Measles Outbreak in Minnesota (2017): Roles of an Immunization Information System

Abstract

The Minnesota Department of Health used its Immunization Information System—the Minnesota Immunization Information Connection—to respond to an outbreak of measles in the state in 2017 by assisting with the exclusion of unvaccinated exposed individuals from public activities, providing members of the public with their immunization records, and monitoring measles, mumps, and rubella vaccine uptake. Use of the Immunization Information System was found to be an efficient and sustainable tool in responding to the outbreak.

In response to an outbreak of measles in Minnesota in 2017, staff at the Minnesota Department of Health’s (MDH’s) Immunization Information System (IIS)—the Minnesota Immunization Information Connection (MIIC)—used already available data and tools to facilitate the public health response.

INTERVENTION

The goals of using MIIC in MDH’s response were to assist public health department workers in excluding unvaccinated individuals exposed to measles from childcare, school, work, and other activities; provide members of the general public with rapid access to their consolidated immunization record; and monitor measles, mumps, and rubella (MMR) vaccine uptake over the course of the outbreak in relation to outbreak-specific recommendations for measles vaccination.

PLACE AND TIME

This response took place between April and August 2017. Although the response was statewide, many activities focused on Hennepin County, Minnesota, the hub of the outbreak.

PERSON

Minnesota experienced 75 measles cases between April and August of 2017. Four of 87 (4.6%) counties statewide reported at least one outbreak-associated case; 66 (88%) cases were in Hennepin County; 61 (81.3%) cases were in the Somali American community; and the median age of all cases was two years.¹ There were more than 8500 known exposed contacts.

PURPOSE

The purpose of MIIC and MDH’s intervention was to reduce the outbreak response time of state and county health department workers, so that the outbreak could be contained more quickly and the effects of the outbreak on the public lessened.

IMPLEMENTATION

MIIC was established in 2002 as a statewide IIS maintained by the MDH’s. It contains consolidated vaccination records for Minnesota residents. MIIC’s goal is to support immunization practices, monitoring, and improvement for health care providers, nursing homes, schools, child care centers, and pharmacies. MIIC has a rapid look-up tool that allows users to upload a list of individuals and receive their immunization records en masse.

Identifying Unvaccinated Exposed Contacts

When a case of measles was suspected or confirmed, MDH identified the infectious period for the ill individual, determined who had been exposed during the infectious period (e.g., at childcare or in a clinic), and used the rapid look-up function in MIIC to receive immunization records for all exposed contacts with MIIC records. Using this feature allowed MDH staff to determine who was undervaccinated and focus staff resources appropriately. Unvaccinated contacts were informed that they needed to stay home and not go to childcare, school, or work.

Immunization Records for the Public

Members of the public have been able to request their consolidated immunization record by telephone since 2013 or by REDCap survey since 2015; this service was available without interruption during the 2017 outbreak. MIIC staff respond to these requests in 3 to 5 business days, sending the records by US mail, fax, or secure e-mail.

Monitoring Vaccine Uptake

Weekly during the outbreak, MIIC staff used the IIS to monitor the number of MMR doses administered. To identify Somali children for MMR vaccination rate comparison, we matched birth certificate data obtained from MDH’s Office of Vital Records to immunization records. After the outbreak, we obtained numbers for MMR doses entered by week for 2016, 2017, and 2018.

EVALUATION

Using an IIS to look up immunization records to prioritize unvaccinated individuals was more efficient than the prior practice of contacting every exposed individual, obtaining permission to contact their health care provider, and calling the provider for the immunization record. On average, looking an individual up in MIIC took five minutes, whereas contacting a provider and obtaining a record took an hour. With an estimated 90% of records being found in MIIC and 10% requiring health care provider contact, MDH determined that more than 1000 hours of staff time and more than $25 000 in salary were saved by using MIIC over the course of the outbreak.²

Public record requests increased during the outbreak, as schools, child care centers, and other organizations sought to confirm the vaccination status of their students and employees. From January through March 2017, MDH received an average of 135 record requests per week. This rose to 282 requests per week in April, May, and early June (a 100% increase). The second quarter of 2017 also saw MIIC’s highest ever total number of public record requests, topping the previous highest total by more than 1000 requests. During the outbreak, MDH staff found 94% of 6980 requested records in MIIC and sent them to the requestors in 2 to 5 business days (Figure 1).

FIGURE 1—

Record Requests Made via Minnesota Department of Health’s Minnesota Immunization Information Connection Record Request Hotline or the Online REDCap Form: Minnesota, 2014–2018

Note. Although record requests have generally increased over time, the service saw a disproportionate increase during the 2017 measles outbreak in quarters 2 and 3.

Analysis of MMR immunization rates in the Somali community showed in increase in MMR vaccination by aged two years compared with 2016 (58.9% vs 42.1%). Unfortunately, when MIIC staff looked at the Somali MMR vaccination rate in 2018, it had declined to 55.4%.

ADVERSE EFFECTS

Few challenges were reported. Occasionally inaccurate MIIC records were found—Somali naming conventions and Minnesotan lack of familiarity with them meant that immunizations were occasionally assigned to the wrong person, creating further follow-up work. Increased awareness of these issues will hopefully reduce incidents in the future.

SUSTAINABILITY

Using IISs in outbreak scenarios is an increasingly viable strategy. They contain consolidated immunization records that save time for public health workers; the Centers for Disease Control and Prevention has even explicitly outlined “control and management of vaccine-preventable disease outbreaks” as one of the goals for immunization programs.³

PUBLIC HEALTH SIGNIFICANCE

Responding to an outbreak can strain the capacity of state and local health departments as well as health care facilities. Our experience using MIIC in the public health response to a measles outbreak in Minnesota demonstrates that use of an existing IIS during a vaccine-preventable disease outbreak can enable

• •public health workers to efficiently triage exposed contacts who may require exclusion from childcare, school, work, or other activities;
• •the public to swiftly obtain their personal immunization records; and
• •public health staff to monitor vaccine uptake in response to outbreak-specific recommendations for vaccination.

These interventions facilitated by an IIS enhance public health capacity to implement an effective response to an outbreak of a vaccine-preventable disease and reduce the time and financial resources demanded of public health staff and health care responders to do so.