About 6.9% of US measles patients who sought medical care were misdiagnosed at least once in the two weeks before they got the right diagnosis, CIDRAP reports. The Independent reports the same finding, calling it nearly 7 percent.

The study was done by researchers at the University of Iowa. CIDRAP says it was published last week in the journal Infection Control and Hospital Epidemiology.

The team used private and federal insurance records, CIDRAP and The Independent report. They found 4,651 US measles cases from 2001 through 2023. They estimated that 381 of those were misdiagnosed at first.

The mean delay before the right diagnosis was just over four days, CIDRAP reports.

Outpatient settings, such as doctor's offices, made up 81% of the missed cases, CIDRAP reports. Emergency rooms made up 14%, and hospital wards made up 3.9%.

Missed cases were more common in children under 2, CIDRAP and The Independent report. They were also more common in patients who got antibiotics for a breathing illness. The authors said very young children may not be able to describe how they feel, CIDRAP says.

The authors said many doctors may never have seen a case of measles, so they may not think of it, CIDRAP reports. The virus can stay in the air for hours, the authors noted. That makes busy waiting rooms a risk.

“The difficulty in diagnosing measles contributes to disease spread,” the authors said, CIDRAP reports. They argue that doctors should think about testing for measles early in patients with breathing symptoms.

The study comes as cases rise. There have been 4,852 confirmed US cases this year, according to federal data, The Independent reports. That is more than double the 2,289 cases recorded in 2025, it says.

What we know: About one in 14 measles patients in the study was misdiagnosed at least once, mostly in outpatient care.
What we don't: How many extra infections those delays caused, and whether early testing will become standard advice.