It's beginning to look like a bad year for whooping cough.

State officials on Thursday reported several new outbreaks of pertussis around the state, primarily among elementary and high school students.

Cases have been reported in Fergus Falls and Albert Lea and in Douglas and Dakota counties. The outbreak in Dakota County includes 16 cases in upper elementary school students. The outbreak in Douglas County includes 24 cases, mostly among high school students.

In all, about 40 new cases have been reported this fall, bringing the total for the year so far to 375.

Whooping cough, or pertussis, usually peaks every three to five years. The last cyclical peak came in 2005, when 1,571 cases were reported. The sudden spurt of outbreaks in many places across the state could be a harbinger of another peak year, health officials say.

"Up until this point we were having a very mild year," said Kris Ehresmann, head of immunization for the Minnesota Department of Health.

Pertussis is a highly contagious bacterial infection that causes intense and persistent coughing in older children and adults. In infants it can be fatal.

Babies routinely get vaccinated for it at 2, 4 and 6 months, but they are not fully protected until after their third shot. Young children get another dose before entering school.

But the vaccine wears off, and older children can become infected. For most of them the illness can result in weeks of coughing, and they can infect vulnerable infants. Last year in Minnesota 11 infants were hospitalized for pertussis.

Since 2005 doctors and health officials have recommended a new vaccine for adolescents and adults, largely to protect infants. But nationally only about a third of adolescents and teenagers have received it, according to the Centers for Disease Control and Prevention.

"We have not reached all populations," said Ehresmann. "It's a good reminder that we have a vaccine that can help address this. We should take advantage of it."

The vaccine is available at most clinics and doctors' offices. One is approved for adolescents ages 10 to 18. The other is for adolescents and adults ages 11 to 64.

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