According to the Arkansas Department of Health, rates of mumps infections have reached non-outbreak levels. The last confirmed new case of mumps in Arkansas is now nearly two months old, and officials are marking the end of an outbreak that neared 3,000 cases in just about 12 months.
A typical year records between one and six new mumps cases.
State epidemiologist Dr. Dirk Haselow says that the department worked closely with communities affected by the outbreak to keep it under control.
Some communities, such as the Marshallese immigrant population in Washington and Benton counties, experienced much higher rates of infection than others. This isn't due to any genetic susceptibility but rather a culture of living densely in available housing, Haselow said, and any similarly dense population could see heavy contagion.
“This outbreak got big enough where it became very difficult to get ahead of it, so we started to identify groups of people where we were seeing more infections and then offer vaccination clinics ahead of time to try to smother out the transmission, and that helped," he said.
Most of the individuals who contracted mumps had already received both doses (in early childhood) of the measles-mumps-rubella, or MMR, vaccination. Other highly-vaccinated communities across the United States are also experiencing mumps outbreaks.
“Outbreaks of mumps are occurring all around the United States right now in a variety of different population groups, many of whom are similar in age and well-vaccinated,” says Dr. Haselow.
Immunity granted by the mumps vaccine may only last about a decade, after which there is an increased risk of contracting mild cases. However, he also stresses the importance of receiving the mumps vaccination anyway to protect against more severe complications caused by the virus.
“People need to sort of change the way they think about this vaccine. It’s not gonna prevent all mild parotitis. But where it pays off is it prevents serious problems like infertility, meningitis, encephalitis — serious side effects is where it’s very, very effective,” he says.
Arkansas's outbreak was the nation's second worst going back to the 1980s, but very few cases involved severe complications.
The Arkansas Department of Health confirms that the vaccine remains the best protection against mumps.
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