APEIR Publication

Answer

How do people get infected with bird flu viruses?

Human infections with bird flu viruses are rare, but have happened in the past, usually after close contact with infected birds (both live and dead) or environments contaminated with bird flu virus.

Infected birds can shed a lot of flu virus, for example, in their droppings or their mucus. If someone touches an infected bird or an environment contaminated with virus and then touches their eyes, nose or mouth, they may be infected with bird flu virus.

There is some evidence that infection may also occur if the flu virus becomes airborne somehow, such as when an infected bird flaps it wings. If someone were to breathe in airborne virus, it’s possible they could get infected.

Is infection with this virus serious?

Most of the reported cases of human infection with this virus have had very serious illness. There also are reports of some milder illness and one possible report of a person who tested positive for the virus who did not have any symptoms.

What are the main symptoms of human infection caused by avian influenza A(H7N9) virus?

Thus far, most patients with this infection have had severe pneumonia. Symptoms include fever, cough and shortness of breath. However, information is still limited about the full spectrum of illness that infection with avian influenza A(H7N9) virus might cause.

Why is this virus infecting humans now?

We do not know the answer to this question yet, because we do not know the source of exposure for these human infections. However, analysis of the genes of these viruses suggests that although the viruses have evolved in birds, they may infect mammals more easily than other avian viruses

Is it possible that this virus will spread from person-to-person?

Yes. Based on what we know about human infections with other bird flu viruses, it’s possible and even likely that there will be some limited person-to-person spread with this virus. The important factor will be to determine whether this virus gains the ability to spread easily from one person to another. Sustainable human to human spread is needed for a pandemic to start. Health officials are watching the situation closely for this.

Is there a vaccine to protect against this new H7N9 virus?

No, right now there is no vaccine to protect against this virus. WHO, CDC and others partners/institution are working to develop a vaccine candidate virus that could be used to make a vaccine if it is needed.

Are there medicines to treat illness associated with this virus?

WHO and CDC US recommend oseltamivir (Tamiflu®) and zanamivir (Relenza®) for treatment of H7N9. Most of the H7N9 viruses that have been studied are likely susceptible (sensitive) to the two influenza antiviral drugs that are used to treat seasonal flu. Those drugs are oseltamivir (Tamiflu®) and zanamivir (Relenza®) (neuraminidase inhibitors). Like seasonal influenza viruses, avian A(H7N9) viruses are resistant to the influenza antiviral drugs known as the adamantanes.It’s important to note that influenza viruses may acquire genetic changes which can make one or more influenza antiviral drugs less effective. This happens with seasonal influenza viruses and could happen with H7N9 viruses found in China.

Source:

CDC US (http://www.cdc.gov/flu/avianflu/h7n9-faq.htm)

WHO (http://www.who.int/influenza/human_animal_interface/faq_H7N9/en/)