Help: Where can I modify the length of certain diseases/infections?

[Ink.]

Hi there. I've actually found the Hediffs_Local_Infections xml but not sure if I can do it here.

Basically, I just want to make it so that certain diseases (i.e. gut worms) last forever, but have a much rarer chance of spawning. Thus making them a permanent condition, IF in the off chance one of your colonists gain them. Any ideas where/what I should be looking to edit?

[Kirby23590]

Gut worms, i think has the <baseTendDurationHours> but i think removing or modifying the disappearsAtTotalTendQuality would make it permanent i think...