(Bloomberg) -- US health officials didn’t find signs of human-to-human bird flu spread after testing a group of people in Missouri with suspicious symptoms.
Five health-care workers with potential symptoms who were exposed to a bird flu patient didn’t show signs of infection with the H5N1 virus, Centers for Disease Control and Prevention officials said Thursday on a call with reporters. The patient, along with a household contact who also showed signs of possible infection, may have been exposed to the same infected animal, officials said.
Both had similar symptoms and periods of infection, supporting a “single common exposure to bird flu rather than person-to-person spread within the household,” the agency said in a statement.
Bird flu has long been considered a pandemic threat, typically killing more than half of those known to be infected worldwide. Although people who have contracted the strain now spreading in US dairy cows and birds generally have had mild symptoms, health officials remain on the alert for signs of human spread.
New Reports
The CDC confirmed two new human cases of bird flu in Franklin County, Washington, and is investigating five other poultry workers who are presumably positive. The investigation is still ongoing, the agency said.
Of 31 people reported with H5N1 bird flu infections in the US this year, only one — the person in Missouri who remains unidentified — didn’t have known earlier exposure to sick animals. Signs of a mild respiratory infection developed in the health-care workers and a close household contact of that person, leading the CDC to investigate.
While the H5N1 virus is changing, it “has not made the jumps that we’re looking for to be able to spread easily person-to-person or to infect people easily,” said Meg Schaeffer, an epidemiologist with SAS Institute Inc., an analytics firm based in Cary, North Carolina. If that occurs, “that could become a very serious and severe pandemic and that’s what we have to detect in order to protect ourselves.”
The Missouri patient is considered a confirmed case of bird flu infection, the CDC said. While showing some signs of an immune response to H5N1, the household contact didn’t meet the criteria for a case, the agency said.
More than 100 health care workers were exposed to the patient during hospitalization, the CDC said.
--With assistance from Ilena Peng and Riley Griffin.
(Updates with CDC comment, Washington cases from third paragraph.)
©2024 Bloomberg L.P.