Tartha pox is an illness that can infect Bajorans.
In 2371, several Bajoran children in Molly O'Brien's day care centre became ill with tartha pox. Several weeks later, Miles O'Brien suggested the disease as a cover story for keeping Julian Bashir's Bajoran assistant away from seeing the Dax symbiont from the future. Benjamin Sisko slyly stated it should be something a little more deadly. (DS9 novel: Time's Enemy)