Parotitis and influenza: unusual association during 2017, in Santa Fe, Argentina

Parotitis is an acute viral disease characterized by swelling and pain in one or both salivary glands, submaxillary or submental, fever, headache, muscle ache and/or fatigue. To investigate the occurrence of influenza virus infection in parotitis cases in a population of Santa Fe during 2017 and analyze clinical and epidemiological characteristics of the cases. We studied patients with diagnosis of mumps without age restriction, who came for examination from week 26 to the network of clinicians forming the Sentinel Influenza Unit in Santa Fe. Between epidemiological weeks 26 and 44, 22 clinical parotitis cases we enrolled. The influenza virus was detected in 68.2%, influenza A (H3N2) 93%, and influenza B, 7%. The clinical signs of cases were mild, with an average swelling development of 5 days and no complications. 74% presented with influenza-like illness in tandem with parotitis. This study provides evidence that a proportion of children presenting with parotitis had influenza A(H3N2) virus infection. It is necessary to implement systematic surveillance of parotitis associated with influenza and differential diagnosis even in the absence of respiratory symptoms.