By JULIET WANG
Capital News Service
LANSING—Chickenpox cases are declining in Michigan, but outbreaks still occur in schools and classrooms despite unprecedented use of vaccines.
There were 5,239 cases reported in 2006, dropping to 1,887 in 2009. So far this year, there have been 1,285, according to the Michigan Disease Surveillance System.
Delta and Berrien counties were among those with the most cases so far this year, Delta with 46 and Berrien with 47. Other counties with many cases include Oakland with 137, Genesee with 106, Macomb with 76, Kent with 54 and Monroe and Saginaw with 48 each.
Nicki Britten, an epidemiologist with the Berrien County Health Department, said the decrease is due to a state guideline for getting a booster shot at around the age of 11.
In some communities in Berrien County, “there is situation where parents don’t want their children to get the vaccines,” Britten said.
“We’ve had a couple of clusters of outbreaks in schools and in classrooms with students who had one vaccine shot but not the second,” said Britten. “With the students who had the vaccine, their case was much milder than those who had none. They had 15 poxes instead of 200 with the unvaccinated students.
“I’m assuming higher vaccination rates for the statewide declining chickenpox cases,” Britten said.
In Delta County, chickenpox outbreaks might have occurred because of exposure at sporting events.
Jenny Miller, immunization and communicable disease coordinator at Public Health of Delta and Menominee Counties, said “I don’t know where it originated from but maybe from an elementary school or a wrestling team where they came into contact with another school’s student who might have been infected.”
Miller said children who didn’t follow up on their booster shots may have contributed to more cases in Delta County.
“In some cases, kids who had two vaccines still broke out. The chickenpox rash was verified by school nurses. With vaccines, some kids get the first one but never follow up on the second,” said Miller.
Miller also blamed waning immune systems for vaccines not protecting children to the fullest. “There’s so many kids in close proximity and with different sporting teams and unprotected kids, it can spread quite a bit.”
© 2010, Capital News Service, Michigan State University School of Journalism. Not to be reproduced without permission.