Avian influenza, commonly known as bird flu, made headlines over winter break when the Iowa Department of Health and Human Services on Dec. 20 reported its first case infecting a human.

Mike Pentella, professor of epidemiology in the University of Iowa College of Public Health and director of the State Hygienic Laboratory at the UI, explains that bird flu is a disease caused by certain influenza viruses that usually spread among birds, not humans, and that public health surveillance is critical to prevent its spread. 

Q: How does bird flu spread, and what species are most at risk? 

A: Wild birds are natural carriers of avian flu and can spread it to poultry. Domestic chickens and turkeys are the most susceptible and get very ill. Waterfowl, including geese and ducks, can be asymptomatic carriers but will sometimes get very ill. Other birds that we usually see in our yards, such as robins and blue jays, are not commonly infected or a source of human exposure.

Q: How can we prevent bird flu from spreading to humans and other animals? 

A: Prevention ranges widely. For example, in poultry, culling is the most likely prevention method because avian flu spreads so quickly through the flock and birds succumb within hours. This method, however, has a very negative impact on the poultry industry because of the decline in the poultry population due to infections. Culling results in a decline of poultry product availability. The U.S. is rebuilding a stockpile of bird flu vaccines for poultry that matches the strain of the virus circulating in commercial flocks and wild birds.

For humans, avoiding direct contact with sick or dead birds is most important. If contact is unavoidable, use personal protective equipment when handling birds. To avoid any type of flu, regular hand-washing and vaccination is important.

Q: How concerned should the general public be about bird flu? 

A: At this time, there is no reason for public concern. The situation is being closely monitored. The low numbers of human cases of avian influenza, only around 65 cases in the U.S. at this time, indicates that the virus is not successfully spreading into the human population. However, influenza viruses mutate easily and could become more infectious to humans. That is why public health surveillance is critical. If a new strain develops, preventing a spread to others is vital.

Q: What are the long-term implications of bird flu for public health and wildlife? 

A: The situation with avian influenza demonstrates the importance of conducting research regarding influenza transmission and prevention. An improved influenza vaccine that protects against all subtypes and does not need to be repeated annually would be a tremendous advantage for us and greatly reduce the threat of emerging influenza viruses.