WowAce

Can see all other deceases on my priest but htat one

Mutating Injection is currently indeed not showing up on Decursive (went there 25), is there a current workaround?

Completed Naxx 10 and 25 over the last few days and Mutating Injection does not show up to dispel on Grobbulus using Decursive.

This is by design because, back in the days, if this disease was removed the player exploded and contaminated everyone around them. Did this change in this re-release of wotltk?

https://www.wowhead.com/wotlk/guides/grobbulus-naxxramas-raid-strategy-wotlk

The disease does still cause a cloud whether it’s dispelled or not. By controlling the dispell it’s too ensure the player moves out of the raid into an appropriate location, and then dispelled/healed. This way the cloud isn’t cast on group and the player with disease can move back into group and won’t be affected by the cloud after being dispelled. If this could be included that would be great. 

This is fixed in 2.7.8.12 that was just released: Added "Mutating Injection" to the "harmful debuff" list instead of the ignore list. You'll hear a sound and a warning will be displayed whenever your mouse cursor enters within a MUF with the Mutating Injection debuff.