3d
cells
contamination
dangerous
disease
duodenalis
duodenum
flagella
germs
giardia
giardiasis
illustration
infection
infectious
intestinalis
invasion
lamblia
microbe
microscopic
parasite
parasites
parasitic
parasitology
pathogen
pathogenic
pathogens
protozoa
protozoan
trophozoite
water
water borne
waterborne