Centers for Disease Control keeping
close watch on Avian flu virus
There is concern from the Centers for Disease Control (CDC) that a bird flu virus sweeping through Asia may mutate to a human form. Although human-human transmission has been rare, the CDC’s assessment is that this is a very high threat based on flu virus history, according to Dr. Julie Gerberding, head of the Centers for Disease Control (CDC). She reported on the Asian Avian flu experience at the 2005 national meeting of the American Association for the Advancement of Science.
"In Asia," says Dr. Gerberding, "there have been a number of deaths among people who caught the flu from chickens or ducks. The mortality rate of these patients is about 72%. The avian flu in Asia is part of the H1 family of flu viruses.
"Avian influenza can also be transmitted to humans directly from birds, or from avian virus-contaminated environments.
"Each time we see a new H1 antigen emerge, we usually experience an influenza pandemic. We are seeing a very dangerous strain of influenza virus emerge across the entire western part of Asia. We may see the emergence of a new strain to which the human population has no immunity."
Dr. Gerberding and her agency are working closely with the World Health Organization and Asian health ministries to prevent a new strain from spreading in Asia and abroad.
"I don’t mean to imply," says Dr. Gerberding, "an avian flu pandemic is imminent. When avian flu evolved to form the 1918 flu strain, it didn’t happen overnight. It happens in a series of progressive steps, where you saw local outbreaks, and the virus gradually evolved toward more efficient person-person transmission. That’s why we’re taking steps now to scale and speed up the global laboratory detection capabilities that are so critically important."
Symptoms of avian influenza in humans include:
- Flu-like symptoms (cough, fever, sore throat, muscle aches);
- Eye infections;
- Acute respiratory distress;
- Viral pneumonia.
Those most at risk are individuals who work outdoors, in environments with exposure to the carriers listed above, and those who travel for business in Asia.
Four antiviral agents – amantadine, rimantadine, oseltamivir and zanamivir – have CDC approval for treating avian influenza. The U.S. government has ordered two million vaccine doses to protect against known avian flu strains. The CDC continues to work on developing additional antiviral agents that will counteract influenza A.
Source: Centers for Disease Control