Dog echinococcosis in northern Spain: comparison of coproantigen and serum antibody assays with coprological exam

Prevalence of Echinococcus granulosus sensu lato in Owned Dogs in Lagos State, Nigeria

Echinococcus granulosus sensu lato (s.l.) infection in dogs poses risk of transmission to their owners and family members. We determined the prevalence and factors associated with E. granulosus s.l. infection among owned dogs presented at veterinary clinics or hospitals in Lagos State, Nigeria. Fecal samples from 217 dogs were screened for the presence of taeniid eggs using a sedimentation test in a cross sectional study. The taeniid eggs were identified at molecular level using a multiplex PCR. A structured questionnaire was used to obtain data on intrinsic and extrinsic factors from 133 dog owners. Out of the 217 dog fecal samples, 13 (6.0%) had taeniid eggs, of which 12 (92.3%) were identified as Echinococcus granulosus s.l. We found that Echinococcus granulosus infection is present among owned dogs in Lagos State with an overall prevalence of 5.5%. Location of the veterinary clinics or hospital and purpose for keeping dogs were significant factors associated with E. granulosus infection among owned dogs. Dogs living in suburban areas and kept for security purposes or guarding have higher probability of infection. Appropriate and regular treatment of dogs with praziquantel is highly recommended to reduce risk of E. granulosus transmission to humans.

Prevalence of cystic echinococcosis in slaughtered livestock in Iran: a systematic review and meta-analysis

BACKGROUND

Hydatidosis is a zoonotic disease and has a great general and economic health importance in both developed and developing countries. Therefore, this systematic and meta-analytic study was conducted to determine the prevalence of cystic echinococcosis in slaughtered livestock in Iran.

METHODS

The present study was conducted as a systematic review and meta-analysis. The SID & Magiran, MEDLINE (PubMed), ScienceDirect, Scopus, and Google Scholar databases were searched with a view to selecting relevant research works. As a result, 31 articles published from April 1970 to April 2020 were selected. The heterogeneity of the studies was assessed using the I² index. Data analysis was conducted within the Comprehensive Meta-Analysis software (CMA) v.3.0 (Biostat, Englewood, NJ, USA) and Arc map (ArcGIS 10.3) software.

RESULTS

The heterogeneity of the studies was evaluated using the I² test which value was 99% showing a high heterogeneity in the studies. The results of publication bias in studies were evaluated by the Egger test, which were not statistically significant (P = 0.144). The overall prevalence of cystic echinococcosis in slaughtered livestock in Iran is 13.9% (95%CI: 10.7-17.7%). The results of the meta-regression analysis indicate the increasing trend of the hydatid cyst prevalence with the increase of sample size and publication year (P < 0.05).

CONCLUSION

According to the results of this study and the relatively high prevalence of cystic echinococcosis in slaughtered livestock in Iran, health policy makers should make effective decisions in this regard, and implement careful inspections and interventions by experts and health authorities.

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.

Although present worldwide, human echinococcosis is at its highest prevalence in western China and particularly in the Tibetan Plateau. Controlling echinococcosis is a national priority and routine monitoring must be established. Dogs are the main infection source in China and surveying Echinococcus worms in dogs is therefore a research priority. Commercial detection kits are currently in use in China to monitor the presence of Echinococcus in dogs. The kits are based on three different technologies including sandwich ELISA with two monoclonal antibodies, (indirect) ELISA, and gold immunodiffusion. National survey programmes are essential for the control of echinococcosis and it is thus very important to assess the efficacy of these kits for the programmes. This work was therefore undertaken to assess efficacy of the 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 performance was lower than expected, in particular for their sensitivity which ranged between 51.5% and 83.9% with only two samples displaying a worm burden lower than 100. Three out of four kits showed non-specific cross-reactions with other parasites. The best results were obtained with the sandwich ELISA technology, whereas gold immunofiltration yielded the poorest results. However, in all cases, further development is strongly needed to improve the performance of these kits which are key components for the control of echinococcosis.

New Insights Into the Peculiar World of the Shepherd-Dog Parasites: An Overview From Maremma (Tuscany, Italy)

Several developments have been recently achieved to understand pet-dog parasites and their relationship with hosts; however, parasites' presence and distribution in shepherd-dog have been mainly neglected; this knowledge gap is of critical sanitary importance, as shepherd-dogs could harbor zoonotic helminths including Echinococcus granulosus sensu lato. The related human disease, cystic echinococcosis, is a worldwide neglected disease, with high endemicity in the Mediterranean Basin. To evaluate the presence of E. granulosus and other parasites, a sheep-dog population from the province of Grosseto (Tuscany, Italy) has been investigated. Overall, 648 dog fecal samples obtained from 50 modern sheep farms, having a total of 216 dogs, were collected. Specimens were analyzed using a standardized centrifugal flotation method (specific gravity = 1.3). Taeniid eggs detected were further isolated using a sieving/flotation technique. DNA was isolated from eggs for PCR and sequence analyses for species identification (gene target: 12S rRNA and nad1). Thirty-nine (78%) farms tested positive for at least one parasite species or genus. The most represented intestinal helminths were Toxocara spp. in 64% of farms, followed by Ancylostomatidae (58%), Trichuris vulpis (50%), Capillaria spp. (34%), and taeniids (32%). Sequence analyses confirmed the presence of Taenia hydatigena in seven farms, Taenia (syn. Multiceps) multiceps in five farms, and T. pisiformis in one farm. No DNA was extracted from four previously taeniid egg-positive farms. No amplification of amplicon corresponding to E. granulosus was achieved in the investigated farms. Although not entirely expected, Spearman's test showed a positive correlation between flock size and the number of dogs per farm (ρ = 0.588, P < 0.001). The quantitative analysis reported that the home slaughter practice was affected neither by the flock size nor by the number of dogs per farm. The probability to diagnose farms positive for taeniids had been increased by about 35% for each dog unit increase [odds ratio (OR) = 1.35, P = 0.012]. In conclusion, the wide distribution of T. hydatigena and T. multiceps detected in the present study clearly reveals that dogs have still access to raw offal, a major risk for the transmission of E. granulosus. Home slaughtering is an unavoidable practice, and more efforts must be undertaken by the public health system to prevent and control potential zoonotic taeniids.

Prevalence of intestinal parasite infections in stray and farm dogs from Spain

Dogs play a potential role as reservoirs for zoonotic parasites, being especially problematic uncontrolled dog populations such as stray and farm dogs with access to populated areas. In order to investigate the prevalence of canine intestinal parasites in at-risk dog populations, we tested a total of 233 faecal samples shed by stray and dairy farm dogs from northern Spain. Telemann method was used to detect the presence of eggs and (oo)cysts of common dog intestinal parasites and Cryptosporidium was detected by PCR. One hundred and forty eight out of 233 samples (63.5%) were positive for at least one intestinal parasite, being Ancylostomidae (35.6%; 83/233) and Trichuris (35.2%; 82/233) the parasites most frequently identified. Cryptosporidium DNA was not detected in any of the faecal samples analysed. The overall prevalence was significantly higher in stray dogs than in farm dogs (72.5% vs 58.8%). Specifically, stray dogs had a significantly higher prevalence of Ancylostomatidae, Toxocara, Toxascaris and Taenidae. These dog populations are an important source of environmental contamination with intestinal parasite forms, which could be of significance to animal and human health.

Epidemiological distribution of Echinococcus granulosus s.l. infection in human and domestic animal hosts in European Mediterranean and Balkan countries: A systematic review

Cystic echinococcosis (CE) is a neglected zoonosis caused by infection with the cestode Echinococcus granulosus sensu lato. We carried out a systematic literature review on E. granulosus s.l. human and animal (cattle, sheep, dog) infection in European Mediterranean and Balkan countries in 2000–2019, to provide a picture of its recent epidemiology in this endemic area. MEDLINE, EMBASE, Scopus, Google Scholar and Open Grey databases were searched. Included cases were: i) for humans, data from hospital records and imaging studies; ii) for dogs, data from necropsy and coprological studies; iii) for ruminants, cases based on slaughter inspection. The NUTS (Nomenclature of Territorial Units for Statistics) classification was used to categorize extracted data in epidemiological units, defined as data referred to one NUTS2 (basic region) in one year time. Data were then aggregated to NUTS1 level (major regions), calculating the average incidence value of included epidemiological units. For prevalence studies covering different epidemiological units, the pooled prevalence was estimated. Data were extracted from 79 publications, 25 on human infection (covering 437 epidemiological units), and 54 on animal infection (52 epidemiological units for cattle, 35 for sheep and 25 for dogs). At NUTS1 level, average annual incidence rates of human CE ranged from 0.10–7.74/100,000; pooled prevalence values ranged from 0.003–64.09% in cattle, 0.004–68.73% in sheep, and 0–31.86% in dogs. Southern and insular Italy, central Spain, Romania and Bulgaria reported the highest values. Bovine data showed a more similar pattern to human data compared to sheep and dogs. Limitation of evidence included the paucity of human prevalence studies, data heterogeneity, and the patchy geographical coverage, with lack of data especially for the Balkans. Our results confirm Italy, Spain, and Eastern Europe being the most affected areas, but data are extremely heterogeneous, geographical coverage very patchy, and human prevalence studies extremely scant. Results also highlight the notorious problem of underreporting of E. granulosus s.l. infection in both humans and animals.

Cystic echinococcosis (CE) is a neglected zoonosis caused by infection with the parasite Echinococcus granulosus sensu lato, naturally transmitted between canids and livestock; CE in humans can be a serious condition. In endemic areas, CE is responsible for significant health and economic losses, but its real burden is difficult to estimate. E. granulosus s.l. is especially present in areas where livestock breeding is practiced, including European Mediterranean and Balkan countries. We carried out a systematic literature review on the epidemiology of E. granulosus s.l. human and animal infection in this area in 2000–2019. Data were extracted from 79 publications, and referred to Nomenclature of Territorial Units for Statistics (NUTS) levels per year. Average annual incidence rates of human CE ranged from 0.10–7.74/100,000; pooled prevalences ranged from 0.003–64.09% in cattle, 0.004–68.73% in sheep, and 0–31.86% in dogs. Bovine data showed a more similar pattern to human data compared to sheep and dogs. Our results confirm that Italy, Spain, and Eastern Europe are the most affected areas, but data are extremely heterogeneous, geographical coverage very patchy, and human prevalence studies extremely scant. Results also highlight the well-known problem of underreporting of E. granulosus s.l. infection in both humans and animals.

Development and Validation of a Copro-Enzyme-Linked Immunosorbent Assay Sandwich for Detection of Echinococcus granulosus-Soluble Membrane Antigens in Dogs

Cystic echinococcosis (CE) is a parasitic zoonosis caused by the larval stage of the tapeworm Echinococcus granulosus. Detection of the adult stage in the canine definitive host is essential for estimating infection rates, surveillance and monitoring of CE control programs. This study sought to develop and validate a coproantigen sandwich enzyme-linked immunosorbent assay (copro-ELISA), based on antibodies against E. granulosus-soluble membrane antigens (EGMA), that is capable of distinguishing infected and noninfected dogs. Anti-E. granulosus polyclonal immunoglobulin G antibodies were obtained from rabbit antiserum against EGMA. Optimization of the test was performed with 51 positive and 56 negative stool samples of canine echinococcosis. Specificity, sensitivity, cross-reactivity, intra- and inter-assay precision, and over time detection were evaluated. According to the receiver operating characteristic analysis, the diagnostic sensitivity and specificity were 96.1% (CI: 85.9-99.6) and 98.2% (CI: 89.5-100), respectively. Negative and positive predictive values were 96.5% (CI: 91.7-100) and 98% (CI: 94.1-100), respectively. No cross-reactivity with Taenia hydatigena, Dipylidium caninum, or Toxocara canis was observed. Intra- and inter-assay repeatability showed values of less than 15% of the variation coefficient. The over time detection was from 20 to 27 days postinfection with E. granulosus. The copro-ELISA based on EGMA detection offers a simplified in-house development of diagnostic testing. This assay showed high specificity and sensitivity and had no cross-reactivity with other parasites. Further studies and development of this test in a kit format may be useful for the detection of active infection in dogs living in CE endemic regions.

Innovative tools for the diagnosis of Echinococcus granulosus in definitive hosts

The aim of this study was to develop and validate an innovative protocol for the diagnosis of Echinococcus granulosus and other Taeniidae in dogs. For this purpose, three experiments were performed, using faecal samples from naturally infected dogs. Firstly, the FLOTAC technique was calibrated with five flotation solutions: saturated sodium chloride (specific gravity, s.g. = 1.20), zinc sulphate (s.g. = 1.35), zinc chloride (s.g. = 1.45), Breza (s.g. = 1.30) and modified Breza (s.g. = 1.40). Then, FLOTAC was compared with four techniques of flotation in centrifuge using: zinc sulphate (s.g. = 1.20), Breza (s.g. = 1.30), modified Breza (s.g. = 1.40), and zinc chloride (s.g. = 1.45). Finally, four different protocols of DNA extraction were compared for Taeniidae identification: QIAamp Tissue Kit and QIAamp Stool from eggs; QIAamp Stool and Wizard Magnetic Purification System for Food from faeces. FLOTAC with zinc sulphate was the most efficient method to detect Taeniidae eggs, showing highest mean of eggs per gram (EPG) of faeces. The QIAamp Stool, using eggs concentrated by FLOTAC, was the best method for DNA extraction. The combination of these protocols provided the highest number of positive samples with PCR, i.e., 47/50 (94.0%). The three negative samples showed a low faecal egg count (2 EPG) below the detection limit (4 EPG) of the protocol. From sequencing of the 47 positive samples: 6 samples were identified as E. granulosus sensu stricto (s.s.), 28 as Taenia hydatigena and 6 as T. pisiformis. A co-infection between different genera of Taeniidae was found in 7 samples.

Control programme for cystic echinococcosis in Uruguay

Cystic echinococcosis is a highly endemic parasitic zoonosis that is present in the Southern Cone countries of America. For several decades, various prevention and control programmes have been implemented in different countries and regions, with varying results. In Uruguay, a new control programme was implemented in 2006 that employed new strategies for canine diagnosis and treatment, dog population control, diagnosis in humans, epidemiological surveillance, and health education, including community participation. The control programme in Uruguay addresses the control and surveillance of the disease from a holistic perspective based on Primary Health Care, which has strengthened the community's participation in developing and coordinating activities in an interdisciplinary manner. Similarly, the control programme that is currently implemented is based on a risk-focused approach. The surveillance and control measures were focused on small villages and extremely poor urban areas. In this study, the strategies used and the results obtained from 2008-2013 are analysed and discussed.

Global Distribution of Alveolar and Cystic Echinococcosis

Alveolar echinococcosis (AE) and cystic echinococcosis (CE) are severe helminthic zoonoses. Echinococcus multilocularis (causative agent of AE) is widely distributed in the northern hemisphere where it is typically maintained in a wild animal cycle including canids as definitive hosts and rodents as intermediate hosts. The species Echinococcus granulosus, Echinococcus ortleppi, Echinococcus canadensis and Echinococcus intermedius are the causative agents of CE with a worldwide distribution and a highly variable human disease burden in the different endemic areas depending upon human behavioural risk factors, the diversity and ecology of animal host assemblages and the genetic diversity within Echinococcus species which differ in their zoonotic potential and pathogenicity. Both AE and CE are regarded as neglected zoonoses, with a higher overall burden of disease for CE due to its global distribution and high regional prevalence, but a higher pathogenicity and case fatality rate for AE, especially in Asia. Over the past two decades, numerous studies have addressed the epidemiology and distribution of these Echinococcus species worldwide, resulting in better-defined boundaries of the endemic areas. This chapter presents the global distribution of Echinococcus species and human AE and CE in maps and summarizes the global data on host assemblages, transmission, prevalence in animal definitive hosts, incidence in people and molecular epidemiology.

Cystic Echinococcosis Epidemiology in Spain Based on Hospitalization Records, 1997-2012

BACKGROUND

Cystic echinococcosis (CE) is a parasitic disease caused by the tapeworm Echinococcus granulosus. Although present throughout Europe, deficiencies in the official reporting of CE result in under-reporting and misreporting of this disease, which in turn is reflected in the wrong opinion that CE is not an important health problem. By using an alternative data source, this study aimed at describing the clinical and temporal-spatial characteristics of CE hospitalizations in Spain between 1997 and 2012.

METHODOLOGY/PRINCIPAL FINDINGS

We performed a retrospective descriptive study using the Hospitalization Minimum Data Set (CMBD in Spanish). All CMBD's hospital discharges with echinococcosis diagnosis placed in first diagnostic position were reviewed. Hospitalization rates were computed and clinical characteristics were described. Spatial and temporal distribution of hospital discharges was also assessed. Between 1997 and 2012, 14,010 hospitalizations with diagnosis of CE were recorded, 55% were men and 67% were aged over 45 years. Pediatric hospitalizations occurred during the whole study period. The 95.2% were discharged at home, and only 1.7% were exitus. The average cost was 8,439.11 €. The hospitalization rate per 100,000 per year showed a decreasing trend during the study period. All the autonomous communities registered discharges, even those considered as non-endemic. Maximum rates were reached by Extremadura, Castilla-Leon and Aragon. Comparison of the CMBD data and the official Compulsory Notifiable Diseases (CND) reports from 2005 to 2012 showed that official data were lower than registered hospitalization discharges.

CONCLUSIONS

Hospitalizations distribution was uneven by year and autonomous region. Although CE hospitalization rates have decreased considerably due to the success of control programs, it remains a public health problem due to its severity and economic impact. Therefore, it would be desirable to improve its oversight and surveillance, since officially reported data are underestimating the real burden of CE in Spain.

[Study of infestation of dogs with Echinococcus granulosus in the province of La Rioja, Argentina]

This work was conducted in the province of La Rioja, located in northwestern Argentina. The aim of this study was to estimate the percentage of dog feces showing the presence of antigens of Echinococcus sp. in different regions of the province. A total of 269 samples of dried canine stool were taken, which were analyzed by the copro-ELISA technique. The most affected area was zone IV, which had 30.5% of positive samples. Zone I corresponding to the Capital Department of the province had 12% of positivity. In other areas, the percentages ranged between 11.4% and 14.8%. This is the first study in the province of La Rioja on the existence of this disease in dogs. The lack of control strategies has allowed the spread of echinococcosis.

Echinococcosis: A 15-year epidemiological, clinical and outcome overview

OBJECTIVE

To analyze the epidemiological and clinical characteristics and mortality of patients with cystic echinococcosis (CE) in northern Spain.

PATIENTS AND METHODS

A retrospective study of the medical records of patients diagnosed with CE and hospitalized from 1997 to 2011 in a University Hospital.

RESULTS

A total of 76 patients (44 men) were diagnosed with CE. The mean age was 57.8 years (SD: 19.1 years; range: 14.9-92.7). The yearly average incidence was 1.08 cases/100,000 inhabitants. The highest incidence was registered in patients aged 70-79 years (22.7% of all cases). Liver was the main organ involved (92.1%), followed by lung (6.6%) and peritoneum (1.3%). Fifty-five patients (72%) received treatment: 2 (3.6%) medical treatment with albendazole, 27 (49%) surgical treatment, 3 (5.4%) medical treatment combined with cyst drainage, and 23 (42%) combined medical and surgical treatment. Eight patients had a recurrence. Twenty-four (31.2%) patients died. No patient's death was attributed directly to hydatidosis, though mortality was significantly higher in the untreated vs. the treated patient group (57% vs. 22%, p=0.003).

CONCLUSIONS

Hydatidosis treatment and diagnostic approaches remain heterogeneous. The liver continues being the main organ affected. Mortality was higher in patients who did not receive treatment. However, this result might have been influenced by other factors, mainly age.

Oxidant/antioxidant status in lambs and sheep with liver and lung cystic echinococcosis diagnosed by ultrasonography and necropsy

The aim of this study was to evaluate total antioxidant capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) in sheep and lambs with cyctic eccinocoocosis (CE) diagnosed by ultrasonography and necropsy findings. A total of 9 sheep and 17 lambs with CE were used in this study and the findings were compared to those of 6 healthy control sheep. Ultrasonography were used for the diagnosis of CE in sheep and lambs, and necropsy was performed to check the presence of cysts in liver and lungs. Serum TOS and TAC were measured by a novel colorimetric method. The TOS-to-TAC ratios were also calculated as OSI values. Serum biochemical profiles were determined by conventional measurement methods as well. The mean values for TOS, TAC and OSI were significantly (p<0.001) lower in sheep and lambs with CE when compared with those of the control sheep, and they were also significantly lower in lambs with CE in comparison to the mean values obtained in sheep with CE. The levels of serum albumin, total cholesterol, creatinine, and triglycerides in lambs with CE were found out to decrease significantly (p<0.001) when compared with those of both sheep with EC and the control group. There were no significant differences between the groups in terms of other serum parameters. In addition, when clinically and some biochemical values were evaluated, CE was found to be more severe in lambs than in sheep. It was concluded that although common diagnostic cyst detection is performed by postmortem examination, ultrasonography could successfully be used in conjunction with serum biochemical profile detection and serum TOS, TAC and OSI measurements for diagnosis of cysts in liver and lungs of severely infected living sheep and lambs. Serum albumin, total cholesterol, creatinine, total protein and triglycerides might be used as indicators in sheep and particularly in lambs for the diagnosis of CE.

Cystic echinococcosis in the Province of Álava, North Spain: the monetary burden of a disease no longer under surveillance

Cystic echinococcosis (CE) is endemic in Spain but has been considered non-endemic in the province of Álava, Northern Spain, since 1997. However, Álava is surrounded by autonomous regions with some of the highest CE prevalence proportions in the nation, casting doubts about the current classification. The purpose of this study is to estimate the frequency of CE in humans and animals and to use this data to determine the societal cost incurred due to CE in the Álava population in 2005. We have identified epidemiological and clinical data from surveillance and hospital records, prevalence data in intermediate (sheep and cattle) host species from abattoir records, and economical data from national and regional official institutions. Direct costs (diagnosis, treatment, medical care in humans and condemnation of offal in livestock species) and indirect costs (productivity losses in humans and reduction in growth, fecundity and milk production in livestock) were modelled using the Latin hypercube method under five different scenarios reflecting different assumptions regarding the prevalence of asymptomatic cases and associated productivity losses in humans. A total of 13 human CE cases were reported in 2005. The median total cost (95% credible interval) of CE in humans and animals in Álava in 2005 was estimated to range between €61,864 (95%CI%: €47,304-€76,590) and €360,466 (95%CI: €76,424-€752,469), with human-associated losses ranging from 57% to 93% of the total losses, depending on the scenario used. Our data provide evidence that CE is still very well present in Álava and incurs important cost to the province every year. We expect this information to prove valuable for public health agencies and policy-makers, as it seems advisable to reinstate appropriate surveillance and monitoring systems and to implement effective control measures that avoid the spread and recrudescence of the disease.

[Diagnosis of cystic echinococcosis in faeces scattered in areas of Puna and Quebrada. Province of Jujuy, Argentina]

Echinococcosis is a parasitic disease common in livestock, caused by the cestode Echinococcus granulosus, the dog being the principal definitive host. The province of Jujuy is an endemic area located in the Northwest of Argentina. Due to the restricted ecological conditions of Quebrada and Puna, the most important activity of the population is formal cattle pastoralism and transhumance, especially of sheep and camelids. The dog acquires the double function of company and shepherd in these communities. The objective of the present study was to conduct a diagnosis of the situation in areas of La Quebrada and Puna where the circulation of E. granulosus is suspected. Five hundred and twenty three (523) samples of canine fecal material scattered in the environment were collected from 2002 to 2012. Prevalence varied from 2% in Susques to 27.7% in Humahuaca, the largest in the province. In Tumbaya, prevalence was 21% in the year 2007, reaching 0% in the year 2010 but increasing again to 10.5% in the year 2011. These results may be related to health education on preventive measures and mass deworming held prior to sample taking in the year 2010. A prevalence between 19.4% and 2% was observed in the rest of the regions studied, suggesting that a lack of strategies for echinococcosis control has allowed the spread of the disease.

[Coproantigens detection for the diagnosis of canine Echinococcosis in the border area of La Quiaca-Villazón]

Cystic Echinococcosis is a major public health issue. Immunodiagnostic techniques based on the identification of parasite antigens in dog dry faeces have been developed as alternatives for the surveillance of canine Echinococcosis. The environmental conditions favouring the parasite cycle were met in the border of La Quiaca-Villazón, given the presence of definitive (dog) and intermediate hosts (sheep and goats). The most important activity in La Puna is sheep and goat rearing; slaughtering is carried out almost exclusively in the field by sheep's owners, and preventive health measures do not apply. The aim of this study was to determine the presence of dogs parasitized by Echinococcus granulosus in this border region. A hundred and sixty eight (168) stool specimens were collected during 2006. La Quiaca samples were taken from the following selected areas: the semi-rural area of Barrios, the rural areas of Santa Catalina, Yavi Chico, El Portillo, Pumahuasi and Cara Cara and the urban area of La Quiaca; selected urban areas in Villazón and the semi-rural area of Ojo de Agua, Lampaya and Matancillas. The samples were analyzed by copro-ELISA -Western blot test. The cities of San Francisco and Barrios had a prevalence of 14.3% and 6.7%, respectively. A prevalence of 3.4% was observed in the urban area of Villazón, which indicates that dogs become infected in the rural areas and bring the risk into the city. Lampaya showed a prevalence of 30%. These findings suggest the need to implement strategies for the control of hydatidosis, both in urban and rural areas to avoid the increase and spread of Echinococcosis in the region.

Canine echinococcosis: global epidemiology and genotypic diversity

Canine echinococcosis is a potential zoonotic infection caused by the adult form of several cestode species belonging to the genus Echinococcus, of which E. granulosus sensu lato and E. multilocularis are the most epidemiologically relevant. Dogs infected with E. granulosus and E. multilocularis are widely regarded as the main source of infection for human cystic and alveolar echinococcosis, diseases that cause substantial morbidity and socio-economic burden in several regions of the world. Following our previous review on the global situation of cystic echinococcosis in livestock species (Cardona and Carmena. Vet. Parasitol. 2013;192:10-32), we summarize here current knowledge on the global epidemiology, geographical distribution and molecular diversity of Echinococcus spp. infection in dogs. We address relevant topics including the implications of the increasing urbanization of wildlife species such as foxes, coyotes, and dingoes in the establishment of urban cycles of Echinococcus spp., or the rising concerns regarding the role of unsupervised translocation of infected dogs in spreading the infection to Echinococcus-free areas. The involvement of wildlife species as natural reservoirs of disease to domestic animals and humans and the epidemiological significance of the sympatric occurrence of different Echinococcus species in the same geographical region are also debated. Data presented are expected to be useful for policy makers, educational and health authorities responsible for designing and implementing effective measures for disease control and prevention.

Echinococcusinfections in Chinese dogs: a comparison of coproantigen kits

Coproantigen test kits forEchinococcusspp. worms in dogs, designed for commercial use, were obtained from three different Chinese producers, and were compared with a laboratory kit using reagents from New Zealand. None of the three producers would provide details of their test validation. From a known set of dog faeces obtained at necropsy from infected and uninfected dogs, and from faeces collected from dogs necropsied in the field, results differed between the kits. For field material, the Tiankang kit showed the best specificity but lacked sensitivity. The Combined kit showed best sensitivity but lacked specificity. Results for the Haitai kit were intermediate. With samples from experimentally infected dogs, both the Haitai and Combined kits lacked sensitivity. Kits will need to be validated by the user before they can be relied on to predict progress inEchinococcusspp. control in China or in other countries.

Challenges for diagnosis and control of cystic hydatid disease

This paper is based on the experience of the authors, with the aim to define the challenges for Echinococcus granulosus (E.g./CE) diagnosis and control for those countries that may now or in the future be contemplating control of hydatid disease. A variety of methods are available for diagnosis in humans but a universal gold standard is lacking. Diagnosis in definitive hosts can avoid necropsy by the use of methods such as coproantigen detection but test performance is variable between populations. A sylvatic cycle adds challenges in some countries and the epidemiology of the parasite in these hosts is poorly understood. Control by solely administering praziquantel to dogs is not effective in developing countries where the disease is endemic. Additional avenues to pursue include the instigation of participatory planning, use of an existing vaccination for intermediate hosts and development of a vaccine and long-acting anthelmitic implants for definitive hosts. Promoting public acceptance of control of the dog population by humane euthanasia and reduced reproduction is also essential.

Worldwide epidemiology of liver hydatidosis including the Mediterranean area

The worldwide incidence and prevalence of cystic echinococcosis have fallen dramatically over the past several decades. Nonetheless, infection with Echinococcus granulosus (E. granulosus) remains a major public health issue in several countries and regions, even in places where it was previously at low levels, as a result of a reduction of control programmes due to economic problems and lack of resources. Geographic distribution differs by country and region depending on the presence in that country of large numbers of nomadic or semi-nomadic sheep and goat flocks that represent the intermediate host of the parasite, and their close contact with the final host, the dog, which mostly provides the transmission of infection to humans. The greatest prevalence of cystic echinococcosis in human and animal hosts is found in countries of the temperate zones, including several parts of Eurasia (the Mediterranean regions, southern and central parts of Russia, central Asia, China), Australia, some parts of America (especially South America) and north and east Africa. Echinococcosis is currently considered an endemic zoonotic disease in the Mediterranean region. The most frequent strain associated with human cystic echinococcosis appears to be the common sheep strain (G1). This strain appears to be widely distributed in all continents. The purpose of this review is to examine the distribution of E. granulosus and the epidemiology of a re-emerging disease such as cystic echinococcosis.

Coprological survey of alimentary tract parasites in dogs from Zambia and evaluation of a coproantigen assay for canine echinococcosis

Faecal samples were collected from the rectum of 540 domestic dogs from four districts (Lusaka, Katete, Petauke and Luangwa) in Zambia between 2005 and 2006 and prevalences of canine alimentary tract parasites were determined by coprological examination. Thirteen different ova and parasites including strongyle (43.3%), Spirocerca lupi (18.7%), taeniid (13.1%), Toxocara canis (7.6%), Sarcocystis sp.* (7.5%), Isospora sp.* (5.7%), Physaloptera sp.* (4.6%), Capillaria sp.* (2.8%), Dipylidium caninum (2.2%), Mesocestoides sp.* (2.0%), Ascaris sp.* (1.7%), Trichuris vulpis* (0.4%) and Schistosoma mansoni* (0.4%) were detected, Ascaris and Schistosoma probably originating from coprophagy. The species with asterisks and later-described Taenia multiceps are for the first time reported from dogs in Zambia. A coproantigen enzyme-linked immunosorbent assay (CoproAg-ELISA) developed for Echinococcus spp. revealed 43 positive dogs and 37 of these harboured taeniid eggs. From 63 of the 71 taeniid egg-positive samples, eggs and DNA thereof were isolated and subjected to a multiplex polymerase chain reaction for differentiating E. granulosus sensu lato, E. multilocularis and Taenia spp. Amplicons indicative for Taenia spp. were obtained from 60 samples. Sequencing of amplicons spanning part of the mitochondrial cytochrome c oxidase subunit 1 gene, which was possible with 38 samples, revealed 35 infections with T. hydatigena and 3 with T. multiceps. Therefore, the CoproAg-ELISA showed some positives, but concrete evidence for the existence of canine E. granulosus infection could not be established. Comparison of the results of the CoproAg-ELISA and Taenia species identification indicated that the CoproAg-ELISA cross-reacts with patent infections of T. hydatigena (57%) and T. multiceps (33%).

Bayesian sample size for diagnostic test studies in the absence of a gold standard: Comparing identifiable with non-identifiable models

Diagnostic tests rarely provide perfect results. The misclassification induced by imperfect sensitivities and specificities of diagnostic tests must be accounted for when planning prevalence studies or investigations into properties of new tests. The previous work has shown that applying a single imperfect test to estimate prevalence can often result in very large sample size requirements, and that sometimes even an infinite sample size is insufficient for precise estimation because the problem is non-identifiable. Adding a second test can sometimes reduce the sample size substantially, but infinite sample sizes can still occur as the problem remains non-identifiable. We investigate the further improvement possible when three diagnostic tests are to be applied. We first develop methods required for studies when three conditionally independent tests are available, using different Bayesian criteria. We then apply these criteria to prototypic scenarios, showing that large sample size reductions can occur compared to when only one or two tests are used. As the problem is now identifiable, infinite sample sizes cannot occur except in pathological situations. Finally, we relax the conditional independence assumption, demonstrating in this once again non-identifiable situation that sample sizes may substantially grow and possibly be infinite. We apply our methods to the planning of two infectious disease studies, the first designed to estimate the prevalence of Strongyloides infection, and the second relating to estimating the sensitivity of a new test for tuberculosis transmission. The much smaller sample sizes that are typically required when three as compared to one or two tests are used should encourage researchers to plan their studies using more than two diagnostic tests whenever possible. User-friendly software is available for both design and analysis stages greatly facilitating the use of these methods.

Cystic echinococcosis in Spain: current situation and relevance for other endemic areas in Europe

Cystic echinococcosis (CE) remains an important health problem in many regions of the world, both where no control measures have been implemented, and where control programs have been incompletely successful with ensuing re-emergence of the disease. In Spain, official data on CE show an increase in the proportion of intermediate hosts with CE during the last few years, and autochthonous pediatric patients have been reported, a sign of active local transmission of disease. A similar picture emerges from data reported to the European Food Safety Authority by other European countries. Nevertheless, several crucial aspects related to CE that would help better understand and control the disease have not been tackled appropriately, in particular the emergence of infection in specific geographical areas. In this respect, while some data are missing, other data are conflicting because they come from different databases. We review the current situation of CE in Spain compared with areas in which similar problems in the CE field exist, and offer recommendations on how to overcome those limitations. Specifically, we believe that the introduction of national registries for CE with online data entry, following the example set by the European Registry for Alveolar Echinococcosis, would help streamline data collection on CE by eliminating the need for evaluating and integrating data from multiple regions, by avoiding duplication of data from patients who access several different health facilities over time, and by providing much needed clinical and epidemiological data that are currently accessible only to clinicians.

Echinococcosis/hydatidosis: a severe threat in Mediterranean countries

Echinococcosis/hydatidosis is one of the most important parasitic zoonotic diseases in the world. Both cystic hydatidosis (CE) caused by Echinococcus granulosus and alveolar echinococcosis (AE) caused by E. multilocularis have been reported in several countries of the Mediterranean region (MR). E. granulosus has always been present in the MR and is the most common species. This parasite depends on the dog-sheep cycle and is actively transmitted in all pastoral regions where sheep, cattle and camelids predominate. E. multilocularis occurs only sporadically in limited areas of France, Serbia and Montenegro, Turkey, Tunisia and Morocco. However recent evidence indicates that it is spreading into other regions of the Mediterranean. Due to the lack of well-documented data, and to the fact that CE is not a notifiable disease in the majority of M countries, the precise incidence and prevalence of CE in humans and animals are not known. Published data suggests that prevalence is rather high in North Africa, Turkey, Greece, and in several regions of Italy and Spain. CE is an increasing public health and socio-economic concern due to the considerable morbidity rates that give rise to high economic losses both in the public health sector and in the livestock industry. Hospitalisation for human CE lasts from 2 weeks to more than 1 month in case of surgery. A number of factors contribute to the increase of prevalence and to the spreading of CE in the MR. These include the diversity of livestock production systems (predominantly extensive, traditional animal husbandry), small, ill-equipped and unsupervised slaughter-houses, illegal and family slaughtering, low public awareness of hydatid diseases, and the high population of stray dogs. Cyprus is the only country where an eradication programme has been successfully implemented. There have been, however, important developments in the last decade in CE epidemiology, in the diagnosis of canine infection, in strain characterisation and in immune strategies against CE in animals. This scientific progress, together with effective health education programmes, will likely improve control programmes and reduce the time required to achieve significant decreases in prevalence or eradication.

Hydatidosis: prevalence and its economic importance in ruminants slaughtered at Adama municipal abattoir, Central Oromia, Ethiopia

A cross-sectional study was conducted from November 2007 to April 2008 to estimate the prevalence of hydatidosis in ruminants slaughtered at Adama municipal abattoir. An attempt was also made to estimate the annual economic loss due to condemnation of organs during meat inspection. A retrospective analysis of data spanning a 10-year period (1997-2007) was also undertaken to determine the presence of the parasite during this period. A total of 1152 ruminants (852 cattle, 92 sheep and 208 goats) were inspected following slaughter. Hydatidosis was prevalent in 46.8% cattle, 29.3% sheep, and 6.7% goats. In cattle, 326 (55.2%) of the lung, 219 (37.1%) of the liver, 21 (3.6%) of the spleen, 15 (2.5%) of the heart and 10 (1.7%) of the kidney were found to be infected with hydatid cysts. In sheep, hydatid cysts were recovered from 22 (55.0%) of the lung, 16 (40.0%) of the liver and 2 (5.0%) of the spleen while none of the heart and kidney were recorded positive. In goats, the degree of infection was 6 (33.3%) of lung, 10 (55.6%) of liver, 1 (5.6%) of spleen and kidney each. According to the retrospective data, a total of 107,333 cattle were slaughtered and during this period 13,519 of the liver, 18,304 of the lung, 1142 of the kidneys, 537 of the hearts and 150 of the spleens were found to be infected with hydatidosis. The total annual economic loss incurred due to hydatidosis in ruminants slaughtered at Adama municipal abattoir was estimated to be to 52,828 ETB (5869.8 USD). The current results suggest that a thorough investigation that leads to a disease control strategy is required to reduce the economic and public health consequences of hydatidosis.

Study of cystic echinococcosis in slaughtered animals in Al Baha region, Saudi Arabia: interaction between some biotic and abiotic factors

The variation in cystic echinococcosis (CE) prevalence and mean intensity was studied in relation to site, season and host age and sex. A total of 12,911 slaughtered animals, 140 camels, 2668 cattle, 6525 sheep and 3578 goats were inspected for hydatid cysts in Al Baha region, Saudi Arabia, in three study areas during four seasons from June 2008 to May 2009. The prevalence of infection was 32.85%, 8.28%, 12.61% and 6.56% in camels, cattle, sheep and goats respectively. The prevalence of the parasite varied significantly in relation to site, season and host age classes and sex in most host species. Spring showed the highest prevalence in camels, cattle and sheep. A significant association was found among host age classes and likelihood of infection in all examined hosts and the oldest age class was significantly more likely to be infected. The main effects in parasite intensity were host sex and age in most examined host species. A positive correlation was found between intensity of CE and host age class in all animal species examined. The most commonly infected organs were liver and lungs which constituted 48.75% and 32.83% respectively, of the total infected organs. There was a significant difference among host species in fertile cysts (P<0.0001). The higher percentages of fertile cysts were in sheep (47.67%) and goats (23.99%) indicating that sheep and goats are the most important intermediate hosts for Echinococcus granulosus. Examined hydatid cysts of the liver had a higher fertility rate (38.79%) than those of the lungs (25.13%). Cysts size ranged from 1 to 8cm in diameter. The mean cyst diameter was found in the lungs higher than that in the liver in all hosts. The range in the number of cysts was 1-33 in infected animals. The mean number of cysts was higher in lungs than that in liver in all examined animals. The viability rate of protoscoleces of liver fertile cysts (62.20%) was significantly higher than that of lung cysts (52.73%). In conclusion, these findings of infection, mean abundance and fertility rates of CE in slaughtered animals, prompt plans for further epidemiological studies and control programmes.

Echinococcosis: diagnosis and diagnostic interpretation in population studies

Diagnosis is a basic component of population studies on echinococcosis. Other than careful necropsy in animals, there is no perfect gold standard. In the definitive host, techniques for direct parasite identification include copro-antigen and copro-DNA detection. In intermediate hosts, necropsy is typically used. In humans, diagnostic imaging and serology are both widely employed. The use of multiple parallel testing or an additional confirmatory test (or tests) in a diagnostic strategy can overcome the lack of a perfect gold standard. This will yield valuable information at population and individual levels, providing the study is well designed and any shortcomings of the tests are incorporated into the analysis. Here, we discuss analytical approaches to population studies of echinococcosis.

Diagnosis of cystic echinococcosis, central Peruvian Highlands

High prevalence was confirmed by ultrasonography, radiography, and 2 serologic tests, although usefulness of serologic testing in the field was limited.

We evaluated prevalence of cystic echinococcosis (CE) in a central Peruvian Highland district by using 4 diagnostic methods: ultrasonography for 949 persons, radiography for 829, and 2 serologic tests for 929 (2 immunoblot formats using bovine hydatid cyst fluid [IBCF] and recombinant EpC1 glutathione S-transferase [rEpC1-GST] antigens). For the IBCF and rEpC1-GST testing, prevalence of liver and pulmonary CE was 4.7% and 1.1% and seropositivity was 8.9% and 19.7%, respectively. Frequency of seropositive results for IBCF and rEpC1-GST testing was 35.7% and 16.7% (all hepatic cysts), 47.1% and 29.4% (hepatic calcifications excluded), and 22.2% and 33.3% (lung cysts), respectively. Weak immune response against lung cysts, calcified cysts, small cysts, and cysts in sites other than lung and liver might explain the poor performance of the serodiagnostic tests. We confirm that CE is highly endemic to Peru and emphasize the limited performance of available serologic assays in the field.

Frequentist and Bayesian approaches to prevalence estimation using examples from Johne's disease

Although frequentist approaches to prevalence estimation are simple to apply, there are circumstances where it is difficult to satisfy assumptions of asymptotic normality and nonsensical point estimates (greater than 1 or less than 0) may result. This is particularly true when sample sizes are small, test prevalences are low and imperfect sensitivity and specificity of diagnostic tests need to be incorporated into calculations of true prevalence. Bayesian approaches offer several advantages including direct computation of range-respecting interval estimates (e.g. intervals between 0 and 1 for prevalence) without the requirement of transformations or large-sample approximations. They also allow direct probabilistic interpretation, and the flexibility to model in a straightforward manner the probability of zero prevalence. In this review, we present frequentist and Bayesian methods for animal- and herd-level true prevalence estimation based on individual and pooled samples. We provide statistical methods for detecting differences between population prevalence and frequentist methods for sample size and power calculations. All examples are motivated usingMycobacterium aviumsubspeciesparatuberculosisinfection and we provide WinBUGS code for all examples of Bayesian estimation.

Epidemiological Study of Non-systemic Parasitism in Dogs in Southeast Mediterranean Spain Assessed by Coprological and Post-mortem Examination

The prevalence and risk factors of non-systemic canine ecto- and endoparasitism and anthelminthic use in Murcia located at the centre of the Spanish Mediterranean coastal arch, was investigated by coprology and necropsy in up to 275 pet, city shelter and stray dogs in 2001-2004. Faecal parasite stages were detected in 25% of dogs. Species frequency was 6-10% for Toxocara canis, Ancylostomatidae spp., Toxascaris leonina and Isospora canis, and 0.4-1% for Trichuris vulpis, Giardia lamblia, and Dipylidium caninum. Logistic regression indicated that the risk of intestinal parasitism was highest for dogs <or=1 year old, in the middle to low weight range and kept at the city shelter. Although risk factors varied according to the species, T. canis was most common in <1 year old and Ancylostomatidae spp. was more prevalent in older dogs. This suggests that the dominant species was Uncinaria spp. and not the more zoonotically important Ancylostoma spp. This was further supported by necropsy findings; however, the degree of agreement between post-mortem and coprological examination for intestinal parasites was generally poor. Necropsy revealed 10%G. lamblia, 12%Taenia spp. 38%D. caninum infections. Fleas, ticks and lice were also found in 38%, 6% and 2% of necropsied stray dogs. These results demonstrate the need for an urgent parasite control programme at the city dog shelter and the need to improve the owner's education on zoonotic risks, the proper use of anthelminthics, and other parasite control practices.