Missouri Health Worker Who Came into Contact with Bird Flu Patient Develops Symptoms, US Officials Report

By Julie Steenhuysen and Bhanvi Satija

A second healthcare worker in Missouri who interacted with a hospitalized patient infected with bird flu has developed mild respiratory symptoms, although they were not tested for the virus, U.S. officials reported on Friday.

The total number of individuals in contact with the hospitalized bird flu patient who exhibited symptoms has risen to three, but all have since recovered. Among the other two symptomatic individuals is a healthcare worker who tested negative for influenza and a household contact of the patient who experienced symptoms simultaneously but was never tested.

In contrast to previous bird flu cases reported in the U.S. this year, the Missouri patient had no known contact with infected animals, raising concerns that the virus currently affecting dairy cattle may have mutated, allowing for easier transmission among humans.

Officials from the CDC indicated in a recent briefing that they have not been able to determine whether the Missouri case is connected to the virus infecting dairy cattle in the U.S. Missouri officials are leading the investigation into the bird flu case with remote support from the CDC.

State health officials mentioned that Missouri is considering taking blood samples to check for antibodies indicating past exposure to bird flu. The CDC plans to provide serology testing to the second healthcare worker involved.

Caitlin Rivers, an epidemiologist from the Johns Hopkins Center for Health Security, highlighted the importance of the blood test results. “We’ll need the serology results to assess whether this is evidence of H5 transmission,” she noted, adding that it might be challenging to differentiate symptoms from COVID-19, which was also prevalent during August.

Michael Osterholm, an infectious disease expert at the University of Minnesota, suggested the symptoms could be indicative of “any number of respiratory illnesses.”

The confirmed case in Missouri marks the 14th instance of bird flu diagnosis in the United States this year. The previous 13 cases were associated with farm workers and linked to outbreaks on poultry or dairy farms.

Since March, bird flu has affected over 200 dairy herds across 14 states, according to data from the U.S. Department of Agriculture.