Exercises for microfilaria

Introduction to Diagnostic Medical Parasitology

Key Diagnostic Features
Exercises

Exercise for microfilaria

Where the sample was taken from?

Skin (multiple skin snips preferred; without blood contamination!)

How does the posterior end of the microfilaria look like? (Use oil immersion and make sure - by clearly seeing nuclei - that the worm is not an artefact)

Nuclei extend to the tip of the posterior end in the unsheathed thin microfilaria. In most cases the tip of the tail has the aspect of a Shepards crook

The tip of the posterior end has no nuclei

Blood sample: Thick smear

Has the microfilaria a sheath? (be aware that mixed infections are quite common!)

The microfilaria has a sheath

How does the posterior (elongated end) of the sheathed microfilaria look like? (watch for the real end in microfilaria which are not nicely stretched out!)

Nuclei do not extend to the tip of the tail

Nuclei extend to the tip in a continuous row

Two separate nuclei at the tip of the tail

The microfilaria has no sheath

How does the posterior (elongated) end of the unsheathed microfilaria look like?

Nuclei extend to the tip of the blunt tail

Nuclei do not extend to the tip of the tail