Missouri Health Worker Who Contacted Bird Flu Patient Develops Symptoms, US Officials Report

By Julie Steenhuysen and Bhanvi Satija

A second healthcare worker in Missouri, who had contact with a hospitalized patient infected with bird flu, has developed mild respiratory symptoms but has not been tested for the virus, according to U.S. officials.

The total number of individuals who came into contact with the hospitalized bird flu patient and subsequently showed symptoms has risen to three. Fortunately, all three individuals have since recovered.

The other two symptomatic cases include one healthcare worker who tested negative for influenza and a household contact of the patient, who developed symptoms simultaneously but was never tested.

Unlike previous bird flu cases reported in the U.S. this year, the Missouri patient had no known contact with infected animals, which raises concerns that the virus being observed in dairy cattle might have mutated, potentially allowing for easier transmission among humans.

Officials from the CDC indicated in a briefing on September 12 that they have not established whether the Missouri case is linked to the virus affecting dairy cattle in the U.S.

Missouri’s health department is spearheading the investigation with support from the CDC. State officials have mentioned they are considering taking blood samples to check for antibodies that may indicate prior exposure to bird flu. The CDC plans to offer serologic testing to the second healthcare worker involved.

Epidemiologist Caitlin Rivers from Johns Hopkins Center for Health Security emphasized the importance of the blood test results, stating, "We’ll need the serology results to assess whether this is evidence of H5 transmission." She also pointed out that the high levels of COVID-19 activity in August could lead to confusion with symptoms.

Infectious disease expert Michael Osterholm from the University of Minnesota noted that the symptoms could be attributed to various respiratory illnesses.

The confirmed bird flu case in Missouri involved a patient with underlying health conditions who was hospitalized and tested for influenza as part of their medical evaluation. It remains uncertain whether the patient’s symptoms were derived from their existing health issues or from the flu itself.

This Missouri case marks the 14th instance of bird flu diagnosis in the United States this year, with the previous 13 cases linked to poultry or dairy farm outbreaks. Since March, bird flu has infected over 200 dairy herds across 14 states, according to data from the U.S. Department of Agriculture.