Perhaps the only good thing that can be said about the newly emerged highly pathogenic H5 avian influenza viruses in North America is that they don’t seem to be able to infect humans. Researchers from the U.S. Centers for Disease Control and Prevention (CDC) and the U.S. Department of Agriculture just published their evaluation of these viruses' ability to infect humans based on the field exposures to date.
In this study, 164 people who self-reported being exposed to birds infected with H5 strains of avian influenza in 60 separate outbreaks in 13 U.S. states were asked by local health departments if they experienced acute respiratory infection within 10 days of exposure to the infected birds. Signs and symptoms considered compatible with avian influenza infection in humans were eye tearing, irritation or redness, fatigue, muscle or body aches, headache, nausea, vomiting, diarrhea, stomach pain, and joint pain.
Five individuals reported having had an acute respiratory infection within 10 days of exposure and respiratory swabs were collected from them. The swabs were tested using reverse transcription polymerase chain reaction to look for evidence of H5 avian influenza infection, and none was found. The researchers conclude that these results suggest that there is currently “a low risk for animal-to-human HPAI H5 virus transmission” for the strains that have emerged in North America over the last year.
Given the fact that 252 people in Egypt have been infected with the H5N1 Asian strain of avian influenza since 2010, and 87 of these people have died, the news from this research is good news for everyone.
I have written a lot about the North American avian influenza situation over the last few months and the monetary cost to the poultry industry and society of these outbreaks. But, it is important to also remember the negative impact the avian influenza virus could have on human health. Vietnam, Egypt and Indonesia have had 167, 114 and 64 human deaths, respectively, attributed to H5N1 Asian virus strain since 2003. Eradicating these strains of avian influenza isn’t just a poultry trade issue or a matter of economics; it is also a human health issue. Poultry producers and processors must work together to find solutions that will eliminate these strains of the virus. We can’t sit around and let the viruses have millions or billions of more chances to mutate into versions that are better adapted to infect humans. Loss of human lives and the resulting loss of confidence in the safety of poultry products would cost far more than control.