Introduction
The H7N9 (Hemagglutinin 7 neuraminidase 9) avian influenza virus is a variant of the bird flu virus that had not been seen in animals or humans before it was identified in March 2013 in China. Since then, it has reappeared every winter. Asia, America, Africa, and parts of Europe have had outbreaks of this variant of bird flu. It has become of serious concern since the virus is now found in animals and humans and has been deadly in many cases. Most cases of infection in humans with the avian H7N9 virus were found to be due to recent exposure to live poultry or potentially contaminated environments, especially in markets where live birds are sold. The spread of the influenza virus from person to person is very rare, although a few cases have been reported.
What Is H7N9 Avian Influenza Virus Infection?
The H7N9 avian influenza virus causes the bird flu. It is naturally found in wild aquatic birds but has recently been reported in domestic poultry, other birds, and animal species. It does not normally affect humans, but recent mutations have made it capable of spreading from animals to humans. Since the virus is new to humans and keeps evolving and changing, humans do not possess immunity against the virus. Hence the infection could be life-threatening or deadly for humans.
How Is the H7N9 Avian Influenza Virus Transmitted?
H7N9 viruses can be present in the infected bird’s saliva, mucous, and feces. Humans can acquire the infection when the virus gets into their eyes and mouth or if they inhale the virus. This may happen when someone touches the infected bird or its droppings and feces and then touches their eye, mouth, or nose. The infection can also spread by inhaling the virus's droplets or dust. Humans may also contract the virus if they consume undercooked meat or egg of the infected bird.
What Are the Symptoms and Signs of H7N9 Avian Influenza Infection?
Most animals and birds often do not show any symptoms of the infection. However, the earliest signs of infection in chickens include decreased egg production and loss of appetite. Symptoms in humans begin within two to seven days of infection and may start with fever and cough.
Symptoms in the early stages include:
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Fever (100 degrees Fahrenheit or 38 degrees Celsius) and shivering.
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Cough with sputum.
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Sore throat.
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Breathing problems.
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Muscle pain.
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Weakness.
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Stomach pain.
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Chest pain.
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Runny nose.
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Nausea and vomiting.
Fever is not a mandatory symptom; the feeling of feverish may be seen.
What Are the Risk Factors for the H7N9 Avian Influenza Virus?
Humans may acquire H7N9 influenza virus infection from infected poultry and other animals.
Risk factors for the infection include:
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People who work on poultry farms.
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Travelers who visit affected areas.
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People who consume raw or undercooked poultry or eggs.
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Healthcare workers.
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People who are close contacts of an infected person, including household members.
What Are the Complications of H7N9 Avian Influenza Virus Infections?
Severe complications may occur within days of the symptoms appearing. The complications include:
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ARDS (Acute respiratory distress syndrome).
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Impaired kidney and liver function.
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Diseases of the brain, encephalopathy.
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Muscle breakdown.
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Septic shock.
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Thrombocytopenia.
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Lymphopenia.
How Is H7N9 Avian Influenza Virus Infection Diagnosed?
Routine tests for influenza would appear positive in patients with bird flu; however, a culture or a PCR (polymerase chain reaction) test of the sputum could help detect the specific organism. In addition, specialized testing for the specific avian influenza virus is available in the centers for disease control and prevention (CDC) and the reference laboratories.
Other tests that the doctor might advise are:
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Auscultation test.
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Nasopharyngeal culture.
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Chest X-ray.
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Blood tests.
What Is the Treatment Available for H7N9 Avian Influenza Virus Infection?
There are currently no specific medications available for H7N9 avian influenza, but antiviral flu treatments effectively reduce the infection's severity. The evolving flu viruses have made it difficult to make specific medications and vaccines for H7N9.
However, antiviral drugs like Oseltamivir and Zanamivir have been found to help in reducing the severity of the condition. The world health organization (WHO) recommends that the drug must be taken immediately after the symptoms start appearing or at least within 48 hours of the symptoms, even before the lab results come.
How Can H7N9 Avian Influenza Be Prevented?
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Avoid touching or having direct contact with wild birds.
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Avoid touching domestic poultry without protective wear if they look sick or are dead.
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Do not touch surfaces that could be contaminated with mucous, saliva, feces, or droppings of an infected animal without protective wear (like gloves, masks, and eyewear).
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Wash hands with soap and change clothes after contact with a wild or infected animal.
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Dispose of used masks and gloves carefully.
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Cook meat and eggs properly before consuming, at a temperature of 70 degrees Celsius.
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Do not keep cooked and uncooked meat together.
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Avoid food that may contain the blood of an animal.
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Get the recommended flu shots.
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Avoid traveling to places that have reported cases of the disease.
If a person contracts the virus, seek medical help immediately and isolate oneself from other people to prevent the spread of the virus. Although direct person-to-person transmission is rare, sporadic transmissions were reported.
Conclusion
H7N9 avian influenza virus is a variant of the bird flu virus with recent outbreaks. The symptoms of the infection include fever, cough, weakness, muscle pain, breathing problems, etc. Within days of the initial symptoms, complications like pneumonia, acute respiratory distress syndrome, septic shock, thrombocytopenia, and lymphopenia can occur. There is currently no specific vaccine or medication for the H7N9 avian influenza virus. Still, antiviral drugs like Oseltamivir and Zanamivir have been found to help reduce the severity of the condition. WHO recommends taking medications at least within 48 hours of the symptoms. Seek medical help if one suspects bird flu and isolate oneself to prevent the spread of the infection.
