It seems really strange this sort of infection, that seems to consume inside out to multiply and spread, but it seems like it doesn't or least directly go after plants, seeking living beings. The artwork may not be top tier, but I'd say it is more than good enough.
Based on how it ended, to purge the infection would be to nearly bleed to death so that it pumps itself out. to fight against what is already there, they have not tried, but throwing rocks, attempting to burn it, or other long reach/indirect contact measure. Unless they can expand their habitable radius, they will surely die within a week or two.
Interesting an infection that targets the blood (red), spreading through the body like a fungal infection, then pouring itself out to lie in wait for something to latch onto.