Colorado Mumps Outbreak Emphasizes Importance of Community Partnerships in Response Efforts

In January of 2017, the Colorado Department of Public Health and Environment (CDPHE) was made aware of 4 cases of mumps that were epidemiologically linked among individuals who were members of the same church in the Denver Metropolitan area.

The outbreak was observed in a Marshallese community, or in a population of people with ties to the Marshall Islands. The outbreak response is detailed in the US Center for Disease Control and Prevention’s (CDC) latest Morbidity and Mortality Weekly Report.

“Response to this mumps outbreak in a Colorado Marshallese community was facilitated by building relationships with church leaders, leading to early active surveillance, public education, and mumps, measles, and rubella (MMR) vaccination clinics,” the authors write in the report. “These interventions might have contributed to the rapid interruption of transmission and limited spread of mumps to other local communities.”

The cases were first identified as being linked to the church on January 19, 2017, when patient interviews indicated that all of the ill individuals had attended events at the church. Local health departments worked in collaboration to launch an outbreak investigation immediately.

Health officials met with leaders of the church to implement active surveillance measures upon learning that facial swelling—a symptom linked to mumps—was circulating though members of the church community. The church leaders provided health officials with addresses and phone numbers of church members to inquire about vaccination history, occurrence and timing of symptoms, travel history, household visitors, and church attendance.

In total, church leaders provided a list of 21 members to officials, and a total of 17 members—representing 15 households—were responsive. The total number of individuals living in the 15 households was 117.

Health officials conducted interviews with the head of household and received information about 76 individuals. Among the 76, 22 individuals reported attending at least 1 other event at an additional Marshallese church. Additionally, 3 households reported visitors from Arkansas where a concurrent outbreak was occurring in the Marshallese population, including 1 visitor who reported a swollen jaw at the time of visit.

In total, there were 47 outbreak cases—17 confirmed and 30 probable—across 2 counties in the Denver Metropolitan area. A probable outbreak case was defined as the occurrence of mumps-compatible symptoms on or after November 1, 2016, and an epidemiologic link to the Marshallese community. A confirmed case was defined as identification by reverse transcription-polymerase chain reaction or culture in an individual with a probable case.

Among ill individuals, 24 were male (51%), the median age was 20 years, and onset of illness ranged from November 1, 2016, to March 28, 2017. Forty-six cases (98%) occurred in Marshallese persons.

Reported symptoms included parotitis in 47% of individuals, bilateral swelling (22%), jaw pain (74%), malaise (62%), fever (57%), and submandibular swelling (47%).

The authors indicate a challenge was faced in determining MMR vaccination status in the patients. None of the confirmed case patients were able to provide personal vaccination records and 34 of 47 patients did not have doses recorded in the Colorado Immunization Information System.

As part of the outbreak response, health officials met with community leaders who disseminated information about mumps to prevent further transmission. As a result, vaccination clinics were held during the 5 weeks following outbreak identification with the goal of vaccinating all eligible individuals in the area. In total, 164 MMR doses were administered to 126 church attendees.

The outbreak was declared over on May 17, 2017, following 50 days or 2 incubation periods after the last reported case. No serious complications or deaths associated with the outbreak were reported.

The authors listed 3 distinct limitations of the findings. First, vaccination status was determined by information recorded in the Colorado Immunization registry, which likely did not consist of all of the affected individuals’ vaccination records due to the highly mobile population in this area.

Language and cultural barriers may have led to the collection of incorrect information despite the use of interpreters and translated documents. Also, there was uncertainty regarding living arrangements which made the identification of household members a challenge and may have resulted in incorrect estimations of household size.

Overall, the ability to stop the spread of the outbreak by working with community leaders emphasizes the importance of using community partnerships in outbreak situations.