Health Questions & Answers #69 ~ [Issue 1005-4]
Oct 28, 2005 08:54 PDT
The bird flu strain that has devastated flocks and killed dozens of
people in Asia has been confirmed in tests on birds from Romania, the
Romanian agriculture ministry announced Saturday. The ministry said
lab tests in Britain showed that the flu detected in wild birds found
dead in the Danube delta is the H5N1 strain. That is the strain
authorities around the world fear could mutate into a form that can
be passed among people, leading to a global pandemic, the Associated
Press reported. The announcement comes a week after H5N1 was
discovered on a farm in Turkey, prompting the European Union (EU) to
ban poultry imports from both Turkey and Romania. Meanwhile, the
International Herald Tribune reported that EU health officials
unveiled tough new measures to help eradicate the virus, including
keeping poultry indoors to prevent contact with wild migratory birds
that are bringing the disease westward from Asia. But the
organization's top veterinary officials sought to temper growing
alarm and stressed that the bird flu outbreak did not currently pose
a public health risk. "Recent information from the outbreaks of this
week in Romania and Turkey suggests that the disease remains confined
to poultry and wild birds, and at this stage no human cases have been
confirmed," the organization said in a statement. "Therefore, at
present, avian influenza does not represent a risk to the general
Key facts about Avian Influenza (Bird Flu) and Avian Influenza A
(H5N1) Virus (excerpted from the Centers for Disease Control (CDC)
web site at http://www.cdc.gov/flu/avian/ ):
Q & A #1:
What is avian influenza (bird flu)?
Bird flu is an infection caused by avian (bird) influenza (flu)
viruses. These flu viruses occur naturally among birds. 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 can make some domesticated birds, including chickens, ducks, and
turkeys, very sick and kill them.
Q & A #2:
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 since 1997.
Q & A #3:
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.
Q & A #4:
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. The spread of avian influenza viruses from one
ill person to another has been reported very rarely, and transmission
has not been observed to continue beyond one person.
Q & A #5:
How is bird flu in humans treated?
Studies done in laboratories suggest that the prescription medicines
approved for human flu viruses should work in preventing bird flu
infection in humans. However, flu viruses can become resistant to
these drugs, so these medications may not always work. Additional
studies are needed to prove the effectiveness of these medicines.
Q & A #6:
What is the risk to humans from bird flu?
The risk from bird flu is generally low to most people because the
viruses occur mainly among birds and do not usually infect humans.
However, during an outbreak of bird flu among poultry (domesticated
chicken, ducks, turkeys), there is a possible risk to people who have
contact with infected birds or surfaces that have been contaminated
with excretions from infected birds. The current outbreak of avian
influenza A (H5N1) among poultry in Asia and Europe is an example of
a bird flu outbreak that has caused human infections and deaths. In
such situations, people should avoid contact with infected birds or
contaminated surfaces, and should be careful when handling and
cooking poultry. In rare instances, limited human-to-human spread of
H5N1 virus has occurred, and transmission has not been observed to
continue beyond one person.
Q & A #7:
What is an avian influenza A (H5N1) virus?
Influenza A (H5N1) virus - also called "H5N1 virus" - is an influenza
A virus subtype that occurs mainly in birds. It was first isolated
from birds (terns) in South Africa in 1961. Like all bird flu
viruses, H5N1 virus circulates among birds worldwide, is very
contagious among birds, and can be deadly.
Q & A #8:
What is the H5N1 bird flu that has been reported in Asia and Europe?
Outbreaks of influenza H5N1 occurred among poultry in eight countries
in Asia (Cambodia, China, Indonesia, Japan, Laos, South Korea,
Thailand , and Vietnam) during late 2003 and early 2004. At that
time, more than 100 million birds in the affected countries either
died from the disease or were killed in order to try to control the
outbreak. By March 2004, the outbreak was reported to be under
control. Beginning in late June 2004, however, new outbreaks of
influenza H5N1 among poultry were reported by several countries in
Asia (Cambodia, China [Tibet], Indonesia, Kazakhastan, Malaysia,
Mongolia, Russia [Siberia], Thailand, and Vietnam). It is believed
that these outbreaks are ongoing. Most recently, influenza H5N1 has
been reported among poultry in Turkey and Romania. Human infections
of influenza A (H5N1) have been reported in Cambodia, Indonesia,
Thailand, and Vietnam.
Q & A #9:
What is the risk to humans from the H5N1 virus in Asia and Europe?
The H5N1 virus does not usually infect humans. In 1997. However, the
first case of spread from a bird to a human was seen during an
outbreak of bird flu in poultry in Hong Kong, Special Administrative
Region. The virus caused severe respiratory illness in 18 people, 6
of whom died. Since that time, there have been other cases of H5N1
infection among humans. Recent human cases of H5N1 infection that
have occurred in Cambodia, Thailand, and Vietnam have coincided with
large H5N1 outbreaks in poultry. The World Health Organization (WHO)
also has reported human cases in Indonesia. Most of these cases have
occurred from contact with infected poultry or contaminated surfaces;
however, it is thought that a few cases of human-to-human spread of
H5N1 have occurred.
So far, spread of H5N1 virus from person to person has been rare and
has not continued beyond one person. However, because all influenza
viruses have the ability to change, scientists are concerned that the
H5N1 virus one day could be able to infect humans and spread easily
from one person to another. Because these viruses do not commonly
infect humans, there is little or no immune protection against them
in the human population. If the H5N1 virus were able to infect people
and spread easily from person to person, an influenza pandemic
(worldwide outbreak of disease) could begin. No one can predict when
a pandemic might occur. However, experts from around the world are
watching the H5N1 situation in Asia very closely and are preparing
for the possibility that the virus may begin to spread more easily
and widely from person to person.
Q & A #10:
How is infection with H5N1 virus in humans treated?
The H5N1 virus currently infecting birds in Asia that has caused
human illness and death is resistant to amantadine and rimantadine,
two antiviral medications commonly used for influenza. Two other
antiviral medications, oseltamavir and zanamavir, would probably work
to treat flu caused by the H5N1 virus, but additional studies still
need to be done to prove their effectiveness.
Q & A #11:
Is there a vaccine to protect humans from H5N1 virus?
There currently is no commercially available vaccine to protect
humans against the H5N1 virus that is being seen in Asia and Europe .
However, vaccine development efforts are taking place. Research
studies to test a vaccine to protect humans against H5N1 virus began
in April 2005, and a series of clinical trials is underway.
Q & A #12:
What is the risk to people in the United States from the H5N1 bird
flu outbreak in Asia and Europe?
The current risk to Americans from the H5N1 bird flu outbreak in Asia
is low. The strain of H5N1 virus found in Asia and Europe has not
been found in the United States . There have been no human cases of
H5N1 flu in the United States. It is possible that travelers
returning from affected countries in Asia could be infected if they
were exposed to the virus. Since February 2004, medical and public
health personnel have been watching closely to find any such cases.
For more information about avian influenza and food safety issues,
visit the World Health Organization web site at
http://www.who.int/foodsafety/micro/avian/en/ For more information
about the H5N1 vaccine development process, visit the National
Institutes of Health web site at