A dangerous even life threatening illness is at it's highest level in decades and those most at risk are young children.
Pertussis, more commonly known as Whooping Cough is reaching alarming rates.
According to the CDC the number of cases in South Dakota has gone up more than 2 fold since last year.
And in Wyoming and Nebraska that number has increased more than 3 fold.
Nationally the number of cases were already over 34,000 as of October 27th. The total number of cases in 2011 was significantly less with under 19,000 cases being reported nationwide.
Doctors are urging parents to vaccinate young children who are at a higher level of risk.
So far this year there have been 16 deaths related to Whooping Cough, mainly in infants.