1. Reinfection by microbes or parasitic organisms on or within the body that have already passed through an infective cycle, such as a succession of boils, or a new infective cycle with production of a new generation of larvae and adults, as by the nematode Strongyloides stercoralis or the cestode Hymenolepsis nana.
2. Self-infection by direct contagion as with parasite eggs passed in the infectious state transmitted by fingernails (anal-oral route), as with the pinworm, Enterobius vermicularis. Syn: autoreinfection, self-infection.