This study was performed to analyze the characteristics of patients with a definitive diagnosis of mumps outside the sentinel surveillance population. Patients aged 15 years or older who visited the otolaryngology department of Yamaguchi Rosai Hospital between October 2015 and April 2017 were included. A definitive diagnosis of mumps was obtained in 8 patients, based on the detection of mumps-specific IgM antibody in the blood. There were 4 male and 4 female patients, ranging in age from 16 to 44 years, with a mean age of 31.4 years. None of the 8 patients had received mumps vaccination. In regard to the swelling of the salivary glands, a single swelling was observed in 4 patients and multiple swellings in the remaining 4 patients. The most commonly affected salivary gland was the left parotid gland (7/8 patients; 87.5%). The complications included hearing loss in 2 of 8 patients, and vertigo and orchitis in one patient each. There were no significant differences in the peripheral blood white blood cell count, serum CRP level, or antibody index between the patients with and without complications. However, the serum amylase level was statistically significantly higher in patients with complications than in those without complications, suggesting the possibility that elevated serum amylase may be marker of the development of complications.
