Search the site

Avian Influenza (Bird Flu) H5N1

What is Avian Influenza (Bird Flu) H5N1?

Avian influenza (H5N1), also known as bird flu, is a disease of wild birds and domesticated poultry like farm chickens, ducks, and turkeys. Although millions of birds have been infected, only a very small number of people have been infected. Because all influenza viruses have the ability to change there is concern that the H5N1 virus 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. World health organizations and the San Francisco Department of Public Health are monitoring the situation and making plans to control avian influenza.


Situational Update

Avian influenza (H5N1) has not been found in the United States. However, it has been detected in wild birds, domestic poultry, and some humans internationally. Find up to date information on animal cases of avian influenza and human cases of avian influenza.


How Avian Influenza is Spread to Humans

The current risk to Americans is 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 improperly cooked poultry while there.


Human Symptoms

Individuals with avian influenza (H5N1) 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 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. Scientists have produced and stockpiled avian influenza (H5N1) vaccines. 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.


There are medicines (antivirals) that are sometimes effective for seasonal flu; however, many seasonal influenza viruses are resistant. Avian influenza virus strains have also frequently been resistant. The San Francisco Department of Public Health strongly discourages the personal stockpiling of antivirals for pandemic influenza. Personal stockpiling will decrease availability to those who need the medications most. To date it is unclear if Tamiflu or other antivirals are effective in treating avian influenza. During an emergency the health department will distribute appropriate medications, as available, to infected individuals and their close contacts.


Traveling to Areas Affected by Avian Influenza

Before traveling to a country affected by H5N1 avian influenza:


  • Check for travel advisories issued by the US State Department or CDC.
  • 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.
  • Avoid direct contact with poultry, wild birds, farms, or live-animal markets. Avoid touching surfaces contaminated with poultry feces (droppings) or fluids.
  • Wash your hands frequently or use alcohol hand sanitizers. Avoid touching your eyes, nose, and mouth. Wash your hands if you are handling raw poultry for cooking.
  • Do not eat undercooked eggs or poultry (pink meat).
  • Pack a travelers health kit and find out about seeking care abroad.


Monitor your health and see a doctor if you develop symptoms (see above) within 10 days of having close contact with birds. Let your doctor know about your travels, symptoms, and contact with birds.


Control measures at the San Francisco Department of Public Health

The San Francisco Department of Public Health is closely monitoring avian influenza H5N1 and is preparing for the possibility of spread 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. We have created an Avian/Pandemic Flu Task Force for all city agencies to ensure that all city departments and agencies have well-developed and coordinated plans.


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 FAQs and Materials


For Everyone

For Clinicians


Useful Avian Influenza Links

© Copyright 1998 - 2015, Department of Public Health, City and County of San Francisco Privacy Policy|Sitemap|Contact Us