Occurrence of the G3 Indian buffalo strain of Echinococcus granulosus in cattle

During a survey carried out to define the occurrence of Echinococcus granulosus in cattle bred in the province of Rieti (Central Italy), molecular diagnostics (PCR amplification and sequencing of a partial region of the mitochondrial CO1 gene) showed that 6/10 positive bovines harboured hydatid cysts (No.=16) genetically identical (95.8-100%) to the Indian buffalo genotype G3. As far the location of the 16 cysts, 11 of them were found in the lungs of three animals, whereas 5 cysts were in the liver of three parasitized hosts. The occurrence of genotype G3 in 60% of parasitized bovines living in an area never studied before provides more definite evidence about the existence of the strain in this region, and proves that cattle have to be considered a non-accidental host.     

Comparative electrophoretic study of phosphoglucose isomerase,phosphoglucose mutase and tetrazolium oxidase in some hydatid cysts of Echinococcus granulosus collected from different mammal hosts

Hydatid cyst scolexes of lung and liver from sheep and water buffalo were electrophoreticaily examined for phosphoglucose isomerase (PGI), phosphoglucose mutase (PGM) and tetrazolium oxidase (Te) activity. One each of phosphoglucose isomerase, phosphoglucose mutase and tetrazolium oxidase activities were found in all of the hydatid cysts studied. PGI and PM in ail hydatid cysts studied appeared te be controlled by two codominant alleles. PGI and PGM proved to be a good taxonomic criterion to differentiate the hydatid cysts of the water buffalo from those from sheep. On the other hand, TO failed to differentiate between the sheep and water buffalo hydatid cysts. The hydatid cysts that parasitise the sheep's organs can be considered as arising from a different strain from the cysts that parasitise the water buffalo organs, while lung and liver hydatid cysts of the sheep appeared to be a similar strain.     

Observations on the suitability and importance of the domestic intermediate hosts of Echinococcus granulosus in Uttah Pradesh, India

The present study investigated the suitability and importance of buffaloes, camels, sheep, goats and pigs in maintaining the life-cycle of Echinococcus granulosus in Aligarh, India. A total of 565 (36%) of 1556 buffaloes, 20 (2%) of 1208 goats, 5 (1%) of 559 pigs, 6 (6%) of 109 sheep and two of three camels were found to harbour hydatid cysts. The frequency distribution of the hydatid cysts in each intermediate host species was over-dispersed and in buffaloes cyst fertility increased with increasing cyst size. Of 2171, 95 and four buffalo, goat, and camel cysts examined 327 (15%), two (2%) and three cysts respectively were fertile. No pig or sheep cysts were found to contain protoscoleces. The unfenced buffalo abattoir and the large number of dogs allowed access to the abattoir coupled to the number of buffalo slaughtered in comparison to the other potential hosts, indicates that the buffalo is the most significant host for maintaining the life-cycle of the parasite in this area of India. Applicable control measures for the region are suggested.     

Hydatidosis in camels (Camelus dromedarius) and their potential role in the epidemiology of Echinococcus granulosus in Iran

Hydatid cysts were recovered from 35.2% (233/661) of camels (Camelus dromedarius) slaughtered in five different regions of Iran. The degree of prevalence between males (34.4%) and females (36.6%) was not statistically significant. The highest rate of infection (59.3%) was found in the Isfahan region (in the central part of Iran) while the lowest (25.7%) was found in Kerman province. The organ distribution of cysts was 49.4% in lungs alone, 30.0% in both liver and lungs, 14.6% in liver only and 6.0% in other organs. Therefore, the lungs were the predominant sites of the hydatid cyst. The range in the number of cysts was 1-48 in infected animals. The majority of the camels had 1-5 cysts, with 21.9%, 11.6% and 5.6% of infected camels having 6-10, 11-20 and 21 or more cysts respectively. There was a direct relationship between the rate and intensity of infection and host age. The fertility rate of lung cysts (69.7%) was higher than that of liver cysts (58.7%) and other organs (50.0%) whilst the viability rate of protoscoleces of liver fertile cysts (80.3%) was significantly higher than that of lung cysts (55.8%) and other organs (57.1%). The role of camels in the epidemiology of Echinococcus granulosus in Iran is discussed.     

The prevalence and fertility of hydatid cysts in buffaloes from Iran

Cystic echinococcosis caused by Echinococcus granulosus is considered to be an important parasitic infection in livestock. In the present study, which aimed to determine the epidemiology of hydatidosis in buffalo in Iran, slaughterhouses of West Azerbaijan (Urmia), East Azerbaijan (Tabriz), Ardabil (Ardabil), Gilan (Rasht and Hashtpar) and Khuzestan (Ahvaz) were inspected. Age, sex and infected organs were recorded separately, and the observed cysts were examined for fertility and viability. Our results showed that 344 (9%) of 3832 inspected buffaloes were infected with hydatid cysts. The maximum and minimum infection rates occurred in Khuzestan (9.9%) and Ardabil (8%) provinces, respectively. There was no significant difference in the rate of infection in all provinces. Of 344 infected buffaloes, the rate of fertility was 7.3% and the rate of viability in fertile cysts was 78.75%. Hydatid cysts were more prevalent in female compared with male buffaloes (P < 0.05). There was a positive correlation between the age and number of infected hosts in all provinces except East Azerbaijan. The prevalence of infection in lungs was significantly higher than that in the livers of buffaloes in the provinces studied (P < 0.001). In conclusion, the fertility of hydatid cysts in buffaloes was low, as previously demonstrated in cattle, and this animal may play a minor role in the epidemiology of hydatidosis in Iran.     

Assessment of prevalence of hydatidosis in slaughtered Sawakny sheep in Riyadh city,Saudi Arabia

Hydatidosis, or echincoccosis, is a serious medical and veterinary problem in many countries, particularly those with rural communities where there is a greater contact between dogs and domestic animals. Domestic livestock act as intermediate hosts which are the main reservoir for the disease in humans. It is therefore very important to estimate the prevalence of hydatid cysts in slaughtered animals since it can be transmitted to humans through dogs, which act as the final host for the disease. From this point of view, the present study was suggested to determine the prevalence of hydatidosis in Sawakny sheep slaughtered in Riyadh city, Saudi Arabia. During the course of the study 12,569 Sawakny sheep were inspected for hydatidosis infection. An overall prevalence of 1.06% was detected among the examined sheep, with the highest prevalence occurring in winter (1.38%) and lowest prevalence in summer (0.67%). Sheep aged 6–12 months had a higher rate of infection than older animals, and males were the predominant carriers of infection (97.7%) compared to females (2.3%). The liver was the most infected organ (79.1%), followed by the lungs (14.6%), while concurrent infections of both the liver and the lungs occurred in 6% of cases. The fertility and viability rates of hydatid cysts in the liver (70.1% and 85.1% respectively) were higher than that in any other organs. In conclusion, it is evident that fertile cysts in slaughtered sheep could have an important role in the continuation of hydatid cyst transmission to humans through dogs. Considerable effort should be devoted to controlling the transmission of cysts from abattoirs by the secure disposal of infected offal. In addition, plans are required for further epidemiological studies and control programs.     

Prevalence of Echinococcosis in Reindeer (Rangifer Tarandus) in Sweden

In Sweden echinococcosis is uncommon in domestic animals. In reindeer in the most northern part of the country echinococcosis was found. Of 1453 pairs of lungs, 23 pairs (1.6 %) were infected with hydatid cysts. These were of two types: typical well-developed hydatid cysts, which were found in nine of the 23 infected lungs, and collapsed hydatid cysts, which were found in 13 of the lungs. In only one lung pair both types of cysts were seen.     

Epidemiological and histomorphic studies in sheep infected with hydatid cyst in Taif area

Hydatidosis is a zoonotic disease caused by Echinococcus granulosus larvae, which affects sheep worldwide, especially in rural communities. This study aims to determine the prevalence and structure of hydatid cyst in sheep. A total number of 1,198 sheep in different age groups G1 (<1 year), G2 (1–2 years) and G3 (>2 years) were slaughtered at Taif abattoirs, then examined for the presence of hydatid cysts in lung, liver, and mesentery. Prevalence of hydatid cyst infection in imported sheep (13.0%) was higher than of local sheep (10.2%). Particularly, as per gender, prevalence of imported females (71.9%) was higher than those of local females (28.1%), while that of imported males (66.3%) was higher than those of local males (33.7%). Large sizes of hydatid cysts and fertility recorded in G3 were higher in both local and imported sheep than those of G1 and G2. Morphometric analysis of pathological lesions in liver of all infected sheep showed a significant increase compared to non-infected healthy sheep (have no lesions) (P < 0.001). In addition, for all infected sheep, histochemical investigation with Masson’s trichrome stain showed collagen fibers inside the hydatid cyst capsules and in pericystic region. The collagen fibers content and the cellular laminated membranes took the green color, while immunohistochemical evaluation detected a positive reaction for CD3.     

Infection Status of Hydatid Cysts in Humans and Sheep in Uzbekistan

Uzbekistan is endemic of cystic echinococcosis (CE). In order to estimate endemicity of CE, we collected data from emergency surgery due to CE in 2002-2010 and also investigated the prevalence of hydatid cysts in the liver and lungs of sheep at an abattoir in Uzbekistan from July 2009 to June 2010. In 14 emergency hospitals, 8,014 patients received surgical removal or drainage of CE during 2002-2010, and 2,966 patients were found in 2010. A total of 22,959 sheep were grossly examined of their liver and lungs, and 479 (2.1%) and 340 (1.5%) of them were positive for the cyst in the liver and lungs, respectively. Echinococcus granulosus is actively transmitted both to humans and sheep, and CE is a zoonotic disease of public health priority in Uzbekistan.     

Analysis of some variables in patients with hydatidosis surgically treated at the Regional Hospital of Valdivia, Chile, 1976-1986

A survey of surgically treated cases of hydatidosis in the province of Valdivia, Chile, was done. Data were provided by the Regional Hospital of Valdivia, and a period of eleven years was covered (1976-1986). Disease, treatment and related data from each patient were consigned. For the analysis, the information was grouped according to: sex, age, cyst location, condition of the cyst, concomitance with another pathology, condition at time of discharge, hospitalization period and number of repeat hospitalizations. In the period studied, 197 cases of hydatidosis were surgically treated. The sex distribution was 53.3% for males and 46.7 for females; the age group 10-19 years was the most affected by the disease (19.3%). The most frequent locations of hydatid cysts were the liver (58.9%) and lungs (36.5%); the 38.6% of the patients showed complicated cysts, mainly with bacterial infections (11.7%); also, 20% of the cases presented a concomitant liver-related pathology. After the operation, 153 (77.7%) clinically recovered and 27 (13.7%) non-recovered patients left the hospital and 7 (3.5%) cases died while hospitalized. The average hospitalization period was 29 days. During 1976-1986, 24 patients were rehospitalized.     

Growth and genotypes of Echinococcus granulosus found in cattle imported from Australia and fattened in Japan

At the abattoir on study in Miyazaki, Japan, 9537 imported cattle from Australia in average were slaughtered annually in the last 5 years (2006 to 2010) and hydatid cysts were constantly detected in about 1.8% of the cattle. In order to assess the risk of Echinococcus granulosus delivered to Japan by imported cattle, 250 cysts found in 103 cattle at the abattoir were examined for their biological characteristics and genotypes. The cattle slaughtered were imported from Australia at an age of 10-12 months old and fattened for 17-18 months in Japan. The cysts showed their size ranging from 4 to 108 mm and were mainly found in the lung. Mature protoscoleces were detected in the three largest cysts, all were of the G1 genotype. Most of the other cysts contained clear cyst fluid and had thin laminated layer with no protoscoleces. The finding implies a potential risk of E. granulosus being established in Japan, thus strict and proper meat inspection and consequent offal condemnation are requisite at abattoirs that deal with imported cattle. Genotyping based on partial fragments of mitochondrial cox1, rrnS and nad1 genes were performed on the 66 cysts, showing that most of the cysts were G1 genotype (common sheep strain). However, two and four cysts were considered as G2 (Tasmanian sheep strain) and G3 (buffalo strain) genotypes, respectively. Since it has been widely recognized that G1 is the only genotype distributing in mainland Australia and that G2 genotype has been eradicated from Tasmania, the finding of those genotypes from Australian cattle indicated that certain genotypes other than G1 genotype are distributing in mainland Australia.     

Vaccination trials in Australia and Argentina confirm the effectiveness of the EG95 hydatid vaccine in sheep.

Experimental vaccine trials against hydatid disease have been undertaken in sheep using the EG95 recombinant vaccine. Challenge infection was with viable Echinococcus granulosus eggs obtained from a New Zealand isolate (dog/sheep cycle), an Australian isolate (dingo/wallaby cycle) and an Argentine isolate (dog/sheep cycle). Vaccination with EG95 conferred a high degree of protection against challenge with all three parasite isolates (protection range 96-100%). Taken together, the trials demonstrated that 86% of vaccinated sheep were completely free of viable hydatid cysts when examined approximately 1 year after challenge infection. Vaccination reduced the number of viable cysts by 99.3% compared with unvaccinated controls. These results suggest that the EG95 vaccine could have wide applicability as a new tool for use in hydatid control campaigns.     

Treatment of hepatic hydatid cysts by percutaneous aspiration and hypertonic saline injection: results of a cooperative work

Percutaneous puncture-aspiration-injection-reaspiration (PAIR) of hydatid liver cysts, was performed in 38 patients 14-80 years old, with a total of 60 liver hydatid cysts. After aspiration under computed tomography guidance, hypertonic saline was injected into the cystic cavities of patients as a scolecidal agent. No major complications were associated with the procedures. In the follow-up period of 18 months, control CT scans of 35 cysts revealed a gradual decrease in cyst size with a mean volume reduction of 66%. Complications included two cases of urticaria, one case of anaphylaxis and one subcapsular hematoma. No mortality occurred. It is concluded that percutaneous aspiration and hypertonic saline injection for liver hydatid cysts appears to be an effective form of treatment and may eventually prove to be an alternative to surgical intervention.     

Magnetic resonance imaging in the diagnosis of nonorganic hydatid disease

This article evaluates MRI diagnostic value in discovering of the non-organic hydatid disease. MRI data of 21 patients, suffering from parasite pathology of liver (n = 12), liver and peritoneum cavity (n = 2), liver and retroperitoneal space (n = 2), liver and thigh's muscles (n = 1), peritoneum cavity (n = 2), retroperitoneal space (n = 1), spine and paravertebral area (n = 1) were analyzed. Based on histopathological results, features of unusually localized hydatid cysts (HC) MRI- semiotics are described in detail and compared with liver echinococcosis. MRI technique for identification of some hydatid cyst's structures is shown. The authors discuss the MRI reliability in differential diagnosis of non-organic HC and several disorders (non-parasite congenital and acquired cysts, hematoma, abscess, metastasis) of the same anatomical region. They underline some MRI advantages in GD disclosing comparing with ultrasonography and computed tomography. However, serological tests are needed for diagnosis verification. The authors also postulate the importance of clinical data being taken into account for radiological conclusion.     

An abattoir-based study on the prevalence of hydatidosis in livestock in Mashhad, Iran

A 6-year (2004-2010) retrospective study was carried out to determine the prevalence of hydatidosis in livestock slaughtered in Mashhad abattoir, Mashhad, in north-eastern Iran and the capital of Khorasan province. Between 20 March 2004 and 19 March 2010, 5,131,485 animals (411,163 cattle; 4,547,618 sheep; 172,704 goats) were slaughtered in the study area and 388,399 (7.5%) livers and 1,139,529 (22.2%) lungs were discarded. Hydatidosis was responsible for 4% and 6.5% of total livers and lungs inspected, respectively. Of the cattle livers and lungs inspected over the survey period, 5.5% and 7.9% were condemned, respectively, because they held hydatid cysts. The corresponding values for livers and lungs of sheep (2%, 4%) and of goats (4.5%, 7.8%), respectively, were also condemned due to hydatidosis. Data showed a prominent seasonal pattern for hydatidosis. Liver condemnations due to hydatidosis were higher in winter and autumn for cattle and sheep, respectively, whereas lung condemnations were higher in summer for sheep and cattle. In goats, liver and lung condemnations were higher in winter. This could be attributed to various factors, such as sources of slaughtered animals, changes in management practice and ecological factors. The present survey provides baseline data for the future monitoring of this potentially important parasitic disease in the region.     

Epidemiology of Echinococcus granulosus in Arbil province, northern Iraq, 1990-1998

During the period 1990-1998, 99 cases of human cystic hydatidosis (12.4 cases per year) were surgically treated at the two main hospitals in Arbil province, northern Iraq, and from this the human occurence for the province was estimated to be 2 per 100,000 inhabitants. In the same area, 1270 sheep, 550 goats and 320 cattle were examined at slaughter for hydatid cysts and prevalence rates were found to be 15.0%, 6.2% and 10.9%, respectively. A decreasing tendency in livestock prevalences was found towards the end of the study period. As in humans, most of the hydatid cysts in livestock were located in the liver. Fertility of sheep cysts, i.e. those containing protoscoleces, was found to be significantly higher (64%) than that of goats (35.7%) and cattle (29.8%). The percentage of fertile cysts containing viable protoscoleces varied between 63 and 82% in the livers and between 72 and 79% in the lungs of the different animal species. A total of 97 stray dogs were examined post-mortem in the years 1991, 1992 and 1998, and Echinococcus granulosus worms were found in the intestines of 48 dogs (49.5%). High worm burdens (> 1000) were observed in 37% of the dogs, medium worm burdens (200-1000) in 41%, and low worm burdens (< 200) in 22%. In 1998, the prevalence of canine echinococcosis (24.3%) was found to be significantly lower than in 1991 (70.4%) and 1992 (60.6%). The prevalence of human hydatidosis did not differ significantly over the years, but the study confirmed that hydatidosis is endemic in northern Iraq, and that housewives, labourers and farmers appear to be at the greatest risk of infection.     

Molecular Characterization of Echinococcus granulosus Sensu Lato from Farm Animals in Egypt

Little is known on the diversity and public health significance of Echinococcus species in livestock in Egypt. In this study, 37 individual hydatid cysts were collected from dromedary camels (n=28), sheep (n=7) and buffalos (n=2). DNA was extracted from protoscoleces/germinal layer of individual cysts and amplified by PCR targeting nuclear (actin II) and mitochondrial (COX1 and NAD1) genes. Direct sequencing of amplicons indicated the presence of Echinococcus canadenesis (G6 genotype) in 26 of 28 camel cysts, 3 of 7 sheep cysts and the 2 buffalo derived cysts. In contrast, Echinococcus granulosus sensu stricto (G1 genotype) was detected in one cyst from a camel and 4 of 7 cysts from sheep, whereas Echinococcus ortleppi (G5 genotype) was detected in one cyst from a camel. This is the first identification of E. ortleppi in Egypt.     

Cystic echinococcosis in children — The seventeen-year experience of two large medical centers in Serbia

Cystic echinococcosis (CE) is a public health problem in countries having such endemic areas. Epidemiological studies of CE, especially pediatric, are rare. The aim of this study was to evaluate epidemiological and clinical characteristics of CE in children in Serbia. Data were obtained retrospectively from the case records of patients under the age of 18 years admitted for surgical treatment of CE at two large pediatric medical institutions in the period 1990–2006. Patients' age, number of cysts and their anatomic location were evaluated in relation to differences by patients' gender and socio-geographic status (urban or rural origin). The study included 149 children with 272 hydatid cysts. The mean age of patients was 10.1 ± 3.8 years. There were no significant differences in the number of patients in relation to gender and urban:rural origin. There were no significant differences in patients' age at the time of surgery or the number of cysts per patient when patients’ gender or socio-geographic status was evaluated. The anatomic location of cysts was as follows: liver (N = 165; 60.7%), lungs (N = 82; 30.1%), and other locations (N = 25; 9.2%). Multiple cysts, and combined liver/lung involvement were identified in 34.2% (N = 51), and 6.0% (N = 9) of patients, respectively. Hepatic cysts were significantly more common in girls than in boys. There were no significant differences in anatomic location of cysts between socio-geographic groups. The large number of infected children during a long period of investigation indicates an active transmission of disease and a lack of program for control and prevention of CE in Serbia.     

Control of hydatid disease in Wales.

OBJECTIVES--To evaluate the success of the south Powys hydatid control programme by analysis of trends in cystic disease in humans and sheep and dog infestation. DESIGN--A review of hospital admissions for human hydatid disease in 1984-90, abattoir prevalence surveys of hydatid cysts in adult sheep, arecoline acetarsol and coproantigen surveys of prevalence of Echinococcus infestation in dogs. SETTING--All hospitals in England and Wales, three abattoirs, and dog populations in mid ands south east Wales. SUBJECTS--Residents of England and Wales admitted to hospital between 1984 and 1990 with a new diagnosis of human hydatid disease (International Classification of Diseases (ICD), ninth revision, code 122) acquired in the United Kingdom. RESULTS--The average annual incidence of human hydatid disease in Powys, mid-Wales, fell from 3.9x10(-5) in 1974-83 to 2.3x10(-5) in 1984-90. Age specific incidence rates in Wales declined over this period only in children, and no cases occurred in children (<15 years) in Powys. Two Welsh children who lived in Gwent and mid-Glamorgan were infected. Prevalence of hydatid cysts in old sheep from south Wales declined during the control period, but in 1993 prevalence of cysts was 13%. Prevalence of E granulosus infestation was zero in the control area in 1993, but it was 2.4% in Powys dogs outside the control area in 1989 and 9.2% in dogs in Gwent in 1991. CONCLUSIONS--Human hydatid disease has been successfully controlled in south Powys but cystic echinococcosis is still endemic in sheep in mid-Wales, and there is a focus of infection in humans, sheep, and dogs in the bordering areas of Gwent and mid-Glamorgan. There is considerable potential for an upsurge in human cases if control measures are relaxed.     

Further studies on prevalence of hydatidosis in slaughtered animals from North Jordan

Examination of 471 sheep, 118 goats, 157 cattle and 56 camels slaughtered in abattoirs in North Jordan was carried out during March-May 1984. Drought conditions that prevailed during the preceding winter led to slaughtering old female sheep (greater than or equal to 4 years) due to scarcity of food, which allowed us to analyse the prevalence of hydatidosis in various age groups of sheep. An overall infection rate of 27.8, 1.7, 5.8 and 10.7 percent was found in sheep, goats, cattle and camels, respectively. The infection rate was as low as 1.5 percent in male and 1.9 percent in female sheep under 2 years of age. However, the rate of hydatid infection increased with age and reached as high as 63.7 percent in ewes 4 years of age and older. The percentage of animals with fertile cysts was also highest in sheep (68.7 percent of infected animals) and increased with age reaching 100 percent in ewes which were 10 years of age or older. Analysis of all cysts recovered from the livers and lungs of infected ewes from various age groups revealed a sharp increase in the mean total number of cysts in age groups over 8 years of age. The fertility rate of the cysts in the liver was significantly greater in ewes 6 years old or more (64.8--78.6 percent) than in younger age groups (8.7-46.2 percent). In the lung, the fertility rate increased progressively with age reaching as high as 97.9 percent in ewes 10 years old or more. These findings of high infection and fertility rates of hydatid disease in sheep, particularly of older age groups, prompt plans for further epidemiological studies and control programmes.