The Los Angeles County Department of Public Health has concluded that the measles outbreak in California has been limited to those who are unvaccinated.
After investigating nearly two dozen measles cases, a spokesman from the Los Angeles County Department of Public Health (LACDPH) told numerous news outlets today that the outbreak "has largely been limited to unvaccinated people in a single social group."
Jeffrey Gunzenhauser, MD, MPH, added, “There have been no infections spreading in the general community.” He also noted that none of the infected individuals were able to show proof of vaccination, despite strict California laws that require everyone to be vaccinated regardless of personal and religious beliefs. However, all of the cases reviewed by the LACDPH were individuals older than 12 years of age who would not necessarily have been affected by the new law. Perhaps even more troubling is the idea that children who had not been vaccinated in the fall of 2015 for kindergarten may have, in some instances, continued on to first grade in the fall of 2016 without meeting vaccination requirements due to the timing of the vaccine schedules.
The first cases of measles were diagnosed and reported in early December 2016. The LACDPH does not disclose information pertaining to locations of potential measles exposure unless they deem the information to be necessary in reaching individuals who have potentially been exposed. However, the department has been working to notify organizations and family members who may have been exposed to the infection. In the recent LA outbreak, Dr. Gunzenhauser said, “At least 15 of the LA County patients [diagnosed as of January 24, 2017] either knew one another or had clear social connections.” He added that residents of Los Angeles County who have not yet been immunized can still protect themselves by receiving the measles-mumps-rubella vaccine (MMR) as soon as they can. He continued, “Two doses of MMR [are] highly effective in preventing measles and [are] the best way to prevent disease.”
As of January 26, 2017, Ventura County had also reported a total of five confirmed cases, although the county’s public health officer, Robert Levin, MD, told local news outlets, “My gut tells me we’re on the downslope of this.” Four of the five Ventura cases were in the same household.
According to the Centers for Disease Control and Prevention (CDC), the majority of people who contract measles are unvaccinated. According to CDC researchers, from January 2, 2016 to December 31, 2016, 70 people from 16 states, including California, were reported to have measles. California recently experienced a large outbreak in 2015 stemming from exposure at Disney theme parks from December 17-20, 2014. A team of researchers headed by Jennifer Zipprich, PhD, of the California Department of Public Health reviewed the outbreak during the event and learned that about half of the patients who developed infections were unvaccinated either due to being too young or because of personal beliefs. Fifteen cases in other states were linked to the outbreak as well.
By the time the outbreak was declared over, 145 people had been infected in the United States and the state legislature had set the wheels in motion to pass California SB277, which requires all children to be vaccinated regardless of parents’ preference or personal beliefs before entering public schools, daycare centers, or private schools. Although the CDC was able to declare measles “eliminated” from the United States in 2000 since there were no reported cases of transmission since a year prior, the rate of unvaccinated populations has rendered that classification largely moot. Peter J. Hotez, MD, PhD, dean of the National School of Tropical Medicine at Baylor College of Medicine, warned that the “anti-vaxxer movement” presence in local communities could lead to increasing numbers of unvaccinated children in schools. “We might soon see a return of measles outbreaks,” he warned in a perspective piece published in PLOS Medicine.
California isn’t the only state that has been hit by the measles. A couple of cases have been popping up in New Jersey recently as well. In Passaic County, an unvaccinated seven-month-old infant who had traveled outside of the country has been confirmed to have measles. In addition, an adult male in Hudson County who had also traveled abroad has been confirmed to have the infection. Due to the fact that measles is so contagious, infections can easily result in outbreaks; the CDC implores parents to keep up-to-date on their own MMR vaccinations and to get their children vaccinated as well.