<prompt> A 20-year-old woman complains of headache and discomfort in both sides of her jaw. Physical examination reveals enlarged parotid glands that are slightly tender on palpation. There is reddening of the orifice of Stensen duct on intra oral examination; her temperature is 38.3degC, and the pulse rate is 80min. Laboratory data show hemoglobin 14 gdL; hematocrit 40; WBC 11000mL, with 33 segmented neutrophils, 7 monocytes, and 60 lymphocytes. Which of the following diagnostic tests will help to confirm the diagnosis of epidemic parotitis?single blood sample for a specific immunoglobulin G IgGblood cell countblood culturesingle blood test for a specific immunoglobulin M IgM  <response>: A single test revealing a specific IgM antibody can confirm the disease. Acute and convalescent titers of specific IgG antibodies will also confirm the diagnosis of mumps. Urine, saliva, and throat swabs will grow the mumps virus, but blood does not. Salivary amylase is elevated but is relatively nonspecific. Of course, a typical presentation during an epidemic probably does not require any confirmatory tests. Sporadic cases require more active confirmation. Other causes of parotitis requiring specific treatment include calculi, bacterial infections, and drugs. Tumors, sarcoid, TB, leukemia, Hodgkin disease, Sjogren syndrome, and lupus erythematosus can also cause parotid enlargement. 