Morbidity is related to number of worms harbored in intestines
Light infections often asymptomatic
Heavier infections with variety of manifestations including GI symptoms (abdominal pain, diarrhea, blood in stool, rectal prolapse), malaise, weakness, impaired cognitive / physical development, malnutrition
Iron-deficiency anemia
Hypochromic microcytic anemia
Adult worms attach to intestinal wall to feed, causing ongoing luminal blood loss
Hypochromic microcytic anemia
Adult worms attach to intestinal wall to feed, causing ongoing luminal blood loss
Hookworm
Taenia saginata
Tapeworm
Taenia solium 
Bed bugs
Diphyllobothrium latum
Pseudoparasites
Hymenolepis nana