Hapthoid Radiation Sickness was a form of radiation poisoning caused by the radiation generated from a Hapthoid reactor unit.
In the 19th century, an outbreak of Hapthoid Radiation Sickness afflicted the village of Klimtenburg when fragments of a crashed Cyber-ship's reactor unit were made into jewellery by Vadim and Nefta and handed out to the villagers. As they were unaware of radiation, the villagers attributed the disease and related deaths to a resurgence of the bubonic plague or, in more bizarre circumstances, the legendary "Plague Warriors".
The Eleventh Doctor and Olga Bordmann dealt with the outbreak. Combating the symptoms with anti-radiation pills, they and Olga's school children gathered up the reactor jewellery for the Doctor to dispose of. (PROSE: Plague of the Cybermen)