Avian Flu
Frequently Asked Questions
What is avian flu?
The avian flu that is currently decimating bird populations around the globe — H5N1 virus — is causing great concern among public health officials. Because this virus does not commonly infect humans, there is little or no immune protection against it in the human population. Therefore, if H5N1 virus were able to infect people and spread easily from person to person, an influenza pandemic could begin.
To date, the great majority of all cases of the avian flu have been due to transmission of the virus from birds to humans. As of May 2006, the deadly H5N1 virus strain has infected more than 200 people in Vietnam, China, Cambodia, Indonesia, Iraq, Thailand, Turkey, and other countries. Slightly more than one-half of all humans infected have died. Human-to-human transmission of the virus appears to have been likely in a small number of family "clusters" of the disorder, although the virus has not spread beyond these families.(Log on to www.pandemicflu.gov for updates.)These deaths, and new poultry and wild bird infections being reported weekly, heighten concern that the virus may mutate into a strain that would easily pass between humans, leading to a pandemic that may kill millions of people.
What is a pandemic?
Pandemics are worldwide epidemics. A pandemic is an epidemic that spreads across the globe, affecting every continent rather than being confined to one geographic area. During flu pandemics, a higher than usual percentage of the population becomes infected and more people die from these infections than during the usual annual flu season. Pandemics occur because a new influenza virus makes its way from birds or swine to humans, resulting in a strain for which we have very little immunity. Pandemics have occurred about every 30 to 50 years in recent history.
When might an avian flu pandemic occur?
Although no one can predict when a pandemic might occur, experts from around the world are watching the H5N1 virus situation very closely and are preparing for the worst. In fact, the World Health Organization predicts that an H5N1 virus human pandemic is not a question of “if” but “when.” Outbreaks of influenza H5N1 virus among poultry have been reported in Asia, Turkey, and Romania and among wild migratory birds in Croatia. The virus continues to spread. In early 2006, avian flu was detected in dead swans and other birds found in Africa, Greece, Germany, Austria, Sicily, Poland, and Israel.
What are the symptoms of avian 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.
How is avian flu treated?
Oseltamivir (Tamiflu) and similar antiviral medications provide moderate protection. They may have some use in moderating the severity of the disease and/or in prophylaxis (prevention) for people working with infectious humans or animals. However, some subtypes of the H5N1 virus are becoming more virulent (stronger) and more resistant to medications such as Tamiflu. Variants of the H5N1 virus that have caused human illness and death are resistant to amantadine and rimantadine, two antiviral medications commonly used for influenza.
Is there a vaccine?
There currently is no vaccine to protect humans against the H5N1 virus that is being seen in Asia. However, vaccine development efforts are under way at the University of Pittsburgh and in a number of laboratories around the country and the world. Research under way at the University of Pittsburgh has resulted in a vaccine for poultry.
How is avian flu transmitted from birds to humans?
Birds are the natural hosts of the disease. The disease spreads rapidly in flocks by direct contact. The virus transmits in feces and discharges from the nasal passages and eyes. Most cases of bird flu infection in humans have resulted from contact with infected poultry or contaminated surfaces. Although not the case today, the concern is that the virus may mutate to a form that is easily transmissible from human to human.
Is there a risk for becoming infected with avian influenza by eating poultry?
There is no evidence that properly cooked poultry or eggs can be a source of infection by avian influenza viruses.
Have scientists estimated how many people may become ill or die if an avian flu pandemic struck the United States?
According to the Centers for Disease Control and Prevention (CDC), the severity of an avian flu pandemic cannot be predicted, but modeling studies suggest that the impact of a pandemic on the United States could be substantial. In the absence of any control measures (vaccination or drugs), it has been estimated that in the United States a “medium-level” pandemic could cause 89,000 to 207,000 deaths, 314,000 to 734,000 hospitalizations, and 18 million to 42 million outpatient visits. Frequently asked questions cont.
What are the other impacts of a pandemic?
Pandemics can cause large surges in the numbers of people requiring or seeking medical or hospital treatment, temporarily overwhelming health services. High rates of worker absenteeism also can interrupt other essential services, such as law enforcement, transportation, and communications.
How long will a pandemic last?
In an affected community, a pandemic outbreak will probably last two or three months. Pandemic influenza occurs in “waves,” with multiple waves possible. When it seems that the outbreak is over, another wave of infections comes along and causes disease among the population again.
What steps might the government take to control the spread of avian flu in a pandemic?
The two main strategies for the prevention of transmission in the public domain involve decreasing contact between infected and uninfected people, and decreasing the probability that contact, if it occurs, will result in infection. This may include travel restrictions, school closures, orders against large public gatherings, isolation, and quarantine.
The government will take measures to restrict contact between people infected with the virus and healthy individuals. Health care professionals have a duty to provide care and cannot avoid contact. However, UPMC will take all available measures to protect staff who care for people infected with the avian flu.
Will the government be able to provide assistance immediately?
The role of federal government, especially in the early stages of a pandemic, will be limited. U.S. Secretary of Health and Human Services Mike Leavitt has stated, “States and communities have an essential responsibility in pandemic preparedness. … A pandemic, unlike other disasters, can happen in a thousand different places all at the same time. It is states and communities that will be on the front lines in fighting the pandemic. They will be the ones making decisions about whether to close schools or cancel public events. They will also be deciding how to handle the influx of patients at local hospitals and how to distribute medicines.”
Steps will be taken at all levels of government to deal with a pandemic. UPMC will cooperate and collaborate with these steps. The government’s response may take considerable time to implement. It is UPMC’s obligation and expectation to be prepared to “go it alone.”
Could quarantine orders be issued?
It is possible that quarantine orders could be issued by a government authority. The CDC defines quarantine as separation and restriction of movement of healthy persons presumed to have been exposed to the virus. Under a quarantine order, people may be instructed to remain in their homes, places of employment, or other locations.
An isolation order is another option. Under isolation, people who are sick with the contagious disease are separated, and their movements are restricted.
Social isolation in which people agree voluntarily to avoid crowds and public events also may be considered. This option preserves the right of the individual to make a choice.
How long is the incubation period for influenza?
The typical incubation period (interval between infection and onset of symptoms) for the usual seasonal influenza is approximately two days. People who become ill may transmit infection for up to one day before onset of symptoms. Viral shedding and the risk of transmission will be greatest during the first two days of illness. The incubation period for flu can be several days longer in children. Adults can be infectious for approximately one day prior to symptoms, whereas children can be infectious for several days before symptoms. The incubation period for the H5N1 virus is under continuing study and, for adults, may be longer than two days.
