Notes from the Field: Complications of Mumps During a University Outbreak Among Students Who Had Received 2 Doses of Measles-Mumps-Rubella Vaccine — Iowa, July 2015–May 2016

Mumps Outbreak in a Highly Vaccinated University-Affiliated Setting Before and After a Measles-Mumps-Rubella Vaccination Campaign—Iowa, July 2015–May 2016

“…Parotitis and fever were present in 280 (98%) and 160 (56%) cases, respectively. Complications included meningitis (n = 1), transient hearing loss (n = 3), orchitis (n = 15), and mastitis (n = 2) [20]. Median illness duration, defined as time from symptom onset to full resolution, was 8 days (interquartile range [IQR], 6–10 days), and median period of self-isolation after diagnosis was 6 days (IQR, 5–7 days).…”

Upward Trends of Parotitis and Mumps in Atlanta over a Decade

“…1,18,19 In the post-vaccine era, rates of orchitis ranged from 3.3% to 10% and pancreatitis and encephalitis rates are less than 1%. 1,14,20 None of these complications were observed in our cohort over a decade. One patient with mumps and 1 patient with parotitis (not tested for mumps) had serious complications of airway impingement requiring a PICU admission, which serves as a reminder than parotitis can have serious consequences in rare instances.…”

“…12 Data suggests that contraction of mumps may be associated with close living situations. 13,14 The most likely explanation for mumps cases in previously immunized persons may be secondary vaccine failure, or waning immunity. Data from a recent study suggest that specific immune outcomes may wane at different rates and highlight our currently incomplete understanding of protective immune responses to mumps and measles.…”

Repeated introductions and intensive community transmission fueled a mumps virus outbreak in Washington State

“…Mumps has historically caused outbreaks in communities with strong, interconnected contact patterns (Barskey et al, 2012;Fields et al, 2019;Nelson et al, 2013), and in dense housing environments (Snijders et al, 2012), highlighted most recently by outbreaks in US detention centers (Lo et al, 2021). In 2016, most outbreaks in the US were associated with university settings (Albertson et al, 2016;Bonwitt et al, 2017;Donahue et al, 2017;Golwalkar et al, 2018;Shah et al, 2018;Wohl et al, 2020), including a separate, smaller outbreak in Washington State associated with Greek housing (Bonwitt et al, 2017). Outside of university settings, other outbreaks in 2016 were reported within close-knit ethnic communities (Fields et al, 2019;Marx et al, 2018).…”

“…Like with other recent mumps outbreaks, most Washington cases in 2016/17 were vaccinated. Unusually though, while most US outbreaks in 2016/2017 were associated with university settings (Albertson et al, 2016;Bonwitt et al, 2017;Donahue et al, 2017;Golwalkar et al, 2018;Shah et al, 2018;Wohl et al, 2020), incidence in Washington was highest among children aged 10-18 years, younger than expected given waning immunity. The outbreak was also peculiar in that approximately 52% of the total cases were Marshallese, an ethnic community that comprises ~0.3% of Washington's population.…”