A Gamma Quadrant people who were punished by the Dominion with a fatal disease known as the blight, which Julian Bashir tried to cure.
The Teplans are a humanoid people of the Gamma Quadrant. Two centuries before Deep Space Nine's crew met them, the Dominion punished their resistance by infecting the entire population with the blight, a disease that marks its victims with lesions and kills them when it reaches its final stage, the quickening.
In The Quickening, Julian Bashir and Jadzia Dax visited the Teplan homeworld, where Trevean offered the dying a painless death. Bashir struggled to find a cure but eventually produced a vaccine, and Ekoria, a pregnant woman, gave birth to a child free of the disease.