ID Consult: national immunization coverage and measles.
On Aug. 28, 2013, vaccination coverage of U.S. children aged 19-35 months was published in Morbidity and Mortality Weekly Review (2014;63:741-8) based on results from the National Information Survey (NIS), which provides national, regional, state, and selected local area vaccination coverage estimates.
Vaccination coverage of at least 90%, a goal of Healthy People 2020, was achieved for receipt of one or more dose of MMR (91.9%); three or more doses of hepatitis B vaccine (Hep B) (90.8 %); three or more doses of poliovirus vaccine (92.7%); and one or more doses of varicella vaccine (91.2%).
Coverage for the following vaccines failed to meet this goal: four or more doses of diphtheria, tetanus, and pertussis vaccine (DTaP) (83.1%); four or more doses of pneumococcal conjugate vaccine (PCV) (82%); and a full series of Haemophilus influenzae type b (Hib) (82%). Coverage for the remaining vaccines also fell short of their respective targeted goals: two or more doses of hepatitis A vaccine (54.7%; target 85%); rotavirus (72.6%; target 80%); and hepatitis B birth dose (74.2%; target 85%).
Compared with 2012, coverage remained stable for the four vaccines that achieved at least 90% coverage. For those that did not, rotavirus was the only vaccine in 2013 that had an increase (4%) in coverage. Of note, there was an increase in the birth dose of 2.6% for Hep B.
Children living at or below the poverty level had lower vaccination coverage, compared with those living at or above this level, for several vaccines, including four or more doses of DTaP; a full series of Hib vaccine; four or more doses of PCV; and rotavirus vaccine. Coverage was between 8 and 12.6 percentage points lower for these vaccines.
Let's take a closer look at measles. Nationally, almost 92% of children received at least one dose of MMR. However, coverage varied by state an observation unchanged from 2012. New Hampshire had the highest coverage at 96.3%, and three states had coverage of only 86% (Colorado, Ohio, and West Virginia). Overall 17 states had immunization rates less than 90%. Additionally, 1 in 12 children did not receive their first dose of MMR on time. Why the concern? In 2013, there were 187 cases of measles including 11 outbreaks. A total of 82% occurred in unvaccinated individuals, and another 9% were unaware of their immunization status.
As of Aug. 25, 2014, there were 595 cases of measles in the United States in 21 states, usually occurring as a result of 18 outbreaks, according to the Centers for Disease Control and Prevention's National Center for Immunization and Respiratory Diseases. This is the highest number of cases reported since endemic measles was eliminated in 2000. Cases are occurring even in states where immunization rates are reported to be at least 90%--a reminder that there can be pockets of low or nonimmunizing communities that leave their citizens vulnerable to outbreaks when a highly contagious virus is introduced.
Since endemic measles was eliminated 14 years ago in the United States, many health care providers have never seen a case of measles or may not realize the impact it once had on our public health system. Prior to the initiation of the measles vaccination program in 1963, 3 million to 4 million cases of measles occurred annually in the United States with 400-500 deaths and 48,000 hospitalizations. Approximately another 1.000 individuals were left disabled secondary to measles encephalitis. Once the vaccine was introduced, the incidence of measles declined 98%, according to "Epidemiology and Prevention of Vaccine-Preventable Diseases," 12th ed., second printing. (Washington, D.C: Public Health Foundation, 2012). Between 1989 and 1991, there was a resurgence of measles resulting in approximately 55.000 cases, 11,000 hospitalizations, and 123 deaths. The resurgence was caused primarily by the failure to vaccinate uninsured children at the recommended 12-15 months of age. Children younger than 5 years of age accounted for 45% of all cases. The Vaccines for Children Program was created in 1993 as a direct response to the resurgence of measles. It would ensure that no child would contract a vaccine-preventable disease because of inability to pay.
Measles remains endemic in multiple countries worldwide that are travel destinations for many Americans. In 2013, 99% of 159 U.S. cases were import related. An overwhelming majority of infections occurred in unvaccinated individuals. In 2014, this trend continues, with the majority of cases occurring in unvaccinated international travelers who return infected and spread disease to susceptible persons including children in their communities (MMWR 2014:63;4969). Of the 288 cases reported by May 23, 2014, 97% were associated with importations from 18 countries.
High immunization coverage must be maintained to prevent and sustain measles elimination in the United States. As a reminder, all children aged 6-11 months should receive one dose of MMR ideally 2 weeks prior to international travel. When the infant is at least 12 months of age, they should receive two additional doses of MMR or MMRV according to the routine immunization schedule. Those children older than 12 months of age should receive two doses of MMR. The second can be administered as soon as 4 weeks after the first dose. It is not uncommon for families to travel internationally and fail to mention it to you. Many have been told their child's immunizations are up to date, not realizing that international travel may alter that definition. It behooves primary care providers to develop strategies to facilitate discussions regarding sharing international travel plans in a timely manner.
Dr. Word is a pediatric infectious disease specialist and director of the Houston Travel Medicine Clinic. She had no relevant financial disclosures. Write to Dr. Word at pdnews@ frontlinemedcom.com. Scan this QR code to view more ID Consult columns or go to pediatricnews.com.
Countries with more than 1,000 confirmed measles cases in 2014 Georgia 2,837 Ukraine 1,960 Italy 1,883 Chad 1,143 Nigeria 6,351 D.R. Congo 1,292 Angola 3,753 Pakistan 1,023 India 13,822 Sri Lanka 1,644 Ethiopia 2,989 Russia 1,799 China 41,270 Indonesia 3,515 Vietnam 3,886 Philippines 37,421 Notes: Total confirmed cases as of Aug. 4. The figure for India represents reported, not confirmed, cases in 2013. Source: World Health Organization
Please note: Illustration(s) are not available due to copyright restrictions.
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|Title Annotation:||INFECTIOUS DISEASES|
|Author:||Word, Bonnie M.|
|Date:||Sep 1, 2014|
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