Hydatidosis of Camels and Sheep Slaughtered in Aswan Governorate, Southern Egypt

Background: Hydatidosis is an infection caused by the cystic larval stage of Echinococcus granulosus. This disease is a zoonotic disease has a worldwide distribution and common in developing and undeveloped countries. Objectives: The objective of the present study is to studying the infection rate and predilection seats of hydatid cyst affections among slaughtered food animals in Aswan Governorate, southern Egypt and study the effect of age and sex of infected slaughtered animals on the infection with hydatid cyst. Also, study the effect of seasonal variations in the infection with hydatid cyst among slaughtered animals. In addition, the macroscopic examination, microscopic examination, scanning electron microscopy and histopathological studies for the collected hydatid cyst are examined. Methods: This investigation was carried out from August 2015 to July 2016 in two main slaughterhouses in Aswan Governorate to study the hydatidosis in camels and sheep. By routine meat inspection, hydatid cyst count and characterization was conducted. Findings: A total of 2080 camels and 674 sheep were examined. Of these, 173 (8.32%) camels and 3 (0.45%) sheep were found to harbour one or more hydatid cysts. Female and older age slaughtered animals were more susceptible to infection with these metacestode than males and younger animals. Hydatid cyst infection in slaughtered animals is most commonly found in lung followed by liver while mixed infection in both lung and liver was found only in camel. Hydatid cyst in slaughtered camels was higher in autumn followed by winter, while hydatid cyst in slaughtered sheep was found only in autumn season. Fertile cysts in lung and liver of slaughtered camels was 83.4% and 30% respectively. While the fertility of hydatid cyst in infected lung and liver of sheep was 100%. Main conclusions: This study reported that slaughtered animals were infected with relatively high infection rate of hydatid cyst may be due to the presence of socio-economic conditions favourable for the disease and maintenance of high level of infection. So must design governmental control programs against hydatidosis to minimize the infection rate in Aswan Governorate and ensure effective protection not only for animal population but also for humans at risk of contracting the infection.


Introduction
Hydatidosis is a zoonotic disease caused by the hydatid cysts which is larval stage of the Echinococcus granulosus tapeworm. The hydatid cyst is diagnosed when animals are slaughter in abattoirs and detected in the different parts of the carcass. This disease has a worldwide distribution and common in developing and undeveloped countries, including the Mediterranean region, Yang et al. (2005).
Hydatid cyst is a fluid-filled, spherical, unilocular cyst that consists of an inner germinal layer of cells supported by a characteristic acidophilic-staining, acellular, laminated membrane of variable thickness containing numerous tiny protoscolexes. Hydatid cyst most often develop in the liver and lungs and also develop in the kidneys, spleen, nervous tissue, bone and other organs, Seimenis (2003).
Camels and sheep slaughtered animals have indicated high rates of infection leading to a nega-Том 12, Выпуск 3'2018 ЭПИЗООТОЛОГИЯ, ЭПИДЕМИОЛОГИЯ И МОНИТОРИНГ tive economic impact and losses in yield in internal organs and other products like milk and meat, Lahmar et al. (2007).
This study was prepared due to lack of available studies on hydatid cyst of slaughtered animals in Aswan Governorate, provide a scientific perception of the prevalence of such parasitic disease that affect negatively on the productivity of animals, work to identify them and prepare recommendations to resist the spread of these metacestodes

Description of the Study Area
The study and determination of hydatidosis was conducted from August 2015 to the end of July in 2016 in Aswan Governorate, southern Egypt in two slaughterhouses (Aswan in Aswan city, and Draw in Draw city).

Examination of Slaughtered animals
A total of slaughtered animals comprising 2080 camels and 674 sheep were examined for detection of hydatid cyst from different ages, sex, seasonal variation and in different organs.

Examination of Unilocular Hydatid Cysts
The hydatid cysts were identified in the slaughtered animals and were examined grossly, microscopically and by scanning microscopy. Generally, all of the cysts were recovered from the livers and lungs.

Determination of the Fertility of Hydatid Cysts
Hydatid cyst was washed several times in sterile PBS, pH 7.2. Cyst surfaces were sterilized by 70% ethyl alcohol and their fertility was determined by the presence of free protoscolexes in cystic fluid by microscopic examination of a wet mount drop. Hydatid fluid with protoscolexes was collected as described by Smyth (1967).

Data analysis
Statistical analysis was done by using SPSS (Statistical Package for Social Science) program. Table 1 Hydatid Cyst Infection Rates in slaughtered animals Table 2 Distribution of Hydatid Cysts According to Sex Table 3 Distribution of Hydatid Cysts According to Age Table 4 Infection Rates of Hydatid cysts in different organs Table 5 Distribution of Hydatid Cysts According to season Table 6 The fertility of Hydatid cyst which was collected from slaughtered animals  In this study the camel possesses the highest infection rate with hydatid cyst this may be due to the owner of the camel has a dog which is the definitive host of Echinococcus granulosus. This may help in spreading the disease. In these communities dogs have an access to the infected offal. This situation was previously described by Mohamed and Magzoub (1989). There was very highly statistically significant in camel infected with hydatid cyst in associated with different metacestodes infection (P < 0.0001). There was no significant differences of hydatid cyst infection in camels in different slaughterhouses (P > 0.05). This study revealed very low infectivity with hydatid cyst in sheep this may be explained by the fact that those animals were slaughtered in early age. Interestingly, reports published by Hassanin et al. (2013) showed a higher infection rate in these species. This, however, might possibly be attributed to the health and aged factor of the animals. The difference in hydatidosis infection rate between countries for infected camel and sheep could be associated with different factors like control measures put in place, the level of community awareness about the disease, education and economic status of the population, the farming community, variation in the temperature, environmental conditions, the nature of the pasture and the way of raising of these animals, levels of exposure and the maturity and viability of eggs Bardonnet et al. (2003).

The infection rate of Hydatid cyst in slaughtered camels and sheep in relation to sex
In this study, females of slaughtered camels and sheep were more susceptible for Hydatid cyst (65.6%) and (1.07%) than males (5.63%) and  Parija (2004). While there were a reports recorded that males more susceptible than females as Anwar and Khan (1998).
Hydatidosis in female camel found to be significantly higher than the male animals (P < 0.05). Similar findings have been reported by Salih et al. (2011), Abdul-Salam and Farah (1988). Another found that the degree of the infection rate between male and female camel was not statistically significant Ahmadi (2005). Hydatidosis in sheep in regards to sex was not significant (P > 0.05).

The infection rate of Hydatid cyst in slaughtered camels and sheep in relation to age
Hydatid cyst was higher in adult camels and sheep, above two years old (61.25%) and (6.9%) than young animals, below two years old (6.2%) ЭПИЗООТОЛОГИЯ, ЭПИДЕМИОЛОГИЯ И МОНИТОРИНГ and (0.15%) respectively. Statistical analysis for hydatid cyst in relation to age was very highly significant in camels (P < 0.0001), while there was highly significant differences in sheep (P < 0.05). This result was in agreement with Abdel-Hafez et al. (1986), Ibrahem and Craig (1998), Kabir et al. (2010), Yildiz and Gurcan (2003), Senlik (2000), Azlaf and Dakkak (2006). The development of hydatid cyst larva is very slow, and its fertility is only acquired in 12 to 18 months after ingestions of eggs Soule (1994). For these reasons, the inspection of slaughtered young sheep (aged 12 months and under) shows no observable hydatid cyst. Also, this age variation can be again associated with difference in exposure to infection because older livestock may have been exposed to more infective stages Ibrahim et al. (2008).
Older animals may have been exposed to more infective stages and the camel in usual are slaughtered in their old age.

The infection rate of Hydatid cyst in slaughtered camels and sheep in relation to season
The highest infection of hydatid cyst in camel was found in autumn (10.4%), followed by winter (9.6%), summer (8.5%) and the lowest was noticed in spring (5.4%). Hydatid cyst in sheep was recorded only in autumn (3.41%). There was not significant differences with statistical analysis of camel infected with hydatid cyst in relation to seasonal variation (P > 0.05) but in sheep there was significant (P < 0.05). This result was in agreement with Kadir and Rasheed (2008), Sameh et al. (2016).
Close contact of camels and sheep with dogs in pastures may help to transmit parasites from infected pasture in autumn and winter were they are rainy and humid seasons. Also, dogs are highly infected by Echinococcus granulosus Eslamiand Hosseini (1998).

The infection rate of Hydatid cyst in slaughtered camels and sheep in relation to predilection seats
The most predilection seats of hydatid cyst in camels were found in the lungs (92.5%), more than liver (4.03%), but in sheep cysts were found in liver (66.67%) more than in lungs (33.33%). While mixed infection of both lungs and liver in camels was (3.47%), but in sheep, mixed infection of both lungs and liver was not found. This result was in agreement with Osman (2013) Lung infection with hydatid cyst was statistically very highly significant in association with other predilection seats (P < 0.0001). The high number of cysts in the lung may be due to the relatively softer consistency of lung compared to the liver. The lung tissue is more softer in consistency allows the easier development of the cyst than the liver tissue

Fertility of Hydatid cyst among slaughtered camels and sheep
In this study, the percentages of fertile and infertile hydatid cyst in infected lung of camels were (83.4%) and (16.6%) respectively. While in liver of camel the rate of fertile and infertile cyst was (30%) and (70%) respectively. On the other hand, the fertility of hydatid cyst in infected lung and liver of sheep was (100%). This was in agreement with Dyab