Keywords
vaccine - otolaryngology - public health - disease outbreaks - disease eradication
- vaccination
Introduction
Vaccines are often considered one of the greatest achievements in medicine and public
health, and have helped to greatly reduce the incidence of several historically common
infectious diseases. The inclusion of vaccinations in the standard of care guidelines
has resulted in record low levels of vaccine-preventable disease (VPD) occurrences
in the U.S.[1] The use of vaccines can greatly reduce the risk of contracting one of these diseases
at an individual level and when vaccination coverage is high enough,[2]
[3] it can also confer herd immunity at a community and population level. For most diseases
in which vaccinations are regularly used, cases of VPDs in the U.S. have been reduced
by 90–100%, with a similar reduction in deaths associated with these diseases.[1] Similar reductions are seen around the world in countries that have developed robust
vaccination programs. Worldwide progress is evident in the eradication of endemic
poliomyelitis in all but three countries and the elimination of both measles and rubella
from the World Health Organization (WHO) Region of the Americas in 2002.[4]
[5] While these are significant advances in public health, most of these diseases are
far from complete elimination and still pose a significant threat to all areas of
the globe.
Individuals and physicians living in the U.S. and other countries with strong immunization
programs are likely to lack any firsthand experience with many VPDs as it has been
decades since diseases such as measles, mumps, rubella and diphtheria were commonplace.
In the decade preceding the implementation of the national measles vaccine program,
in 1963, it was estimated that there were 3 to 4 million cases of measles every year
in the U.S., with an average of 500 deaths.[6] Rubella was even more prevalent, with at least 12.5 million cases occurring in the
mid-1960s and an estimated 20,000 children born with congenital birth defects as a
result.[7] To put this into perspective, the CDC data indicate that the highest reported yearly
total of measles cases since the year 2000 is 667, which occurred in 2014.[8] The CDC also reports that there have been less than 100 reported cases of rubella
in the U.S. in the past 10 years. This reduction in incidence leads to a decreased
perception of the severity and individual susceptibility to these diseases.[9] This distancing from the effects of these diseases may be one of the reasons that
nonmedical exemptions (NMEs) are not only increasing, but increasing at a greater
rate when compared with data going as far back as 1991.[10] As more individuals choose the route of NMEs, there may be an increased likelihood
of outbreaks.
A whole generation of physicians has trained after the time of near-universal vaccinations.
Many otolaryngologists, like other physicians, are unlikely to have experience in
diagnosing and treating patients with VPDs. As these patients often present with symptoms
in the head and neck, it is important that otolaryngologists be reminded of these
diseases. This lack of familiarity with these infections and their variable presentations
can result in these patients being seen by an otolaryngologist without prior diagnosis.
Because these VPDs can occur in both unvaccinated children and adults, patients may
present at any age. Therefore, it is important that regardless of the patient population
the otolaryngologist serves, familiarity with these diseases is accomplished.
This article will review the current state of vaccination rates and VPD rates in both
the U.S. and the world. Additionally, this review will examine how these diseases
might present and remind physicians of the current treatment guidelines.
Review of Vaccination Rates and Disease Incidence
Review of Vaccination Rates and Disease Incidence
The United States childhood vaccination rate estimates for the 19–35 months age group
were obtained from data collected by the Centers for Disease Control's (CDC) National
Immunization Survey (NIS). National kindergarten vaccination rate data were obtained
from publications within the CDC's Morbidity and Mortality Weekly Report (MMWR). World
vaccination rates were obtained via annual reports from the World Health Organization
(WHO) and the United Nations Children's Fund (UNICEF) joint reporting process. The
WHO/UNICEF vaccination rate data represent official reports from the 194 WHO member
states that participate in the reporting process.
The vaccine preventable diseases incidence data for the U.S. were obtained through
the annual Summary of Notifiable Diseases reports from the CDC's National Notifiable
Diseases Surveillance System (NNDSS). The international VPDs incidence data were obtained
from the WHO/UNICEF database of disease incidence, which collects reported cases from
194 participating WHO member states.
The national and state level vaccine exemption data for kindergarteners were obtained
from the CDC's MMWR reports. A literature review of the current state of vaccination
exemptions and the reasons parents choose to exempt children in the U.S. was conducted
through a PubMed search using the key words “vaccine exemption,” “medical exemption”
and “nonmedical exemption.”
Clinical information regarding the presentation of these diseases and the current
treatment guidelines was obtained from the Red Book: Report of the Committee on Infectious
Diseases and from the Manual for the Surveillance of Vaccine-Preventable Diseases
published by the CDC.
United States Vaccination Rates
The most recent data from the CDC regarding U.S. vaccination rates for children (19–35
months) for the period of January-December of 2014 contains vaccination rate estimations
using NIS results. National and statewide vaccination levels are reported and can
be found in [Table 1].
Table 1
Estimated US vaccination rates for children aged 19–35 months in 2014 and children
enrolled in kindergarten for the 2014–2015 school year.
|
|
19–35 months[50]
|
|
State
|
DTaP 3rd dose (%)
|
DTaP 4th dose (%)
|
MMR 1st dose (%)
|
Hib full series (%)
|
|
US National
|
94.7 ± 0.7
|
84.2 ± 1.2
|
91.5 ± 0.9
|
82.0 ± 1.3
|
|
Alabama
|
92.6 ± 5.7
|
84.1 ± 7.4
|
92.0 ± 5.6
|
85.3 ± 7.0
|
|
Alaska
|
92.5 ± 3.9
|
78.7 ± 6.3
|
90.2 ± 4.3
|
80.8 ± 6.2
|
|
Arizona
|
90.6 ± 5.1
|
81.4 ± 6.4
|
84.1 ± 6.3
|
77.0 ± 7.1
|
|
Arkansas
|
93.8 ± 3.3
|
80.0 ± 6.8
|
89.1 ± 5.4
|
78.3 ± 7.5
|
|
California
|
94.9 ± 3.5
|
87.3 ± 5.3
|
90.5 ± 4.7
|
84.7 ± 6.0
|
|
Colorado
|
94.2 ± 3.8
|
85.4 ± 4.9
|
87.4 ± 5.4
|
85.3 ± 5.3
|
|
Connecticut
|
94.8 ± 4.3
|
86.0 ± 6.0
|
93.2 ± 4.6
|
84.4 ± 6.5
|
|
Delaware
|
95.0 ± 4.0
|
85.4 ± 6.0
|
90.8 ± 4.8
|
84.5 ± 6.1
|
|
Dist. of Columbia
|
92.6 ± 4.3
|
80.6 ± 6.6
|
90.9 ± 4.8
|
80.9 ± 6.9
|
|
Florida
|
98.3 ± 1.5
|
86.2 ± 6.1
|
91.2 ± 4.8
|
84.9 ± 6.3
|
|
Georgia
|
94.9 ± 3.9
|
85.7 ± 6.2
|
94.2 ± 3.9
|
81.1 ± 7.1
|
|
Hawaii
|
94.5 ± 3.3
|
82.4 ± 5.9
|
92.5 ± 3.7
|
84.5 ± 5.1
|
|
Idaho
|
92.2 ± 5.2
|
77.7 ± 7.2
|
89.7 ± 5.1
|
80.4 ± 6.5
|
|
Illinois
|
93.6 ± 3.1
|
87.8 ± 3.9
|
93.2 ± 2.8
|
82.8 ± 4.6
|
|
Indiana
|
94.8 ± 3.7
|
82.8 ± 5.7
|
91.5 ± 4.5
|
82.0 ± 5.7
|
|
Iowa
|
93.4 ± 4.8
|
87.4 ± 5.7
|
91.1 ± 5.2
|
79.8 ± 7.6
|
|
Kansas
|
92.1 ± 5.0
|
85.3 ± 6.2
|
93.4 ± 4.0
|
82.7 ± 6.7
|
|
Kentucky
|
94.6 ± 4.0
|
83.2 ± 6.5
|
88.6 ± 5.5
|
79.7 ± 7.2
|
|
Louisiana
|
95.4 ± 3.5
|
83.3 ± 5.6
|
91.8 ± 4.1
|
81.9 ± 6.4
|
|
Maine
|
97.5 ± 2.0
|
93.1 ± 3.5
|
97.2 ± 2.0
|
90.5 ± 4.1
|
|
Maryland
|
97.0 ± 2.8
|
85.4 ± 6.4
|
94.9 ± 3.3
|
86.2 ± 6.1
|
|
Massachusetts
|
98.2 ± 1.7
|
89.8 ± 5.0
|
94.7 ± 3.2
|
86.8 ± 6.0
|
|
Michigan
|
89.4 ± 6.1
|
77.7 ± 8.1
|
87.4 ± 6.5
|
77.4 ± 7.7
|
|
Minnesota
|
95.3 ± 3.9
|
87.1 ± 6.2
|
94.3 ± 4.2
|
79.9 ± 7.6
|
|
Mississippi
|
96.2 ± 4.0
|
83.3 ± 7.6
|
95.0 ± 4.3
|
80.3 ± 7.9
|
|
Missouri
|
96.8 ± 3.1
|
79.2 ± 7.3
|
90.3 ± 4.7
|
77.6 ± 7.5
|
|
Montana
|
95.9 ± 3.5
|
83.1 ± 7.0
|
93.4 ± 4.4
|
86.4 ± 5.7
|
|
Nebraska
|
97.2 ± 2.6
|
87.3 ± 5.4
|
96.0 ± 2.9
|
87.7 ± 5.0
|
|
Nevada
|
91.4 ± 4.0
|
81.0 ± 5.8
|
90.4 ± 4.2
|
78.8 ± 5.9
|
|
New Hampshire
|
97.8 ± 1.8
|
91.3 ± 4.2
|
93.1 ± 3.8
|
91.9 ± 4.1
|
|
New Jersey
|
97.5 ± 2.1
|
85.4 ± 5.4
|
93.3 ± 3.8
|
80.2 ± 6.1
|
|
New Mexico
|
95.8 ± 2.7
|
87.5 ± 5.1
|
94.6 ± 3.0
|
87.2 ± 5.4
|
|
New York
|
97.6 ± 1.6
|
85.4 ± 4.0
|
93.1 ± 2.9
|
80.5 ± 4.5
|
|
North Carolina
|
96.5 ± 3.5
|
86.9 ± 5.9
|
94.3 ± 4.1
|
89.3 ± 5.4
|
|
North Dakota
|
96.2 ± 3.1
|
81.8 ± 6.2
|
94.9 ± 3.3
|
80.8 ± 6.3
|
|
Ohio
|
95.3 ± 3.1
|
85.1 ± 6.0
|
95.6 ± 2.9
|
81.4 ± 6.6
|
|
Oklahoma
|
93.6 ± 4.7
|
80.4 ± 7.2
|
92.0 ± 5.4
|
84.0 ± 6.6
|
|
Oregon
|
91.8 ± 4.6
|
80.7 ± 6.8
|
85.1 ± 6.0
|
76.4 ± 7.3
|
|
Pennsylvania
|
94.8 ± 2.4
|
87.0 ± 4.2
|
92.0 ± 3.3
|
86.7 ± 4.1
|
|
Rhode Island
|
98.4 ± 2.0
|
88.8 ± 5.5
|
94.6 ± 3.7
|
89.5 ± 5.5
|
|
South Carolina
|
94.0 ± 4.3
|
85.1 ± 6.3
|
90.8 ± 5.3
|
81.8 ± 7.1
|
|
South Dakota
|
98.5 ± 2.1
|
87.8 ± 6.5
|
94.1 ± 4.2
|
89.0 ± 5.9
|
|
Tennessee
|
96.6 ± 2.4
|
80.7 ± 7.2
|
95.8 ± 2.4
|
80.5 ± 7.1
|
|
Texas
|
93.1 ± 2.9
|
78.2 ± 4.9
|
90.4 ± 3.2
|
76.2 ± 4.9
|
|
Utah
|
90.7 ± 4.9
|
81.9 ± 6.5
|
85.3 ± 6.4
|
78.8 ± 6.9
|
|
Vermont
|
96.1 ± 2.8
|
86.1 ± 5.4
|
93.2 ± 3.4
|
86.9 ± 5.5
|
|
Virginia
|
91.5 ± 5.8
|
87.2 ± 6.7
|
91.5 ± 5.1
|
87.5 ± 6.3
|
|
Washington
|
93.0 ± 4.8
|
81.6 ± 6.7
|
86.3 ± 6.2
|
75.6 ± 7.5
|
|
West Virginia
|
92.1 ± 5.0
|
77.2 ± 7.2
|
88.9 ± 5.4
|
78.4 ± 7.0
|
|
Wisconsin
|
94.9 ± 3.4
|
84.4 ± 5.8
|
93.2 ± 4.2
|
80.4 ± 6.7
|
|
Wyoming
|
93.1 ± 4.7
|
72.8 ± 8.7
|
90.4 ± 5.0
|
75.1 ± 8.2
|
|
|
Kindergarten[19]
|
|
State
|
Varicella (%)
|
Pneumococcal full series (%)
|
MMR* (%)
|
DTaP* (%)
|
|
US National
|
91.0 ± 0.9
|
82.9 ± 1.3
|
94.7**
|
95**
|
|
Alabama
|
92.1 ± 5.6
|
84.3 ± 7.3
|
≥ 93.5
|
≥ 93.5
|
|
Alaska
|
88.4 ± 4.7
|
79.8 ± 6.3
|
92.7
|
92.7
|
|
Arizona
|
84.6 ± 6.2
|
79.8 ± 6.7
|
94.2
|
94.3
|
|
Arkansas
|
91.1 ± 4.5
|
78.9 ± 7.0
|
88.4
|
85.6
|
|
California
|
90.3 ± 4.8
|
84.1 ± 6.1
|
92.6
|
92.4
|
|
Colorado
|
87.9 ± 5.1
|
84.8 ± 5.3
|
86.9
|
84.3
|
|
Connecticut
|
93.1 ± 4.5
|
84.2 ± 6.6
|
97
|
97
|
|
Delaware
|
90.2 ± 4.9
|
85.9 ± 5.8
|
97.8
|
97.7
|
|
Dist. of Columbia
|
92.4 ± 4.3
|
84.3 ± 6.3
|
90.4
|
90.2
|
|
Florida
|
92.4 ± 4.8
|
81.6 ± 8.0
|
≥ 93.3
|
≥ 93.3
|
|
Georgia
|
94.5 ± 3.8
|
81.3 ± 7.2
|
≥ 94.0
|
≥ 94.0
|
|
Hawaii
|
90.0 ± 4.4
|
86.3 ± 4.8
|
NA
|
NA
|
|
Idaho
|
90.0 ± 5.0
|
83.6 ± 6.2
|
89.5
|
89.4
|
|
Illinois
|
92.8 ± 2.6
|
80.9 ± 4.9
|
94.7
|
94.9
|
|
Indiana
|
89.7 ± 4.8
|
80.1 ± 6.2
|
89.3
|
92.7
|
|
Iowa
|
86.4 ± 6.2
|
84.2 ± 6.6
|
≥ 91.9
|
≥ 91.9
|
|
Kansas
|
95.0 ± 3.3
|
85.9 ± 6.2
|
89.2
|
89.6
|
|
Kentucky
|
92.4 ± 4.4
|
84.5 ± 6.8
|
92.7
|
94.4
|
|
Louisiana
|
91.4 ± 4.1
|
83.4 ± 5.3
|
96.8
|
98.3
|
|
Maine
|
94.5 ± 2.8
|
91.4 ± 3.9
|
92.1
|
95.4
|
|
Maryland
|
94.8 ± 3.7
|
87.5 ± 6.2
|
99.1
|
99.6
|
|
Massachusetts
|
93.6 ± 3.9
|
88.6 ± 5.3
|
94.7
|
92.9
|
|
Michigan
|
85.3 ± 6.7
|
74.4 ± 8.1
|
94.3
|
95.1
|
|
Minnesota
|
91.2 ± 5.2
|
86.3 ± 6.8
|
93.5
|
93.7
|
|
Mississippi
|
92.0 ± 6.0
|
82.8 ± 7.4
|
≥ 99.2
|
≥ 99.2
|
|
Missouri
|
89.8 ± 4.7
|
82.6 ± 6.4
|
95.8
|
96
|
|
Montana
|
90.9 ± 4.8
|
82.4 ± 6.6
|
94.6
|
94.6
|
|
Nebraska
|
95.1 ± 3.2
|
90.2 ± 4.5
|
96
|
96.4
|
|
Nevada
|
89.7 ± 4.3
|
78.8 ± 5.8
|
94
|
93.2
|
|
New Hampshire
|
94.5 ± 2.9
|
90.6 ± 4.5
|
≥ 91.4
|
≥ 91.4
|
|
New Jersey
|
92.1 ± 4.0
|
84.5 ± 5.8
|
≥ 92.3
|
≥ 92.3
|
|
New Mexico
|
92.4 ± 4.0
|
86.3 ± 5.6
|
97.7
|
96.4
|
|
New York
|
91.7 ± 3.2
|
84.9 ± 3.9
|
98.2
|
97.5
|
|
North Carolina
|
94.9 ± 3.9
|
87.2 ± 6.1
|
98.5
|
98.4
|
|
North Dakota
|
92.2 ± 4.1
|
84.3 ± 5.9
|
89.8
|
89.6
|
|
Ohio
|
92.9 ± 3.6
|
83.3 ± 6.4
|
91.9
|
92.2
|
|
Oklahoma
|
92.2 ± 5.1
|
83.4 ± 6.6
|
90.3
|
90
|
|
Oregon
|
83.3 ± 6.2
|
77.4 ± 7.2
|
94.1
|
93.8
|
|
Pennsylvania
|
92.8 ± 3.1
|
87.5 ± 3.9
|
91.7
|
NReg
|
|
Rhode Island
|
93.9 ± 4.0
|
88.9 ± 5.3
|
95.7
|
96.1
|
|
South Carolina
|
91.5 ± 5.0
|
81.6 ± 7.2
|
96.5
|
97.2
|
|
South Dakota
|
92.6 ± 4.4
|
87.2 ± 6.8
|
97.1
|
97.2
|
|
Tennessee
|
92.4 ± 4.0
|
85.5 ± 6.1
|
≥ 95.1
|
≥ 95.1
|
|
Texas
|
89.9 ± 3.3
|
78.6 ± 4.7
|
97.4
|
97.2
|
|
Utah
|
86.3 ± 6.0
|
80.0 ± 6.9
|
94
|
93.8
|
|
Vermont
|
87.0 ± 4.6
|
86.1 ± 5.3
|
92.7
|
93.2
|
|
Virginia
|
92.2 ± 4.7
|
83.2 ± 7.6
|
93.4
|
97.4
|
|
Washington
|
86.7 ± 5.8
|
79.5 ± 6.9
|
89.4
|
90.7
|
|
West Virginia
|
87.1 ± 5.5
|
77.7 ± 7.0
|
97.6
|
97.6
|
|
Wisconsin
|
91.7 ± 4.1
|
86.4 ± 5.2
|
91.6
|
96.5
|
|
Wyoming
|
86.4 ± 6.3
|
80.3 ± 7.2
|
96.8
|
96.7
|
Abbreviations: DTaP, diphtheria, tetanus and pertussis; Hib, haemophilus influenzae
type b; MMR, measles-mumps-rubella; NA, not available; NReg, no registry.
*Kindergartners were considered up to date if they received all doses required for
school entry in their jurisdiction.
**National Median.
Additional vaccination rate data provided by the CDC's MMWR reports were collected
for children enrolled in kindergarten. Both national and statewide vaccination levels
were reported and can also be found in [Table 1]. Diphtheria, tetanus and pertussis (DTaP) vaccination rates were determined according
to individual state regulations of either four or five required doses for enrollment
in kindergarten. Data from Pennsylvania was not included as pertussis is not required
for kindergarten.
WHO/UNICEF Regional Vaccination Rates
WHO/UNICEF vaccination rate data represent official national reports via the standardized
Joint Reporting Form and draws from the most recently updated report released in July
of 2015. The data are representative of all age groups. WHO/UNICEF regional vaccination
rate estimates are summarized in [Table 2]. Countries in the Americas region (North and South America) that had a notably low
three dose DTaP vaccination rate were: Ecuador (83%), Venezuela (78%), Guatemala (73%)
and Haiti (48%). Two dose measles-containing vaccine (MCV) rates were considerably
lower, as over one third of the countries in the region reported a vaccination rate
of less than 85%. Haemophilus influenzae type b (Hib) (three doses) vaccination rates
were similar to those seen in DTaP, with Ecuador (83%), Panama (80%), Venezuela (78%),
Guatemala (73%), and Haiti (48%) reporting the lowest rates.
Table 2
World Health Organization regional average estimated vaccination coverage for 2014[51]
|
|
Vaccine
|
|
|
WHO Region
|
DTaP 3rd dose (%)
|
MCV 2nd dose (%)
|
Hib 3rd dose (%)
|
|
African
|
77
|
11
|
77
|
|
Americas
|
90
|
51
|
90
|
|
Eastern Mediterranean
|
82
|
66
|
72
|
|
European
|
95
|
84
|
85
|
|
South East Asia
|
84
|
59
|
30
|
|
Western Pacific
|
96
|
93
|
21
|
|
Global
|
86
|
56
|
56
|
Abbreviations: DTP, diphtheria, tetanus and pertussis; Hib, haemophilus influenzae
type b; MCV, meningococcal vaccine.
In the European region ([Table 2]), countries reporting DTaP (three doses) rates below 85% were: Austria (83%), San
Marino (80%) and Ukraine (76%). Countries with MCV (two doses) rates below 85% were:
Denmark (84%), Greece (83%), San Marino (76%), France (74%), Austria (64%) and Ukraine
(54%). Countries reporting Hib (three doses) below 85% were: Austria (83%), Bulgaria
(83%), Ukraine (83%), San Marino (79%), Bosnia and Herzegovina (79%), Russian Federation
(31%) and Belarus (20%).
Regional vaccination rate data from the Eastern Mediterranean, Africa, Southeast Asia
and West Pacific regions are also summarized in [Table 2]. Individual country vaccination rates data can be found on the WHO website.[11]
Global and U.S. Reported Disease Incidence
Global VPD incidence data represent official figures reported to WHO/UNICEF through
the Joint Reporting Form for 2014, and was last updated in January of 2016. WHO/UNICEF
region incidence data are summarized in [Table 3] and the U.S. incidence data for 2005-2014, 2000 and 1995 are displayed in [Table 4]. WHO/UNICEF reports that there were 7,324 reported cases of diphtheria in 2014,
worldwide; this number increased significantly from 2013. According to the most recent
data, there have been only two cases (2012, 2014) of diphtheria in the U.S. over the
past 10 years. Diphtheria cases appear to be heavily concentrated in India (6094 cases)
and Nepal (1079).
Table 3
World Health Organization 2014 regional vaccine-preventable disease incidence data[34]
|
Disease
|
|
WHO Region
|
Diphtheria
|
Measles
|
Mumps
|
Rubella
|
|
African
|
1
|
73914
|
7
|
7402
|
|
Americas
|
9
|
1966
|
15643
|
10
|
|
Eastern Mediterranean
|
40
|
18080
|
9608
|
2945
|
|
European
|
35
|
14176
|
10807
|
653
|
|
South East Asia
|
7217
|
28403
|
34623
|
9263
|
|
Western Pacific
|
22
|
131043
|
234473
|
12814
|
|
Global
|
7324
|
267582
|
305161
|
33087
|
Table 4
Annual US national vaccine reportable disease incidence from the CDC's Summary of
Notifiable Diseases reports
|
Vaccine-Preventable Diseases Incidence
|
|
Year
|
Diphtheria
|
Measles
|
Mumps
|
Rubella
|
Haemophilus Type B*
|
|
2014[8]
|
1
|
667
|
574
|
2
|
40
|
|
2013[8]
|
0
|
187
|
584
|
9
|
31
|
|
2012[8]
|
1
|
55
|
229
|
9
|
30
|
|
2011[8]
|
0
|
212
|
370
|
4
|
14
|
|
2010[8]
|
0
|
63
|
2612
|
5
|
23
|
|
2009[52]
|
0
|
71
|
1991
|
3
|
38
|
|
2008[53]
|
0
|
140
|
454
|
16
|
30
|
|
2007[54]
|
0
|
43
|
800
|
11
|
22
|
|
2006[55]
|
0
|
55
|
6584
|
11
|
29
|
|
2005[56]
|
0
|
66
|
314
|
11
|
9
|
|
2000[57]
|
1
|
86
|
338
|
176
|
NA**
|
|
1995[58]
|
0
|
309
|
906
|
128
|
NA**
|
Abbreviation: NA, not available.
* The National Notifiable Diseases Surveillance System (NNDSS) only requires Haemophilus
serotype reporting in those < 5 years of age
** Serotype reporting not required in 2000 or 1995
In 2014, there were 267,582 reported cases of measles worldwide, and 667 cases in
the U.S. The reported cases of measles were highest in Africa and Asia, with the greatest
number of cases occurring in the Philippines (58,848), China (52,628), the Democratic
Republic of the Congo (33,711), India (24,977), Vietnam (15,033), Ethiopia (12,739),
Angola (11,699) and Somalia (10,229). There were 21 countries that had over 1,000
reported cases.
Mumps cases worldwide in 2014 were noted to be 305,161, with 574 occurring in the
U.S. The greatest incidence was reported in China (187,500), Japan (46,340), Nepal
(34,034), Egypt (7,626), Colombia (7,368), Mexico (4,143) and the United Kingdom (2,958).
Worldwide, there were 33,087 reported cases of rubella, and two cases in the U.S.
The countries with the highest reported cases were China (11,793), India (4,870) and
Indonesia (3,267).
Specific country-level reported disease incidence data can be found on the WHO website.[12]
Discussion
The recent outbreaks of measles in California, and of mumps at numerous college campuses
in 2015 serve as a reminder that even countries with relatively high vaccination rates
remain at risk for future outbreaks. Despite the elimination of endemic measles from
the U.S. in 2000,[13] 2014 saw the highest levels of measles cases over the past two decades. While this
incidence increase has several likely contributing factors, it has brought an alarming
trend of vaccine avoidance and exemption to the national spotlight.
Parental concerns about vaccine safety have increased over the past 15 years, and
more parents are choosing to seek alternative vaccination plans or forgo vaccination
altogether.[14] All 50 states have a set of vaccination requirements that children must meet before
enrollment in school. Because laws regarding vaccination are determined at a state
level, regulations differ from state to state. All states allow for medical exemptions
when vaccinations are medically contraindicated and all but three states, Mississippi,
West Virginia and California, allow some form of NME.[15]
[16] As of October of 2016, 47 states allow for a religious exemption, while only 18
allow for a philosophical exemption.[17] An increasing amount of literature has been published in recent years in an attempt
to quantify and understand trends in NMEs. On a national level, NMEs have shown a
general increase over the last decade, with states such as Arkansas, California and
Oregon tripling their NME rate between 2005 and 2013.[18] Kindergarten vaccine exemption rates are compiled yearly using CDC data and are
summarized in [Table 5] and presented in [Fig. 1]. The data show that while the national median NME rate is only 1.7, states such
as Idaho, Vermont, Oregon and Colorado have NME rates of over 5.0%.[19] This regional disparity is backed by several sources that identify the clustering
of exemptions across state and even county lines.[20]
[21]
[22] When communities of any size experience higher clusters of NMEs and lower vaccination
rates, herd immunity can be compromised and the risk of VPD outbreaks can increase.
Herd immunity relies on the reduction of susceptible persons in the population and
works to reduce the efficiency with which a microbe is transmitted from one person
to another. When there are enough immune individuals to stop effective transmission,
outbreaks no longer occur. Several studies have shown a strong association between
small regional clusters of NMEs and higher risks of pertussis and measles outbreaks.[23]
[24] Increased attention to the effects of NMEs on preventable disease incidence is necessary
to better explain these changes and their effects on public health.
Fig. 1 Estimated percentage of children enrolled in kindergarten in each state that obtained
a nonmedical exemption from receiving one or more vaccines in the United States for
the 2014–2015 school year.
Table 5
Estimated percentage of children enrolled in kindergarten in the US with medical and
nonmedical vaccination exemptions by state for the 2014–15 school year[19]
|
State
|
Kindergarten Exemption Rates
|
|
Medical (%)
|
Nonmedical (%)
|
|
US National Median
|
0.2
|
1.5
|
|
Alabama
|
0.1
|
0.7
|
|
Alaska
|
1.3
|
4.5
|
|
Arizona
|
0.1
|
4.6
|
|
Arkansas
|
< 0.1
|
1.2
|
|
California
|
0.2
|
2.5
|
|
Colorado
|
< 0.1
|
5.4
|
|
Connecticut
|
0.3
|
1.6
|
|
Delaware
|
0.4
|
0.9
|
|
Dist. of Columbia
|
0.6
|
0.5
|
|
Florida
|
0.3
|
1.8
|
|
Georgia
|
0.1
|
2.0
|
|
Hawaii
|
< 0.1
|
3.3
|
|
Idaho
|
0.3
|
6.2
|
|
Illinois
|
NA
|
NA
|
|
Indiana
|
0.5
|
0.8
|
|
Iowa
|
0.3
|
1.4
|
|
Kansas
|
0.3
|
1.1
|
|
Kentucky
|
0.2
|
0.7
|
|
Louisiana
|
0.1
|
0.6
|
|
Maine
|
0.5
|
3.9
|
|
Maryland
|
0.4
|
0.8
|
|
Massachusetts
|
0.3
|
1.1
|
|
Michigan
|
0.3
|
5.0
|
|
Minnesota
|
NA
|
NA
|
|
Mississippi
|
< 0.1
|
NA
|
|
Missouri
|
NA
|
NA
|
|
Montana
|
0.3
|
3.6
|
|
Nebraska
|
0.6
|
1.1
|
|
Nevada
|
0.3
|
1.1
|
|
New Hampshire
|
0.2
|
2.7
|
|
New Jersey
|
0.2
|
1.6
|
|
New Mexico
|
0.1
|
1.2
|
|
New York
|
0.1
|
0.7
|
|
North Carolina
|
0.1
|
0.9
|
|
North Dakota
|
0.3
|
2.4
|
|
Ohio
|
0.3
|
1.8
|
|
Oklahoma
|
0.1
|
1.4
|
|
Oregon
|
0.2
|
5.8
|
|
Pennsylvania
|
0.3
|
1.8
|
|
Rhode Island
|
0.2
|
0.9
|
|
South Carolina
|
0.1
|
1.0
|
|
South Dakota
|
0.2
|
1.5
|
|
Tennessee
|
0.2
|
0.9
|
|
Texas
|
NA
|
1.3
|
|
Utah
|
0.2
|
4.1
|
|
Vermont
|
0.2
|
5.9
|
|
Virginia
|
0.3
|
0.8
|
|
Washington
|
1.2
|
3.5
|
|
West Virginia
|
0.2
|
NA
|
|
Wisconsin
|
0.4
|
4.9
|
|
Wyoming
|
NA
|
NA
|
Abbreviation: NA, not available.
A subset of the literature attempts to explain the increasing trend in NMEs. Traditionally,
under-vaccination was associated with lower access to health care and it was more
prevalent among the impoverished, inner city ethnic and racial minorities, and those
with a lower level of education.[25]
[26] However, increasingly, under-vaccination is resulting from higher NME rates reported
among white, highly educated and wealthier populations.[20]
[27]
[28] The most prevalent concerns voiced by parents are associated with vaccine safety
and common themes include the potential for adverse reactions, developmental problems,
dangerous vaccine ingredients and the need for too many shots at one time under the
national guidelines.[18]
[29]
[30] Other sources have mentioned an inverse relationship between the difficulty of receiving
an exemption and NME levels,[15] and an additional analysis shows a greater increase in NMEs in states where both
religious and philosophical exemptions are allowed.[10] It is clear that legislation can have an impact on vaccination rates.
Families who choose to not vaccinate or intentionally under-vaccinate their children
rely on herd immunity to protect their children from VPDs. For herd immunity to be
established, there must be enough protected individuals in a population to exceed
the herd immunity threshold, which is defined as the fraction of a population that
must be immune to confer herd immunity on those not protected from a disease. An important
objective of the public health departments is to meet vaccination rate goals that
are likely to ensure herd immunity. Although critical vaccination coverage values
have been identified for common VPDs, it is important to note that the heterogeneity
of populations, vaccine effectiveness and virus strain reproductive numbers (R0) cause significant variation in the critical vaccination coverage values over time
and in different populations.[31] Ranges of some of the more accepted herd immunity thresholds and critical vaccination
rates can be seen in [Table 6]. Based on the CDC's estimated vaccination rate data for 19–35-month-olds, there
are currently 19 states that are right at or below the lower bound of estimated herd
immunity threshold for measles (91%). There are also nine states that are at or below
estimated herd immunity thresholds based on the CDC's kindergarten data. While this
type of analysis is useful in determining trends, both datasets are estimates based
on telephone and immunization program surveys and reporting/sampling bias could be
a factor in overestimating rates.
Table 6
Estimated herd immunity thresholds and critical vaccination coverage using generally
accepted reproductive numbers for common vaccine-preventable diseases
|
Vaccine-Preventable Disease
|
R0*[59]
[60]
|
Herd Immunity Threshold (%)[31]
|
Critical Vaccination Coverage** (%)[31]
|
|
Diphtheria
|
4 to 5
|
75–80
|
79–84
|
|
Measles
|
11 to 18
|
91–94
|
96–99
|
|
Mumps
|
7 to 14
|
86–93
|
90 to 98
|
|
Rubella
|
6 to 14
|
83–94
|
87 to 99
|
*R0 values indicate the number of individuals that can be directly infected by one infectious
case. Herd immunity thresholds are a function of this value.
**herd immunity thresholds are adjusted to account for vaccine effectiveness.
In most cases, the sources of U.S. outbreaks have been linked to international travel
and immigration. This is especially true in the case of measles. A recent MMWR report
looking at measles cases in the first half of 2014 indicated that 97% of 288 cases
were associated with importation from 18 countries.[32] Forty-five of these cases were reported to be direct importation and half were travelers
returning from the Philippines, where a large outbreak was occurring. Of those who
became infected, 69% were unvaccinated and 20% had an unknown vaccination status.
The remaining importations were spread relatively evenly amongst the WHO world regions.
A similar analysis was performed on the 911 confirmed cases of measles in the U.S.
between 2001 and 2011.[33] A total of 801 (88%) of these cases were determined to be import-associated from
a total of 57 countries. China, Japan, India, Italy, the Philippines and the U.K.
were all shown to be associated with 20 or more of these imported cases. Unsurprisingly,
the Philippines, China and India were countries reporting a high incidence of measles
in 2014.[34]
In an increasingly interconnected world, the chances for exposure to infectious diseases
grow and vaccination rates in developed and developing countries directly affect each
other. An estimated 1.9 million U.S. children travel overseas each year, often to
countries where these diseases are still endemic.[35] It is highly recommended that parents consult their physicians about vaccination
recommendations before taking children abroad. In some cases, it is even recommended
that children receive vaccines ahead of schedule to protect them from exposure abroad.[36]
Disease Presentation and Clinical Guidelines
Disease Presentation and Clinical Guidelines
Many of these commonly vaccinated diseases have not been seen in the U.S. in large
numbers and, therefore, are unlikely to have been encountered during physician training
or practice. With the possibility of encountering these diseases both at home and
abroad and the likelihood of head and neck presentations, the following review of
clinical presentations and treatment guidelines will serve as a guide to VPDs that
may present to the otolaryngologist.
Measles[37]
[38]
Measles is an acute viral infection characterized by the prodrome of fever (as high
as 105), malaise, cough, coryza and conjunctivitis followed by a maculopapular rash.
The rash starts ∼ 14 days after exposure, starts on the head and spreads to the trunk
and extremities. Measles can result in complications such as pneumonia, encephalitis
and death, with a death rate of 2–3/1000.
The average incubation period is 14 days with a range of 7–21 days. Patients are considered
infectious from 4 days before to 4 days after the onset of the rash. Laboratory testing
is required for all suspected cases of measles and includes measles-specific immunoglobulin
M (IgM) antibodies and measles ribonucleic acid (RNA) detection by real-time polymerase
chain reaction (RT-PCR). These samples are obtained via a serum sample and throat
swab. Virus isolation and RNA detection are much more likely to be successful early
in the infection (first 3 days of rash) but may be successfully isolated up to 10
days after the start of the rash.
Patients should be isolated for 4 days post rash onset. Airborne precautions should
be instituted in a hospital setting. Measles, mumps and rubella (MMR) vaccine, if
administered within 72 hours of initial measles exposure, and immunoglobulin (IG),
if administered within 6 days of exposure, may provide some protection or modify the
clinical course of the disease. Individuals who are at high risk for severe disease
and complications from measles (infants aged < 12 months, pregnant women without evidence
of measles immunity and severely immunocompromised persons) should receive IG.
Children who are malnourished are at a much higher risk of severe complications. In
the developing world, this population has a death rate as high as 10%. The WHO recommends
two doses of vitamin A (separated by 24 hours) to infected children in the developing
world. This has been shown to not only reduce blindness but it can also cut the death
rate by 50%.
Mumps[39]
[40]
Mumps is an acute viral illness caused by a paramyxovirus. The classic symptom of
mumps is parotitis lasting at least 2 days and it may persist for longer than 10 days.
The parotitis typically develops 16 to 18 days after exposure and is present in 31–65%
of cases. Non-specific symptoms may precede the parotitis by a few days, including
low-grade fever, myalgia, anorexia, malaise and headache. Mumps may also present as
a nonspecific respiratory infection or subclinical infection. Fifty percent of individuals
with mumps have cerebrospinal fluid pleocytosis, but fewer than 10% have symptoms
of central nervous system infection.
In the pre-vaccine era, unilateral deafness caused by mumps occurred in 1 in 20,000
infected individuals and orcheitis presented in 11.6–66% of infected post-pubertal
males. The virus is known to cross the placenta but has not been associated with any
known congenital defects.
Mumps viral count is highest around the time of onset of parotitis and decreases rapidly
after that. Most transmission likely occurs before and within 5 days of parotitis
onset.
If mumps is suspected, laboratory tests should be performed. Acute mumps infection
can be detected with serum levels of IgM (enzyme immunoassay is preferred over immunofluorescence
assay), a significant rise in immunoglobulin G (IgG) titers, positive mumps viral
culture or detection of the virus by RT-PCR. Parotid duct swab yields the best sample,
especially when the gland area is massaged for 30 seconds prior to collection. Samples
should be collected as close to the onset of parotitis as possible.
There are currently no medications that have been shown to treat the mumps virus.
Treatment is focused on relieving symptoms and preventing its spread. This includes
pain control, hydration, warm or cold compresses to the parotid region, soft diet
and isolation for 5 days.
Rubella[41]
[42]
Rubella is caused by the Rubivirus and is characterized by a generalized erythematous
maculopapular rash. Children usually develop no constitutional symptoms but adults
may experience headaches, malaise, mild coryza and conjunctivitis. Postauricular,
occipital and posterior cervical lymphadenopathy is characteristic and precedes the
rash by 5–10 days. The transient polyarthralgia is rarely present in children but
is more common in adolescents and adults. Encephalitis and thrombocytopenia are rare
complications. Congenital rubella has much more common and severe complications including
miscarriage, fetal death and congenital anomalies. The classical presentation of congenital
rubella includes ophthalmologic issues, cardiac defects, sensorineural hearing loss,
and neurological issues. Mild forms of the disease may be associated with few obvious
abnormalities but more outward presentations include purpuric skin lesions (blueberry
muffin appearance), thrombocytopenia, hepatosplenomegaly and radiolucent bones. The
severity of these anomalies is often associated with the gestational age at onset
of infection, with a much higher rate of a clinically significant effect in infants
infected in the first 4 weeks of gestation.
Maximal contamination period is from a few days before to 7 days after the presentation
of the rash. A small number of infants with congenital rubella may shed the virus
for up to a year in their nasopharyngeal secretions and urine. The incubation period
for postnatal infection is from 14 to 23 days.
The clinical diagnosis of rubella is unreliable; therefore, cases must be confirmed
by laboratory testing. The rubella virus can be detected from nasal, throat, blood,
urine and cerebrospinal fluid (CSF) specimens. Throat swabs and urine sample collected
for RT-PCR are recommended. Cerebrospinal fluid testing should be reserved for patient
suspected to have rubella encephalitis. Enzyme immunoassays (EIAs) can be used to
detect IgG and IgM antibodies. This test is sensitive and relatively easy to perform.
Because this disease is rare in the U.S., a high proportion of IgM-positive tests
will be false positives.
Patients with rubella should be isolated for 7 days after rash onset. All persons
who are at risk and cannot provide evidence of vaccination should be revaccinated.
There is no effective antiviral treatment for rubella. Immunoglobulins are sometimes
used in pregnant women who have been exposed.
Diphtheria[43]
[44]
Diphtheria is caused by the toxigenic strains of gram-positive Corynebacterium diptheriae. Diphtheria typically presents with a sore throat, difficulty swallowing, malaise
and low-grade fever. The hallmark of respiratory diphtheria is the gray-whitish pseudomembrane
over the tonsils, pharynx or larynx that bleeds when removed. Swelling of the cervical
lymph nodes gives rise to a “bull-neck” appearance. As the pseudomembrane extends
from the pharynx to the larynx, it may cause obstruction of the airway and if left
untreated may be fatal with a case fatality rate of 10%. Diphtheria toxin can also
cause systemic complications with damage to the myocardium, nervous system and kidneys.
Cutaneous diphtheria is usually mild, typically consisting of non-distinctive sores
or shallow ulcers and it rarely causes toxic effects (1–2%).
Diagnostic tests used to confirm diphtheria include isolation of the bacteria in culture
and toxigenicity testing. There are no other commercially available tests but the
CDC can perform polymerase chain reaction (PCR) tests on clinical specimens. Clinical
specimens for culture should be taken from the nose or nasopharynx and throat from
all persons with suspected cases and those in close contact with them. Material should
be taken from the pseudomembrane or the area just below the pseudomembrane. Toxigenicity
testing using the Elek test should be done to determine whether the organisms produce
diphtheria toxin.
The mainstay of treatment is prompt administration of diphtheria antitoxin in suspected
cases, even before laboratory confirmation. The amount of antitoxin used depends on
the extent of the disease. To obtain the antitoxin, the clinician should contact the
CDC Emergency Operations Center (770–488–7100). In addition, the patient should receive
antibiotics with erythromycin or penicillin administered as a 14-day course. Droplet
precautions are recommended until two nasal and pharyngeal cultures are negative.
Haemophilus influenzae Infection[45]
[46]
Haemophilus Influenzae (H. influenzae) is an invasive disease caused by the gram-negative coccobacillus bacterium haemophilus influenzae. The bacteria may either be encapsulated (types a-f) or non-encapsulated (non-typeable).
Invasive H. influenzae may cause meningitis, bacteremia or sepsis, epiglottitis, pneumonia, septic arthritis,
osteomyelitis, pericarditis and cellulitis. Before effective vaccination, Hib was
the cause of more than 95% of all invasive haemophilus infections. Meningitis occurred in more than two thirds of the cases of Hib disease
with resulting hearing impairment or severe permanent neurological sequelae, paralysis
in 15–30% of survivors and 4% of all cases were fatal.
Gram stain of infected fluid may demonstrate small gram-negative coccobacilli suggestive
of invasive haemophilus disease and positive culture establishes the diagnosis. All isolates of H. influenzae should be serotyped. Antigen testing of body fluid may be performed in addition to
cultures in those patients who have received antimicrobial therapy.
Treatment includes either a third-generation cephalosporin (cefotaxime or ceftriaxone)
or chloramphenicol in combination with ampicillin. Ampicillin-resistant strains of
Hib are now common, so Ampicillin should not be used as a monotherapy. Patients showing
signs of airway obstruction should be given supplemental oxygen and taken to the operating
room (OR) for management of the airway according to the local hospital's epiglottitis
protocol.
Final Comments
The recent rise in NMEs in school-age children has led to a higher risk of VPD occurrence.
This trend coincides with an increase in the severity and risk of outbreaks within
the U.S. Increasing global mobility allows for ease of disease transmission and limits
the extent to which outbreaks can be contained. Most otolaryngologists have not cared
for patients with these diseases and this paper serves as a review of the clinical
presentations and treatment guidelines for these VPDs.
Due to the increased chance of exposure to patients with VPDs and their presentation
in the head and neck, it is recommended that otolaryngologists familiarize themselves
with these disease processes, their treatment, and the agencies involved in reporting
occurrences. Each state and country maintains its own set of reportable diseases and
mandates reporting to the respective department of health. Physicians should familiarize
themselves with reportable diseases in their state of practice and identify the forms
necessary for notification. The VPDs discussed in this article are included on most
state's reportable disease lists.
The misconception is often that these diseases only present in young unvaccinated
children. The recent 2015 measles outbreak in California showed that 40% of the intentionally
unvaccinated patients who contracted measles were adults.[47] Similarly, recent outbreaks of mumps in college campuses are primarily affecting
students in their late teens and early twenties. However, certain VPDs are more likely
to present in early childhood. Children under the age of 18 comprise 30–35% of the
patient population of general otolaryngologists and most children receiving otolaryngologic
care in the US receive care from a general otolaryngologist.[48]
While the likelihood that an individual otolaryngologist will see one of these VPDs
is small, as global mobility increases and social changes affect the number of patients
choosing not to vaccinate, exposure may increase with time. With this increased likelihood
of exposure, otolaryngologists need to be aware of the variable presentations of these
diseases and include them in their differential diagnosis where appropriate.
While the majority of work otolaryngologists perform is in the diagnosis and management
of diseases of the head and neck, they do play a role in disease prevention by recommending
vaccinations. Otolaryngologists often recommend immunization for influenza to prevent
recurrent ear and sinus infections in susceptible populations. They also recommend
pneumococcal vaccinations to prevent increased risk of meningitis in patients undergoing
cochlear implantation. More recently, otolaryngologists are playing a larger role
in recommending HPV vaccines to prevent oropharyngeal cancer. Data consistently suggests
that the more patients and families are encouraged to vaccinate, the more likely they
are to actually undergo vaccinations.[49] As part of the medical community, otolaryngologists who treat children and adults
should encourage routine vaccinations.
