Abstract: Objective To analyze the epidemiological characteristics and trends of mumps in Shandong Province from 2005 to 2021, so as to provide reference for the prevention and control of this disease. Methods The monthly incidence data of mumps were collected. The age and vaccination status of the patients were descriptively analyzed. The trend was analyzed with seasonal index and circular distribution method. Results There were 158,271 cases of mumps in Shandong Province from 2005 to 2021. From 2011 to 2013, the incidence was high, with children and adolescents under the age of 20 accounting for a large proportion of the cases. After 2014, more than 90% of residents were immunized. The seasonal index was >100% in January and April-July from 2005 to 2010 and from 2014 to 2021, and >100% in January, April-July and December from 2011 to 2013. Based on the circular distribution results, the peak day from March to August was May 31, and the peak period was May 12 to June 19; the peak day from September to February was December 18, and the peak period was from November 30 to January 3. The peak period of mumps was the longest from 2011 to 2013, and the shortest from 2014 to 2021. Conclusion The incidence of mumps in Shandong Province showed a decreasing trend from 2005 to 2021. Children and adolescents aged 5-14 years are the key population of the disease. Vaccination can effectively prevent the occurrence. It is still necessary to supervise and control mumps every year, and targeted measures should be taken in the year of high incidence.

Key words: Mumps, Incidence, Seasonal index, Circular distribution method, Seasonal