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154 CHAPTER 6

Source: Centers for Disease Control and Prevention (CDC)

FIGURE 6-14 Life cycle of Strongyloides stercoralis, the causal agent of Strongyloidiasis

normally only be obtained through a surgical procedure
but if the surgical procedure is done, definitive iden-
tification of the species is possible.

STRONGYLOIDES STERCORALIS
Rhabditiform (L) larvae that hatch from eggs are 250 Source: Centers for Disease Control and Prevention (CDC)
to 300 μm long, and approximately 15 to 20 μm wide.
They have a long buccal canal, and the rhabditiform lar-
vae are usually not found in the stool (Figure 6-15). But
if examination of the stool is delayed, eggs may hatch and
there may be abundant larvae present. If larvae are seen
in stool, these larvae of Stronyloides stercoralis must be FIGURE 6-15 Morphologic structure of a hookworm
differentiated from that of the hookworms N. americanus rhabditiform larva of Stronyloides stercoralis