August 27, 2008
Measles, a childhood disease nearly eradicated with vaccinations, appears to be making a comeback. Since the beginning of the year, more measles cases have been reported in the U.S. than during the same period in any year since 1996, according to the Centers for Disease Control and Prevention's Morbidity and Mortality Weekly Report.
Between January 1 and July 31, 2008, 131 cases were reported to CDC's National Center for Immunization and Respiratory Diseases (NCIRD). At least fifteen patients, including four children younger than 15 months of age, were hospitalized. No deaths have been reported.
In the decade before the measles vaccination program began, an estimated 3-4 million people in the United States were infected each year. Of these, 400-500 died, 48,000 were hospitalized, and another 1,000 developed chronic disability from measles encephalitis.
"Measles can be a severe, life-threatening illness," said Dr. Anne Schuchat, director of NCIRD. "These cases and outbreaks serve as a reminder that measles can and still does occur in the United States."
Of the 131 patients, 112 were unvaccinated or had unknown vaccination status. Among the 112 unvaccinated U.S. residents with measles, 16 were younger than 12 months of age and too young for vaccination, and one had presumed evidence of measles immunity because the person was born before 1957.
Of the 95 patients eligible for vaccination, 63 were unvaccinated because of their or their parents' philosophical or religious beliefs.
Although immunization coverage rates for measles vaccine remain high, unvaccinated people are at risk for measles, and sizeable measles outbreaks can occur in communities with a high number of unvaccinated persons.
Measles is consistently one of the first diseases to reappear when immunization coverage rates fall. Increases in the proportion of the population declining vaccination for themselves or their children might lead to large-scale outbreaks in the U.S.
Currently, Israel and a number of countries in Europe -- including Switzerland, Austria, Italy, and United Kingdom -- are reporting sizeable measles outbreaks among populations refusing vaccination.
"These cases resulted primarily from failure to vaccinate, many because of philosophical or religious belief," said Schuchat. "The vaccine against measles is highly effective in preventing infections, and high immunization levels in the community are effective at preventing or drastically decreasing the size of outbreaks."
