Avian (Flu) Influenza

Avian Influenza A (H7N9)

At the end of March 2013, China reported human and bird (poultry) infections with a new strain of H7N9. H7N9 is a subtype of influenza A viruses that have been found in birds. However, this strain designated as influenza A (H7N9) is very different from previously examined strains and was the first known human infection with an H7N9 virus.

Most of the reported cases of human infection with H7N9 report very severe respiratory illness; however a few reports of some milder illnesses have been reported. Approximately one-third of cases have resulted in death.

The first case outside of China was in Malaysia and was reported on February 12, 2014. The case was detected in a traveler from an H7N9-affected area of China. The new H7N9 virus has not been detected in people or birds in the United States.

Frequently Asked Questions (FAQs)

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Click on a question below to see the answer.

How are people becoming infected with H7N9?

The virus has been found in poultry in places where human infections have occurred. It is believed that people have been infected after coming into contact with infected poultry.

Is an H7N9 infection serious?

Most reported cases have had serious illness. However, there have been some mild cases and one person was reported to be asymptomatic, yet tested positive for the virus.

What are symptoms of an H7N9 infection?

Symptoms of shortness of breath, fever, and cough have been exhibited in most of the infections. Serious illness has developed in many cases, including severe pneumonia, acute respiratory distress syndrome (ARDS), multi-organ failure and septic shock that have led to death. However, there is still limited information on the full range of illness.

Is the virus spreading between people?

The Chinese health authorities have followed up with hundreds of close contacts of infected people and it does not seem that there is any sustained human-to-human transmission. However, it would NOT be surprising to see some limited human-to-human transmission.

How are people diagnosed with H7N9 infections?

A specific test for H7N9 has been developed by CDC for use by qualified public health laboratories in the United States and internationally, which includes the Arizona State Public Health Laboratory. The test requires a respiratory sample from a sick patient that is then sent to the laboratory where a procedure known as rRT-PCR (real-time reverse transcriptase polymerase chain reaction) is conducted. rRT-PCR is sensitive and accurate in detecting influenza viruses. Results are usually obtained within 4 hours depending on the conditions.

Is there a vaccine that can protect against avian influenza A (H7N9)?

No. Currently, there is no vaccine available, but efforts are underway by the Centers for Disease Control and Prevention (CDC) and others to develop a candidate virus that could be used to create a vaccine if necessary.

Are there medications to treat people infected with avian influenza A (H7N9)?

Yes, CDC has reviewed antiviral resistance to H7N9 viruses sent from China and found that they are susceptible to the neuraminidase inhibitors oseltamivir (Tamiflu®) and zanamivir (Relenza®), which are used to treat seasonal influenza.

Are there cases of avian influenza A (H7N9) in the United States?

No. There have been no cases of avian influenza A (H7N9) detected in the United States. It is possible that a traveler from China could come to the United States with an H7N9 infection. Guidance and recommendations have been made by CDC to public health officials and clinicians to identify travelers that have returned from affected areas with flu-like symptoms. Currently, there would be a low-risk to the public since the virus does not easily transmit from person-to-person.

Is it safe to cook and eat chicken, other poultry and eggs?

Yes. It is safe to eat poultry and eggs. There is no evidence that humans can become infected with avian influenza by eating properly cooked poultry and eggs. Even if poultry with avian influenza would enter the United States food supply, washing utensils and cooking poultry to at least 165˚ F kills the virus.

What if I want more information?

The CDC has a page devoted to avian influenza A (H7N9). The World Health Organization (WHO) also has a page with more information.

How are avian, pandemic, and seasonal flu different?

Avian flu is caused by bird flu viruses, which occur naturally among birds. Sometimes these viruses can be transmitted to humans and in rare instances have the potential to cause a pandemic if they mutate to spread easily from person-to-person.

Pandemic flu is a global human outbreak, or pandemic, of serious flu illness that spreads easily from person to person and is caused by a new influenza A virus. Currently there is no pandemic flu anywhere in the world.

Seasonal flu is a contagious respiratory illness caused by human flu viruses which occur every year during October through April during the United States’ “Flu Season.”