain is only infectious from bird to human, and not from human to human contact.  If it were to mutate to a form that made it easy to pass from one person to another, it could cause a major health crisis.

Because of all of the confusion, the World Health Organization (WHO) has published specific guidelines for defining bird flu cases in humans.  These guidelines clearly break up human cases into three categories:  people who are suspected of having the bird flu, those who have a probable infection of the bird flu, and those that have been confirmed by laboratory diagnosis to have the bird flu.  For statistical information, WHO only wants probably and confirmed cases to be reported to them, while suspected cases are useful for local governments to monitor the situation.  A confirmed case is via laboratory diagnosis.  A suspected case is based on symptoms and exposures.  Those with a probable diagnosis have a combination of preliminary tests that are positive, as well as symptoms and exposure.

Many people are still unsure of what exactly the bird flu means.  They are concerned about catching it from a neighbor with a cold, or a bird at a backyard feeder.  Misinformation can be a source of panic for the general population.

As with many diseases, the best cure is prevention.  If you work with chickens or other birds you should be extra cautious.  Avoid contact with wild birds, including ducks and other waterfowl.  Limit the number of people coming in and out of the poultries to essential personnel only.  Always use proper disinfection procedures in the poultries, and follow all regulatory hand washing and cleaning requirements.  Any unusual sickness or death among the birds should be reported to authorities, as well as any illnesses experienced by workers.

If you are going to be traveling in an area where bird flu has been diagnosed, there are some things that you can do to protect yourself as well.  Always wash your hands thoroughly with soap and water before and after handling chicken meat or other forms of poultry.  Thoroughly clean and disinfect kitchen surfaces and utensils before and after use.  Chicken should be cooked thoroughly at a boiling temperature.  Do not buy or sell live chickens in a market where there is a threat of the bird flu.  If you keep chickens as pets or a food source, do not allow them to roam freely.  Avoid wild birds.  Any unusual deaths or sickness among birds should be reported to authorities, as well as any respiratory illness in a person who has been exposed to dead or sick birds.

There are several reasons why people are concerned with the bird flu.  The bird flu has been known to cause very serious illness and even death in humans – with about a 50% mortality rate.  The concern is that it could recombine with a regular flu bug to create a new version of the bird flu that is capable of being spread from person to person.  If it were to do so, there is no known vaccine or medication that would stop it, and the death toll could be in the millions.  Even in birds, the bird flu is very severe, spreading rapidly and causing epidemics and mass deaths of infected birds.  This is particularly a concern for those who work in the poultry industry, as it could mean the loss of much needed revenue.

At the moment, though, bird flu can only be transmitted to human via infected birds.  The person has to come in contact either with the infected bird itself, or through handling contaminated surfaces.  The people most at risk are those who work in the poultry industry and come in direct contact with the animals, or where they can inhale particles of dried discharges and feces that are contaminated with the virus.  This includes positions such as slaughtering, removing feathers, butchering and other preparation of infected birds for consumption.  In some instance, infection has been linked to exposure to feces from infected birds, free ranging domestic or wild, in school yards and bodies of water.  However, while the disease spreads easily from one bird to another, it is slow to spread to the human population – despite tens of millions of domestic poultry birds becoming infected, there are fewer than 200 documented human cases with laboratory confirmation.

The biggest fear of scientists and health professionals is that the bird flu virus will eventually make the leap to human to human transmission, similar to what the SARS virus did.  This could occur gradually over time, where each new strain of the virus is gradually stronger and more transmittable.  Or it could be a single event, where a person or an animal that has a regular flu virus comes down with the bird flu virus and the two merge and mutate.  Should this occur a fast moving pandemic is a possibility.   This could have dire consequences on the economy of the areas that it infects, as the potential numbers of ill persons could overwhelm local hospitals and shut down business and commerce.

Following basic health practices will help to protect you should a pandemic situation occur.  Wash your hands frequently with soap and water, particularly before you eat and after close contact with strangers or animals.  If soap and water are not readily available, consider carrying a bottle of waterless, alcohol-based hand sanitizer for in between washings.  Cover your nose and mouth whenever you need to cough or sneeze.  Avoid crowds as much as possible, particularly those in close confines such as a plane or subway.  Get all illnesses looked at by a doctor, and if you are sick, do everyone else the courtesy of staying home.  Follow all vaccination schedules as recommended by your local health department.

An ounce of prevention is worth a pound of cure, so taking precautions now will help to ensure that the bird flu never makes the jump to person to person transmit ion, and if it does, to limit the spread as much as possible.

A bird flu pandemic returned in 1968 with a pandemic caused by the H3N2 influenza virus. This flu pandemic killed 700,000 people. The H2N2 and H3N2 viruses, were likely to have arisen after an exchange of genes between avian and human flu viruses. A new bird flu virus surfaced in 1997, the virus was known as H5N1. The virus was first discovered in a human patient in Hong Kong. After the first occurrence, the virus infected 18 patients who had contact with poultry, which resulted in six deaths. However, this virus does not spread from human-to-human. After the small outbreak in Hong Kong, the entire chicken population was slaughtered to prevent further outbreaks.  In 1998 the development of two new drugs, Relenza and Tamiflu is announced, which are used to target the flu virus.

In March 1999, two children in Hong Kong were diagnosed with avian influenza caused by the strain H9N2, which is a milder strain than H5N1. The two children recovered from their viruses, and no other cases of H9N2 were confirmed in Hong Kong. In January 2001 the World Health organization outlined a new global plan to improve the range, speed and quality of the flu virus surveillance. February 2003 saw the reappearance of the bird flu virus H5N1. On February 28, 2003, an outbreak of bird flu in the Netherlands killed a veterinarian, and infected more than 80 other people, which were mainly poultry workers and their families. These illnesses were caused by a strain of the avian influenza virus, known as H7N7, which causes eye infections and respiratory problems. In December 2003 another bird flu illness is reported; this bird flu infected a child in Hong Kong, and was caused by another strain, known as the H9N2. The child was hospitalized for the illness, but later recovered. Again in December 2003, an outbreak of bird flu was confirmed in South Korea.

In 2004, the World Health Organization confirmed 11 human cases of H5N1 in Thailand and Vietnam, which resulted in eight deaths. However, no person-to-person transmission cases were identified. Vietnam also announced that the H5N1 avian flu virus had spread to many of their poultry farms. Pakistan also confirmed an outbreak of this form of the bird flu, and Indonesia discovers an outbreak of bird flu among chickens. Later in 2004 the H5N1 virus was reported to have killed three more people in Vietnam. In November 2004, WHO warns the public that the H5N1 flu virus could spark a flu pandemic that would likely kill millions of people. In February 2005, thirteen more deadly bird flu cases occurred in Vietnam, and a report of likely person-to-person transmission is reported in the New England Journal of Medicine. Later in 2005, the European Union urges member countries to prepare for bird flu pandemic.

In November 2005, President Bush outlined a $7.1 billion strategy to prepare for possible bird flu pandemic. By the end of 2005 the death toll for the bird flu pandemic had reached 74 in Asia. By February 2006 the death toll had reached 88, with the last two deaths being reported in Indonesia. In March 2006 the UN stepped up its efforts to battle the spread of the bird flu after China reported its 10th death caused by the virus. In 2006 the bird flu had spread to many countries in Asia and Africa and Europe, including Cambodia, Egypt and Russia.

According to Dr. Thomas Frieden, the City Health Commissioner, the worst the city can expect would be 2.5 million people infected and 56,000 deaths throughout the city. The city would have a difficult time obtaining medicine and equipment, and it would take six to nine months for a vaccine to be developed. New York City’s primary contingency plan is to communicate with city doctors, in order to detect early occurrences of the virus. New York’s Department of Health and Mental Hygiene has developed a system that can monitor ambulance runs, emergency room visits and pharmacy sales. However, the basic flu-containment strategies will be employed by the city first. Officials urge citizens to cover their mouths when they cough or sneeze, and not to go outside if they have a fever or a cough. People are the city’s first line of defense against the spreading of the bird flu, and precautionary measures taken by citizens can help stop a possible pandemic.

New York City’s bird flu contingency plan covers all major health areas involved in a pandemic, such as disease monitoring, laboratory capacity, vaccine and medicine delivery, and hospital preparedness. The contingency plan shows how the city will implement infection control, address surge capacity in hospitals, and enact disease containment measures. The disease containment measures include closing schools, and limiting public gatherings. According to New York health officials, even the best contingency plan could not prevent the social and economic chaos a pandemic would bring, although good plans could help lessen the impact of a pandemic. If there was an outbreak of the bird flu, the health care system would be overburdened and there would be massive reductions in workforce availability in all business sectors. Employees in all sectors will become ill or will remain home to care for ill family members.

New York City’s contingency plan includes measures from large-scale emergency responses exercises to a simulated biological attack on the city. The contingency plan is essentially a response to the spread of the deadly H5N1 bird flu virus, which was found in 60 countries in the past few years. The H5N1 virus does not spread between people, but people who come in contact with sick birds can contract the disease. The disease may become a pandemic if it mutates into a disease transmissible between humans. New York City’s contingency plan is preparing the city for any occurrence of the bird flu. The bird flu is not a pandemic, but New York’s official are aware of the possibility of the bird flu becoming a pandemic. New York City is one of the biggest cities in America, and a pandemic in that city could be disastrous for the rest of the country. Therefore, New York has taken precautionary measures to prevent bird flu pandemic.

First, it is important to stay up to date on the current bird flu news.  This will let you know what areas of the country are being affected and how at risk you really are.  Medical science is also currently changing, so keeping abreast of the news will allow you to be informed if any new recommendations are being made.

Next, practice good personal hygiene.  You should wash your hands with soap and water frequently, especially before eating and handling food and after handling pets.  Cover your nose and mouth if you need to sneeze or cough, and encourage your kids to do the same.

If you eat poultry, particularly chicken, make sure that it is prepared in such a way that eliminates the possibility of cross-contamination to other foods and surfaces.  Ensure that it is stored properly, and is thoroughly cooked before eating.

Cats have become infected with the bird flu virus in other countries.  Therefore it is important to keep pet cats inside whenever possible.  This will limit their exposure to wild birds, particularly those that are sick or dead.  Do not feed your cat raw meat.  The bird flu virus can be passed from cat to cat, so should an outbreak occur be cautious on handling strays in affected areas.  Do not touch sick or dead stray cats, but do contact your area’s health department or animal control to come and take care of the animal.  If one of your pet cats gets sick, particularly with breathing trouble or a nasal discharge, take it to the vet for medical treatment immediately.

It is not clear at the present time whether or not dogs can contact the bird flu virus, but it is better to err on the side of caution.  Keep your dog on a leash whenever it is outside, and limit contact between the dog and birds, as well as dead animals.  Any unusual illness in your dog should be reported to your vet immediately.

Pet birds can become infected with the bird flu if they are exposed to infected birds or their droppings.  Keep pet birds indoors.  Do not introduce any new birds into your home without first having them quarantined and tested for bird flu.  Anyone who interacts with the birds should ensure that they have clean hands, clothes, and shoes before doing so.  Do not use any bird supplies that may have been contaminated.

If you look after wild birds with a feeder or bird bath, do not allow your children or pets to come in contact with them or the surrounding area.  You should wear gloves to protect yourself when touching any items used by wild birds and wash your hands thoroughly afterwards.  Avoid touching any wild birds or their droppings or feathers.

It is important to have a plan for your family and your pets should a pandemic situation occur.  This includes having on hand:  a two week supply of water and food for all family members and pets; a few changes of clothing for all family members, in current sizes and season; prescription medications for all family members and pets; essential nonprescription drugs and first aid supplies;  any crucial supplies for dealing with small children such as diapers, formula, and toys; supplies needed to move pets if necessary such as leashes and pet carriers; a current medical history of all family members; and a list of emergency contacts and other essential information.  Keep all items in a central location in your home, and make sure that all family members know where it is located in case of an emergency.

Wild waterfowl can then be responsible for the primary introduction of the infection into domestic poultry. In farms where poultry is raised young turkeys and laying hens are usually the most affected species. They in turn can pass it to humans.

People catch bird flu by contact with infected birds or bird droppings. In general, it is important to remember that people don’t catch the virus from eating fully cooked chicken or eggs. While there have been a few cases where one infected person caught the bird flu virus from another person, this only happened after close personal contact.

According to a joint statement by the UN Food and Agriculture Organization (FAO) and the World Health Organization (WHO),  chicken and other poultry are safe to eat if cooked properly. There is no scientific justification for worrying about eating chicken products in relation to acquiring the bird flu. However, no birds from flocks with disease should enter the food chain.

There are some hygienic practices that should be followed to reduce exposure to the virus in areas with outbreaks in poultry.

To start, all efforts to keep birds from flocks with the disease out of our food chain should be made. In addition, you should not eat raw poultry parts, including raw blood or raw eggs. Raw meat should be separated from cooked or ready-to-eat foods to avoid contamination. Do not use the same chopping board or the same knife. Do not handle both raw and cooked foods without washing your hands in between and do not place cooked meat back on the same plate or surface it was on prior to cooking. Do not use raw or soft-boiled eggs in food preparations that will not be heat treated or cooked.

In addition, washing your hands may aid in the prevention of spreading the virus. After handling frozen or thawed raw poultry or eggs, wash your hands thoroughly with soap. Wash and disinfect all surfaces and utensils that have been in contact with the raw meat.

Also, it is important to cook food thoroughly. Thorough cooking of poultry meat will inactivate the virus. Insure that the poultry meat reaches 165 degrees Fahrenheit at the center of the product or that the meat is not pink in any part. If you’re cooking a whole chicken or other bird, pierce the thickest part of the leg (between drumstick and thigh) with a clean knife or skewer until the juices run clear. The juices shouldn’t have any pink or red in them and there should be no pink meat.

Egg yolks should not be runny or liquid. People should not eat raw eggs or use raw eggs in dishes that will not be cooked. Eggs should be cooked until the whites are solid.

The highly pathogenic avian influenza virus can be found inside and on the surface of eggs laid by infected birds. Although sick birds will normally stop producing eggs, eggs laid in the early phase of the disease could contain viruses in the egg-white and yolk as well as on the surface of the shell. Proper cooking inactivates the virus present inside the eggs. Pasteurization used by industry for liquid egg products is also effective in inactivating the virus.

In conclusion, experts agree cooking chicken properly, washing your hands frequently, washing work surfaces and utensils, avoiding cross contamination and chilling and storing food properly will help insure you and your family’s health and prevent chances of acquiring the bird flu.

While the susceptibility to the pandemic influenza virus will be universal, some persons will become infected but not develop clinically significant symptoms.  Asymptomatic or minimally symptomatic individuals can transmit infection and develop immunity to subsequent infection.

The number of hospitalizations and deaths will depend on the virulence of the pandemic virus.  Estimates differ about 10-fold between more and less severe scenarios.  Officials are taking certain public health measures, like closing schools and quarantining household contacts of infected individuals, will likely decrease risk of transmission in these specific groups of individuals who may be more vulnerable to the virus.  It is estimated that on average, infected persons will transmit infection to approximately two other people.  Also, in an affected community a pandemic outbreak will last about 6 to 8 weeks.

While the World Health Organization said there was “appropriate alarm” each time the virus, especially the H5N1 strain shows up in a new country, they say it is important to keep the risk to humans in perspective.  Dick Thompson, WHO spokesman said, “People confuse it with pandemic influenza, but they’re very different diseases,” and if “people just paid attention to the human risk” from bird flu, they’d understand that “the possibility of infection is very low.”

These health officials have been tracking the strain out due to a concern that it could mutate into a form more easily transmitted between people, and trigger a human pandemic.  However, at the moment the flu is mostly a bird disease.  H5N1 type A influenza has killed about 60 people in Asia, but most were poultry farmers who were infected directly by birds.  A WHO statement said, “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.”

It is difficult to identify who is most vulnerable to the bird flu.  Flu in general is usually most dangerous to young children and to the elderly.  A lot depends on whether there is any immunity to the flu in certain populations.  The 1918 flu pandemic was more deadly to young adults than to those over 40.  It is believed that a similar virus may have circulated more than 40 years before, giving some immunity to those who caught it.

Although it is very difficult to predict the consequences of an influenza pandemic, it is likely that several age groups would be seriously affected.  The greatest risk of hospitalization and death, as seen during the last two pandemics in 1957 and 1968 and during annual influenza, will be infants, the elderly, and those with underlying health conditions, such as pregnant women.  However, in the 1918 pandemic, most deaths occurred in young adults.  Few, if any people would be immune to this virus.

Right now the risk from avian influenza is generally low to most people, because the virus doesn’t usually infect humans.  H5N1 is one of the few avian influenza viruses to have crossed the species barrier to infect humans, and is the most deadly of those that have crossed the barrier.

Although the risk to humans in general is low, in the case of a world wide pandemic, the most vulnerable members of the human species will be the most likely to contract the bird flu and die from it.  However, if it follows the patterns of previous outbreaks, it cannot be predicted at this time who will suffer the greatest from the H5N1 avian influenza virus.

Indonesia, an archipelago of 17,000 islands with a population of 220 million people, has a collage of local, regional and national bureaucracies that often give the impression that no one is truly “in charge”. In May of 2006 Indonesia averaged one human bird flu death every 2 1/2 days in May, putting it on pace to soon surpass Vietnam as the world’s hardest-hit country.

There have been 43 deaths out of 53 human cases so far in Indonesia this year, a significant proportion of the 73 human deaths recorded worldwide since the start of 2006.Undoubtedly, the Asian region has been hardest hit by the virus, which spreads through contact with infected birds.

Indonesia has reported the virus has been detected in 30 out of 33 provinces.

Seven family members became infected in the Kubu Sembelang village, Karo District, of North Sumatra. Of the seven who are infected, six have died.

Although the investigation is still ongoing, preliminary findings indicate that three of the confirmed cases spent a night in a small room together with the initial case at a time when she was symptomatic and coughing frequently. These cases include the woman’s two sons and a second brother. Other infected family members lived in neighboring homes.

All seven people affected were in close contact with the initial patient when she was severely ill, but researches are searching for other alternatives besides human-to-human transmission. After studying the eight-gene virus, no mutations that would indicate that the virus has begun to be spread through humans was found. Researchers are working on the hypothesis that the family members involved in the cluster were genetically more susceptible to H5N1, since spouses did not get sick.

Health agencies fear that the H5N1 virus will evolve so as to allow easy person-to-person transmission, leading to a pandemic. Only one probable instance of person-to-person transmission has been documented so far, that of an 11-year-old Thai girl who apparently passed the virus to her mother and an aunt last September. Person-to-person transmission was also suspected in some family case clusters in Vietnam this year.

U.N. health experts warn that the virus could (if it hasn’t already) either mutate or obtain new genetic material, allowing it to spread more easily among humans, which could spark a global pandemic and kill tens of millions of people. This fear is why Indonesia is being kept under a watchful eye.

Indonesia has taken much criticism lately for not being more efficient in stopping the spread of the bird flu. An Indonesian leader explained that they have had a difficult time containing the virus because the country faces unique challenges. Its population is spread over 17,000 islands, domestic fowl roam everywhere, and there is widespread resistance to the central government among many of its diverse cultures.

In an effort to control the possible outbreak the country’s largest zoo was closed after 19 birds tested positive for avian flu. A zoo vendor and a guide may have come down with the illness and had been admitted to the capital’s leading infectious disease hospital.

In order to deal with the possibility of an outbreak hundreds of millions of poultry have been culled. There have also been changes to commercial bird rearing and also better preparedness to deal with outbreaks.

Indonesia has formed a special team to prepare for any bird flu pandemic and coordinate foreign assistance and funding. The formation of this steam under the ministry’s National Pandemic Aid Plan was announced in September 2005.

Avian influenza is an infectious disease of birds caused by a type A strain of the influenza virus.  Most species of wild birds that carry this disease show no apparent signs of infection or harm.  This disease occurs worldwide, and other bird species, including domestic poultry, develop disease when infected with avian influenza virus.

These influenza viruses are usually species-specific, which means that viruses that infect an individual species stick to that species.  Since 1959, instances of human infection with an avian influenza virus have been only documented on 10 occasions.

The first documented outbreak among humans infected with H5N1 occurred in Hong Kong in 1997.  There were 18 human cases, which coincided with an outbreak of highly pathogenic avian influenza, caused by an identical virus, in poultry farms and live markets.  The source of infection was determined by extensive studies of the human cases to be the direct contact with diseased poultry.  Studies carried out in family members, and social contacts of patients, health workers engaged in their care, and poultry cullers found that there was very limited, if any human to human transmission.  Hong Kong’s entire poultry population was immediately destroyed and within three days, human infections ceased.  The destruction of almost 1.5 million birds has some experts believing that the drastic action may have averted an influenza pandemic.

The principal source of human infection with the H5N1 virus is shown by all evidence to date to be close contact with dead or sick birds.  Particularly risky behaviors for risk of infection include slaughtering, defeathering, butchering, and preparation for consumption of infected birds.  Children playing in an area frequented by free-ranging poultry, and exposure to the chicken’s feces, are thought to have been the source of infection in a few cases.  Another possible source of infection is swimming in water bodies where the carcasses of dead infected birds have been discarded or which may have been contaminated by feces from infected animals.

In some cases, investigators have not been able to identify the exposure source, which suggests that there may be some as yet unknown environmental factor that could involve contamination with the deadly virus.

The flu virus can be found in nature with several types of wild aquatic birds and has persisted in these animals for millions of years.  The virus does not typically cause illness, however the flu viruses that frequently mutate can easily jump the species barrier from these wild birds to domestic ducks and then chickens.  Pigs can then be infected with the avian influenza and the form that infects the human population.  If humans and pigs live together in close proximity, then a mutation can occur when a pig is infected with the avian and human flu resulting in a virus whose genes have been resorted and can now spread from pigs to humans.  Depending on the precise assortment of bird flu proteins that make it into the human population, the resulting flu may be more or less severe.

In 1997 it was discovered by scientists that the bird influenza skipped the step where it would have to infect a pig, and went directly to infecting humans.  This alarmed health officials to think that a pandemic was possible.  Fortunately at that time the virus was not able to pass between people, and therefore did not cause an outbreak.  Scientists are now speculating that chickens may be able to contract these human type viruses and cause the same problem.

The infamous type A avian influenza virus got its start in nature, but through the continuous mutation of the virus, coupled with the new forms of human infection methods, the bird flu has become a much more serious illness than when it first got its start.