Do I spend too much time worrying about stuff like this, or do I not spend enough time on it?
Harris County is one of the nation’s most vulnerable counties to a measles outbreak, according to a new study based on international travel and the prevalence of non-medical vaccine exemptions.
The study, published Thursday in the journal Lancet Infectious Diseases, ranks Harris County as the county 9th most at risk of having clusters of people contract measles, the highly contagious, potentially fatal virus that has re-emerged as a public health threat after having been largely eradicated at the turn of the century. Tarrant and Travis counties also are at high risk of an outbreak, according to the study.
“Texas’ showing is on par with the other 16 states that allow vaccine exemptions for conscientious or personal reasons,” said Sahotra Sarkar, a University of Texas Austin professor and the study’s lead author. “You can expect the state, like other parts of the nation, to see more cases.”
Sarkar said Harris County’s vulnerability is mostly the result of its considerable international travel. The county’s number of non-medical vaccine exemptions was not among the state’s highest in a Texas health department report released earlier this week.
The new study was conducted by Sarkar and a Johns Hopkins University researcher using risk assessment models similar to one they used to correctly predict that Zika, the mosquito-born virus that can cause serious birth defects, would first affect Texas and Florida after it began spreading from the Southern Hemisphere midway through this decade. It also correctly predicted areas already experiencing measles outbreaks, such as Washington, Oregon and New York.
The authors didn’t consider the locations of measles cases already recorded. Instead, they looked at non-medical vaccine exemptions, international air travel and the incidence of measles in countries from which people came to the United States, particularly India, China, Mexico, Japan, Ukraine, Philippines and Thailand. In all, some 112,000 people have been diagnosed with measles outside the U.S. this year, according to the World Health Organization.
Peter Hotez, a Baylor College of Medicine professor of infectious disease and vaccine advocate, called the new study an advance over research he published last year that identified “15 hotspots” of vaccine exemptions among a subset of states. Harris County ranked seventh on that list.
“I think this is a nice refinement on our first attempt,” said Hotez. “It confirms the high risk of Texas counties to measles, something that we’ll need to consider seriously when planning for epidemics.”
It’s not clear what if anything can be done to mitigate this particular risk, so I’m back to wondering how much I should worry about it. Keep working to close the gap in vaccination rates, I guess. It annoys the crap out of me that we have to worry about this sort of thing in 2019, but here we are.