Tree Fever was a lethal disease that affected some Grand Line islands 400 years ago.
Symptom and Cure
The only one known symptom is the apparition of some dark spots (resembling green rash or moss in the anime) on the skin. It can be transmitted from animals to plants and vice versa.
Four hundred years ago, this disease affected Jaya and most of the Shandia that believes it to be a curse of gods. To stop it, the dying Pantri, Chiya, ordered to sacrifice Mousse to the snake god Kashigami.
As the sacrifice was about to happen, the botanist Mont Blanc Noland landed on the island and found an affected indigenous named as Seto and cured Seto. After curing him, Noland went on to kill Kashigami to stop the sacrifice. After some initial misunderstandings, the botanic had been capable to use the Conine to cure all the tribe.
To stop the spread of the disease, Noland and his crew chopped down the infected forest, also known as the sacred forest of Shandia which caused a misunderstanding between the Shandia and Noland and his crew.
- The Tree Fever symptom resembles the effects of Daft Green's toxic spores. Both of them make green spots appear on the skin.
- Yorki's lethal disease, its symptoms (dark blots on the skin) and the way he contracted it (in a jungle), greatly resemble the Tree Fever. However, no links between the two diseases are confirmed.
- One Piece Manga and Anime — Vol. 31 Chapter 291 and Episode 189, A Noland's crew member explains they chopped down the sacred forest as the disease can be transmitted from animals to plants and vice versa.
- One Piece Manga and Anime — Vol. 31 Chapter 287 and Episode 187, The dying Pantri orders Mousse's sacrifice to Kashigami.