THURSDAY, Aug. 22, 2019 (HealthDay News) -- Some cities in Texas are susceptible to measles outbreaks, according to a study published online Aug. 21 in JAMA Network Open.
David R. Sinclair, Ph.D., from the University of Pittsburgh, and colleagues simulated measles transmission in the Texas population using a synthetic population of Texas. Real schools were represented and the 2018 vaccination rate of each school was applied to a simulated hypothetical equivalent. The outcomes of further decreases in vaccination coverage were estimated using additional simulations in schools with populations that are currently undervaccinated.
The researchers found that the median number of cases in large metropolitan areas was typically small at 2018 vaccination rates, varying from one to three cases. In both the Austin and Dallas metropolitan areas, the upper limit of the distribution of plausible outbreaks exceeded 400 cases. In schools with undervaccinated populations in 2018, decreases in vaccination rates correlated with exponential increases in the potential outbreak size: A 5 percent decrease in vaccination rate correlated with an increase of 40 to 4,000 percent in the potential outbreak size. A mean of 64 and 36 percent of cases occurred in students for whom a vaccine had been refused and in others, respectively.
"If the vaccination rate among students in Texas continues to decrease in schools with undervaccinated populations, the potential number of cases associated with measles outbreaks is estimated to increase exponentially," the authors write.
Two authors disclosed financial ties to the medical technology industry.