I was playing a Huge galaxy as the Altarians, and everyone was fighting the Drengin. They probably wouldn't have won, but put up a good fight. Then the galactic disease hit. I researched the cure in two turns (putting all my efforts into research), but others didn't. The Drengin, for example, blithely kept researching Phasors VII. Okay, maybe they'll research the cure when they're done? I don't know. They never finished. Apparently, their morale was so low already that when the disease hit, all of their colonies stopped producing anything. No social, military, or research, nothing. Then the plague event occurred, and their population plummeted. It's been quite a while and nobody else seems to have cured it.
Probably the weirdest thing is that they were still ranked #1, because of their large military. It was mostly those worthless Super Dominator corvettes (I destroyed 78 of them when they attacked one medium hull in waves of 3 with no damage).
I'm curious, though: What, exactly, were the Drengin doing that caused them to crash so badly when the disease occurred?