Causes of persistent cough include post-nasal drip, acid reflux, blood pressure medications, and infections like pertussis.

And if you have asthma or are older or immunocompromised ... low-grade fever (less than 100.4°) and a mild cough, according to the CDC. Unfortunately, people with pertussis are very contagious ...

Although babies are most at risk from severe disease, infections are rising in older ... people to test their inoculations.