Whooping cough skyrockets in Minnesota, WisconsinWisconsin and Minnesota were hit hard by whooping cough in 2012, with Minnesota reporting its biggest number of cases since World War II.
By: News Tribune staff and news service reports, Duluth News Tribune
Wisconsin and Minnesota were hit hard by whooping cough in 2012, with Minnesota reporting its biggest number of cases since World War II.
More than 4,300 Minnesota residents had confirmed, probable or suspected cases of the respiratory infection as of Dec. 13 this year, according to the Centers for Disease Control and Prevention. There were 661 in 2011.
Wisconsin had 5,668 cases as of Dec. 14, compared with 1,192 in 2011, the CDC reported.
Whooping cough, also known as pertussis, is a highly contagious respiratory illness that can seem like a bad cold in adults but that can be deadly in infants. Outbreaks tend to happen every three to five years. Before the first pertussis vaccine became available in the United States in 1943, Minnesota had as many as 5,000 cases some years.
Wisconsin had the highest rate of whooping cough in the country — 93.4 cases for every 100,000 people as of Nov. 23, the CDC reported. Minnesota had risen from the fourth-most in the country to the second-most — 78.1 cases for every 100,000 people.
There’s no particular reason Wisconsin and Minnesota are the leading states, said Dr. Linda Van Etta, infectious disease specialist at St. Luke’s hospital in Duluth. One reason that Minnesota might have high numbers is that the state Department of Health has a particularly robust reporting system, she said.
The Northland was not immune to whooping cough outbreaks in 2012.
South Shore School in Port Wing closed for several days in February as more than a third of the student body was treated for the infection.
Other, lesser outbreaks were reported during the year in the Ashland school district and at Lakewood Elementary School near Duluth.
Experts say the reason for the high number is a redesigned vaccine that was introduced in 1991 to reduce the side effects.
Patsy Stinchfield, director of pediatric infectious disease services for Children’s Hospitals and Clinics of Minnesota, said the vaccine’s protection doesn’t last as long.
“It’s evolutionary,” Stinchfield said. “You have to sort of watch how it evolves. You make a change to a vaccine in the ’90s and you evaluate it a decade later.”
Immunity begins to wane about three years after vaccination, said Kris Ehresmann, director of infectious disease epidemiology at the Minnesota Department of Health. So by the time fully immunized kids reach adolescence, they have very little protection left.
“My hope is that with some changes in the immunization recommendations that this won’t continue to be the new normal,” Ehresmann said.
One recommendation that’s being considered is that the booster vaccine be given to children as young as 9, Van Etta said. It’s currently recommended for adolescents ages 11-18, but the original vaccination appears to be wearing off sooner than that. The current outbreak has been hitting 9- and 10-year-olds hardest, she said.
One of the Minnesotans affected in 2012 was Heather Chasse, now 3 months old.
Her mother, Rachel, said she took her daughter into the clinic with a severe cough when she was 2 weeks old. Rachel Chasse was waiting in an exam room when her daughter had a particularly bad coughing episode and had trouble breathing.
The baby was taken by ambulance to Children’s Hospital in Minneapolis, where she spent two weeks. The baby is much better now, but when she gets agitated, there still are remnants of her pertussis cough, Chasse said.
Although there have been no deaths attributed to pertussis in Minnesota this year, the disease can be deadly when infants get it, Van Etta said. That’s why the CDC, as of Oct. 24, recommends that every pregnant woman be given a booster vaccination.