Answer:
use insect repellent.
wear long sleeved shirts and pants.
use windows and door screens.
sleep with a bed net.
stay in air conditioned rooms.
avoid areas with still or stagnant water.
Explanation: These are all ways of preventing an insect born disease
Fiction or Fantasy because obviously no man is going to turn into a monstrous vermin overnight and Gregor is still rational and acts like a human which vermin do not do.
