Transmission dynamics of the Echinococcus granulosus sheep–dog strain (G1 genotype) in camels in Tunisia

Lahmar, Samia; Debbek, H.; Zhang, L.H.; McManus, Donald P.; Souissi, A.; Chelly, S.; Torgerson, Paul R.

doi:10.1016/j.vetpar.2004.02.016

Cited by 69 publications

(47 citation statements)

References 19 publications

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“…Thus, the higher reported hydatidosis prevalence of 10.1% in a previous study undertaken in the same area was due to a larger number of older dromedaries in that particular sample (Lahmar et al, 2004). This is confirmed by the parameter b which was 0.025 in the previous study (Lahmar et al, 2004) as compared to that observed in the current study (0.022). Similarly, there was no significant difference in the parameter h recorded for the two studies.…”

Section: Discussionsupporting

confidence: 76%

“…Ibrahim (2010) reported that optimal environmental conditions, such as high humidity with lower temperatures and sunlight, promote the transmission of the parasite in Saudi Arabia. Such conditions lead to a higher viability of E. granulosus (Lahmar et al, 2004) was lower than that of sheep (Lahmar et al, 1999), the number of cysts per infection in dromedaries was similar to that of sheep. This was possibly due to the ingestion of fewer clusters of viable eggs by dromedaries rather than their lower viability in the southern areas.…”

Section: Discussionmentioning

confidence: 87%

“…In previous studies carried out in Tunisia, CE prevalence varied from 40 to 65% (Lahmar et al, 1999(Lahmar et al, , 2007 and was up to 10% (Lahmar et al, 2004) in sheep and *E-mail: drlsamia@yahoo.fr Journal of Helminthology, page 1 of 8 doi:10.1017/S0022149X12000430 q Cambridge University Press 2012 dromedaries, respectively. However, there are no reports on the prevalence and intensity of E. granulosus hydatid cysts in cattle and goats, and data on cyst fertility and viability in cattle and small ruminants are lacking.…”

Section: Introductionmentioning

confidence: 99%

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Cystic echinococcosis in slaughtered domestic ruminants from Tunisia

Lahmar¹,

Trifi²,

Naceur³

et al. 2012

J. Helminthol.

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A total of 10,818 domestic ruminants (3913 cattle, 2722 sheep, 3779 goats, 404 dromedaries) slaughtered in various abattoirs in Tunisia between 2003 and 2010 were examined for the presence of Echinococcus granulosus hydatid cysts. The prevalence of cystic echinococcosis (CE) was 16.42% in sheep, 8.56% in cattle, 5.94% in dromedaries and 2.88% in goats. CE prevalence increased with age according to an asymptotic model and there was evidence of variation in infection pressure depending on the region of Tunisia where the animals were slaughtered. Cattle appeared to have the highest infection pressure of the species examined. The mean intensity of hepatic cysts was higher than that of pulmonary cysts in all species. The highest mean intensity of infection with E. granulosus larvae was observed in cattle (18.14) followed by sheep (9.58), goats (2.31) and dromedaries (2.12). The abundance of infection increased in a linear fashion with age in all animal species. Cyst abundance varied with species of animal and district of Tunisia. Cysts from dromedaries were more fertile (44.44%) than those from sheep (30.25%), goats (30.32%) and cattle (0.95%). The viability of the protoscoleces from fertile cysts from cattle (78.45%) was higher than those from sheep (70.71%) and camels (69.57%). The lowest protoscolex viability was recorded for hydatid cysts from goats (20.21%). This epidemiological study confirms the importance of CE in all domestic ruminant species, particularly in sheep, throughout Tunisia and emphasizes the need to interrupt parasite transmission by preventive integrated approaches in a CE control programme. The prevalence of cystic echinococcosis (CE) was 16.42% in sheep, 8.56% in cattle, 5.94% in dromedaries and 2.88% in goats. CE prevalence increased with age according to an asymptotic model and there was evidence of variation in infection pressure depending on the region of Tunisia where the animals were slaughtered. Cattle appeared to have the highest infection pressure of the species examined. The mean intensity of hepatic cysts was higher than that of pulmonary cysts in all species. The highest mean intensity of infection with E. granulosus larvae was observed in cattle (18.14) followed by sheep (9.58), goats (2.31) and dromedaries (2.12). The abundance of infection increased in a linear fashion with age in all animal species. Cyst abundance varied with species of animal and district of Tunisia. Cysts from dromedaries were more fertile (44.44%) than those from sheep (30.25%), goats (30.32%) and cattle (0.95%). The viability of the protoscoleces from fertile cysts from cattle (78.45%) was higher than those from sheep (70.71%) and camels (69.57%). The lowest protoscolex viability was recorded for hydatid cysts from goats (20.21%). This epidemiological study confirms the importance of CE in all domestic ruminant species, particularly in sheep, throughout Tunisia and emphasizes the need to interrupt parasite transmission by preventive integrated approaches in a CE control programme.

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Section: Discussionsupporting

confidence: 76%

Section: Discussionmentioning

confidence: 87%

Section: Introductionmentioning

confidence: 99%

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Cystic echinococcosis in slaughtered domestic ruminants from Tunisia

Lahmar¹,

Trifi²,

Naceur³

et al. 2012

J. Helminthol.

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“…Using multilocus enzyme electrophoresis in a previous study, we demonstrated that sheep, cattle and children are infested by the same common sheep strain strain in Tunisia (Oudni et al, 2004). Prevalence of hydatid cysts is low in Tunisian dromedaries (6.5 %: Lahmar et al, 2004), compared to neighbouring countries such as Algeria (24.8 % to 42.1 %: Lahmar et al, 2004;Dabbek, 2002), Lybia (48 %: Ibrahem & Craig, 1998), Egypt (31 %: Rahman et al, 1992) or Morocco (80 %: Pandey et al, 1996). It was firstly attributed to the presence of unadapted sheep strain (Lahmar et al, 2004), but further studies demonstrated that it was the G6 camel strain (M'rad et al, 2005) using sequences of the mitochondrial cytochrome C oxydase CO1.…”

mentioning

confidence: 86%

“…Prevalence of hydatid cysts is low in Tunisian dromedaries (6.5 %: Lahmar et al, 2004), compared to neighbouring countries such as Algeria (24.8 % to 42.1 %: Lahmar et al, 2004;Dabbek, 2002), Lybia (48 %: Ibrahem & Craig, 1998), Egypt (31 %: Rahman et al, 1992) or Morocco (80 %: Pandey et al, 1996). It was firstly attributed to the presence of unadapted sheep strain (Lahmar et al, 2004), but further studies demonstrated that it was the G6 camel strain (M'rad et al, 2005) using sequences of the mitochondrial cytochrome C oxydase CO1. This difference, based on a single gene, is not useful to study population genetic structure.…”

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confidence: 97%

Genetic differences between Tunisian camel and sheep strains of the cestodeEchinococcus granulosusrevealed by SSCP

Oudni-M’rad¹,

Cabaret

M’rad³

et al. 2006

Parasite

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Summary :Ovine and dromedary Echinococcus granulosus isolates from Tunisia were identified as G1 and G6 strains based on polymorphism of the mitochondrial cytochrome C oxydase CO1. Single strand conformation polymorphism (SSCP) was used in order to examine the genetic variation within and between Tunisian G1 and G6 strains and to estimate the extent of selfing. The dromedary isolates are genetically distinct from sheep isolates (high value of genetic variation between populations: F st = 0.46). No significant deficiency in heterozygotes was found in sheep isolates, whereas heterozygote deficiency (suggesting selfing) was found in a limited number of camel isolates. Résumé : DIFFÉRENCES GÉNÉTIQUES ENTRE LES LIGNÉES TUNISIENNES OVINE ET CAMELINE DU CESTODE ECHINOCOCCUS GRANULOSUS

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Apoptosis as a possible mechanism of infertility in Echinococcus granulosus hydatid cysts

Paredes

Jiménez

Cabrera

et al. 2006

J of Cellular Biochemistry

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Echinococcus granulosus is a parasitic cestode causing hydatidosis in intermediate hosts (human and herbivorous). Most symptoms of the disease occur by the pressure exerted on viscera by cysts that are formed upon ingestion of the parasite eggs excreted by definitive hosts (canines). Protoscoleces, the developmental form of the parasite infective to definitive hosts, are formed in the germinal nucleated layer of fertile hydatid cysts. For unknown reasons, some cysts are unable to produce protoscoleces (infertile hydatid cysts). In this study, analysis of DNA fragmentation using TUNEL and agarose gel electrophoresis showed higher levels of apoptosis in infertile cysts as compared to fertile cysts. Additionally, caspase 3 was detected both in fertile and infertile cysts; the activity of this enzyme was found to be higher in infertile cysts. We conclude that apoptosis may be involved in hydatid cyst infertility. This is the first report on the presence of programmed cell death in E. granulosus.

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Transmission dynamics of the Echinococcus granulosus sheep–dog strain (G1 genotype) in camels in Tunisia

Cited by 69 publications

References 19 publications

Cystic echinococcosis in slaughtered domestic ruminants from Tunisia

Cystic echinococcosis in slaughtered domestic ruminants from Tunisia

Genetic differences between Tunisian camel and sheep strains of the cestodeEchinococcus granulosusrevealed by SSCP

Apoptosis as a possible mechanism of infertility in Echinococcus granulosus hydatid cysts

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