Federal health officials say they haven’t been able to pinpoint how a person in Missouri was infected with bird flu, the 14th case in the U.S. this year but the first that appears not to involve animal exposure.
“Our influenza surveillance system is designed to find needles in haystacks,” Nirav Shah, principal deputy director at the Centers for Disease Control and Prevention, told reporters Thursday. “In this case, we found such a needle, but we don't know how it got there.”
CDC is classifying the virus the person had as an H5 virus related to the H5N1 strain found in dairy cows in 14 states. However, the agency has been unable to fully characterize the genetic sequence because of low levels of viral RNA in the person.
“We have not been able to generate a full flu genome,” Shah said. “The data that we do have and that have been generated thus far show an H5 virus that is closely related to the H5 virus circulating among dairy cows.”
Shah said there was no evidence the individual who was infected had “direct contact with animals” or consumed raw milk. The person was given flu medication and has recovered.
CDC insists the risk to the general population of being infected with avian flu is low.
Also on the call, USDA's deputy undersecretary for marketing and regulatory programs, Eric Deeble, said testing conducted so far has confirmed that three of the eight dairy herds infected in California “were found to have the same H5N1 variant as that found in other states” – genotype B3.13.
“This variant is unique in that it has only, to our knowledge, been transmitted between herds through the movement of animals or individuals and equipment,” Deeble said. “We don't see anything in the sequence that would indicate that it was spread by wildlife or migrating birds.”
However, he emphasized, “We don't know the answer yet. We do know that [the California Department of Food and Agriculture] is working very hard to trace this back. … Now it becomes increasingly complex to figure out what, or who, or how, the virus might have been introduced into California, and where it might have come from.”
For more news, go to www.Agri-Pulse.com.
