and filariform larvae were isolated by stool culture (Figure, panel B).
The parasite is, then, swallowed and penetrates the duodenal wall where rhabditiform
larvae hatch from the eggs to be expelled in feces; and restart the asexual cycle in soil.
Characteristic of Halicephalobus deletrix, a rhabditiform esophagus containing a corpus, isthmus, and bulb was observed (Figure 2, E).
The typical morphologic features of Halicephalobus deletrix are the distinctive rhabditiform esophagus with corpus, isthmus, and bulb and the dorsiflexed ovary.
Distinguishing morphological characteristics of the larvae were consistent with the rhabditiform
larvae stage of the parasite.
The diagnosis is made with the detection of characteristic eggs on faecal samples, the exception being Strongyloides, where rhabditiform
larvae in stool are diagnostic.
Trichrome stains on smears prepared from stool concentrates on all three specimens were negative for protozoa but revealed Strongyloides stercoralis rhabditiform
The eggs mature into noninfectious feeding forms called rhabditiform
larvae, which, after being expelled with feces, can mature in the soil, reproduce, and infect other hosts, or the larvae can mature into filariform larvae within the human host.
S stercoralis has the unusual property that rhabditiform
larvae may develop into infective filariform larvae and be passed in the feces.
After the eggs hatch in the intestinal mucosa, they release rhabditiform
larvae, the diagnostic stage of the organism.
Stool examination for ova and parasites revealed S stercoralis rhabditiform
larvae, eggs, and parasitic females.
The molting of S stercoralis rhabditiform
larvae into filariform larvae, with a subsequent increase in number of parasites per host and anatomic dissemination, was proposed by Genta as a possible trigger.