ContagionLive Video at the link – The origins of the recent H5N1 (avian flu) case in Texas remain unknown, but a researcher offers insights into transmission between animals and humans, the likelihood of more cases, vaccine availability, and treatment.
Earlier this month, the first human case of avian influenza A (H5N1 this year) in the United States was reported.1-3 The person became infected following contact with dairy cows presumed to be infected with avian influenza. The person’s primary symptom has been conjunctivitis and is being treated with an antiviral. The person was told to isolate while in recovery. As of today, there is just 1 isolated case in Texas.
It remains unclear as to how the Texas case happened. Richard Webby, PhD, director of the World Health Organization Collaborating Centre for Studies on the Ecology of Influenza in Animals and Birds and Department of Host-Microbe Interactions, Division of Virology, St. Jude Children’s Research Hospital, says that if you make the assumption there were sick birds nearby, somehow cows got infected and then likely passed the virus along to the person in Texas.
Overall these are wild, migratory birds that might be traveling great distances and could be infected from hosts thousands of miles away.
According to the Centers for Disease Control and Prevention (CDC), the general public should avoid unprotected exposure to sick or dead animals including wild birds, poultry, other domesticated birds, and other wild or domesticated animals (including cattle), as well as with animal carcasses, raw milk, feces, litter, or materials contaminated by birds or other animals with confirmed or suspected HPAI A(H5N1)-virus infection.3,4
People should not prepare or eat uncooked or undercooked food or related uncooked food products, such as unpasteurized (raw) milk, or products made from raw milk such as cheeses, from animals with confirmed or suspected HPAI A(H5N1)-virus infection.
Webby has been involved in research around avian influenza ecology, influenza vaccination, and influenza virus pathogenicity. He explains transmission is a 2-step process where it goes first from birds to humans, and then from human to human. It is the latter that is the more serious, concerning threat.
“When we think about this from a virus perspective, there does seem to be 2 different barriers to this virus, getting into humans—that’s first,” Webby stated. “So, bird to human is a little bit lower [transmission] than that second, which is the human-to-human transmission. But now, that’s why we get a little bit worried when we see mammals infected with this virus…In that environment, that’s where we think the virus is going to get the most chances to make the changes, it needs to successfully go human to human.”