How to Recognize the Types of Bird Flu

Influenza viruses come in three major categories: A, B and C viruses. While birds can only be infected with influenza A viruses, the strains of bird flu that can transmit from birds to human have a considerable range of sub-types, depending on the type of surface protein the virus bonds with in your body. Read on to learn how to recognize the types of bird flu.

Instructions

Difficulty: Challenging

Things You’ll Need:

• Physician

1. Understand how influenza viruses are classified. The letter "H" and a number (indicating the specific strain) are used to differentiate sub-types of the influenza A virus that can be transmitted from birds to humans. There are three known types of influenza A that pass between birds and people: avian influenza A H5, H7 and H9.
2. Recognize that further sub-types of each of the three major categories of Asian influenza virus are designated by placing the letter "N" after the "H-plus-numeral" classification and assigning a number to the "N" value. This number identifies the specific type of protein the virus binds to. Nine are known. Thus, there are 27 possible combinations, from avian influenza A H5N1 through H5N9, H7N1 through H7N9 and H9N1 through H9N9.
3. Know that avian influenza A H5 infections are the most common types of bird flu transmitted to humans. They can cause symptoms ranging from mild to severe, and there have been a number of documented cases where an H5 strain of the virus caused the death of a human being.
4. Recognize that while H7 strains of the bird flu remain quite rare, they do occur in cases where humans have come into direct physical contact with birds carrying the disease. H7 strains frequently cause only eye infections that can be mistaken for conjunctivitis, or pinkeye, but potentially serious respiratory symptoms have also been reported.
5. Bear in mind that while H9 infections remain the least common, with only a handful of confirmed cases worldwide, they do occur, generally causing symptoms that are not overly severe.
6. Visit the Centers for Disease Control and Prevention's avian flu pages for an in-depth explanation of types of bird flu. See the Resources section below for a link.

Tips & Warnings

• All strains of bird flu should be considered dangerous and potentially life-threatening, even if only minor symptoms are present at first. If you have visited a region of the world where the avian influenza is common and you begin to recognize symptoms, consult a doctor immediately.