Recent media reports on a national measles outbreak overemphasized the impact of the disease in Arkansas, state Health Department officials say. But they are nevertheless worried about the rising number of children exempted from vaccines. Exemptions have more than doubled statewide since the 2003-04 school year, to nearly 2,000 children.
The Centers for Disease Control and Prevention first highlighted an increased occurrence of measles in April. The notice drew attention to outbreaks in Arizona and San Diego, both of which originated in Switzerland. Since then, Reuters and USA Today have reported that the outbreak had expanded to include 127 people in 15 states, including Arkansas.
According to the Health Department, there have been two documented cases of measles in Arkansas this year, both in adults. The CDC definition of an outbreak is three or more cases. Still, CDC spokesman Curtis Allen said, “If there’s one case of measles, it’s cause for concern. It’s important to realize that this is a serious disease that could return if vaccinations decrease.”
“We should have never been included in those reports,” said Dr. James Phillips, branch chief for infectious disease at the Health Department. “Although we couldn’t absolutely verify this, there were a number of things about those two cases that suggested they really didn’t have measles. It’s unknown what they had, but we didn’t have enough evidence not to report them.” Phillips added that he believes the cases in Arkansas are unconnected to the outbreaks in Arizona and San Diego.
Health officials are concerned, however, about an increase in the number of children who have claimed exemptions from the 11 vaccinations the health department requires for private and public school students. “For us, these newspaper stories represent a reason to discuss a rise in exemptions,” department spokesman Ed Barham said.
In the 2001-02 school year, 529 students requested an exemption; in 2007-08, 2,016 did. Of the latter requests, 1,997 were granted. Home-schooled children are not required to be immunized, so the actual number of unvaccinated children could be higher.
The number of exemptions is highest in Northwest Arkansas: 222 in Benton County and 202 in Washington County in 2007-08. Pulaski County had 133, including 81 of the Little Rock School District’s 26,000 students. “We’re monitoring and tracking those kids,” LRSD health services coordinator Margo Bushmiaer said.
Under state law, school children can opt out of vaccinations if they claim medical, religious or philosophical reasons for doing so. Medical claims must be approved by the Department of Health and are not uniformly accepted. Exemptions for religious and philosophical reasons require only a check mark on an application and are granted without exception.
Exemptions began to take off after 2003, when the state legislature created the philosophical exemption. Requests for medical reasons have remained steady since the 2003-04 school year; the number of religious exemptions granted has risen by 64 percent. Philosophical exemptions, on the other hand, have increased by 369 percent since 2003-04, the first year they could be claimed. They currently account for 74 percent of all exemptions.
The state does not track reasons given for taking a philosophical exemption. CDC spokesman Allen said many exemption requests have stemmed from the fear of a connection between thimerosal, a mercury-containing substance used in some vaccines, and autism. Research has found no proven link between thimerosal and autism, Allen said. Thimerosal has not been used in any vaccine except flu since 2002, and thimerosal-free flu vaccinations are available. Thimerosal was never used in measles vaccines.
The last major measles outbreak nationwide was in 1989-1991, when 120 people died of the disease. Measles routinely killed 400 people annually before a vaccine was approved in 1963. The primary danger today is importation of the disease from countries where the immunization rate is lower than in the U.S., where the rate is over 90 percent.
Less than 1 percent of the 460,000 pupils in public schools are unvaccinated, and state law requires them to stay home during an outbreak. But state health officials still worry that there’s a danger to public health if the rise in exemptions continues.
“The trend is going in the wrong direction,” Phillips said. “It’s very disturbing to see this occurring.”
Not all vaccinations are 100 percent successful, and some people who are vaccinated might still be vulnerable. But as more and more people get vaccines, the chance of vaccinated people contracting the disease decreases. Basically, there is strength against disease in numbers. Doctors refer to this principle as the “herd effect.”
“Most people believe that if you vaccinate over 98 percent of the population, then you’re going to get the majority of the herd effect,” Dr. Phillips added. “But still, that leaves some individuals at risk.”
Phillips wants a change to the exemption system. “Whenever you get a number of exemptions, the protection of immunization is not only eroded away for those individuals that get the exemption, but there comes a point where those exempted individuals can become the source of dissemination for epidemics of various preventable diseases,” Phillips said.
Any change to the way exemptions are granted would have to go through the legislature. Sen. Jack Critcher of Batesville, a lead sponsor of the 2003 bill creating the philosophical category, could not be reached for comment.