The largest mumps outbreak ever recorded in Arkansas has surpassed 2,300 cases, but there are signs it is slowing down, according to state health officials.
“The number of new cases per day has decreased in the last few weeks,” the Arkansas Department of Health (ADH) said in a statement to Infectious Disease News. “We are not yet sure how the Christmas and New Year’s holidays may impact the outbreak, but we are hopeful that it will continue to slow down.”
According to the ADH, the outbreak has largely affected school-aged children who have been fully immunized. The outbreak coincides with a nationwide surge in mumps cases this year, with 46 states and the District of Columbia reporting more than 4,200 cases, according to the CDC — the most in a decade.
As of Dec. 28, there were active mumps cases in nine Arkansas counties, the ADH reported. The outbreak is currently impacting 51 workplaces, 44 schools, five colleges or vocational schools — including the University of Arkansas — and five private schools.
Any children who have an MMR vaccine exemption are being required to stay home from school for 26 days after the date of their exposure.
According to the ADH, the outbreak continues to be focused in the northwestern part of the state. Overall, 2,368 patients in 20 counties — 65% of them aged younger than 17 years — have either displayed symptoms of mumps or had their cases confirmed by a laboratory since the outbreak began several months ago.
Some 90% to 95% of school-aged children and 30% to 40% of adults involved in the outbreak have been fully immunized, the ADH said. According to the CDC, receiving two doses of the MMR vaccine is 88% effective at preventing infection.
Mumps is spread through saliva or mucus and causes symptoms that include puffy cheeks and swollen and tender salivary glands. Most people recover completely within a few weeks.
Only a few patients during the Arkansas outbreak have experienced complications such as swelling of the brain or testicles, according to the ADH — an indication that even though some vaccinated patients are being infected, they are experiencing a mild form of the disease, the department said.
“This outbreak will end. We just cannot predict with certainty when that will be,” the ADH told Infectious Disease News. “We won’t know for sure it has ended until at least a month has passed with no new cases because of the long incubation period of mumps.” – by Gerard Gallagher