Avian influenza "Bird Flu" The Facts & Guidelines

Avian influenza "Bird Flu"

Bird flu is an infection caused by avian influenza viruses. Wild birds carry the viruses in their intestines and usually do not get sick from them. However, bird flu is very contagious among birds and can kill some domesticated birds including chickens, ducks and turkeys.

Bird flu viruses do not usually infect humans, but dozens cases of human infection with bird flu viruses have occurred since 1997. It is believed that most cases of bird flu infection in humans has been a result of contact with infected poultry or contaminated surfaces.

Why all the recent attention?

An especially virulent strain of the bird flu has spread from Asia to Europe. The virus, known as H5N1, can infect humans as well as birds. Health officials throughout the world are taking the threat of an outbreak of this virus over an extensive geographical area seriously and pressure is on to develop effective containment measures and treatments.

The number of human cases involving H5N1 has been small. However the potential for the virus to change into a more serious threat to humans is real. That’s why we has created this booklet to generate awareness and provide suggestions addressing fundamental health issues, particularly in the workplace and for first responders.

Avian Flu Protection

The Occupational Safety and Health Administration (OSHA) has published personal protection guidelines on its Web site regarding bird flu. The document, entitled “Guidance for Protecting Workers against Avian Flu,” provides background information on the disease and offers recommendations for employees or individuals who could potentially be exposed to the disease.

According to OSHA’s guidelines, “Exposure to infected poultry and their feces or dust contaminated with feces has been associated with human infection; however this is a rare occurrence.” OSHA advises that everyone who has been in close contact with infected animals wash their hands frequently. Proper hand washing consists of washing with soap and water for a minimum of 15 to 20 seconds.

Further guidelines are given for those involved in the culling, transporting or disposal of infected birds. OSHA advises the use of protective clothing and gloves capable of being disinfected or disposed, goggles, boots or protective foot covers that can be disinfected or disposed, and respiratory protection. The minimum form of respiratory protection OSHA recommends is an N95, N99 or N100 disposable respirator. It’s also recommended that anyone involved in handling infected birds receive the current season’s influenza vaccine.

Symptoms of bird flu in humans have ranged from typical flu-like symptoms such as fever, cough, sore throat and muscle aches, to eye infections, pneumonia, severe respiratory diseases and other severe and life-threatening complications. Prescription medicines approved for human flu viruses may work to prevent bird flu infection in humans, but flu viruses have shown an ability to develop resistance to drugs. There are currently no vaccines to protect humans against the Asian virus, but efforts are being made to develop them. Research studies to test just such a vaccine began in April of 2005.

Handling & Eating Poultry

Contrary to popular opinion, bird flu cannot be contracted by humans by eating cooked chicken and eggs. Chickens that are cooked at 56 degrees Celsius for three hours or at 60 degrees Celsius for 30 minutes are safe. In fact, the only way people can get the disease is if they come in close contact with the secretions of the infected animals. This makes people who raise chickens and those who work in farms or deliver chickens more at risk. People who prepare chickens and eggs may also be infected provided that the virus is fresh enough to infect them. This often occurs to people who cook food for families in the farms. If you are one of the many turning your nose at poultry due to the threat of bird flu, you may be interested to know there are measures you can take in order to continue to eat your favorite foods. There have been contradictory reports on whether the virus has been spread from the consumption of undercooked poultry, but you should err on the side of safety in this regard to avoid becoming infected.

Interestingly enough, many of the bird flu precautions are the same precautions you should already be taking to avoid bacteria such as salmonella. A little common sense and good hygiene will go a long way in preventing infection.

The first and most obvious tip is – DO NOT EAT RAW POULTRY! You should fully cook all meat you ingest. How do you tell if the meat is fully cooked? It should not retain any pink color, the juice should run clear, and the meat should reach a temperature of at least 70 to 75 degrees Celsius or roughly 165 degrees Fahrenheit. While freezing will not kill the disease, heat will - but only at sufficient temperatures. Therefore, you should be sure to thoroughly cook all poultry.

Other tips from the World Health Organization (WHO) include a few more of the basics. You should not handle raw meat without washing your hands thoroughly before and after (with antibacterial soap, preferably); you should take special care not to cross contaminate cooked food and raw meat by allowing the two to come in contact, using the same knife or other utensils, or handling food without properly washing your hands; and do not place cooked food back on the same plate or dish it was on when it was raw. Each of these is basic information that applies to, not only poultry, but all meat.

Also, thoroughly wash all surfaces and dishes that come in contact with raw meat (with antibacterial cleanser or soap). You should also avoid using raw or undercooked eggs in food preparation and cook eggs thoroughly (they suggest cooking until yolks are no longer runny).

In handling meat, you should also remember that the bird flu virus is not killed by freezing; therefore, all precautions should also be taken in handling frozen poultry as though it had just come from the market. With these simple steps, you can feel comfortable ingesting poultry, free from worry about bird flu.

Migratory Birds & Birds As Pets

Apart from being difficult to control, outbreaks in backyard flocks are associated with a heightened risk of human exposure and infection. These birds usually roam freely as they scavenge for food and often mingle with wild birds or share water sources with them. Such situations create abundant opportunities for human exposure to the virus, especially when birds enter households or are brought into households during adverse weather, or when they share areas where children play or sleep. Poverty exacerbates the problem: in situations where a prime source of food and income cannot be wasted, households frequently consume poultry when deaths or signs of illness appear in flocks. This practice carries a high risk of exposure to the virus during slaughtering, defeathering, butchering, and preparation of poultry meat for cooking, but has proved difficult to change. Moreover, as deaths of birds in backyard flocks are common, especially under adverse weather conditions, owners may not interpret deaths or signs of illness in a flock as a signal of avian influenza and a reason to alert the authorities. This tendency may help explain why outbreaks in some rural areas have smoldered undetected for months. The frequent absence of compensation to farmers for destroyed birds further works against the spontaneous reporting of outbreaks and may encourage owners to hide their birds during culling operations.

The Role of Migratory Birds

During 2005, an additional and significant source of international spread of the virus in birds became apparent for the first time, but remains poorly understood. Scientists are increasingly convinced that at least some migratory waterfowl are now carrying the H5N1 virus in its highly pathogenic form, sometimes over long distances, and introducing the virus to poultry flocks in areas that lie along their migratory routes. Should this new role of migratory birds be scientifically confirmed, it will mark a change in a long-standing stable relationship between the H5N1 virus and its natural wild-bird reservoir. Evidence supporting this altered role began to emerge in mid-2005 and has since been strengthened. The die-off of more than 6000 migratory birds, infected with the highly pathogenic H5N1 virus, that began at the Qinghai Lake nature reserve in central China in late April 2005, was highly unusual and probably unprecedented. Prior to that event, wild bird deaths from highly pathogenic avian influenza viruses were rare, usually occurring as isolated cases found within the flight distance of a poultry outbreak. Scientific studies comparing viruses from different outbreaks in birds have found that viruses from the most recently affected countries, all of which lie along migratory routes, are almost identical to viruses recovered from dead migratory birds at Qinghai Lake. Viruses from Turkey’s first two human cases, which were fatal, were also virtually identical to viruses from Qinghai Lake.

The role of migratory birds in the spread of highly pathogenic avian influenza is not fully understood. Wild waterfowl are considered the natural reservoir of all influenza A viruses. They have probably carried influenza viruses, with no apparent harm, for centuries. They are known to carry viruses of the H5 and H7 subtypes, but usually in the low pathogenic form. Considerable circumstantial evidence suggests that migratory birds can introduce low pathogenic H5 and H7 viruses to poultry flocks, which then mutate to the highly pathogenic form. In the past, highly pathogenic viruses have been isolated from migratory birds on very rare occasions involving a few birds, usually found dead within the flight range of a poultry outbreak. This finding long suggested that wild waterfowl are not agents for the onward transmission of these viruses.

Recent events make it likely that some migratory birds are now directly spreading the H5N1 virus in its highly pathogenic form. Further spread to new areas is expected.

Advice To Travelers

Avoid contact with high-risk environments in affected countries

Travelers to areas affected by avian influenza in birds are not considered to be at elevated risk of infection unless direct and un-protected exposure to infected birds (including feathers, feces and under-cooked meat and egg products) occurs.

World Health Organization (WHO) continues to recommend that travelers to affected areas should avoid contact with live animal markets and poultry farms, and any free-ranging or caged poultry. Large amounts of the virus are known to be excreted in the droppings from infected birds. Populations in affected countries are advised to avoid contact with dead migratory birds or wild birds showing signs of disease.

Direct contact with infected poultry, or surfaces and objects contaminated by their droppings, is considered the main route of human infection. Exposure risk is considered highest during slaughter, defeathering, butchering, and preparation of poultry for cooking. There is no evidence that properly cooked poultry or poultry products can be a source of infection.

Travelers should contact their local health providers or national health authorities for supplementary information.

Children, School & Bird Flu

Classrooms can be a breeding ground for viruses One of the most important preventative measures that can be done to prevent a child from contacting colds, seasonal flu and the avian bird flu virus is the practice of good hand washing skills. Children do not hand the same hygiene practices as most adults and while at school tend to share desks, tables, toys, cups, plates and utensils. Many times children pick their runny noses or simply wipe their nose with their arms or shirts, which then could come into contact with other children. That's why it is so crucial to wash these organisms off to prevent their spread."

Studies have shown that 40 percent to 60 percent of people don't wash their hands after using the restroom. And those who do wash their hands often don't know the proper technique.

"Most people who do wash their hands do so much too quickly," In order to be effective, hands should be washed with soap from 20 to 25 seconds. The three keys are soap, friction and water. "If we could get the world to embrace hand washing, we would have much less illness."

Hands should be washed after playtime that includes close contact with other children; before and after eating; after a child uses a restroom or when helping a child to use the bathroom; after changing a diaper; after a nose blowing; coughing or sneezing into hands; after handling animals and pets; and before going to a vehicle on the way home.

These simple precautions can limit the spread of bird flu to other people. It is important to keep your child home from school if they feel under the weather or are exhibiting signs of illness to avoid carrying germs to school.

Child Pandemic Defense Kit™

Your children may be exposed to many flu viruses in a school classroom throughout the season. The items in this kit if properly used can go a long way towards defending your children from exposure from many of those viruses as well as the possibility of an avian bird flu virus outbreak. You may want to purchase additional items from our store to add to this kit, but we added the basic items such as respiratory protection, Pocket tissues, individually packaged soap toweletes and a nylon storage bag with cord lock.

The Child Pandemic Defense Kit™ can be easily stored in a School locker, child's classroom cubby, and may even be carried in a backpack to assure your child will have immediate access. Caution should be the rule when providing a repirator mask or other protective items contained in these kits to a child as these items will be of no use if not properly worn or instructions for use are not followed. A phyician should be consulted Prior to purchasing a respirator mask for a child. Please read all instructions provided with masks and practice them with your children. Children using respirator masks should always be under the direct supervision of an adult.

The Science of an Outbreak

The Science is present for a pandemic outbreak

Scientists are certain another pandemic will strike at some point -- they just don't know whether the current bird flu virus will be the spark. Their worries are heightened because the bird flu is mutating in a manner similar to the virus that caused the 1918 Spanish flu, which killed more than 40 million worldwide.

For now, people can contract the bird flu -- which has killed more than 100 people but has not yet reached the United States (As of the printing of this booklet) -- only through contact with an infected bird. But experts fear the longer the virus circulates, the greater the odds it will mutate or combine with a different virus to create a new strain easily passed among humans. Because people would have no immunity, such a strain could spark a global pandemic that could kill tens of millions

Experts say the bird flu virus could arrive in the United States in coming months. It likely would show up first in Alaska, in birds that migrated from Asia, but could spread through the rest of North America as birds migrate southward this fall.

A pandemic could swiftly overwhelm health providers and disrupt everything from transportation systems to schools. Experts estimate that up to 30 percent of the population could contract the virus. The potential is very real; the science is there."

History of the bird flu virus

During the 20th century, influenza pandemics caused millions of deaths, social disruption and profound economic losses worldwide. Influenza experts agree that another pandemic is likely to happen but are unable to say when. The specific characteristics of a future pandemic virus cannot be predicted. Nobody knows how pathogenic a new virus would be, and which age groups it would affect. The impact of improved nutrition and health care needs to be weighed against the effect of increased international travel or simultaneous health threats. The level of preparedness will also influence the economic and medical impact of the disease and the final death toll. However, even in one of the more conservative scenarios, it has been calculated that the world will face up to several 100 million outpatient visits, more than 25 million hospital admissions and several million deaths globally, within a very short period.

Consequences of an influenza pandemic

In the past, new strains have generated pandemics causing high death rates and great social disruption. In the 20th century, the greatest influenza pandemic occurred in 1918 -1919 and caused an estimated 40–50 million deaths world wide. Although health care has improved in the last decades, epidemiological models from the Centers for Disease Control and Prevention, Atlanta, USA project that today a pandemic is likely to result in 2 to 7.4 million deaths globally. In high income countries alone, accounting for 15% of the world’s population, models project a demand for 134–233 million outpatient visits and 1.5–5.2 million hospital admissions. However, the impact of the next pandemic is likely to be the greatest in low income countries because of different population characteristics and the already strained health care resources.

The Outbreak

Influenza pandemic

An influenza pandemic occurs when a new influenza virus appears against which the human population has no immunity, resulting in several, simultaneous epidemics worldwide with enormous numbers of deaths and illness. With the increase in global transport and communications, as well as urbanization and overcrowded conditions, epidemics due the new influenza virus are likely to quickly take hold around the world.

A new influenza virus: how it could cause a pandemic Annual outbreaks of influenza are due to minor changes in the surface proteins of the viruses that enable the viruses to evade the immunity humans have developed after previous infections with the viruses or in response to vaccinations. When a major change in either one or both of their surface proteins occurs spontaneously, no one will have partial or full immunity against infection because it is a completely new virus. If this new virus also has the capacity to spread from person-to-person, then a pandemic will occur.

Outbreaks of influenza in animals, especially when happening simultaneously with annual outbreaks in humans, increase the chances of a pandemic, through the merging of animal and human influenza viruses. During the last few years, the world has faced several threats with pandemic potential, making the occurrence of the next pandemic just a matter of time.

If an influenza pandemic appears, we could expect the following:

• Given the high level of global traffic, the pandemic virus may spread rapidly, leaving little or no time to prepare.
• Vaccines, antiviral agents and antibiotics to treat secondary infections will be in short supply and will be unequally distributed. It will take several months before any vaccine becomes available.
• Medical facilities will be overwhelmed.
• Widespread illness may result in sudden and potentially significant shortages of personnel to provide essential community services.

The effect of influenza on individual communities will be relatively prolonged when compared to other natural disasters, as it is expected that outbreaks will reoccur.

Symptoms & Treatment

In many patients, the disease caused by the H5N1 virus follows an unusually aggressive clinical course, with rapid deterioration and high fatality. Like most emerging disease, H5N1 influenza in humans is poorly understood. Clinical data from cases in 1997 and the current outbreak are beginning to provide a picture of the clinical features of disease, but much remains to be learned. Moreover, the current picture could change given the propensity of this virus to mutate rapidly and unpredictably.

The incubation period for H5N1 avian influenza may be longer than that for normal seasonal influenza, which is around two to three days. Current data for H5N1 infection indicate an incubation period ranging from two to eight days and possibly as long as 17 days. However, the possibility of multiple exposure to the virus makes it difficult to define the incubation period precisely. WHO currently recommends that an incubation period of seven days be used for field investigations and the monitoring of patient contacts.

Initial symptoms include a high fever, usually with a temperature higher than 38oC, and influenza-like symptoms. Diarrhea, vomiting, abdominal pain, chest pain, and bleeding from the nose and gums have also been reported as early symptoms in some patients. Watery diarrhea without blood appears to be more common in H5N1 avian influenza than in normal seasonal influenza. The spectrum of clinical symptoms may, however, be broader, and not all confirmed patients have presented with respiratory symptoms. In two patients from southern Viet Nam, the clinical diagnosis was acute encephalitis; neither patient had respiratory symptoms at presentation. In another case, from Thailand, the patient presented with fever and diarrhea, but no respiratory symptoms. All three patients had a recent history of direct exposure to infected poultry.

One feature seen in many patients is the development of manifestations in the lower respiratory tract early in the illness. Many patients have symptoms in the lower respiratory tract when they first seek treatment. On present evidence, difficulty in breathing develops around five days following the first symptoms. Respiratory distress, a hoarse voice, and a crackling sound when inhaling are commonly seen. Sputum production is variable and sometimes bloody. Most recently, blood-tinted respiratory secretions have been observed in Turkey. Almost all patients develop pneumonia. During the Hong Kong outbreak, all severely ill patients had primary viral pneumonia, which did not respond to antibiotics. Limited data on patients in the current outbreak indicate the presence of a primary viral pneumonia in H5N1, usually without microbiological evidence of bacterial supra-infection at presentation. Turkish clinicians have also reported pneumonia as a consistent feature in severe cases; as elsewhere, these patients did not respond to treatment with antibiotics.

In patients infected with the H5N1 virus, clinical deterioration is rapid. In Thailand, the time between onset of illness to the development of acute respiratory distress was around six days, with a range of four to 13 days. In severe cases in Turkey, clinicians have observed respiratory failure three to five days after symptom onset. Another common feature is multiorgan dysfunction. Common laboratory abnormalities, include leukopenia (mainly lymphopenia), mild-to-moderate thrombocytopenia, elevated aminotransferases, and with some instances of disseminated intravascular coagulation.

What drugs are available for treatment?

Two drugs (in the neuraminidase inhibitors class), oseltamivir (commercially known as Tamiflu) and zanamivir (commercially known as Relenza) can reduce the severity and duration of illness caused by seasonal influenza. The efficacy of the neuraminidase inhibitors depends, among others, on their early administration ( within 48 hours after symptom onset). For cases of human infection with H5N1, the drugs may improve prospects of survival, if administered early, but clinical data are limited. The H5N1 virus is expected to be susceptible to the neuraminidase inhibitors. Antiviral resistance to neuraminidase inhibitors has been clinically negligible so far but is likely to be detected during widespread use during a pandemic.

An older class of antiviral drugs, the M2 inhibitors amantadine and rimantadine, could potentially be used against pandemic influenza, but resistance to these drugs can develop rapidly and this could significantly limit their effectiveness against pandemic influenza. Some currently circulating H5N1 strains are fully resistant to these the M2 inhibitors. However, should a new virus emerge through reassortment, the M2 inhibitors might be effective.

For the neuraminidase inhibitors, the main constraints – which are substantial – involve limited production capacity and a price that is prohibitively high for many countries. At present manufacturing capacity, which has recently quadrupled, it will take a decade to produce enough oseltamivir to treat 20% of the world’s population. The manufacturing process for oseltamivir is complex and time-consuming, and is not easily transferred to other facilities.

So far, most fatal pneumonia seen in cases of H5N1 infection has resulted from the effects of the virus, and cannot be treated with antibiotics. Nonetheless, since influenza is often complicated by secondary bacterial infection of the lungs, antibiotics could be life-saving in the case of late-onset pneumonia. WHO regards it as prudent for countries to ensure adequate supplies of antibiotics in advance.

Limited evidence suggests that some antiviral drugs, notably oseltamivir (commercially known as Tamiflu), can reduce the duration of viral replication and improve prospects of survival, provided they are administered within 48 hours following symptom onset. However, prior to the outbreak in Turkey, most patients have been detected and treated late in the course of illness. For this reason, clinical data on the effectiveness of oseltamivir are limited. Moreover, oseltamivir and other antiviral drugs were developed for the treatment and prophylaxis of seasonal influenza, which is a less severe disease associated with less prolonged viral replication. Recommendations on the optimum dose and duration of treatment for H5N1 avian influenza, also in children, need to undergo urgent review, and this is being undertaken by the World Health Organization (WHO).

In suspected cases, oseltamivir should be prescribed as soon as possible (ideally, within 48 hours following symptom onset) to maximize its therapeutic benefits. However, given the significant mortality currently associated with H5N1 infection and evidence of prolonged viral replication in this disease, a

AvianFlu