The Oklahoma State Department of Health reports that the number of outbreak-associated mumps cases in the state has risen to 26 in September, with an additional seven cases under further investigation.
The Oklahoma cases center around Enid in Garfield County, and health officials in Arkansas are dealing with a larger outbreak that has afflicted more than 200 people so far.
The outbreaks highlight the continued need for vaccinations in the face of growing skepticism about their benefits.
The vaccine debate
The current mumps outbreak has reignited the debate about the MMR (measles, mumps and rubella) vaccine and autism-spectrum disorders. UK medical journal The Lancet popularly reported a possible link between vaccination and autism in 1999, but that study was later found to be fraudulent.
For parents who might be reluctant to have their children vaccinated, know this: No large-scale epidemiological studies have shown convincing evidence of a correlation between the MMR vaccine and autism. In fact, one of the larger population-based studies of more than 30,000 children done in Yokohama, Japan, where the MMR vaccine was discontinued in 1993 in favor of individual vaccinations, showed that autism rates actually increased in the period after discontinuation.
A serious condition
What is known is that mumps is a highly contagious illness that, although rarely, can lead to significant complications. It usually affects the salivary glands, but the mumps virus can also infect the central nervous system, causing aseptic meningitis or sometimes permanent hearing loss. It can also cause acute pancreatitis after migrating to the GI tract.
Even the bread-and-butter parotitis (salivary gland inflammation) caused by mumps is no laughing matter. Painful swelling of the jaw and neck can be severe, not to mention additional burdens on the health care system and on children or families from missing school or work.
On the cusp of preventing mumps in Oklahoma
Oklahomans actually do a reasonable job when it comes to vaccinating their children.
The MMR vaccine is offered to children in two doses: the first dose at 12 to 15 months of age and the second dose at 4 to 6 years of age. An OSDH survey obtained by NonDoc shows that 90.3 percent of Oklahoma kindergarten students from 2014 to 2015 had completed the full dose of the MMR vaccine series. Of note, that number represents the 96 percent of Oklahoma kindergartners whose schools responded to the survey.
Still, the OSDH graphic above indicates that Oklahoma lags behind the nation as a whole regarding overall vaccination compliance, and Garfield County ranks toward the bottom counties in the state.
But the vaccination itself is not 100 percent effective.
According to the CDC, the MMR vaccine series is about 88 percent effective at preventing mumps. In an interview with The Norman Transcript, Vaccinate Oklahoma spokesperson Dr. Thomas Kuhls reports that immunity in about 90 percent of the population is sufficient to preventing outbreaks. This suggests that Oklahoma is on the cusp of being able to stop major outbreaks in the future.
Looking forward, the challenge will be convincing parents of the remaining 10 percent who are not being vaccinated. Education about the disease and the vaccine is a good first step. The CDC and the Oklahoma State Department of Health websites both offer helpful information about mumps and the MMR vaccine.