The Arkansas Department of Health (ADH) has declared the end of the recent mumps outbreak in the state. The last confirmed case was on July 13, 2017. The number of infections in the state has returned to the baseline (non-outbreak) levels.
The ADH began investigating the outbreak of Mumps in August of 2016. There were 2,954 total cases between August 2016 and August 2017. The typical yearly case count is between one and six. This outbreak was the second largest outbreak of mumps in the United States in the last 30 years. Several other states are currently experiencing outbreaks.
“ADH staff worked closely with local affected communities, particularly schools, churches, physicians, and businesses, to coordinate resources,” said Dr. Dirk Haselow, ADH State Epidemiologist. “This collaborative effort was key in bringing the year-long outbreak to an end.”
According to the Centers for Disease Control and Prevention (CDC), mumps is no longer common in the United States. Annually, cases can range from a few hundred to a few thousand. For example, in 2016, there were approximately 6,366 cases reported to the CDC, and in 2012, there were 299. Before the United States mumps vaccination program began in 1967, about 186,000 cases were reported each year.
Two doses of the Measles, Mumps and Rubella (MMR) vaccine are considered 88% effective, but outbreaks can still occur in highly vaccinated communities, particularly in close-contact settings. High rates of vaccination can help to protect individuals in communities that are unable to receive vaccines. In addition, the vaccine may still provide a protective effect to those who are vaccinated, and still contract the disease. During this outbreak, ADH observed that very few people ill with mumps experienced complications such as swelling of the pancreas or testicles. In a typical outbreak of this size, 50-100 times more persons with complications due to mumps would be expected; however, in this outbreak, many of those who were vaccinated who contracted mumps only experienced mild disease. The vaccine remains the best protection against the mumps.