The new case, in a Michigan farmworker, did not suggest that bird flu was widespread in people, health officials said, adding that the risk to the general public remained low.
The exact number of chickens, cows and pigs being transported on trucks, ships, planes and trains within the United States is difficult to pinpoint because there is no national system for tracking the movement of livestock.
The Food and Drug Administration said regulators had examined 201 commercial dairy samples, including milk, cottage cheese and sour cream, and had so far not found evidence that potentially infectious virus was on grocery shelves.
The C.D.C. maintained Wednesday that the risk for the public was still low, with no changes in the genetic makeup of the virus that would allow it to spread more easily to or between humans.
Some poultry growers are turning to innovative tactics to protect their flocks, deploying deterrents like drones, air horns, balloons and decoy predators.
Some poultry growers are turning to innovative tactics to protect their flocks, deploying deterrents like drones, air horns, balloons and decoy predators.
Login
