TheWoWDBUnfortunately as of Cataclysm this quest was removed from the game. The quest, and it's rewards, are no longer obtainable.
The change was made to accompany the change of Garrosh as Warchief of the Horde.Here is the Gamemaster chat I had as confirmation of this change.
http://i.imgur.com/vpfZB.jpg
Quest
A Debilitating Sickness
A World of Warcraft quest in Hellfire Peninsula. Facts and objectives from the current retail game data.
The highest voted Wowhead comments for this page. They are community notes, not TheWoWDB comments.
I was not offered this quest until I had finished the "Envoy to the Mag'har" quest from Thrall ( http://www.wowhead.com/?quest=9441 ). I am not sure whether that quest in particular was required, or whether a certain level of reputation with The Mag'har faction was.
Once this quest is finished, the quest "Administering the Salve" ( http://www.wowhead.com/?quest=9447 ) opens up.
I found my Drycap mushroom at 34, 64.
Quest facts
LevelLevel 10-30
Quest ID9442
The client quest POI data records no map location for this quest, so no map is shown.
Check whether you have already completed this quest
in-game: /run print(C_QuestLog.IsQuestFlaggedCompleted(9442))
Requirements
FactionHorde only
ReputationThe Mag'har: Neutral or higher
Read from the Blizzard quest API.
Description
It is good that you've offered to aid us, {name}. Our grunts have fallen sick from drinking contaminated water and I'm missing an ingredient to produce a healing salve. I'm in need of a rare mushroom called drycap. Our foremost orders are to keep our location secret and not risk being spotted while looking for it, or I would go myself. The only place in Hellfire Peninsula where drycap grows is a cave at the Great Fissure, south of here. Be extremely careful if you choose to seek it.
Community notes from Wowhead · 37 comments
Top 3 shown aboveThe comments below were written by Wowhead users. They are community notes, not TheWoWDB comments. See them in context on Wowhead.
The top 3 are shown in Top Comments above. Read all 37 on Wowhead.
Experience4,100 XP
ReputationThe Mag'har +250
Reward details
Reputation: The Mag'har +250
This reclusive group of brown-skinned orcs has escaped any form of demonic corruption. They have retained their traditional way of life in the face of great changes in Outland.
Reputation group: The Burning Crusade.
Other quests in Hellfire Peninsula that reward The Mag'har reputation: The Mag'har (+250), A Spirit Guide (+350), Administering the Salve (+250).
Item facts are the current retail client’s (ItemSparse); the specialisations for a pick-one item are the ones the Blizzard quest API lists; faction and currency text is the client’s own. Lowest listed price = the US commodity auction house now.