Assiut university researches
Studies on Echinococcosis in some Mammals
in Misurata, Libya
Studies on Echinococcosis in some Mammals
in Misurata, Libya
Studies on Echinococcosis in some Mammals
in Misurata, Libya
‫درا سات ع لى االك ي نوك وك وزي س ف ى ب عض‬
)‫ (ل ي ب يا‬،‫ال ثدي يات ف ى م صرات ه‬
Layla Omran Mohammed El-Magdoub
‫ل ي لى عمران محمد ال مجدوب‬
Refaat Mohmmed Ahmed Khalifa, Nawal Abd El-Samie Mazen, Aziza
Marwan Ahmed
‫ عزي زة مروان أحمد‬،‫ ن وال ع بدال سم يع مازن‬،‫رف عت محمد أحمد خ ل ي فة‬
Abstract:
Hydatidosis of livestock is a worldwide parasitic infection.
Libya is not an exception. Hence, the aim of the present study
was to study the incidence of hydatid cyst (the larval stage of
Echinococcus granulosus) in different organs of sheep, cattle
and camels slaughtered in Misurata abattoirs, the fertility and
viability rates of encountered cysts as well as the gross
appearance, light and scanning electron microscopy of cyst
wall layers and hydatid sand elements. Total infection rate in
slaughtered animals was found to be 12.42%, while infection
rate in sheep, cattle and camels was 38.98%, 32.83% and
8.03% respectively. Regarding rate of infection in different
organs, it was estimated to be 88.76%, 3.37%, 6.74% and
0.75% in liver, lung, mesentry and kidney of sheep
respectively. It is worth mentioning that in one female 5 years
old sheep, a triple infection was encountered in liver, lung and
heart (sub-pericardial). In that case, hepatic cysts were fertile
while those in lung and heart were sterile (acephalocysts).
Regarding camels, infection rates were 88.49%. 27.55% and
3.96% in lung, liver and in both lung and liver respectively.
Regarding cattle, infection rates were 78.16%, 20.69% and
0”.75% in liver, lung and both organs respectively. During the
present study, seasonal variations in the rate of infection
were studied. Sheep infection was higher in Autumn (47.5%),
which was more or less similar to Winter (47.2%) while in
Summer it was 36.41% and in spring (24.23%). Camel
infection was higher during summer (9.29%) followed by
Spring (8.89%), Autumn (7.37%) and Winter (6.25%). Cattle
infect! was higher in Summer (55.25%) followed by Winter
(27.33%) and 25% during Spring and Autumn. Generally
speaking, total infection rate in all. slaughtered animals was
higher in Summer (13.5%) although it was not much higher
than other seasons (12.69 % in winter 11.32% in spring and
11.74% in Autumn).Statistical study showed non-significant
difference (P0.01), while infection rate of sheep was higher
than cattle, but the difference was non¬significant (P0.05).
Lung infection in camel was higher than sheep and cattle
(high statistical difference, P>0.01), while infection rate was
higher in lung of cattle than that in sheep (non-significant
difference, P0.01) between length of protoscolices of liver,
lung, kidney and mesentry of sheep cysts of liver and lung as
well as between lung and kidney and mesentry. Statistical
analysis of length of protoscolices of camel cysts showed
highly significant difference between those of lung and liver
(P>0.01). Regarding width of protoscolices the difference was
also significant between those of lung and liver (P>0.05).
Detailed studies were done on rostellar hooklets. Differences
in their number and measurements are known to be an
important criterion in ”strain” differentiation. In sheep cysts,
the number varied from 25-42 in hepatic cysts, 30-43 in
pulmonary cysts, 27-47 in kidney cysts and 26-37 in mesentry
cysts. High statistical difference was found between the
number of rostellar hooklets of lung, kidney and mesentry,
and between-those of liver and mesentry (P>0.01). In camel
cysts, number of rostellar hopklets was 27-43 in liver cysts
and 24-48 in lung cysts with non-significant statistical
difference. It is worth mentioning that statistical studies
protoscolices measurements and number of their hooklets
were done for the first time in the present study. During the
present study, large and small rostellar hooklets were
measured for their total length, blade and handle length and
width. In sheep, the total length of large hooklets measured
27.3-27.6, 27.9-28.6, 28.2-28.5 and 27.4-27.8µ from hepatic,
pulmonary, kidney and mesenteric cysts respective Blade
length varied from 14.7-19.7 µ from liver, 14,3-14.8 µ from
lung, 15.1-15.2 µ from kidney and 14.6-16.1 µ in mesenteric
cysts. Handle length varied from 13.13-13.7 µ from liver,
13.7- 14.2 µ from lung, 13.1-14.1 µ from kidney and 13.4-13.7
µ from mesentry. Width of those hooklets varied from 10.710.8 µ from liver, 11.1-11.4 µ from lung, 11.2-11.3 µ from
kidney and 10.4- 10.6 µ from mesenteric cysts. Statistical
analysis of these data illustrated high significant difference
(P>0.01) between the total length of large booklets of liver,
lung and kidney, between lung and mesentry, between kidney
and mesentry. Blade length also showed high significant
difference (P>0,01) between large hooklets from liver and
kidney, lung and kidney and kidney and mesentry. Handle
length also showed high significant difference (P>0.01)
between hooklets from liver and lung, kidney and mesentry,
lung and mesentry and kidney and mesentry. High significant
difference (P>0.01) was also found between width of large
booklets from liver and lung, kidney and mesentry. Regarding
small rostellar hooklets of sheep cysts, total length, blade
length, handle length and width were 22.7-22.8 µ 11-11.2 µ,
12.4-12.6 µand 11.9-12.5 µ for liver cysts, 21.7-22.6 µ, 11.111.5 µ, 11.7-12 µ and 8.31-8.65 µ for lung cysts, 22.4-22.9 µ,
11.1-11.4 µ, 12-12.3 u and 8.36-8.53 µ for kidney cysts and
21.8-23.1 µ, 11-11.5 µ, 11.9-12.5 µ and 8.02-8.41 µ for
mesentry cysts respectively. High statistical difference
(P>0.01) was found between blade length of liver, lung and
mesentry, between handle length of liver, lung, kidney and
mesentry, between handle length of lung, kidney and
mesentry, between width of booklets of liver, lung and
mesentry, between width of booklets of lung and mesentry,
width of booklets of kidney and mesentry. Also significant
statistical differences (P>0.05) were found between total
length of hooklets of liver and lung, total length of hooklets of
lung and kidney, width of hooklets of liver and kidney. from
camels the total length, blade length, handles length and
width of large booklets were 29.7-30 µ, 16.2-16.6 µ, 14.314.6 µ and 11.4-11.6 µ for liver cysts and 31.2-31.6 µ, 16.817 µ, 15.5-15.8 u. and 11.6-11.8 u. for lung cysts. There was
high significant difference (P>0.01) between all the length
measurements of hooklets of liver and lung origin and a
significant difference (P>0.05) between the width of the
hooklets of both organs. Regarding small booklets from
camel cysts, total length, blade length, handle and width were
24.5-25.3 µ, 12.£-12.7 µ, 13.1-13.3 µ and 9.06-9.28 µ for liver
cysts and’25.4-26.9 µ, 12.5-1 12.6 µ, 14.2-14.5 u and 9.079.12 µ for lung cysts. Highly significant statistical difference
(P>0.01) was found between total length and handle length of
hooklets of liver and lung origin and significant difference
(P>0.05) was found between the width of small hooklets in
both organs. Statistical analysis of the measurements of
protoscolices and the number of hooklets of hepatic origin in
sheep and camel showed that there was highly significant
difference (P>0.01) between the number of hooklets and
significant difference (P>0.05) between the width of
protoscolices denoting the possible occurrence of specific
Echinococcus granulosus ” strain ” for liver of sheep and liver
of camel. This was confirmed by getting a high statistical
difference (P>0.01) between the total length, blade length,
handle length and width of large and small hooklets obtained
from the liver of sheep and camel. The same statistical
differences were obtained for protoscolices measurements,
number of rostellar hooklets and the measurements of all
parts of large and small hooklets obtained from lung cysts
from sheep and camel. Therefore, it was concluded that
strains of E. granulosus in Libya are not only sheep strain and
camel strain, but also sheep-liver strain, sheep-lung strain,
camel-liver strain and camel-lung strain. Very small and tiny
hooklets were encountered during the present study in
protoscolices derived from sheep and camel. Their presence
was confirmed by SEM examination and it was concluded
that some E. granulosus strains might have a complete or
incomplete 3rd or even 4th rostellar circles. Hydatid cysts
from liver, lung and mesentry of sheep were described in
detail for-measurements, gross appearance of intact and
opened cysts, the cyst wall layers and the hydatid sand
elements. Normal and abnormal appearance of protoscolices
was illustrated. Viable protoscolices inside intact brood
capsules took the stain gradually, the outer most ones are
stained before the inner ones. Staining properties of intact
and sectioned protoscolices and rostellar hooklets were
studied and described. Generally speaking, sectioned hooklet
usually take the stain in its core while intact hooklets were
usually unable to take the stain in their horny peripheral layer.
Staining of T.S. of cyst wall layers by different stains was
done and showed that the 3 layers were differently stained
according to the stain peculiarities and the tissue elements
e.g. presence of acid fast elements, glycogen or collagenous
materials. from kidney of sheep, only one 5 years old male
sheep was found infected in both kidneys. These cysts
showed abnormal presentation. They were multiple, with
solitary large cysts and small cysts having 2-3 locules with no
separation of cyst walls. Cysts in one kidney were fertile while
in the other kidney they were sterile. Protoscolices were
found to be solid as light and even heavy finger pressure
failed to separate their hooklets. Steps of protoscolices
development were shown. No other cysts were found in
different organs of the infected sheep. The shape of cysts
may have been affected by the dense texture of the kidney
tissue. Hydatid .cysts from liver of cattle were described but
all of them were sterile, hence only the gross appearance and
the cyst wall layers were illustrated. Hydatid cysts were
collected from liver and lung of camel. They were described
as previously mentioned. However, a special abnormal
presentation of one hepatic cyst was encountered. It
appeared normal in size (2.5cm in diameter) and shape.
However, when opened it was found to contain no hydatid
fluid, but full of glassy gelatinous matter. Only snips taken
from the periphery of cyst contents showed brood capsule,
full of invaginated protoscolices and few free viable
protoscolices. Germinal layer was detached from the cyst wall
or collapsed inside the cyst. from lung of camel, brood
capsule of some cysts were found to develop protoscolices
on the outer surface of the brood capsule. Scanning electron
microscopic studies were done on hydatid elements from liver
and lung cysts of sheep and camel. These studies illustrated
detailed morphological features of protoscolices, suckers,
rostellar hooklets and calcareous corpuscles. Interesting
findings were illustrated in the rostellart hooklets
arrangement, holes made by the handle and guard of large
and small hooklets in rostellum devoid of its hooklets. An
apical hollow between the inserted hooklets was seen. It may
indicate the place of a previously described apical gland used
for scolex attachment to the final host intestinal epithelium.
Normal and abnormal shape of large and small hooklets were
illustrated. The presence of protoscolices on the outer surface
of brood capsule was also confirmed. Presence of small and
very small as well as markedly -small (tiny) hooklets was also
illustrated. Even a tiny hooklet without a guard was found in
hydatid sand from liver of sheep