National prevalence of larval echinococcosis in sheep in slaughtering plants Ovis aries as an indicator in control programmes in Uruguay

A systematic review and meta-analysis on prevalence and distribution of Taenia and Echinococcus infections in Ethiopia

Background

Tapeworm infections are among the tropical neglected parasitic diseases endemically occurring in Ethiopia. This systematic review and meta-analysis aims at estimating the pooled prevalence and distribution of Taenia and Echinococcus infections in humans and animals from reports from Ethiopia.

Methods

The systematic search was conducted in four bibliographic databases (PubMed, Google Scholar, Africa Journal Online and Science Direct). Additional data were retrieved from grey literature. Studies that met the inclusion criteria were considered for the systematic review and meta-analysis. The meta-analysis was conducted using MetaXL add-in for Microsoft Excel. Heterogeneity and inconsistency were evaluated using Cochran’s Q and I² statistics, respectively.

Results

The study provides a country-based database of Taenia and Echinococcus infections consisting of 311 datasets from 201 publications which were mostly abattoir surveys; of these, 251 datasets were subjected to meta-analysis. Most of the studies were from Oromia (32.8%) followed by Amhara (22.9%) regional states. The pooled prevalence of cystic echinococcosis in intermediate and accidental hosts was calculated as 22% (95% CI 18–26%) and high study variability (Q = 24,420.65, I² = 100%, P = 0.000). Moreover, a pooled prevalence of Echinococcus infections in final hosts was calculated as 33% (95% CI 20–48%) and low study variability (Q = 17.24, I² = 65%, P = 0.001). Similarly, study subjects (human, cattle, sheep, goat and wolf) were infected by Taenia spp. with pooled prevalence of 3% (95% CI 2–4%) and moderate study variability (Q = 279.07, I² = 89, P = 0.000). Meanwhile, the pooled prevalence of Taenia hydatigena, T. ovis and T. multiceps infections in intermediate hosts were calculated as 38%, 14% and 5%, respectively. The random effect meta-analysis of bovine cysticercosis showed a pooled prevalence of 7% (95% CI 5–9%) and high study variability was of (Q = 4458.76; I² = 99%, P = 0.000). Significant differences in prevalence of Taenia and Echinococcus infections between study sites or different livestock origins have been reported.

Conclusion

The study evidenced a comprehensive dataset on the prevalence and distribution of Taenia and Echinococcus infections at different interfaces by regions and hosts and hence can aid in the design of more effective control strategies.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04925-w.

Meta-Analysis of the Prevalence of Echinococcus in Sheep in China From 1983 to 2020

Echinococcosis is a zoonosis caused by the larval stage of cestode species that belong to the genus Echinococcus. The infection of hydatid in sheep is very common in China, especially in the northwestern China. Here, we conducted the first systematic review and meta-analysis of echinococcosis in sheep in China. Six databases (PubMed, ScienceDirect, Baidu Library, CNKI, Wanfang, and VIP Chinese Journal Database) were used to retrieve the literatures on echinococcosis in sheep in China from 1983 to 2020, and 74 studies. The random effects model was used in the “meta” package of the R software and the PFT was chosen for rate conversion. The research data were analyzed through subgroup analysis and univariate meta-regression analysis to reveal the factors that lead to research heterogeneity. The combined prevalence of Echinococcus in the selected period was estimated to be 30.9% (192,094/826,406). In the analysis of sampling year, the lowest positive rate was 13.9% (10,296/177,318) after 2011. The highest prevalence of Echinococcus was 51.1% (278/531) in the southwestern China. The highest infection rate in sheep was 20.1% (58,344/597,815) in the liver. The analysis based on age showed that the infection rate of elderly sheep was significantly higher than that in younger animals (P < 0.05). We also evaluated the effects of different geographic and climatic factors on the prevalence of Echinococcus in sheep. The results showed that the prevalence of Echinococcus was higher in high altitude, cold, humid, and high rainfall areas. It is necessary to carry out long-term monitoring and control of echinococcosis, cut off the infection route, and reduce the risk of infection in the high risk areas.

Molecular characterization of Cysticercus tenuicollis isolates from sheep in the Nile Delta, Egypt and a review on Taenia hydatigena infections worldwide

The predator–prey-transmitted cestode Taenia hydatigena infects a wide range of definitive and intermediate hosts all over the world. Domestic and sylvatic cycles of transmission are considered as well. The parasite has considerable economic importance, particularly in sheep. Here, the molecular characters of T. hydatigena cysticerci in sheep from the Nile Delta, Egypt were investigated for the first time. For this purpose, 200 sheep carcasses and their offal were inspected at the municipal abattoir, Dakahlia governorate, Egypt. Cysticerci of T. hydatigena were collected and molecularly characterized employing the mitochondrial 12S rRNA gene. Cysticerci were found in 42 (21%) sheep, mostly attached to the omenti, mesenteries and livers. After molecular confirmation, nine isolates were sequenced displaying six different haplotypes. Analysis of the T. hydatigena 12S rRNA nucleotide sequences deposited in GenBank revealed 55 haplotypes out of 69 isolates, displaying high haplotype (0.797) and low nucleotide (0.00739) diversities. For the Tajima D neutrality index, a negative value (−2.702) was determined, indicating the population expansion of the parasite. Additionally, global data summarized in this study should be useful to set up effective control strategies against this ubiquitous parasite.

Pilot field trial of the EG95 vaccine against ovine cystic echinococcosis in Rio Negro, Argentina: 8 years of work

Cystic echinococcosis (CE) is endemic in the Rio Negro province of Argentina. After 30 years of control using praziquantel in dogs the transmission rate to humans and sheep has decreased significantly, however transmission persists. The objective of the study was to assess the inclusion of the EG95 for sheep in the control program and to determine the vaccine's operative feasibility in field conditions. An intervention study was defined in Rio Negro Province in Argentina comprising, in total, an area of 5820 Km2. Lambs received two vaccinations with the EG95 vaccine followed by a single booster injection when the animals were 1-1.5 years of age. Vaccination of lambs born into one trial site was introduced and continued for 8 years. Evidence for Echinococcus granulosus transmission was monitored before and after vaccination by coproantigen ELISA in faecal samples of dog, purgation of dogs to detect E. granulosus worms, necropsy on adult sheep and by ultrasound screening in children of 6-14 years old. 29,323 doses of vaccine were applied between 2009 and 2017, which a vaccination coverage of 80.1%/85.7% (57.3% average for fully vaccinated). Before the introduction of the vaccine 56.3% of the 6-year-old sheep were infected with E. granulosus at necropsy and 84.2% of the farms had infected sheep; 4.3% of the dogs were positive for E. granulosus infection using the arecoline test, and with coproELISA 9.6% of dog fecal samples were positive and 20.3% of the farms had infected dog.After the vaccine was introduced, 21.6% of sheep older than 6 years were found to be infected at necropsy and 20.2% of the farms were found to be infected; in dogs, 4.5% were found positive for E. granulosus using arecoline purgation and with coproELISA 3.7% of samples were positive, with 8.9% of farms having a positive dog. In 2016 only one case of E. granulosus infection was diagnosed by US screening in a 6-14 years old child. Included in the analysis are discussions of difficulties experienced in the field which affected correct vaccine administration as well as social features and practices that may impact on echinococcosis control and the EG95 vaccination program in Rio Negro. Vaccination of sheep with the EG95 vaccine provides a valuable new tool which improves the effectiveness of CE control activities. Vaccination was effective even in a difficult, remote environment where only approximately half the lambs born into the communities were fully vaccinated.

Prevalence of Cystic Echinococcosis in Slaughtered Sheep as an Indicator to Assess Control Progress in Emin County, Xinjiang, China

Hydatid disease imposing serious threat on human health and great loss in live¬stock pastoralism remains a major public health problem in western China. To assess and monitor the effect of control program on transmission dynamics, we used the prevalence of cystic echinococcosis in slaughtered sheep at slaughterhouse as an indicator during the period of 2007 to 2013 in Emin County, Xinjiang Uygur Autonomous Region, China. The results showed a significant decline trend of prevalence in all age groups during the 7 years when the control program was implemented; particularly, the rate was reduced by 72% after first 3 years. Among the sheep slaughtered, the age distribution evidenced that the prevalence increased significantly as the sheep grew older. The baseline data indicated that the rate was 4.5% at the age <1, 6.7% at age 2~, and reached to the highest 17.9% at age ≥4 years. Earlier response to the intervention pressure was seen in the sheep at the younger age. Significant decline started from 2008 at the age <1, from 2009 at age of 1~, 2010 at 2~ to 3~, and the latest, in 2012 at age ≥4. This study demonstrated that the prevalence of cystic echinococcosis in slaughtered sheep may be used as an indicator to assess and monitor the transmission status during and after control program providing information for betterment of performance to sustain control strength.

Pilot field trial of the EG95 vaccine against ovine cystic echinococcosis in Rio Negro, Argentina: early impact and preliminary data

Cystic echinococcosis is endemic in the Rio Negro province of Argentina. After 30 years of control using praziquantel in dogs the transmission rate to humans and sheep has decreased significantly, however transmission persists. The objective of the study is to assess the impact of the inclusion of the EG95 vaccine for sheep in the control programme, including analysis of the vaccine's operative feasibility in field conditions. The vaccine was applied in an area comprising four communities of native people including 79 farms with 3146 lambs and 311 dogs in total. Seventy one farms were designated as control areas where no vaccinations were undertaken while vaccinations of lambs undertaken on 91 farms. Lambs received two vaccinations with the EG95 vaccine followed by a single booster injection when the animals were 1-1.5 years of age. Farm locations were defined using GPS coordinates for the houses. Evidence for Echinococcus granulosus transmission was monitored by coproantigen ELISA on samples of dog faeces, by E. granulosus-specific PCR using soil samples, and anti-E. granulosus antibody assessments in sera from 2 to 4 teeth lambs, purgation of dogs to detect E. granulosus worms and necropsy on adult sheep. Before the vaccine was introduced, 26.2% of sheep with 2-4 teeth were positive using ELISA/WB, the prevalence decreased to 7.8% at the third year following use of the vaccine. Necropsy of animals older than 6 years (not vaccinated) showed that 66.1% of animals were infected with E. granulosus. In dogs, 4% was found positive for E. granulosus using arecoline purgation and 24.7% of the farms were infected using coproELISA/WB. During the first year of vaccination 2721 lambs received the first vaccine dose and 2448 received a booster. In the second year 2138 lambs were initially vaccinated and 1745 received a booster, and 1308 animals received the third dose. During the third year 1110 lambs received the first dose from which 539 received a booster and 723 animals received the third dose. An analysis of advantages and limitations of the diagnostic techniques used and the ability of the geospatial analysis to detect risk area are included. Based in the immunodiagnostic techniques, the EG95 vaccine has been able to prevent the infection in animals up to 3 years old. Also, the difficulties in the field for the correct vaccine administration and the social features and habits that may impact on echinococcosis control are included in the analysis.

Cysticercosis and echinococcosis

Cysticercosis and cystic echinococcosis are zoonotic parasitic diseases commonly transmitted by livestock animals. Past and future efforts to reduce transmission of these diseases adopt a One Health approach where control measures are implemented largely in the parasites' animal hosts in order to bring about, indirectly, a reduction in human disease. New and highly effective vaccines have been produced which are capable of preventing infections with Echinococcus granulosus (cystic echinococcosis) and Taenia solium (cysticercosis) in their animal intermediate hosts. Application of vaccines, together with taeniacides in the parasites' definitive hosts, provides new opportunities for control of these diseases and a reduction in the global burden of human cysticercosis and cystic echinococcosis.

Immunology and immunodiagnosis of cystic echinococcosis: an update

Cystic echinococcosis (CE) is a cosmopolitan zoonosis caused by the larval cystic stage of the dog tapeworm Echinococcus granulosus. This complex multicellular pathogen produces various antigens which modulate the host immune response and promote parasite survival and development. The recent application of modern molecular and immunological approaches has revealed novel insights on the nature of the immune responses generated during the course of a hydatid infection, although many aspects of the Echinococcus-host interplay remain unexplored. This paper summarizes recent developments in our understanding of the immunology and diagnosis of echinococcosis, indicates areas where information is lacking, and suggests possible new strategies to improve serodiagnosis for practical application.

Development of PCR/dot blot assay for specific detection and differentiation of taeniid cestode eggs in canids

We report the development of a colourimetric PCR/dot blot assay targeting the mitochondrial gene NADH dehydrogenase subunit 1 (nad1) for differential diagnosis of taeniid eggs. Partial sequences of the cestode nad1 gene were aligned and new primers were designed based on conserved regions. Species-specific oligonucleotide probes (S-SONP) for canine taeniid cestodes were then designed manually based on the variable region between the conserved primers. Specifically, S-SONP were designed for the Taenia crassiceps, T. hydatigena, T. multiceps, T. ovis, T. taeniaeformis, Echinococcus granulosus (genotype 1), E. multilocularis and E. vogeli. Each probe showed high specificity as no cross-hybridisation with any amplified nad1 fragment was observed. We evaluated the assay using 49 taeniid egg-positive samples collected from dogs in Zambia. DNA from 5 to 10 eggs was extracted in each sample. Using the PCR/dot blot assay, the probes successfully detected PCR products from T. hydatigena in 42 samples, T. multiceps in 3 samples, and both species (mixed infection) in the remaining 4 samples. The results indicate that the PCR/dot blot assay is a reliable alternative for differential diagnosis of taeniid eggs in faecal samples.

Fact or hypothesis: concomitant immunity in taeniid cestode infections

Sustained research efforts over the last 50 years have revealed a considerable amount of information about immunity to taeniid cestode infections in the parasites’ intermediate hosts. As a product of this research, a series of effective recombinant vaccines have been developed which have no parallel in any other group of parasitic organisms. There are, however, many important aspects relating to immunity that remain to be elucidated. Some concepts have come to be firmly held as facts and yet the supportive data are either conflicting or unconfirmed. This review considers the phenomenon of immunity to re-infection with taeniid cestodes in their intermediate hosts, examining carefully the nature of the evidence that is available to support conclusions that have been drawn in this area.

Morphological and biological characterization of cell line developed from bovine Echinococcus granulosus

The taeniid tapeworm Echinococcus granulosus is the causative agent of echinococcal disease, a major zoonosis with worldwide distribution. Several efforts to establish an in vitro model of E. granulosus have been undertaken; however, many of them have been designed for Echinococcus multilocularis. In the present study, we have described and characterized a stable cell line obtained from E. granulosus bovine protoscoleces maintained 3 yr in vitro. Growth characterization, morphology by light, fluorescent and electronic microscopy, and karyotyping were carried out. Cell culture origin was confirmed by immunofluorescent detection of AgB4 antigen and by PCR for the mitochondrial cytochrome c-oxidase subunit 1 (DCO1) gene. Cells seeded in agarose biphasic culture resembled a cystic structure, similar to the one formed in secondary hosts. This cell line could be a useful tool to research equinococcal behavior, allowing additional physiological and pharmacological studies, such as the effect of growth factors, nutrients, and antiparasitic drugs on cell viability and growth and on cyst formation.

A new method for quantifying three-dimensional interactions between biological structures

In this paper we examine a new distance-based method for identifying and characterizing possible interactions between biological structures and objects, with respect to the initial developmental stages of Echinococcus granulosus. By adopting the surface of the foramen as the distance reference, several interesting results have been identified, including the fact that the cell nuclei tend to be organized with respect to the foramen surface as well as the stability of the spatial distribution of these nuclei along the development stages.

Ovine echinococcosis

Immunodiagnosis in sheep presents problems of sensitivity and specificity, limiting its applicability in surveillance systems. The objective of this study was to develop a sensitive, specific and accessible technique for diagnosing cystic echinococcosis in naturally infected sheep and to evaluate the validity of necropsy as a reference test. A total of 247 sheep were studied at slaughterhouses, confirming the parasitological diagnosis with histology. Serum was processed with enzyme immunoassay (EIA) using three antigen preparations: total hydatid liquid (LHT), purified fraction of LHT (S2B) and purified lipoprotein (B). Western Blot (WB) was used as a control. EIA proved effective for differentiating Echinococcus granulosus from larval stage of Taenia hydatigena and intestinal cestodes in all three antigen preparations. Serums from macroscopically negative sheep were reactive to EIA and positive with WB. In the whole flock, sensitivity was 89.2% for LHT, 80.0% for S2B and 86.4% for B. Sensitivity in lambs was 78.6% for LHT, 75.0% for S2B and 64.3% for B. Macroscopic diagnosis at the time of slaughter was found to have limitations as a reference test for immunodiagnosis of cystic equinococcosis in sheep, so it was necessary to include histology and WB as reference tests. LHT was the antigen preparation of greatest value and EIA proved to be a sensitive and specific technique, adequate for surveillance systems and for evaluating control programmes.

Control of cystic echinococcosis/hydatidosis: 1863-2002

Echinococcosis/hydatidosis, caused by Echinococcus granulosus, is a chronic and debilitating zoonotic larval cestode infection in humans, which is principally transmitted between dogs and domestic livestock, particularly sheep. Human hydatid disease occurs in almost all pastoral communities and rangeland areas of the underdeveloped and developed world. Control programmes against hydatidosis have been implemented in several endemic countries, states, provinces, districts or regions to reduce or eliminate cystic echinococcosis (CE) as a public health problem. This review assesses the impact of 13 of the hydatid control programmes implemented, since the first was introduced in Iceland in 1863. Five island-based control programmes (Iceland, New Zealand, Tasmania, Falklands and Cyprus) resulted, over various intervention periods (from <15 to >50 years), in successful control of transmission as evidenced by major reduction in incidence rates of human CE, and prevalence levels in sheep and dogs. By 2002, two countries, Iceland and New Zealand, and one island-state, Tasmania, had already declared that hydatid disease had been eliminated from their territories. Other hydatid programmes implemented in South America (Argentina, Chile, Uruguay), in Europe (mid-Wales, Sardinia) and in East Africa (northwest Kenya), showed varying degrees of success, but some were considered as having failed. Reasons for the eventual success of certain hydatid control programmes and the problems encountered in others are analysed and discussed, and recommendations for likely optimal approaches considered. The application of new control tools, including use of a hydatid vaccine, are also considered.

Recent advances in the immunology and diagnosis of echinococcosis

Echinococcosis is a cosmopolitan zoonosis caused by adult or larval stages of cestodes belonging to the genus Echinococcus (family Taeniidae). The two major species of medical and public health importance are Echinococcus granulosus and Echinococcus multilocularis, which cause cystic echinococcosis and alveolar echinococcosis, respectively. Both cystic echinococcosis and alveolar echinococcosis are serious diseases, the latter especially so, with a high fatality rate and poor prognosis if managed inappropriately. This review highlights recent advances in immunity to infection and vaccination against both parasites in their intermediate and definitive hosts and procedures for diagnosis of cystic echinococcosis and alveolar echinococcosis, including the value of immunodiagnostic and DNA approaches. There is discussion also of progress in genomics and related technologies that is providing valuable insights on the functional biology of the Echinococcus organisms. These studies will underpin future research that will reveal a better understanding of the Echinococcus-host interplay, and suggest new avenues for the identification of additional targets for diagnosis, vaccination and chemotherapy.

Epidemiological study of the cystic echinococcosis in Morocco

The objectives of this epidemiological study on cystic echinococcosis (CE) in Morocco (2001-2004) were to update the prevalence of CE in different animal species living in the most important areas of the country and to collect protoscoleces and germinal layers for genetic research purposes. The post mortem inspection concerned 2948 sheep, 2337 goats, 618 cattle, 482 camels and 455 equines (325 horses, 60 mules and 70 donkeys) in five different regions: the Rif (Mediterranean coast and high mountains of the Rif), the Loukkos (Atlantic northwest plain), the center (Rabat and Casablanca regions), the Middle Atlas mountains and the south (arid and semi desert areas). The global CE infection prevalence rates obtained were 22.98% in cattle, 10.58% in sheep, 12.03% in camels, 17.80% in equines and 1.88% in goats. The infection rates were especially high in the Middle Atlas in cattle (48.72%) and in the Loukkos in cattle and sheep (37.61 and 31.65%, respectively). The majority of infected cattle (49.6%) and sheep (52.1%) had hydatid cysts in both liver and lungs. Except for cattle, the liver was more infected than lungs in all the other animal species. Animals more than 5 years old were the most infected in all species. The mean CE infection rates of these animals were about 56% in cattle, 40% in sheep, 20% in camels, 17.80% in equines and 7% in goats. These rates were much higher in the Loukkos (85% of cattle and 59% of sheep) and in the Middle Atlas (68% of cattle and 45% of sheep) than in the other regions. Results showed that Echinococcus granulosus is in an endemic steady state with no evidence of protective immunity in the intermediate hosts. The mean numbers of infections per year are 0.099 for cattle, 0.063 for sheep, 0.03 for camels and 0.010 for goats.

Cystic echinococcosis in the Americas

Echinococcus granulosus and related genotypic variants, the agents of cystic hydatid disease, occur widely in the American continents from Alaska and Northern Canada in North America to Tierra del Fuego in South America. Here we review the historical and current distribution and prevalence of these infections throughout the American countries and the results of programs to control or eliminate the infection.

Cystic echinococcosis in slaughtered sheep in Sardinia (Italy)

Of 771 regularly slaughtered Sardinian breed sheep, 580 (75%) were found infected with Echinococcus granulosus hydatid cysts. Seventy-nine sheep (10.3%) had at least 1 fertile cyst. The prevalence of sheep infected with purulent/caseous cysts, calcified cysts and sterile cysts was 13, 59 and 28%, respectively. The age of sheep was positively associated with the probability of infection that increased 1.15 fold for each further year of age. Fertile cysts were found in the lungs of 46 sheep (6%) and in the liver of 13 sheep (1.7%), and in the lung and the liver of 20 sheep (2.6%). Most fertile cysts were found in the lungs (314) and most sheep were infected with less than 10 cysts. When analyzed by a mixed-effect logistic model, the probability to find fertile cysts in the lungs was three times higher compared to the liver and it increased with the age of the sheep (rho = 0.70, p < 0.001). Of 4072 collected cysts, 532 were fertile, 178 purulent/caseous, 2339 calcified and 1023 sterile.

Cellular organization and appearance of differentiated structures in developing stages of the parasitic platyhelminthEchinococcus granulosus

Echinococcus granulosus is the causative agent of hydatidosis, a major zoonoses that affects humans and herbivorous domestic animals. The disease is caused by the pressure exerted on viscera by hydatid cysts that are formed upon ingestion of E. granulosus eggs excreted by canine. Protoscoleces, larval forms infective to canine, develop asynchronously and clonally from the germinal layer (GL) of hydatid cysts. In this report, we describe the cellular organization and the appearance of differentiated structures both in nascent buds and developed protoscoleces attached to the GL. Early protoscolex morphogenesis is a highly complex and dynamic process starting from the constitution of a foramen in the early bud, around which nuclei are distributed mainly at the lateral and apical regions. Similarly, distribution of nuclei in mature protoscoleces is not homogenous but underlies three cellular territories: the suckers, the rostellar pad, and the body, that surrounds the foramen. Several nuclei are associated to calcareous corpuscles (Cc), differentiated structures that are absent in the earlier bud stages. The number of nuclei is similar from the grown, elongated bud stage to the mature protoscolex attached to the GL, strongly suggesting that there is no significant cellular proliferation during final protoscolex development. The amount of DNA per nucleus is in the same range to the one described for most other platyhelminthes. Our results point to a sequential series of events involving cell proliferation, spatial cell organization, and differentiation, starting in early buds at the GL of fertile hydatid cysts leading to mature protoscoleces infective to canine.

Epidemiology, clinical manifestations and diagnosis of zoonotic cestode infections: an update

This paper reviews the literature on zoonotic cestode infections with specific reference to the years 1999-2003. The sources and prevalence of various zoonotic tapeworm infections caused by adult and larval stages of the genera Taenia, Echinococcus, Diphyllobothrium, Hymenolepis and Dipylidium continue to be an important cause of morbidity and mortality, not only in most underdeveloped countries but also in industrialized countries, particularly in rural areas or among immigrant groups from endemic areas. The review gives a detailed report on recent molecular epidemiological studies on the taxonomy and phylogenetic variations in Echinococcus granulosus, immunological tests and imaging techniques used in epidemiological surveys and clinical investigations of important adult and larval tapeworm infections of animals and humans. Larval stages or metacestodes of Taenia solium, Echinococcus spp. and pseudophyllidean tapeworms (Spirometra syn. Diphyllobothrium spp.) may reside in various tissues of their intermediate hosts, including humans. In particular, Cysticercus cellulosae (T. solium) and the larvae of E. granulosus, and E. multilocularis, which are predominantly located in the liver, lungs and central nervous system forming various types of cysts, lead to a complex of systemic diseases such as cysticercosis, cystic echinococcosis and alveolar echinococcosis, respectively. Relatively rare clinical manifestations are seen in the muscles, subcutaneous tissue, spleen, kidneys, bones and body cavities.