Answer: Whipworm, Trichuris trichiura
Congratulations to everyone who wrote in! You all recognized the long slender head and larger body which gives this worm it’s name ‘whipworm’. In this case, the worm was immediately recognizable, and the expression of eggs provided confirmatory identification.
There are many other instances, however, when what is received in the clinical parasitology lab is not clearly a worm. This is when the identification of eggs is extremely useful. This is done by the following method:
Wearing gloves, the worm is gently ‘prodded’ with a blunt object, such as a sterile wooden applicator stick, to attempt to express eggs from its uterus. It is helpful to have the worm in a small amount of saline or formalin, so that this fluid can then be pipetted onto a slide for examination. Similarly, if the worm is received in fluid, it can be centrifuged briefly, and the supernatant removed, leaving the pelleted material behind. This material may also contain eggs to aid in the identification.