Cystic echinococcosis in Italy from the 1950s to present

In Italy the epidemiological pattern of cistic echinococcosis (CE) is incomplete and the information for most regions is out of date, contradictory, and almost exclusively limited to the intermediate hosts. The disease is found most frequently in particular social and economic conditions: widespread use of extensive or semi-extensive sheep farming, illegal slaughtering, and high numbers of sheepdogs and other types of dogs. The highest incidence in sheep is found in Sardinia (70.6-92.8%), Sicily (6.5-36.5%), Basilicata (5-28%), Abruzzo (22%) and Tuscany (47%). It North Italy, it is never higher than 0.5% in slaughtered sheep. No data are available on the biomolecular characterization of the strains of E. granulosus in Italy, apart from Sardinia and recently Lazio. G1 (Sheep strain), G7 (Pig strain) G2 (Tasmanian sheep strain) have been identified in Sardinia and G1 and G3 (Buffalo strain) have been recently isolated in Lazio. In Italy, CE has was also found in buffaloes (2.63-9.8%) and horses (<1%). However, further epidemiological surveys and genotyping study are necessary. The small quantity of up to date information on the diffusion of E. granulosus in dogs (Abruzzo 4%, Sardinia 6-10% and Sicily 19.3%) highlights the need for modern, fast, sensitive and low risk diagnostic methods which would provide a true picture of the pattern of the infection in this host.     

Study on immunobiology in endoparasites of public health interest: echinococcosis-hydatidosis

Cystic echinococcosis caused by Echinococcus granulosus is one of the most widespread zoonoses in the Mediterranean, endemic in some regions such as Sardinia. Some aspects of the research conducted in this area are briefly reviewed for an integrated analysis of both epidemiological and immunobiological knowledge, gained from field observations and experimental studies. Data on epidemiology in intermediate hosts, immunological assessment of exposure in humans, immune response and Th1/Th2 polarization in secondary experimental hydatidosis, kinetics of response in definitive host and cytokine production in experimental models are briefly reported. They confirm the usefulness of an immunobiological approach both in intermediate and definitive hosts and their potential in prevention, monitoring and control of E/H.     

Cystic echinococcosis in Greece. Past and present

Cystic echinococcosis is a zoonotic disease with a wide geographical distribution, Greece included, and is considered to be a serious problem for the public health and the livestock economy. Although the disease was widespread in Greece since ancient times, cystic echinococcosis was identified as a serious problem around 1970, and since then national surveillance programmes are running, based on meat inspection and stray dogs management. Ever since, there are official records of the parasite's prevalence in humans and livestock which show a continuous decline. More precisely, human hydatidosis, according to the official records, declines from an annual incidence of 14.8 per 100,000 inhabitants during 1967-1971 to 0.3 in 2008. Late surveys reveal that in Greece the prevalence of echinococcosis was 23-39.2% for sheep, 7.6-14.7% for goats, 0% in cattle and 0.6% in pigs, while further molecular analyses in Southern Greece showed the existence of the genotypes G1 and G3 in sheep and G7 in goats in that area. All data presented demonstrate that the parasite is still present in Greece. Surveillance is nowadays being performed under EU regulations but it is highly important to improve and adopt corrective and preventive measures to avoid animal and human infection.     

Immunodiagnostic tests for hydatidosis in sheep: an evaluation of double diffusion, immunoelectrophoresis, indirect hemagglutination, and intradermal tests

Immunoelectrophoresis (IEP), double diffusion (DD5), indirect hemagglutination (IHA), and intradermal (ID) tests were evaluated to determine their ability to detect echinococcosis in sheep. Four sheep were infected per os with approximately 4,00, 1-wk-old eggs of Echinococcus gradulosus; four more sheep were similarly infected with approximately 3,000 1-wk-old eggs of Taenia hydatigena, and two additional sheep were used as uninfected controls. Blood samples were collected from each sheep prior to infection, at 2 and 4 wk postinoculation, and monthly thereafter for 1 yr. Serum from each blood sample was tested by IEP and DD5 for antiantigen "5" activity and by IHA for Echinococcus-specific hemagglutination activity. Following the last blood collection, an ID test for echinococcosis was performed on each sheep, after which all sheep were necropsied, and the type, location, and size of all larval tapeworms recorded. The DD5 test was found to be more sensitive and at least as specific as IEP in detecting echinococcosis in sheep. The IHA test approached the specificity and sensitivity pattern of DD5 and IEP if a titer of greater than or equal to 1:1,024 was considered positive. The ID test supported DD5 and IEP results but demonstrated a lack of specifiity. Necropsy data verified that all sheep were infected according to the experimental design. We conclude that DD5 reliably detects echinococcosis in experimentally infected sheep, and that further research is warranted to evaluate this test for detecting echinococcosis in naturally infected sheep.     

Lichen diversity on dolmen and menhir in the Megalithic complex of Sa Coveccada (Mores,Sardinia)

This work describes the lichen diversity found on the megalithic Dolmen of Sa Coveccada (Mores, Sardinia) until 2010. After that year, a restoration with chemical removal of lichen crusts took place, which destroyed a great part of the lichen communities. These were studied again after removal and lichen communities occurring on rock outcrops in the surroundings of the Dolmen and on a contiguous menhir were investigated as well for comparison. Before the restoration, 33 species had been recorded on the Dolmen, most being crustose, followed by foliose and fruticose forms. Among these, eight species are regarded as rare in Sardinia and five rare at lower elevations. Most of the recorded species are typical for eutrophic substrates and for meso- to xerophytic conditions. Studies on lichen diversity on archaeological monuments in Sardinia are limited. This is the first report on the lichens of a Sardinian dolmen. This paper questions whether the lichen diversity of such monuments should be preserved as lichens have been an important part of the monument ecosystem and of the landscape for many centuries. This work also aims to improve collaboration among lichen and monument experts, in order to avoid hasty restoration decisions.     

Help from the sky: Can vultures contribute to Cystic Echinococcosis control in endemic areas?

Cystic echinococcosis (CE) is endemic in Sardinia and constitutes a serious public health concern due to high prevalence in livestock and humans. Despite sustained efforts, control of the disease had been unsuccessful in the region. Problematic carcass disposal due to soaring incineration costs and free access of dogs to infected carrion are dominant factors, fueling endemicity among other. As sole obligate scavenger, griffon vultures (Gyps fulvus) are uniquely specialized to eliminate carcasses swiftly and efficiently, saving on unnecessary environmental and economic costs for carrion disposal. However, following drastic population declines across Europe, griffon vultures practically went extinct in Italy. A conservation expansion program in Sardinia successfully reinforced the last remaining Italian vulture population by mitigating the main threats to its survival; food shortage. Through the establishment of supplementary feeding stations, permanent supply of livestock cadavers was provided. In this research, the management and conservation implications on the controlled disposal of carcass disposal through vulture feeding stations on the control of CE in Sardinia were assessed. During the course of the project, vultures scavenged a total of 81,361 kg of biomass, saving €90,041 in incineration costs and € 1,054 in CO₂ emission. Through extrapolation of these results, a total of 5,304 kg of suspected CE infected sheep carcasses (65.3%) was calculated to have been disposed by griffons, considerably reducing the CE risk and burden in Sardinia. A quantification of the amount of biomass that could be eliminated by griffon in a succeeding conservation project was also made. These calculations implied that 162,722 kg of biomass, including 10,608 kg of infected biomass from sheep, would be consumed over a period of 5 years, further lowering the CE burden in Sardinia. Our results, driven under one health approach, emphasize the crucial and direct role of griffons in breaking the lifecycle of CE as well as their indirect role in rendering multiple ecosystem and economic services through the elimination of carcasses. Please view a video Abstract here: https://youtu.be/Tm820nPq5KE.     

Hydatidosis in Sardinia. Co-involved parameters and hypothesis for a control campaign

Although hydatidosis provokes in man and livestock losses of economic significance, there has been no comprehensive study on this disease. This article is an account of Sardinia as an important area of echinococcosis-hydatidosis. The incidence and distribution of infection in the intermediate and definitive hosts are reviewed and the current status of hydatid disease is evaluated. The review is divided into main sections: (a) geographical and environmental data; (b) domestic intermediate hosts; (c) definitive host; (d) human infections. An average of 85% of the sheep are infected and about 75% of cysts are fertile, 13% of the dogs are parasitized and mainly live as strays, up to 39% of the shepherd's dogs were found to harbour the mature worm of Echinococcus granulosus. Hospital data indicate that even nowadays about 200 people are operated every year with an incidence of 11.1/100.000 inhabitants. The socio-cultural factors (seminomadism, slaughtering practice, etc.) involved in the dissemination, the economic implication of this disease, the benefits due to an eradication, the feasibility of a campaign and the organizational structure aimed at eradicating echinococcosis/hydatidosis in this area, are discussed.     

Animal echinococcosis in Italy: epidemiological update

Cystic Echinococcosis (CE) is one of the most widespread parasitoses in the Mediterranean Region (MR). This is due to various factors, the most important being the close association between man, sheep and dogs in areas where open farming is practised. Although this disease has been known for several years and many studies have been carried out, nowadays in Italy there are no complete epidemiological data on its diffusion and distribution. The available data show that CE is mainly diffused in those districts where the sheep-dog cycle can be perpetuated, such as central and southern Italy, and the islands. Furthermore, no data are available on biomolecular characterisation of the strains of Echinococcus granulosus in Italy, apart form those in Sardinia, where the G1 (sheep-dog) and G7 (pig-dog) strains were recently isolated. One of the reasons why CE is a problem with no easy solution is undoubtedly the difficulty of making a certain diagnosis in the dog, the principal definitive host of E. granulosus.     

Frequency of hemochromatosis C282Y and H63D mutations in Sardinia

Hereditary hemochromatosis (HH) is one of the most common autosomal recessive disorders of iron metabolism among Caucasians, and it is associated with C282Y mutation of the HFE gene in populations of Celtic origins. A second mutation, H63D, shows a very high widespread frequency, although its role in iron metabolism is still inconclusive. There are no data on the frequencies of these two mutations in Sardinia, an island in the Mediterranean sea that has not been invaded by Celtic peoples. We examined 836 chromosomes from Sardinian subjects and tested for the mutation by restriction enzyme digestion of PCR products. Among the 836 analyzed chromosomes, we found a C282Y allele frequency of 0.0036 and an H63D allele frequency of 0.173. These data could explain the observed rarity of HH in Sardinia. The high allele frequency of H63D and the rarity of HH in Sardinia is suggestive that this mutation is not a major contributor to this disease.     

Epidemiology of hydatid disease in Sardinia: a study of fertility of cysts in sheep

Hydatidosis, caused by Echinococcus granulosus, is a cyclozoonotic disease of economic significance in Sardinia. The life-cycle involves stray and sheep dogs as definitive hosts and sheep, pigs, goats and cattle as intermediate hosts. The most important intermediate host is sheep, due to home slaughtering with ready access of the viscera to dogs. This survey was undertaken in 1987 to ascertain the epidemiological significance of sheep in maintaining the life-cycle. A total of 700 (91.3%) of 767 sheep harboured hydatid cysts. The frequency distribution of the number of hydatid cysts was over-dispersed. Of 497 infected sheep, 7.6% had fertile cysts, 75.7% sterile cysts and 16.7% fertile + sterile cysts.     

Serodiagnosis of Echinococcosis by ELISA Using Cystic Fluid from Uzbekistan Sheep

According to increase of travel, the cases of imported echinococcosis have been increasing in Korea. The present study was undertaken to develop a serodiagnostic system for echinococcosis in Korea. For diagnosis of echinococcosis, the fluid of Echinococcus granulosus hydatid cysts was collected from naturally infected sheep in Uzbekistan. Also serum samples of infected patients who were surgically confirmed were collected in a hospital in Tashkent, Uzbekistan. According to the absorbance of 59 echinococcosis positive and 39 negative control serum samples, the cut-off value was determined as 0.27. The sensitivity and specificity of ELISA with hydatid fluid antigen were 91.5% and 96%, respectively. The antigen cross-reacted with the serum of some cysticercosis or clonorchiasis patients. However, immunoblot analysis on the cystic fluid recognized antigenic proteins of 7-, 16-, and 24-kDa bands in their dominant protein quantity and strong blotting reactivity. In conclusion, the present ELISA system using hydatid cyst fluid antigen from Uzbekistan sheep is sensitive and specific for diagnosis of echinococcosis cases.     

Parasitoses and development: malaria and echinococcosis]

After having placed emphasis on the cyclic oscillations characterizing the interest of the scientific and political world for parasitology, the author analyzes the various standpoints from which parasitic diseases, and above all malaria, have been dealt with ever since the beginning of this century. Specific criticism is addressed to the military model, which has provided the basis for many eradication campaigns. The author also analyzes the "vicious circle theory", which labelled the activity of the WHO in its first decade of life, and which assumed that breaking the disease and underdevelopment circle was possible by acting mainly or even exclusively on endemic and debilitating diseases. Both these models were tested with success in Sardinia with the 1947-49 antimalaria campaign. However, socio-economic development of the island did not occur as expected, and attempts to export the same approaches to other parts of the world soon disclosed their limitations, leading to major failures. The experience on the fight against echinococcosis is subsequently examined. The conclusions drawn are that many successes may be obtained through a systemic rather than a sectorial approach; and that a "conflicting cohabitation" with diseases is foreseen as a long-lasting reality, and must thus be controlled with the appropriate means.     

Evaluation of fecal immunoassays for canine Echinococcus infection in China

Human echinococcosis is present worldwide but it is in China that disease prevalence is the highest. In western China, especially in the Tibetan Plateau, the burden of echinococcosis is the most important. Dogs are a major definitive host of Echinococcus and monitoring the presence of Echinococcus worms in dogs is therefore essential to efficiently control the disease. Detection kits based on three different technologies including sandwich ELISA, (indirect) ELISA, and gold immunodiffusion, are currently marketed and used in China. The objective of this work was to assess the efficacy of these kits, in particular with respect to sensitivity and specificity. Four fecal antigen detection kits for canine infection reflecting the three technologies were obtained from companies and tested in parallel on 220 fecal samples. The results indicate that the performance is lower than expected, in particular in terms of sensitivity. The best results were obtained with the sandwich ELISA technology. The gold immunofiltration yielded the poorest results. In all cases, further development is needed to improve the performance of these kits which are key components for the control of echinococcosis.     

Geographical Detector-based influence factors analysis for Echinococcosis prevalence in Tibet,China

Echinococcosis, caused by genus Echinococcus, is the most pathogenic zoonotic parasitic disease in the world. In Tibet of the People’s Republic of China, echinococcosis refers principally to two types of severe zoonosis, cystic echinococcosis (CE) and alveolar echinococcosis (AE), which place a serious burden on public health and economy in the local community. However, research on the spatial epidemiology of echinococcosis remains inadequate in Tibet, China. Based on the recorded human echinococcosis data, maps of the spatial distribution of human CE and AE prevalence in Tibet were produced at city level and county level respectively, which show that the prevalence of echinococcosis in northern and western Tibet was much higher than that in other regions. We employ a geographical detector to explore the influencing factors for causing CE and AE while sorting information on the maps of disease prevalence and environment factors (e.g. terrain, population, and yak population). The results of our analysis showed that biological factors have the most impact on the prevalence of echinococcosis, of which the yak population contributes the most for CE, while the dog population contributes the most for AE. In addition, the interaction between various factors, as we found out, might further explain the disease prevalence, which indicated that the echinococcosis prevalence is not simply affected by one single factor, but by multiple factors that are correlated with each other complicatedly. Our results will provide an important reference for the evaluation of the echinococcosis risk, control projects, and prevention programs in Tibet.     

Molecular identification of unilocular hydatid cysts from domestic ungulates in Ethiopia: implications for human infections

To identify the etiologic agents of cystic echinococcosis in Ethiopia, unilocular hydatid cysts were collected from 11 sheep, 16 cattle and 16 camels slaughtered in abattoirs of Aweday, Jijiga, Haramaya and Addis Ababa during June 2010 to February 2011. A PCR-based DNA sequencing of the mitochondrial cytochrome oxidase c subunit 1 gene (cox1) was conducted for 40 cysts. The majority of cysts (87.5%) were identified as Echinococcus granulosus sensu stricto and the rest as Echinococcus canadensis. The fertile cysts of E. granulosus s.s. were found only from sheep, although it occurred in all the host species. The predominance of E. granulosus s.s. has important implications for public health since this species is the most typical causative agent of human cystic echinococcosis worldwide. The major cox1 haplotype of E. granulosus s.s. detected in Ethiopia was the same as that has been reported to be most common in Peru and China. However, a few cox1 haplotypes unique to Ethiopia were found in both of the two Echinococcus species. The present regional data would serve as baseline information in determining the local transmission patterns and in designing appropriate control strategies.     

Molecular characterization of Echinococcus granulosus from Peru by sequencing of the mitochondrial cytochrome C oxidase subunit 1 gene

Echinococcus granulosus, the etiologic agent of cystic echinococcosis (CE) in humans and other animal species, is distributed worldwide. Ten intra-specific variants, or genotypes (G1-G10), have been defined based on genetic diversity. To determine the genotypes present in endemic areas of Peru, samples were collected from cattle (44), sheep (41) and humans (14) from Junín, Puno Huancavelica, Cusco, Arequipa and Ayacucho. DNA was extracted from protoscolex and/or germinal layers derived from 99 E. granulosus isolates and used as templates to amplify the mitochondrial cytochrome C oxidase subunit 1 gene. The resulting polymerase chain reaction products were sequenced and further examined by sequence analysis. All isolates, independent of the host, exhibited the G1 genotype. Phylogenetic analysis showed that three isolates from Ayacucho shared the same cluster with microvariant G1(4). The G1 genotype is considered the most widespread and infectious form of E. granulosus worldwide and our results confirm that the same patterns apply to this country. Therefore, these findings should be taken into consideration in developing prevention strategies and control programs for CE in Peru.     

Genetic diversity of Echinococcus granulosus sensu stricto in Sardinia (Italy)

Cystic echinococcosis (CE) is a severe parasitic zoonosis caused by the metacestode of the tapeworm Echinococcus granulosus sensu lato (s.l.). The disease has a global distribution representing a significant public health concern. Based on mitochondrial DNA analysis E. granulosus s.l. has been subdivided into five species: E. granulosus sensu stricto (s.s.) (G1, G3 genotype), E. equinus (G4 genotype), E. ortleppi (G5 genotype), E. canadensis (G6-G8, G10 genotype) and E. felidis. E. granulosus s.s., and in particular G1, is the most widespread genotype and the major responsible of human CE cases worldwide. In Italy G1 genotype is higly represented with larger percentages in some hyperendemic areas such as Sardinia. Molecular studies represent a valuable tool to improve our understanding of the E. granulosus epidemiology and CE control strategies. In the present study we investigated genetic variability of E. granulosus s.s. in Sardinia. To this purpose 83 hydatid cysts were collected from different animal species including humans and the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene was partially sequenced (720 bp). Nucleotide sequences from Mediterranean basin were also analyzed for comparison. The phylogenetic network revealed 30 haplotypes grouped around a predominant isolate that had been already reported from other world regions. Haplotype diversity (0.8495 ± 0.0336) and nucleotide diversity (0.003305 ± 0.002014) were similar in Sardinia respect to other Mediterranean countries. Neutrality indices obtained by Tajima's D and Fu's Fs test were significantly negative (p ≤ .01) suggesting expansion of Sardinian population. Low Fixation indices (Fst), ranging from negative values (Algeria, Greece, Spain, other part of Italy) to 0.089 (Albania, France), indicated absence of genetic differentiation, and gene flow between Sardinia and other Mediterranean countries.     

Cattle and small ruminant piroplasmosis in Macedonia, Greece

Macedonia is an endemic region of cattle as well as of sheep and goat piroplasmosis In cattle, Theileria orientalis (=T. buffeli?), the agent of Eurasian benign theileriosis, is the most common and widespread piroplasm species. T. annulata, the agent of tropical theileriosis, seems to be rare and limited to few foci, but causes very severe clinical cases, especially in imported pure-bred or cross-bred animals. Babesia bovis and B. bigemina are present in several localities, and often coexist. Cattle babesiosis cases are due to both piroplasms, but B. bovis is considered responsible for the severe and acute clinical cases. Ovine and caprine babesiosis is due to B. ovis and mainly affected imported animals as well as indigenous animals which have been transported from localities where the infection was absent. B. ovis is extremely widespread in both sheep and goats. During the last decades, no clinical cases of small ruminant theileriosis have been registered in this region. However, T. ovis, a non-pathogenic theileria, is common in sheep, but not in goats. Anaplasma ovis, a protobacterium of small ruminants, is also present in the region.     

Updates on morphobiology, epidemiology and molecular characterization of coenurosis in sheep

Taenia multiceps (Leske, 1780) is a taeniid cestode that in its adult stage lives in the small intestine of dogs and other canids. The metacestode, previously known as Coenurus cerebralis, is usually found in the nervous system including brain and spinal cord in sheep and other ruminants. The presence of cysts typically leads to neurological symptoms that in the majority of cases result in the death of the animal from starvation after some weeks. Coenurosis could cause high losses in sheep farms because the disease affects young animals that the farmers grow up each year as replacements of the older individuals. Coenurosis is also a zoonosis with more than 100 human cases described in literature, of which the last in Italy and almost 5 reported in Sardinia. In the last years, the popularity of coenurosis has increased in sheep breedings because of the necessity to operate a differential diagnosis from another neurological disease, scrapie, particularly in atypical cases of coenurosis that could occur also in adult (2-3 years of age) sheep.     

The action of albendazole on hydatid cysts in sheep experimentally infected with eggs of Echinococcus granulosus

According to the Brazilian Agricultural Ministry, the prevalence of cystic echinococcosis in the state of Rio Grande do Sul, Brazil has decreased between 1990 and 1998, possibly due to the common use of albendazole to control parasites in sheep. Therefore, albendazole (ABZ) action was tested on hydatid cysts of sheep experimentally infected with eggs of Echinococcus granulosus in Uruguaiana County (RS) with the aim of evaluating the observed changes in the parasite's prevalence. The sheep were divided into three groups of 15 animals each and treated as follows. Group 01 was a control (without treatment), groups 02 and 03 received 7.5 mg/kg and 15 mg/kg, respectively, of ABZ orally for 12 months, at intervals between 36 and 45 days. At the end of the studied period the animals were necropsied and the viability of the hydatid cysts was evaluated. Lung and hepatic cysts of sheep treated with ABZ were reduced in size. Degeneration and evident calcification were seen in 87.3% (group 02) and 75.7% (group 03), which were significantly different (P < 0.01) from the 17.3% demonstrated in the control group. It could be concluded that ABZ used early and over long periods, even in small doses, is capable of promoting lesions that devitalize the cysts. This leads to a decrease in fertility of E. granulosus in sheep and could be the reason why the prevalence of cystic echinococcosis has decreased in recent years.