US Measles Increase Due to Declining Vaccinations
August 28, 2008 — Measles is making a comeback in the United States, according to public health authorities, and parents who object to the measles vaccine for religious or other reasons appear to be driving the increase.
From the beginning of January through the end of July 2008, more measles cases were reported in the United States than during the first 7 months of any year since 1996, the Centers for Disease Control and Prevention (CDC) reported in the August 22 issue of Morbidity and Mortality Weekly Report (MMWR).
Of the 131 measles cases reported to the CDC′s National Center for Immunization and Respiratory Diseases this year, 112 were either unvaccinated or had unknown vaccination status. At least 15 children, including 4 younger than 15 months, were hospitalized, but no deaths were reported. Two thirds of the cases did not receive the measles vaccination for religious or philosophical reasons, according to the MMWR report.
Of the 131 cases, 13% were contracted by either US residents who traveled abroad or by foreign visitors to the United States. Source countries for infection included Italy, Switzerland, Belgium, India, Israel, China, Germany, Pakistan, the Philippines, and Russia. An additional 76% of infections were linked either through virology or epidemiology to imported measles. The source of infection for the remaining 11% of cases could not be determined.
Resistance to Vaccination
Despite exhaustive studies and evidence to the contrary, many parents of young children are worried that vaccination may cause autism spectrum disorders. Others have religious reasons for declining vaccinations.
Joanne Cox, MD, associate chief of general pediatrics at Children's Hospital Boston, in Massachusetts, told Medscape Medical News that parents' concerns about autism are understandable although misguided.
"I've been in practice for more than 20 years and I almost never used to see cases of autism, and now I frequently see it in children I've cared for since birth," she said. "There is something in the environment — plastics, chemicals, who knows. Parents are scared and looking for answers and blame vaccines, but there is no credible evidence linking vaccination to autism."
Some parents hoping to avoid mandatory vaccinations even go so far as to deliberately expose their children to the infection at "measles parties." As one such mother told The New York Times in April, "I refuse to sacrifice my children for the greater good."
Neal Halsey, MD, director of the Institute for Vaccine Safety at the Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland, told this reporter in April that "to deliberately give a child measles in this day and age is not only inappropriate, but it actually might be considered to be criminal, because it's preventable."
"Measles can be a severe, life-threatening illness," said Anne Schuchat, MD, director of the CDC's National Center for Immunization and Respiratory Diseases, in a statement. "These cases and outbreaks serve as a reminder that measles can and still does occur in the United States."
In addition to protecting individual children against measles, universal vaccinations provide herd immunity to cover those children who are either too young to receive the first dose (<12 months) or who are at risk for infection because they are immunocompromised by disease or chemotherapy.
Dr. Cox said that when parents balk at vaccines for their children, she asks them about their concerns and tries to allay their fears with information.
Information Clinicians Can Give to Patients
Vaccination for children entering school is mandatory in all 50 states, but all states allow exemptions for medical reasons.
All states except Mississippi and West Virginia also allow exemptions from immunizations for deeply held religious beliefs, and 18 allow exemptions for "philosophical" objections, according to the National Vaccine Information Center, a consumer-oriented vaccine safety watchdog group.
Measles kills about 500,000 people worldwide annually.
Measles can cause spontaneous abortion or premature delivery.
Before the inception of the measles vaccination program in the United States in the mid-1960s, measles caused about 450 annual deaths, 48,000 hospitalizations, 7000 cases of seizures, and 1000 cases of permanent brain damage or deafness.
Inform parents who are concerned about "immune overload" from multiple vaccinations provided at a single visit that Streptococcus bacteria typically have hundreds of surface antigens and provide a far greater challenge to the immune system than multiple vaccinations delivered at a single visit, which typically present only about 20 antigens.
There is no scientific evidence linking mercury-containing thimerosal-preserved vaccines with autism. When thimerosal was removed from childhood vaccines in Denmark, Sweden, and California, the rate of reported autism cases continued to climb.
Vaccines Resource Center
MMWR study on CDC Web site
Neil Osterweil is a freelance writer for Medscape.
Medscape Medical News 2008. © 2008 Medscape