As Thanksgiving draws nearer in the United States, turkeys, ducks and geese on a number of farms in the United Kingdom may have been exposed to the H5N1 strain of influenza, more commonly known as avian or bird flu.
As a precautionary measure, thousands of the birds are being slaughtered to stop the spread of the virus. Initial reports suggest that the virus entered the UK from migratory birds.
This week I spoke with Associate Professor of Environmental and Population Health at the Cummings School of Veterinary Medicine Joann Lindenmayer, an expert in veterinary public health and public health surveillance. I sought to better understand the situation on the other side of the pond and to learn what the Cummings School is doing globally.
Jamie Bologna: In the UK, they are slaughtering the turkeys to prevent the spread of the virus. I can't help but think about Thanksgiving coming up and the turkey sales here in the U.S. Is this something that American consumers should be worried about?
Joann Lindenmayer: Right now, this highly pathogenic avian influenza is not here among the domestic poultry populations.
Typically, domestic poultry produced for widespread consumption [are] produced by highly commercial establishments that employ very high bio-security measures, so there is no connection with wild birds. Now, [in the case of] this outbreak in Britain, apparently the birds were being raised free-range, and so there is a potential connection there with wild birds. And while that's still not established, that's what they are thinking...
At this point in the United States, I don't think we have any concerns about it affecting Thanksgiving turkeys this year. ... We're pretty secure right now, so I don't think it could be a problem for next week, but I can't say the same thing for next year.
JB: Are there migratory birds that fly across the Atlantic that could pose a threat to the U.S.?
JL: Well, absolutely. Wild birds are susceptible to carrying the virus without being affected by it. In general ... they seem to be able to be infected with the virus without [showing the] clinical signs. They do shed the virus in their feces. That has been the concern, since these birds do migrate.
JB: There are reports of an H5N1 influenza outbreak in the UK. What does that even mean?
JL: It is helpful to distinguish between what's called bird flu and what's standard human influenza (the flu), which people get every year. The type of influenza that circulates, for example, in the United States from November to about February or March is a type that actually is very well adapted to humans.
Every year there are about 40,000 people in the United States that die from that. ... The bird flu, which is H5N1 and isn't normally transmitted to humans, is a type that's found in [birds] far more commonly. There have only been around 300 human deaths worldwide [as a result of H5N1].
Every year the human type of flu causes probably hundreds of thousands of deaths worldwide. The potential, however, for the bird flu to become a pandemic is what everybody is worried about.
JB: What about the situation in Britain right now? They've been killing thousands of poultry. Does that stop the spread of the virus?
JL: What they'll do is kill the infected flocks because they're probably harboring viruses, and then they establish a surveillance zone around [the farm], a three-kilometer quarantine zone and then a 10-kilometer surveillance zone. ...
Up until this point, there [has] always been a concern that it is going to be transmitted by wild birds. As it turns out, most of the cases ... have been transmitted from far places by human vectors: by trucks, by people, by people bringing birds or bird products into other places.
JB: How is the virus spread to humans?
JL: It is not always clear. In cases where they have been able to actually establish an association or a connection, there has been a close connection with people who are poultry workers who have very close contact ... with poultry.
In Hong Kong, it has been [found] in people who have actually worked slaughtering poultry in live bird markets. So again, [these are] people who are in very close contact either with poultry respiratory secretions or [with] fecal secretions. The fecal route might be more important for some of these migratory birds.
JB: What is the Cummings School doing about the avian flu?
JL: Actually, we're doing quite a bit. Our department has a staff of eight veterinarians at this moment; they are subcontracted to the [Food and Agriculture] Organization of the U.N. They are working in Indonesia to train and establish what we call "participatory disease surveillance and response teams."
These teams are Indonesian veterinarians and agriculture and extension agents. ...Right now, there are over 1,200 people on teams who have been trained and are actually in the field doing surveillance for avian influenza in Indonesia.
Jamie Bologna is a senior majoring in political science and Spanish. He can be reached at james.bologna@tufts.edu.
