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Avian Influenza

Avian Influenza (H7N9); Source: CDC Image Library


What is Avian Influenza (Bird Flu)?

Avian influenza, also known as bird flu, is a disease of wild birds and domesticated poultry like farm chickens, ducks, and turkeys. Several avian influenza strains have been known to cause illness in humans.  Although millions of birds have been infected, only a small number of people have been infected. No sustained person-to-person spread of avian influenza has occurred.  Because all influenza viruses have the ability to change, there is concern that avian flu viruses could mutate and be spread easily and widely by humans. If that happens, it is possible that a pandemic or widespread outbreak of human disease could occur.  Monitoring for human infection with avian influenza is important in order to detect any changes in the virus that may occur. 


Situational Update

Avian influenza H5N1 has caused human illnesses in Asia, the Middle East, Africa, and Europe, and a single case in Canada in a traveler returning from overseas.  No cases have been reported in the United States. As of June 2015 the strain is endemic in poultry in Bangladesh, China, Egypt, India, Indonesia, and Vietnam. Find up to date information on animal cases of avian influenza H5N1 and human cases of avian influenza H5N1.


Avian influenza, type H7N9 has caused human illnesses in China since 2013, with an additional case in Malaysia in a traveler from China.  Review information on avian influenza H7N9


Since December 2014, there have been outbreaks of avian influenza in commercial poultry flocks in the United States and Canada.  The avian influenza was spread to the poultry by wild birds.  No human illness has resulted from the outbreaks, and the outbreaks are NOT due to the strains that have caused illness in humans in other countries.  The affected flocks of poultry have been destroyed, and potentially exposed people have been monitored.  Several poultry outbreaks have occurred in California.  No avian influenza has been detected in San Francisco. CDC, the United States Department of Agriculture (USDA), the California Department of Public Health (CDPH), and the California Department of Food and Agriculture are working closely to monitor the situation


How Avian Influenza is Spread to Humans

The current risk to US residents from avian influenza is very low. Avian influenza is not easily passed from birds to humans. People may get avian influenza by touching an infected bird, fluid or surfaces contaminated with fluids from infected birds and then touching their eyes, nose, or mouth. People who could be at risk in the US are those who travel to countries with outbreaks of avian influenza and have close contact with live or dead poultry, or with environments contaminated with fluids from infected birds.  Health officials are monitoring people who have had contact with potentially infected birds in the United States, and none have developed avian influenza. 


Human Symptoms

Individuals with avian influenza usually develop symptoms within 10 days of contact with infected birds, become very ill, and require hospitalization. Symptoms are usually severe and include high fever, muscle aches, cough, mucus production and shortness of breath. Abdominal pain and diarrhea can also occur.


Vaccine and Treatment

A vaccine for birds against avian influenza H5N1 is being used in areas that have infected birds. Vaccines and medicines are useful tools that may help us fight off avian or pandemic flu in humans. No vaccine is yet available for avian influenza H7N9.  Scientists have produced and stockpiled avian influenza H5N1 vaccines for humans. However, if the virus mutates it is unclear how well these vaccines will work. A new vaccine could take 6 months or more to create.


Traveling to Areas Affected by Avian Influenza

Before traveling to a country affected by avian influenza:

  • Check for travel advisories issued by the US State Department or the US Centers for Disease Control and Prevention (CDC): [H5N1] [H7N9]  
  • Get a flu vaccine before traveling, preferably at least 2 weeks prior to leaving. Make sure you are up to date on all your vaccinations.  Although the flu vaccine will not protect you against avian influenza, it will help you avoid seasonal influenza. 
  • Avoid direct contact with poultry, wild birds, farms, or live-animal markets. Avoid touching surfaces contaminated with poultry feces (droppings) or fluids.
  • Pack a travelers health kit and find out about seeking care abroad


Control measures at the San Francisco Department of Public Health

The San Francisco Department of Public Health is preparing for the possibility of spread of human avian influenza illness to our region. We are working to ensure that our hospitals and clinicians are educated about avian and pandemic flu. We provide updates to the clinical community on the status of avian flu, consultation to clinicians who suspect avian flu, guidance on how to care for infected patients, infection control recommendations, and laboratory testing.


Where to Find Information During an Infectious Disease Emergency
During an Avian Influenza outbreak, San Francisco specific emergency information can be found at:


Avian Influenza Frequently Asked Questions (FAQs) and Materials

For the Public


For Medical Providers       


Useful Links for Additional Information


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