It's been three years since Pima County and the state of Arizona had a whooping cough outbreak, and a University of Arizona infectious diseases specialist says we might be due for the next one.

Dr. Sean Elliot, a pediatric infectious diseases specialist for the University of Arizona Health Network, said pertussis, better known as whooping cough, outbreaks occur in a three to five year cycle.

The disease has infected 58 people in Pima County so far this year, according to the Arizona Department of Health Services.

Figures from ADHS showed only 46 cases of the highly contagious respiratory disease were reported last year.

“Pima County and the state of Arizona are just about due for our next outbreak," he said "We’re three years out from our last major cluster of diseases. A major contributor to that is not just the natural cycle of whooping cough but also the immunity or vaccination status of adults, young adults and adolescents.”

Elliot explained the vaccine for whooping cough is effective but the immunity doesn’t last as long as an older version of the vaccine. He said that puts a large population of young adults and children at risk for the disease, but he added a pertussis booster can help ensure the vaccine’s effectiveness.

Whooping cough is spread by a person inhaling infected respiratory droplets from another person. Elliot said initially a person will have a cold-like illness that can last for up to three weeks. And, that is followed by the coughing portion of the disease that can last for up to three months.