An unannounced 'patient-zero' drill put US health facilities to the test, and many failed, the article reports.

Actors posed as infected bird flu patients to measure how well clinics handle emerging pathogens.

Fewer than 1 in 10 initial screenings asked about exposure to sick animals.

Actors posing as bird flu patients often did not trigger infection protocols.

Many facilities skipped critical exposure history questions and struggled with basic infection control.

Experts say missing the link between animal exposure and symptoms lets contagious illness slip past the front desk.

Public health agencies are reviewing the data, and regulators plan revised screening guidance for clinics.

Read the full article on the patient-zero drill results and what clinics missed.