The document summarizes and analyzes the 2015 measles outbreak linked to Disneyland in California. It makes three key points:
1) The outbreak originated from a single unidentified individual infected with measles who visited Disneyland in December 2014. It led to over 100 cases, mostly in California, but had largely ended spreading by mid-February 2015.
2) Media coverage of the outbreak peaked in early February even as new cases dropped to near zero. This hysteria coincided with efforts in several states to introduce bills restricting non-medical vaccine exemptions.
3) While concerning, the Disneyland outbreak was relatively small and not as serious as portrayed. Measles generally poses little risk in the US
2. • Part 1: Why measles is no longer a public
health threat in the United States
• Part 2: The Disney land measles outbreak and
its aftermath
3. PART 1:
WHY MEASLES IS NO LONGER A THREAT IN THE U.S.
The U.S population risk of dying from measles has fallen essentially to zero
during the 20th century, for one major and one minor reason
1. Most important, measles long ago became a “self-limiting infection of short
duration, moderate severity, and low fatality.”1 Death rates among those
infected fell to very low levels
2. Of lesser importance, wild-type measles cases have also fallen to very low
levels following the introduction of the live virus measles vaccine
Since 2006,
• There have been over 1500 cases of wild-type measles in the U.S.
• There have been zero deaths from wild-type measles (the last in 2003)2
• Over 80 cases of deaths related to measles containing vaccines have been
reported to VAERS3
1. Alexander D. Langmuir et al., The Importance of Measles as a Health Problem, 52 AM. J. PUB. HEALTH 1, 1 (1962).
2. CDC spokesperson Helen (Amy) Rowland to Health Choice , January 30, 2015
3. Search for measles-containing vaccines, vaccination years 2006-2015 and death
http://www.medalerts.org/vaersdb/index.php
4. Summary points
• The hysteria over measles is unfounded. Measles is not Ebola
• Measles has long since ceased to be a dangerous illness for healthy
children. Most adults born before the mid-1960s acquired measles in
childhood and experienced it as a minor inconvenience
• The predominant experience of measles infection as a subclinical
illness caused by live-virus vaccine injections has made wild-type
measles very rare and easier to fear. Measles should not cause panic
• The measles vaccine virus can shed and cause infections in unhealthy
children. Vaccinees should avoid those at health risk of viral infections.
Measles vaccination to protect the ill is not a civic duty
• Measles-containing vaccines like MMR now cause many more deaths
than measles
• The “Disneyland measles” episode is neither larger nor more serious
than other recent outbreaks
5. Part 2:
The Disneyland Measles Outbreak and it Aftermath
• An unknown individual (presumed to be an international traveler) infected with measles
visited Disneyland around December 17-20, 2014.
• Approximately 40 California residents (and a smaller number of out-of state residents)
were exposed to measles and infected during this period. These ~50 original cases
eventually infected about 100 more, mostly California residents
• The CDC was first notified of these new cases in early January and began publicizing the
outbreak aggressively soon after
• Intensive media coverage commenced in late January (January 21-24), peak coverage
was reached in early February (February 3-6) and continued until month-end
• However, by mid February, measles infections were no longer spreading. The last
reported California case connected to Disneyland caught the virus around February 20
• Prompted by the media hysteria over measles, a new outbreak of vaccine anti-
exemption legislation was launched. In 11 states, legislators introduced new bills
revoking exemption rights starting with a bill filed in Oregon on January 20th
• Four of these bills (the earliest ones introduced) have been withdrawn or tabled in the
face of strong grassroots opposition
6. The origins of the outbreak
“On January 5, 2015, the California Department of Public Health (CDPH) was notified about a
suspected measles case. The patient was a hospitalized, unvaccinated child, aged 11 years with
rash onset on December 28. The only notable travel history during the exposure period was a
visit to one of two adjacent Disney theme parks located in Orange County, California. On the
same day, CDPH received reports of four additional suspected measles cases in California
residents and two in Utah residents, all of whom reported visiting one or both Disney theme
parks during December 17–20. By January 7, seven California measles cases had been
confirmed…
“The source of the initial Disney theme park exposure has not been identified. Specimens from
30 California patients were genotyped; all were measles genotype B3, which has caused a large
outbreak recently in the Philippines, but has also been detected in at least 14 countries and at
least six U.S. states in the last 6 months
Annual attendance at Disney theme parks in California is estimated at 24 million… including many
international visitors from countries where measles is endemic. The December holiday season
coincides with the exposure period of interest…. International travel to countries where measles
is endemic is a well-known risk factor for measles, and measles importations continue to occur
in the United States”
Source: MMWR Feb 20, 2015 /64(06);153-154
7. By late January, CDC was publicizing reports from a
“multi-state outbreak linked to an amusement park in
California”; by mid March, new reports had subsided
Date of report Total cases New reports
All US cases CA cases All US reports CA reports*
(as of 1/7)
MMWR Feb 20, 2015 /64(06);153-154
9 7 9
(12/17-1/7)
7
1/23/2015 (as of 1/21)
http://emergency.cdc.gov/han/han00376.asp
51 42 42
(1/7-21)
35
2/13/2015 (as of 2/11)
MMWR Feb 20, 2015 /64(06);153-154
125 110 74
(1/21-2/11)
68
3/2/2015 (as of 2/27)
http://www.cdc.gov/measles/multi-state-
outbreak.html
140 125 15
(2/11-27)
15
3/9/2015 (as of 3/6) 142 126 2
(2/27-3/6)
1
3/16/2015 (as of 3/13) 145 129 3
(3/6-13)
3
3/23/2015 (as of 3/20) 146 130 1
(3/13-20)
1
3/30/2015 (as of 3/27) 146 130 0
(3/20-27)
0
*CDC weekly reports lag behind the California DPH reports
8. As of mid-February, the Disneyland outbreak had
largely run its course, with very few new measles rashes
CDC MMWR Early Release: February 13, 2015. Number of confirmed measles cases
(N = 110), by date of rash onset — California, December 2014–February 2015
9. Confirmed reported cases in California residents from the
Disneyland measles outbreak stopped increasing in early
March; new case reports dropped to zero after March 13
0
20
40
60
80
100
120
140
Source: California Department of Public Health, Measles Surveillance Updates:
http://www.cdph.ca.gov/HealthInfo/discond/Pages/MeaslesSurveillanceUpdates.aspx
Cases
exposed at
Disneyland
(40)
Cases directly
linked to a
Disneyland case
(41)
Unknown link,
but presumed
Disneyland
connection (50)
10. As of mid-March, it was clear the Disneyland measles
outbreak had stopped spreading by February 20th
“California Measles Surveillance Update: March 20, 2015”
“Since December, 2014, there have been 133 confirmed measles cases reported in
California residents.
• “No new confirmed cases have been reported to CDPH since the publication of the
last report on March 13, 2015.
• “The outbreak will be considered over when 42 days have elapsed from the end of
the infectious period of the last known B3 measles cases that was a not a new
importation. As of today, that date will be April 17, 2015.”
Pinpointing key milestones for the last California known measles case
• March 6: end of the infectious period (42 days before April 17)
• March 2*: rash appears (4 days before end of infectious period, confirmed on 3/27)
• February 26: beginning of infectious period (4 days before rash onset, estimated)
• ~February 20: approximate date of last known infection (estimated)
* The March 2nd date of rash onset for the last confirmed case was confirmed by CDPH in the March 27th update
11. Measles hysteria in the media was peaking as the outbreak was
ending and a push to restrict vaccine exemptions had begun
0
20
40
60
80
100
120
2014-03-30 - 2014-
04-05
2014-05-25 - 2014-
05-31
2014-07-20 - 2014-
07-26
2014-09-14 - 2014-
09-20
2014-11-09 - 2014-
11-15
2015-01-04 - 2015-
01-10
2015-03-01 - 2015-
03-07
First week of February:
• headlines peak
• new cases near zero
“Google trends” index for news
headlines on “measles”
Third week of February:
• Headlines still strong,
• Last new case
Jan 20-Feb 20
• 8 state bills filed to
revoke exemption rights
12. State legislators seized on the publicity around the Disneyland
measles outbreak as an occasion to attack longstanding
vaccine exemption rights
Oregon Senator to introduce bill to eliminate 'personal belief' exemption for
vaccines
The "personal belief" exemption to vaccinations may soon be history in Oregon, which
has the highest opt-out rate in the country.
Sen. Elizabeth Steiner Hayward is sponsoring a bill to eliminate exemptions for
nonmedical reasons, including personal or religious beliefs.
Lawmakers in California and Washington already introduced similar legislation earlier
this week, amid an outbreak of measles originating at Disneyland.
Steiner Hayward said her bill would apply to all vaccines, not just the measles-
mumps-rubella shot.
Source: Portland Business Journal, February 5, 2015
13. Starting with Oregon, state bills seeking to revoke
exemption rights have been launched in 11 states
State Bill Date filed Targeted
exemptions
Status
Oregon SB442 1/20/15 Philosophical
Religious
WITHDRAWN
Washington HB2009 2/6/15 Personal belief WITHDRAWN
New Mexico HB522 2/9/15 Religious TABLED
Maryland HB687 2/12/15 Religious WITHDRAWN
Vermont S87
H212
2/12/15
2/13/15
Philosophical
Phil/religious
ON HOLD
ON HOLD
California SB277 2/19/15 Personal belief
Religious
Pending
Illinois SB1410 2/20/15 Religious Pending
Rhode Island S381 2/25/15 Religious Pending
Maine LD606/HP419 3/3/15 Philosophical Pending
New Jersey S1147/A1931 3/9/15 (2nd reading) Religious PASSED Sen Comm
North Carolina SB346 3/19/15 Religious Pending
Progress on four of the earliest bills have been halted in the face of strong grassroots opposition
14. Other state bills seek to restrict exemption rights
State Bill Date filed Exemptions restriction Status
Minnesota SF380/HF393 1/29/15 MD certification
required for PBE
PASSED Senate
Committee 3/23
Texas HB1674 2/19/15 MD counseling required
for conscientious and
religious exemptions
Pending
Maine LD471/HP310 2/24/15 MD certification
required for PBE
Pending
15. Organizations opposing exemption bills
• Oregon: No on SB442, Yes on Medical Freedom http://www.noonsb442.com/
• Washington: no known formal organization
• New Mexico: no known formal organization
• Maryland: no known formal organization
• Vermont: Vermont Coalition for Vaccine Choice http://www.vaxchoicevt.com/
• California: No on SB447, Keep Medical Freedom for California (Facebook)
• Illinois: SB1410 Restricting Exemptions in Illinois (Facebook)
• Maine: Maine Coalition for Vaccine Choice http://mainevaxchoice.org/
• Minnesota: Vaccine Safety Council of Minnesota
http://vaccinesafetycouncilminnesota.org/
• New Jersey: no known formal organization
• North Carolina: North Carolina Parents for Vaccine Rights, North Carolina
People for Vaccine Choice (Facebook)
• Texas: Texans for Vaccine Choice http://www.texansforvaccinechoice.com/