Telurian plague

Telurian Plague was a deadly disease discovered sometime prior to the mid 22nd century.

Stocks of Telurian Plague pathogen were stored at Cold Station 12 in 2154 for medical study. That year, these samples were stolen by Malik, with the intent of using them as biogenic weapons. 

There was still no cure for the Telurian Plague in the mid 24th century. When she encountered time-traveler Berlinghoff Rasmussen in 2368, Doctor Beverly Crusher asked him if a cure had been found in the 26th century. 

In 2376, while visiting Mariposa, Lieutenant Commander Domenica Corsi worried that the planet's biosynthesizers could be used to create the Telurian Plague pathogen.