"There has been a resurgence of measles cases, among other vaccine preventable diseases, in the US and other countries in recent years", coauthor Lauren Gardner, an associate professor in the Johns Hopkins Department of Civil Engineering, said in a media release.
The results were published yesterday in the peer-reviewed journal Lancet Infectious Diseases. "It is therefore critical that we proactively identify areas most likely to experience outbreaks to strategically target for surveillance and control".
Only four months into 2019, the number of measles cases reported in the U.S.is "already the highest since measles was declared eliminated in 2000", the report said. Travelers are coming to the US from measles-stricken countries.
To compile the map, analysts counted nonmedical vaccine exemption rates per county and compared those to each county's rate of travel, population size, and proximity to other global measles outbreaks.
The recent spike in cases, the researchers say, is due to reintroduction by global travelers from countries experiencing measles outbreaks, compounded by low-vaccination rates in certain localities, which an increasingly visible anti-vaccination movement fuels.
The report, published Thursday in the journal Lancet Infectious Diseases, said that although Cook County has only reported one case of measles in 2019, the disease could become an issue here because of the presence of Chicago's two major global airports. The study's authors said travel from countries including India, China, Mexico, Japan, Ukraine, Philippines and Thailand appeared to pose the greatest measles risk.
Sarkar adds that policymakers must focus on centers of vaccination resistance, as well as regions with a lot of passenger inflow from affected countries worldwide if there are even small local pockets of unvaccinated people.
"The New York borough of Brooklyn is a ideal example with a large number of unvaccinated members of an orthodox Jewish community even though the overall county vaccination rate is not low", Sakar says.
Other authors on this study include Aleksa Zlojutro of the University of New South Wales Sydney and Kamran Khan of St. Michaels Hospital in Toronto.