Prognosis
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Images
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Risk factors|
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The greatest risk factor for bird flu seems
to be contact with sick birds or with surfaces contaminated by their feathers,
saliva or droppings.
Risk factors include caring for sick birds,
killing sick birds, and preparing sick birds for consumption. Despite the large
number of people who have contact with poultry every day in the world, human
cases of bird flu remain rare. This highlights how difficult it is for the bird
flu virus to infect human cells, but mutations like antigenic shifts may reduce
such difficulties. The H1N1 pandemic that started in Mexico is an example of
such a mutation (swine flu to human flu).
Although direct
contact with sick poultry poses the highest risk for bird flu, indirect
exposure to bird feces or other materials such as bird eggs is also a risk.
Contact with unwashed eggs from sick birds or water contaminated by poultry
feces poses a potential risk of disease.
Bird flu is
very contagious among many bird species. In general, bird flu is not very
contagious to humans, even to poultry workers. However, human-to-human spread
has occurred in isolated cases. In human outbreaks, the first individual to
become infected usually has had contact with infected birds or poultry and then
caregivers become infected. Thus, caring for a person infected with bird flu is
also a risk factor for the disease. There is a theoretical risk in laboratory
workers who handle the avian flu virus.
Complications|
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People with bird flu may develop
life-threatening complications. The complications of bird flu are frequently
dire and include:
- Shortness of breath or difficulty breathing,
- Pneumonia,
- Acute respiratory distress syndrome (ARDS),
- Abdominal pain,
- Lung collapse,
- Shock,
- Altered mental status,
- Seizures,
- Organ system failure, and
- Death.
Although bird
flu may kill more than half the people it infects, the number of fatalities is
still low because so few people have had bird flu. Fewer than 500 bird flu
deaths have been reported to the World Health Organization since 1997.
Diagnosis|
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Routine tests for human influenza A will be
positive in patients with bird flu but are not specific for the avian virus. If
bird flu is suspected, the following tests will be carried out to establish
whether you have the infection:
Laboratory tests
Samples of fluids from your nose or throat
can be tested for evidence of bird flu virus. These samples must be taken within
the first few days after symptoms appear. The virus can be detected in sputum
by several methods, including culture or polymerase chain reaction (PCR).
Cultures should be done in laboratories that have an appropriate biosafety
certification. PCR detects nucleic acid from the influenza A virus. Specialized
PCR testing is available in reference laboratories to identify avian strains;
the CDC is a primary source for available tests for the newest strains of bird
flu and can identify the specific type of virus (for example, H5N1 or H7N9).
Imaging tests
X-rays may be
useful in assessing the condition of your lungs, which can help determine the
proper diagnosis and the best treatment options for your signs and symptoms.
