The Disneyland Measles Outbreak and California's most dangerous school districts for kindergartners

In late January 2015, a serious outbreak of Measles began in Disneyland in Orange County, California. The Golden State has long been known for its high concentration of parents who have not  vaccinated their children. In some parts of California, vaccination rates have dropped far below the required level to maintain herd immunity. This Silk examines data on the California public school districts and schools with the lowest vaccination rates. You can map them, build charts, and gain a visual understanding of which schools and regions have the lowest rates of vaccination - and therefore present the greatest risk. 

How to Use This Silk: Browse the charts and maps below. Click "Explore" anywhere on the site to go into visualization and filtering mode. Search for individual pages or entities in the top search box.

The Most Dangerous Kindergartens in California -  133 Districts Have MMR Vaccination Rates of 80% or Lower

Page Title
Without Measles, Mumps, Rubella - Percentage
County
Without Measles, Mumps, Rubella - Percentage
Coordinates
Big Sur Unified77%Monterey County77%35.959352,-121.461389
Siskiyou County Office of Education73%Siskiyou County73%41.726562,-122.643713
Nevada County Office of Education72%Nevada County72%38.906426,-121.081317
Southern Humboldt Joint Unified60%Humboldt County60%40.167716,-123.826093
Lagunitas Elementary62%Marin County62%38.007691,-122.672184
Marcum-Illinois Union Elementary53%Sutter County53%38.858474,-121.567125
Mattole Unified72%Humboldt County72%40.290761,-124.169252
Lucerne Valley Unified53%San Bernardino County53%34.420236,-116.776979
Camptonville Elementary45%Yuba County45%39.430875,-121.100589
Burnt Ranch Elementary44%Trinity County44%40.889439,-123.43256
Dehesa Elementary43%San Diego County43%32.779465,-116.832604
Arcata Elementary46%Humboldt County46%40.872587,-124.077619
Butte County Office of Education43%Butte County43%39.513089,-121.609187
Shasta Union Elementary39%Shasta County39%40.646236,-122.478776
Bolinas-Stinson Union46%Marin County46%37.978661,-122.792894
Harmony Union Elementary38%Sonoma County38%38.37543,-122.985795
Spencer Valley Elementary37%San Diego County37%33.108788,-116.648321
Nuestro Elementary36%Sutter County36%39.193928,-121.692378
Dunsmuir Elementary35%Siskiyou County35%41.213522,-122.392429
Sebastopol Union Elementary42%Sonoma County42%38.408936,-122.83482
San Lorenzo Valley Unified38%Santa Cruz County38%37.140875,-122.115279
Mesa Union Elementary42%Ventura County42%34.276591,-119.08335
Mt. Baldy Joint Elementary33%San Bernardino County33%34.25651,-117.606706
Maricopa Unified32%Kern County32%34.990618,-119.264246
Calaveras County Office of Education45%Calaveras County45%38.080814,-120.555233
Julian Union Elementary45%San Diego County45%33.047023,-116.459073
Hickman Community Charter32%Stanislaus County32%37.607709,-120.731277
Happy Valley Elementary47%Santa Cruz County47%37.046154,-121.981377
Twin Ridges Elementary46%Nevada County46%39.405197,-120.760479
Monte Rio Union Elementary38%Sonoma County38%38.442765,-123.089021
El Dorado County Office of Education53%El Dorado County53%38.722023,-120.866814
Big Springs Union Elementary29%Siskiyou County29%41.581443,-122.380705
Waterford Unified30%Stanislaus County30%37.661768,-120.725174
Hughes-Elizabeth Lakes Union Elementary36%Los Angeles County36%34.664086,-118.497151
Pacific Elementary27%Santa Cruz County27%37.1246,-122.245267
Bonny Doon Union Elementary31%Santa Cruz County31%37.066496,-122.15082
Blochman Union Elementary31%Santa Barbara County31%34.912985,-120.168895
Montecito Union Elementary29%Santa Barbara County29%34.416833,-119.640325
Gorman Elementary29%Los Angeles County29%34.710648,-118.756386
Fieldbrook Elementary42%Humboldt County42%40.963023,-124.030253
Big Oak Flat-Groveland Unified29%Tuolumne County29%37.843709,-119.75976
Twin Hills Union Elementary27%Sonoma County27%38.364779,-122.848384
Petaluma Joint Union High25%Sonoma County25%38.19854-122.634294
Freshwater Elementary33%Humboldt County33%40.779709,-124.030003
Laytonville Unified30%Mendocino County30%39.764718,-123.533064
Ravendale-Termo Elementary22%Lassen County22%40.847981,-120.398794
Ventura County Office of Education28%Ventura County28%34.214483,-118.999407
Summerville Union High24%Tuolumne County24%38.141434-119.927617
Mountain Valley Unified29%Trinity County29%40.542256,-123.240706
Rancho Santa Fe Elementary20%San Diego County20%33.040958,-117.199791
Mendocino Unified37%Mendocino County37%39.245807,-123.624116
Mountain Empire Unified32%San Diego County32%32.750333,-116.39144
McCloud Union Elementary20%Siskiyou County20%41.335364,-121.860127
Belleview Elementary20%Tuolumne County20%38.055861,-120.296158
Oak Grove Union Elementary20%Sonoma County20%38.44203,-122.85279
Knights Ferry Elementary20%Stanislaus County20%37.772205,-120.649462
Weed Union Elementary20%Siskiyou County20%41.546432,-122.179908
Santa Barbara County Office of Education20%Santa Barbara County20%34.451791,-119.769659
Helendale Elementary26%San Bernardino County26%34.760677,-117.350103
Clear Creek Elementary24%Nevada County24%39.120098,-121.168127
Kern County Office of Education20%Kern County20%35.387358,-119.016896
Riverside County Office of Education25%Riverside County25%33.978856,-117.380605
Sierra Unified20%Fresno County20%36.957373,-119.007414
Ready Springs Union Elementary24%Nevada County24%39.162906,-121.189821
North Cow Creek Elementary30%Shasta County30%40.610157,-122.197541
Chawanakee Unified24%Madera County24%37.396373,-119.402251
Del Norte County Office of Education58%Del Norte County58%41.772354,-124.206782
South Bay Union Elementary25%Humboldt County25%40.686505,-124.156749
Gravenstein Union Elementary31%Sonoma County31%38.360397,-122.784213
Columbia Union23%Tuolumne County23%38.043731,-120.428275
Ferndale Unified25%Humboldt County25%40.523099,-124.326421
Newcastle Elementary22%Placer County22%38.875585,-121.144747
Tulare County Office of Education21%Tulare County21%36.328171,-119.320309
Lucerne Elementary21%Lake County21%39.090779,-122.785045
Alta-Dutch Flat Union Elementary38%Placer County38%39.224657,-120.718212
Laguna Beach Unified21%Orange County21%33.546508,-117.801358
Vallecito Union26%Calaveras County26%38.312139,-120.278284
Cayucos Elementary29%San Luis Obispo County29%35.478605,-120.894747
Mupu Elementary21%Ventura County21%34.509069,-119.04769
Cold Spring Elementary25%Santa Barbara County25%34.447443,-119.65556
William S. Hart Union High44%Los Angeles County44%34.4865-118.552041
Liberty Elementary21%Sonoma County21%38.282745,-122.709724
Black Oak Mine Unified27%El Dorado County27%38.912766,-120.634853
Beverly Hills Unified24%Los Angeles County24%34.07923,-118.402437
Carmel Unified26%Monterey County26%36.324454,-121.665781
Soquel Union Elementary22%Santa Cruz County22%37.001389,-121.952059
Jamul-Dulzura Union Elementary21%San Diego County21%32.693868,-116.775337
Merced County Office of Education24%Merced County24%37.297454,-120.488456
El Tejon Unified24%Kern County24%34.843282,-118.989745
Trinidad Union Elementary68%Humboldt County68%41.045469,-124.020816
Johnstonville Elementary22%Lassen County22%40.352478,-120.581412
Scott Valley Unified20%Siskiyou County20%41.510419,-122.897037
Pacific Grove Unified21%Monterey County21%36.610823,-121.932831
Gold Oak Union Elementary31%El Dorado County31%38.684773,-120.721087
Golden Feather Union Elementary20%Butte County20%39.734099,-121.488887
San Juan Unified27%Sacramento County27%38.647441,-121.306336
Needles Unified30%San Bernardino County30%34.491091,-115.109654
Mt. Shasta Union Elementary20%Siskiyou County20%41.304513,-122.351828
Biggs Unified20%Butte County20%39.457582,-121.759854
Capistrano Unified22%Orange County22%33.505002,-117.625816
Jacoby Creek Elementary23%Humboldt County23%40.831459,-124.0304
Larkspur-Corte Madera29%Marin County29%37.924139,-122.499366
Monterey County Office of Education22%Monterey County22%36.6533,-121.639748
Calaveras Unified22%Calaveras County22%38.249621,-120.620577
Wilmar Union Elementary48%Sonoma County48%38.229088,-122.690344
Redding Elementary25%Shasta County25%40.552084,-122.394582
Sonoma County Office of Education39%Sonoma County39%38.455403,-122.721082
Soulsbyville Elementary29%Tuolumne County29%37.988349,-120.270212
Lakeside Joint21%Santa Clara County21%37.188308,-122.059884
Happy Camp Union Elementary40%Siskiyou County40%41.818904,-123.552483
Curtis Creek Elementary36%Tuolumne County36%37.953883,-120.306342
Pollock Pines Elementary20%El Dorado County20%38.698324,-120.271996
McKinleyville Union Elementary25%Humboldt County25%40.977114,-123.95415
Three Rivers Union Elementary25%Tulare County25%36.436989,-118.671532
Willits Unified22%Mendocino County22%39.472709,-123.356825
Alpine Union Elementary26%San Diego County26%32.825968,-116.701963
Sierra Sands Unified26%Kern County26%35.55529,-117.779315
Camino Union Elementary44%El Dorado County44%38.826597,-120.626986
Fall River Joint Unified26%Shasta County26%40.963333,-121.466606
Fort Bragg Unified62%Mendocino County62%39.533381,-123.683007
Palo Verde Unified21%Riverside County21%33.763663,-114.725168
Emery Unified30%Alameda County30%37.839907,-122.298964
Eureka City Schools23%Humboldt County23%40.796205,-124.149541
San Antonio Union Elementary25%Monterey County25%35.953567,-121.22539
Brittan Elementary20%Sutter County20%39.172726,-121.805819
Westwood Unified29%Lassen County29%40.518769,-121.103782
Blue Lake Union Elementary40%Humboldt County40%40.861271,-123.884047
Fort Sage Unified23%Lassen County23%39.9745,-120.090101
Black Butte Union Elementary24%Shasta County24%40.512417,-121.784181
Cinnabar Elementary36%Sonoma County36%38.256265,-122.665418
Warner Unified53%San Diego County53%33.27701,-116.571836
Shaffer Union Elementary48%Lassen County48%40.453033,-120.215954
McSwain Union Elementary21%Merced County21%37.25109,-120.630636



To attend a public or private U.S. elementary school, children must be up to date with the following vaccinations: Polio, Diphtheria-Tetanus-Pertussis, Measels-Mumps-Rubella, Hepatitis B and Varicella. In this Silk we look at the numbers behind public kindergartens enrollments and the relative immunization statistics. The source of the data is the California Department of Public Health. We've focused on public kindergartens, and have aggregated statistics on public vs. private. 

Here's 5 things we found:

  • In 22 Californian schools districts 50% or more of the children are not up to date with vaccinations. Of these, almost a fourth are located in Humboldt County. Explore this fact here.
  • 7.5% of the children in CA public kindergartens are missing the Diphtheria, Tetanus and Pertussis vaccine. Explore this fact here.
  • In 8 public school districts more than half of the kindergartners don't have all mandatory vaccinations because of parents' personal beliefs. Explore this fact here.
  • At Big Sur Charter, 10 out of 13 children (77%) aren't up to date with vaccinations because of personal beliefs. Explore this fact here.
  • Personal beliefs exempt from required vaccinations 6% of grade-K children enrolled in California's private schools. In public school the number is "only" 3%. Explore this fact here.

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About this site

This site was created with Silk, a platform for easily structuring information, so that it can be organized, queried, visualized and shared in a few clicks. The Silk team built this as a demonstration project. You can contact us at feedback@silk.co

To download the cleaned dataset imported to create this DB, click here

You'll find four spreadsheets, all released under Creative Commons

  • All schools
  • Public school districts aggregation & Census data
  • Types of vaccines
  • Public vs. Private

To read more on how to interpret the variables and on the data processing/aggregation carried out to build this Silk, click here.