Officials at the Centers for Disease Control report that the country is suffering from a Whooping Cough epidemic.
Nationally, health officials say the country is on track to have the worst year for whooping cough since the late 50s.
Whooping cough is also known as pertussis.
Nearly 18 thousand cases have been reported nationally so far this year.
That's more than twice the number reported at this time last year.
Arizona falls 11th in the number of reported cases.
In the first 5 months of this year, 420 probable cases have been reported in Arizona. That's 3 times as many as the 5 year median over the same period.
Whooping cough is highly contagious, and in rare cases it can be fatal, especially for very young children.
The CDC is urging adults and especially pregnant women to get vaccinated so that they don't spread the disease to infants.
While Arizona's incidence of pertussis is much higher than the national average, it's not nearly as high as Washington and Wisconsin.
Those state's have each reported more than 3000 cases this year.