Case Presentation: A 34-year-old male from Puerto Rico with unclear childhood vaccination history came in to emergency room with bilateral facial swelling noted since awakening. His temperature was 38.1° C with white blood count of 14.2 x10 3/uL and mildly elevated lactate. He was started on broad- spectrum IV antibiotics and maxillofacial CT showed enlargement of both parotid and submandibular glands with mild edema of surrounding fat without mass or sialolith. HIV testing was negative. Amylase level was elevated. Due to fever with parotitis and an unknown vaccine history, mumps was suspected, and droplet precautions were initiated. Neurologic and testicular exam was unremarkable. Mumps titers came back positive. Antibiotics were discontinued and supportive care was provided. Department of Health was contacted as well.

Discussion: Mumps was common in the United States until 1967 when vaccination became routine, but is prevalent in underdeveloped countries with limited access to vaccinations. Occasional outbreaks in unvaccinated populations still occur, so physicians must still know how to recognize the disorder.

Conclusions: Mumps is a highly infectious virus presenting with fever, parotitis (in 95%) and in some cases, meningitis and orchitis. Recognition and prompt isolation is still necessary as outbreaks in the US still occur in non-vaccinated cohorts