Gigantiasi
da filariosi linfatica |
 |
 |
|
 |
loa loa
|
|
 |
Microfilaria
of Wuchereria bancrofti, from a patient seen in Haiti. Thick
blood smears stained with hematoxylin. The microfilaria is sheathed,
its body is gently curved, and the tail is tapered to a point. The
nuclear column (the cells that constitute the body of the microfilaria) is
loosely packed, the nuclei can be visualized individually and do not
extend to the tip of the tail. The sheath is slightly stained with
hematoxylin. |
|
 |
Microfilaria
of Brugia malayi. Thick blood smear, hematoxylin stain.
Like Wuchereria bancrofti, this species has a sheath (slightly
stained in hematoxylin). Differently from Wuchereria, the
microfilariae in this species are more tightly coiled, and the nuclear
column is more tightly packed, preventing the visualization of individual
cells. |
|
 |
Microfilaria
of Wuchereria bancrofti collected by filtration with a Nucleopore®
membrane. Giemsa stain, which does not demonstrate the sheath of
this sheathed species (hematoxylin stain will stain the sheath lightly).
The pores of the membrane are visible |
 |
Microfilaria
of Brugia malayi, collected by the Knott (centrifugation)
concentration technique, in 2% formalin wet preparation. Note the
erythrocyte ghosts (for size comparison). Note the clearly visible
sheath that extends beyond the anterior and posterior ends of the
microfilaria. (There are four sheathed species: Wuchereria
bancrofti, Brugia malayi, Brugia timori, and Loa loa.) |
 |
Detail
from the microfilaria of Brugia malayi (see image above) showing
the tapered tail, with a subterminal and a terminal nuclei (seen as
swellings at the level of the arrows), separated by a gap without nuclei.
This is characteristic of B. malayi. |
 |
Microfilaria
of Onchocerca volvulus, from skin snip from a patient seen in
Guatemala. Wet preparation. Some important characteristics of
the microfilariae of this species are shown here: no sheath present;
the tail is tapered and is sharply angled at the end. |
 |
Microfilariae
of Loa loa (right) and Mansonella perstans (left).
Patient seen in Cameroon. Thick blood smear stained with hematoxylin.
Loa loa is sheathed, with a relatively dense nuclear column; its
tail tapers and is frequently coiled, and nuclei extend to the end of the
tail. Mansonella perstans is smaller, has no sheath, and has
a blunt tail with nuclei extending to the end of the tail. |
 |
Microfilaria
of Mansonella streptocerca from a skin snip. Fixed in 2%
formalin and stained with hematoxylin. The microfilaria is
unsheathed, has a nearly straight body attitude, the tail is typically
coiled into a “shepherd’s crook”, and terminal nuclei extend as a
single row to the end of the tail |
 |
Microfilaria
of Mansonella ozzardi. Thick blood smear, stained with Giemsa.
The microfilaria is typically small, unsheathed, and has a slender,
tapered tail that is hooked ("button hook"). The nuclei do
not extend to the end of the tail. |
|
 |
An
artifact resembling a microfilaria. This is a mycelium of the fungus
Helicosporum. It can be differentiated from microfilariae by
its small size (compare with the erythrocytes in this thin shear), its
characteristic shape and staining, and the absence of regularly organized
nuclei. |
Potete
inviare a