Using methods that successfully predicted many outbreaks last year, a team of researchers has projected 25 U.S. counties at highest risk for measles.

The scientists from The University of Texas at Austin and Johns Hopkins University also warned of a resurgence of whooping cough — a disease that is especially dangerous for elderly people.

The highest-risk areas that have yet to report a case are near international airports.

In its projections this year and last year, the team identified areas with substantial numbers of unvaccinated children, near international airports that transport travelers from places that also come up short on vaccination. (A recent New York Times article points out that every U.S. measles outbreak since 2000 has begun with an overseas traveler.)

The team published its results this month in The Lancet Infectious Diseases.

According to the new study, the highest-risk areas that have yet to report a case are near international airports. They include Travis County in Texas, Honolulu County, Salt Lake County and multiple Florida counties. Travel from countries such as India, China, Mexico, Japan, Ukraine, Philippines and Thailand appears to pose the greatest measles risk.

A map of the top 25 counties with the highest risk of a measles outbreak.

Adults born before 1957 are considered immune from measles because they were exposed before development of a vaccine. Most people born after that date are considered immune if they were vaccinated or already contracted measles, although some adults vaccinated between 1963 and 1967 received an unsuccessful version of the vaccine and should be vaccinated again.

Meanwhile, the researchers are urging their methods be applied to other diseases anti-vaccination advocates are failing to vaccinate against, including mumps, rubella, and pertussis (aka whooping cough).

“The vaccine avoidance problem is not limited to measles. Pertussis — whooping cough — is another disease making a comeback because of dropping vaccination rates, and we predict serious outbreaks in the U.S. in the near future,” Sarkar said.

Pertussis can cause serious medical problems for elderly adults whose booster shots have waned. Doctors recommend adults receive the booster, called TDap.

More pertussis advice: If your elderly relative has a persistent cough, runs a low fever, coughs up phlegm or displays flu-like symptoms such as nasal congestion or eye irritation, bring them to a doctor.

See the 25 counties at the highest risk for a measles outbreak ranked in order below, and the team’s assessment of each county’s “relative risk” when it comes to the size of the outbreak.

On the subject of relative risk, study co-author Lauren Gardner, an associate professor of civil engineering at Johns Hopkins, told Considerable: “I think it’s easiest to think of it as the relative expected size of an outbreak. So if there were 100 cases reported in Chicago (Cook county), we would expect to see 43 in Los Angeles.”

RankCountyStateRelative Risk
2Los AngelesCalifornia0.432
4QueensNew York0.293
13Multnomah Oregon 0.047
15Essex New Jersey 0.045
17 Hillsborough Florida 0.019
18 San Mateo California 0.019
19 Salt Lake Utah 0.018
20 Suffolk Massachusetts0.017
21 Clayton Georgia 0.013
22 Travis Texas 0.013
23 Hennepin Minnesota 0.012
24 Loudoun Virginia 0.012
25 San Diego California 0.010

Source: The Lancet Infectious Diseases

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