Arizona Measles Outbreak Underscores Importance of Vaccines

A recent outbreak of measles at an immigration detention center in Arizona highlights the importance of “mandatory vaccination programs” in certain “high-exposure risk” facilities and the need for “re-education on the true risks and benefits of vaccination” in light of the still growing “anti-vaccination” movement,” experts tell Contagion.

The outbreak, which started in late May at an Immigration and Customs Enforcement (ICE) facility in Eloy, Arizona, has grown to 31 cases, 9 of whom are employees at the center, at press time. The number of confirmed cases in the outbreak has been attributed to the reluctance of some employees at the center, which holds approximately 1,250 immigrants awaiting court proceedings and/or deportation, to be vaccinated. As reported in The New York Times, the center is operated by Corrections Corporation of America (CCA), a private prison company with more than 300 employees, 100 of whom work at the affected center.

This is believed to be the first measles outbreak at an ICE detention center, although according to Shruti Gohil, MD, MPH, associate medical director for Epidemiology and Infection Prevention at University of California Irvine Health, facilities such as healthcare buildings, prisons, daycares, and schools have long been known as potential “high-exposure” areas. Measles was formally declared as “eliminated” in the United States in 2000, but annual outbreaks have occurred since, typically as a result of cases imported from other countries and transmitted to unvaccinated people.

The Centers for Disease Control and Prevention (CDC) reports that from 2001 to 2012, there were a median of 4 outbreaks and 60 cases reported annually nationwide. In 2015, there was a multi-state outbreak linked to Disneyland in Anaheim, California, in which 111 people were infected. A CDC analysis of this outbreak suggests that the majority of cases involved people who were either unvaccinated or whose vaccination was unknown.

It is unclear how many of the Arizona detention center’s employees had been vaccinated in advance of the outbreak. However, Thomas Schryer, the director of public health for Pinal County, where the center is located, told the Times he was surprised by “failure [of] the organizations that run the facility to make sure their staff was vaccinated.” After the first case was confirmed on May 25 (the identity of the first person to become ill at the facility is still not yet known) and it was clear the outbreak had spread to staff members, local health officials asked CCA executives and ICE officials to provide proof that employees at the center were being vaccinated or had been vaccinated in the past. Although CCA quickly complied, the Times reported, ICE officials said they could not legally compel its employees to do so.

Employees at the center have been offered free vaccination, and all of the immigrants in detention there have since been vaccinated, if they hadn’t been previously. At press time, no one had died in the Arizona outbreak. The last confirmed case was reported on July 2.

According to the World Health Organization, although measles has been eradicated in the Americas, there are still more than 20 million cases reported annually worldwide, and more than 100,000 die from the disease each year. Experts say the virus’ status as eradicated in the Americas is jeopardized by segments of the population who refuse to be vaccinated for political, religious, and/or other reasons. In a survey published July 8 by the journal PLoS One, a “substantial minority” of parent respondents said they had refused (15%) or delayed (27%) measles vaccination for their children.

“The US has eliminated indigenous transmission of measles and we aggressively respond to importations of measles to stop outbreaks, but our public health system depends on people protecting themselves by getting vaccinated,” explained Kimberly Thompson, ScD, professor of medicine at the University of Central Florida in Orlando. “Measles outbreaks are very expensive, both in health cost for the people who develop serious complications, but also financial costs for treatment, public health response efforts, and lost productivity. Until all countries stop measles and we eradicate it, we are vulnerable to importations. We need to support global measles eradication efforts and continue to keep our vaccination rates very high.”

“[A] lesson highlighted here is the critical importance of occupational and public health infrastructure,” Dr. Gohil added. “How well policies and practices within these systems are adhered to can have enormous impact on disease containment and risks for the population at large, and [there is a] need for re-education on the true risks and benefits of vaccination in the context of a growing anti-vaccination movement. [Recent] vaccination campaigns have been so successful that our communities have forgotten how things used to be before the introduction of vaccines.”

Brian P. Dunleavy is a medical writer and editor based in New York. His work has appeared in numerous healthcare-related publications. He is the former editor of Infectious Disease Special Edition.