The United States is on pace to have the worst measles outbreak since 1994, with 555 cases across 20 states since Jan. 1 and four confirmed cases in Santa Clara County, public health officials said Tuesday.
Calling it a major public health concern that strains county resources, Public Health Officer Sara Cody said the country is "swimming in measles," including 21 cases in California, eight of which are in the Bay Area. Unlike places like Brooklyn, which are experiencing localized outbreaks, the four cases in Santa Clara County all appear to be "independently imported," meaning they likely originated from measles outbreaks elsewhere in the world and were not spread within the county.
Unlike past cases, which prompted county health officials to list all of the potential dates, times and places that residents could have been exposed to measles, the latest confirmed case came with a short statement by the Santa Clara County Public Health Department saying that the public health risk is "very low."
Four cases -- three of which were found in adult patients and one in a child under age 18 -- may not seem like much in a county of nearly 2 million residents, but Cody said investigating each case is "incredibly resource intensive" because of the sheer size of the county and the potential for contact with the infection.
The last big uptick in measles was in 2014, when there were 667 cases in the United States over the course of the whole year. At 555 cases as of the first week of April, the country is slated to quickly outpace that number.
At a recent county Health and Hospital Committee meeting, Cody said she is "very concerned" about preserving Santa Clara County's high vaccination rates against all preventable diseases, particularly measles because it is so highly contagious. Parents can no longer cite personal belief exemptions to avoid the Measles, Mumps, and Rubella (MMR) vaccine for their children, but some physicians are exploiting a loophole by signing off on fictitious medical exemptions.
"There are some providers, who are known to the community who don't want to vaccinate their child, that will sign off on their medical exemption," Cody said.
Although some school districts in Santa Cruz and Marin counties saw a decline in vaccinations in recent years, Mountain View's track record remains solid. Mountain View Whisman School District's MMR vaccination rates fall anywhere from 95% at Castro Elementary School to 99% at Huff Elementary and Crittenden and Graham middle schools, which is consistent with the rate at schools in the Los Altos School District.
Preschools and child care centers in the city, both public and private, also have MMR vaccination rates in excess of 98%, including the German International School of Silicon Valley, Action Day Primary Plus, the Mountain View Parent Nursery School and Google's child care center on the former Slater Elementary School campus.
Cody said those rates need to remain high in order to protect the small population that can't be vaccinated for a medical reason, particularly infants who don't get their first shot of the MMR vaccine until they are a year old.
"If the people around them are not vaccinated, they can't be protected," she said. "The only way to protect your baby from becoming really ill from measles is to ensure everyone in contact with your baby gets vaccinated."
Information about the measles is available on the county's website.