How is Bird Flu Different from Regular Seasonal Flu?

Published by Contra Costa Times

Posted on Wed, Dec. 07, 2005

By Francie Wise, RN, MPH

Recently our health information line received a call from a county resident wondering if he could get avian flu from migratory birds.

This and other calls indicate more uncertainty and confusion than usual about the flu. First, some facts:

Both the seasonal ("regular") flu and avian (or "bird") flu are caused by the influenza virus, but by different types.
The avian and seasonal flu viruses each have a number of different types and subtypes. One subtype of the avian flu virus (called a "pathogenic strain of H5N1") can cause deadly illness in poultry and people. This virus can live in migratory birds, but generally does not cause them to become ill.
Since viruses cause all types of flu, they are not treated with antibiotics used for bacterial infections. Certain antiviral medicines may reduce symptom severity in both types of flu, and antibiotics may be used to treat bacterial complications of the flu.
To date, no humans or poultry in North America are known to have been infected with or died of avian flu, nor have birds with the dangerous form of the virus been found here. (The virus recently found in a Canadian bird is said to be of a less dangerous variety.)
The most important steps you can take to avoid "regular" flu now are to get a flu shot and wash or sanitize your hands often. The current flu vaccine does not protect against the avian flu, though one is being developed.

To return to the caller's question: could he get bird flu from migratory birds? The short answer is "yes." But, it is highly unlikely.

In Asia, millions of birds are infected with the H5N1 avian flu, but only slightly more than 100 people have become infected in the current outbreak.

In almost all cases, human bird flu illness has occurred in families that live among and around flocks of birds or in poultry workers. Therefore, bird to people transmission is difficult and rare, and birds in North America are not known to be infected.

The USDA has banned poultry imports from countries known to be affected by the avian flu virus, so getting the disease here by eating infected bird flesh is unlikely.

It is always important to cook all meat and poultry thoroughly, and to wash hands and utensils after preparing raw meat.

Some additional facts:

One reason the seasonal flu is so common is that it can be spread easily from one person to another. So far, transmission of the avian flu (including H5N1) from one person to another has been extremely rare.
The dangerous type of avian flu is thought to kill about half (50 percent) of those infected, including healthy children and young adults. The seasonal flu kills less than 1/1,000 (less than .001 percent) of those infected, or about 36,000 people per year in the United States last season, more than 90 percent of whom were elderly.
If the dangerous form of the H5N1 avian flu virus changes to allow easy person-to-person spread, it could cause widespread illness and death, including here in the United States.

For more information about avian flu, visit Contra Costa Health Services Web site at www.cchealth.org or call 1-888-959-9911 or 211. More information is available at www.cdc.gov or www.pandemicflu.gov.

Wise is Director of Communicable Disease Programs and Public Health Nursing for Contra Costa Health Services.