Genetic variation within and between G1 and G3 genotypes of Echinococcus granulosus in Italy revealed by multilocus DNA sequencing

Numerous studies have provided evidence that Echinococcus granulosus exists as a complex of different strains, that differ in a wide variety of criteria that have an impact on the epidemiology, pathology and control of cystic hydatid disease (CHD) and, to date, 10 distinct genotypes (G1-G10) have been identified. In Italy, sequence analysis of the mitochondrial cox1 and nad1 genes showed the occurrence of the G1 genotype, the common sheep strain, the G3 genotype, the buffalo strain and of one isolate identified as G2 genotype, the Tasmanian sheep strain. In the present work, we have analysed E. granulosus strains in Italy, by genotyping a large sample of isolates and by checking out the genetic differentiation within and among the G1 and G3 genotypes using an additional mitochondrial gene as marker, the rrnS gene. Sequencing of the rrnS gene revealed a significant genetic differentiation between isolates identified as belonging to the G1 and G3 genotypes, with fixed nucleotide substitutions. This study provides further evidence of the occurrence of the E. granulosus G3 buffalo strain in Italy, a strain previously thought to be confined to the Indian region.     

Echinococcus ortleppi and E. granulosus G1, G2 and G3 genotypes in Italian bovines

To increase the knowledge on Echinococcus genotypes infesting cattle and water buffaloes (Bubalus bubalis) born and bred in Italy, the germinal layer of hydatid cysts was collected from the liver and the lungs of 80 animals slaughtered in 2007. Two mitochondrial genes (the cytochrome c oxidase subunit I and the NADH subunit I) were tested by PCR. Four genotypes were identified: G1 (sheep strain), G2 (Tasmanian sheep strain), G3 (buffalo strain), and G5 (cattle strain). Fertile cysts were detected only in the lungs of 4.5% of the total G1 lung cysts, of 9.4% of the total G3 lung cysts, and in the only G5 infected animal. This is the first report of Echinococcus ortleppi (genotype G5) in Italy.     

Morphological and molecular characteristics of Echinococcus multilocularis and Echinococcus granulosus mixed infection in a dog from Xinjiang, China

The Xinjiang plateau of western China has been shown to have a high prevalence for human cystic echinococcosis (CE) caused by Echinococcus granulosus, and human alveolar echinococcosis (AE) caused by Echinococcus multilocularis. The domestic dog is suspected to be the primary definitive host for the transmission of both E. granulosus and E. multilocularis to humans in this locality. Seventeen of 30 stray dogs from Hejing County of Xinjiang were found positive for E. granulosus post mortem, and one double infection was suspected. Worm samples were collected, dyed by carmine, and observed microscopically. Carmine staining examination clearly revealed the differences in number of proglottids and appearance of uterine branches and lateral genital pore for those two species of Echinococcus. Furthermore, gene target DNA fragments were amplified for formal identification of the two parasite species, based on 12s rRNA mitochondrial gene. The PCR products were purified and sequenced. Compared with NCBI GenBank, the DNA sequences demonstrated 100% identity with E. granulosus (sheep strain, G1 genotype) and E. multilocularis.     

Cystic echinococcosis in water buffaloes: epidemiological survey and molecular evidence of ovine (G1) and buffalo (G3) strains

A survey of cystic echinococcosis (CE) in the water buffalo (Bubalus bubalis) of the Italian Mediterranean breed was carried out in Campania, a region of southern Italy. In addition, a molecular study was performed on 48 hydatid cysts coming from 48 water buffaloes in order to determine the Echinococcus granulosus strain(s) present in this host. Out of a total of 722 water buffaloes examined for CE, 76 (10.5%) were found infected. The average number of cysts per buffalo was 4.3 (minimum 1, maximum 45). Seventeen buffaloes had hydatid cysts only in the liver (with an average of 5 cysts/liver), 34 only in the lungs (with an average of 1.8 cysts/lungs), and 25 buffaloes had cysts both in the liver and in the lungs. Fertile cysts were found in 10 (13.2%) out of the 76 positive buffaloes. The sequencing of the mitochondrial cytochrome C oxidase subunit 1 (CO1) gene of the 48 hydatid cysts produced sequences of 419 bp for each sample analysed. For 33 samples, alignment of the obtained sequences with those present in GenBank showed a total homology with the common domestic sheep strain G1; for 15 samples, sequences obtained showed 100% homology with buffalo strain G3. The findings of the present survey represent the first epidemiological and molecular comprehensive studies on CE in water buffalo from an endemic area for E. granulosus.     

Genotypic characterisation of Indian cattle, buffalo and sheep isolates of Echinococcus granulosus

Twelve isolates of Echinococcus granulosus, collected from domestic animals, including cattle, buffalo and sheep were analysed for DNA nucleotide sequence variation within mitochondrial cytochrome c oxidase I (coxI), NADH dehydrogenase subunit I (nadI) and internal transcribed spacer gene I (ITS1). After analysis of sequence information this was found that the fragment size of ITS1 of buffalo isolate was more in comparison to cattle and sheep isolates. Based on the nadI genotype this was found that Indian cattle, buffalo and sheep isolates could be grouped into E. granulosus sensu stricto. Based on coxI genotype two sheep isolates and one buffalo isolate were homologous to G2 genotype. Rests of the isolates were microvariants of G2 genotype. Presence of G2 genotype in buffalo is the first report of this genotype from this host.     

Echinococcus ortleppi (G5) and Echinococcus granulosus sensu stricto (G1) loads in cattle from Southern Brazil

Echinococcus granulosus sensu stricto (G1) and Echinococcus ortleppi (G5) are haplotypes of the parasite formerly known as Echinococcus granulosus sensu lato, which in its larval stage causes cystic hydatid disease, endemic in Southern Brazil. Epidemiological and molecular knowledge about the haplotypes occurring in a region is essential to control the spread of the disease. The aim of this work was to analyze the haplotype frequency and fertility of hydatid cysts in cattle from the state of Rio Grande do Sul. Cysts were collected and classified according to their fertility status. DNA was extracted from protoscoleces and germinal layers and then used as template for the amplification of the cytochrome c oxidase subunit 1 gene by PCR. Amplicons were purified and sequenced, and the sequences were analyzed for haplotype identification. A total of 638 fertile cysts collected in the last ten years were genotyped. On average, G1 (56.6%) was more frequent than G5 (43.4%). In lungs, the G5 haplotype exhibited a higher parasite load (52.8%), whereas in the liver, G1 was more frequent (90.4%). The analysis revealed an increase in the frequency of G5 haplotype cysts during the period of sampling, and an increase in the abundance of fertile cysts has also been observed in the last several years. Most infertile cysts were genotyped as G1. The possible factors involved in the increase in the proportion of E. ortleppi (G5) and the consequences of this increase are discussed. This study suggests that the proportion of E. ortleppi (G5) loads in cattle may be increasing overtime.     

Molecular characterization and prevalence of cystic echinococcosis in slaughtered water buffaloes in Turkey

The present study was carried out between March 2006 and June 2010. During the study nine abattoirs were visited and 166 water buffalo internal organs were examined in Black Sea Region of Turkey. It was found that 10.24% buffaloes were infected with cystic echinococcosis (CE). The rate of CE found as 3.77% in males and 21.66% in females, 37.93% in older and 4.38% in young animals. The degree of prevalence according to age and sex was statistically significant (p<0.05). CE was observed 29.41% only in liver, 47.06% only in lungs and 23.53% in both liver and lungs. Therefore, the lungs were the predominant sites of the CE in buffaloes. Molecular identification on nine isolates, based on mitochondrial cox1 sequencing analyses, revealed that six cysts belonged to G1 genotype (domestic sheep strain) while 3 samples showed variant genotypes of Echinococcus granulosus complex G1-G2-G3. Two of them showed a thymine in position 52, like G2 strain, but the rest of sequences were completely identical to strain G1; also one specimen showed a single nucleotide change compared to strain G1 (C122T).     

Molecular update on cystic echinococcosis in cattle and water buffaloes of southern Italy

Cystic echinococcosis (CE)--caused by the larval stage (hydatid cyst) of the cestode Echinococcus granulosus--is one of the most widespread zoonoses of veterinary and medical importance. Molecular techniques have allowed the identification of 10 different genotypes (G1-G10) of the parasite. The present paper is an update regarding the E. granulosus genotypes infecting water buffaloes and cattle bred in the Campania region of southern Italy. The molecular study was performed on 30 hydatid cysts (11 from water buffaloes and 19 from cattle). Two different mitochondrial DNA genes, namely the cytochrome c oxidase subunits 1 and the 12S ribosomal DNA (12S rDNA) were used as genetic markers. Three different genotypes of E. granulosus were unequivocally identified, i.e. the G1 (common sheep), G2 (Tasmanian sheep) and G3 (buffalo) genotypes, as well as some G1 and G2 variants. It should be noted that the present study demonstrated for the first time: (i) the presence of the G2 genotype in water buffaloes from a Mediterranean area; and (ii) the fact that the analysed portion of the 12S rDNA gene can not discriminate between the G2 and G3 genotypes of E. granulosus. The finding of the G1, G2 and G3 genotypes in large ruminants from southern Italy is of epidemiological relevance and immediate public health importance because of their recognized infectivity in humans.     

Cystic echinococcosis in Sardinia: farmers' knowledge and dog infection in sheep farms

Cystic Echinococcosis (CE) is one of the most widespread parasitic diseases in Sardinia, the second largest Mediterranean island where almost 3,558,000 milk sheep were raised extensively. The aim of this survey was to evaluate the level of farmers' knowledge on CE transmission, focusing on the role of human to facilitate the persistence of this zoonosis in Sardinia after 14 years after the last campaign against CE. The other goal of the survey is to update on presence of Echinococcus granulosus in its definitive hosts through three ELISA coproantigen tests. An interview was carried out with 172 farmers. The questionnaire was designed to include possible factors associated with the transmission of Echinococcosis: ownership and number of dogs, the use of anthelmintic drugs against dog cestode, frequency of anthelmintic treatment in dogs, home slaughtering and offal disposal. Individual faecal samples were retrieved from 300 dogs, and after a preliminary macroscopic examination to discover adult worms and/or proglottids, was submitted to copromicroscopic examination. Coproantigens were then extracted according to the protocol described by Allan et al. (1992), and subsequently stored at -20°C until use. Faecal soluble antigens from E. granulosus were detected using three different ELISA coproantigen assays: (a) the commercially produced Chekit Echinotest (Bommeli, Bern, CH) based on polyclonal antibodies against adult excretory/secretory (E/S) antigens; (b) a sandwich ELISA that uses rabbit polyclonal antibodies against adult E/S antigens and biotinylated monoclonal antibody EmA9 produced against adult Echinococcus multilocularis somatic extract (Malgor et al., 1997); and (c) a sandwich assay that uses monoclonal antibody EgC3 produced by immunization with adult E. granulosus E/S products (Casaravilla et al., 2005). Questionnaire results reveal that on all farms home-slaughtering was done, and offal was used as dog meal raw (17%) or after boiling (37%), discarded in the trash (23%), or buried superficially (15%). Most farmers (69%) declared to deworm their dogs, but only 10% used cestodicidal drugs. The coprological survey of 300 farm dogs using sedimentation, flotation and three different coproantigen (CA) ELISAs resulted in a faecal prevalence of 8.3% for taeniid eggs, while the CA tests gave prevalences of 3% (Chekit Echinotest, Bommeli), 6% (EmA9 sandwich ELISA) and 10% (EgC3 sandwich ELISA). Our results show that this is not only an educational problem, but also an economic one, stressing the need that future control plans should follow an integrative approach including veterinary and medical services, farmers, breeders' associations and the Government.     

Molecular identification of Echinococcus granulosus genotypes (G1 and G7) isolated from pigs in Mexico

With the aim of genotyping Echinococcus granulosus cysts found in Mexican livestock, we collected hydatid cysts from the livers and lungs of pigs in slaughterhouses in the state of Morelos, Central Region of Mexico. DNA was extracted from the parasites and examined by polymerase chain reaction (PCR) of rDNA internal transcribed spacer 1 (ITS1-PCR), Eg9-PCR, Eg16-PCR, and PCR-restriction fragment length polymorphism (PCR-RFLP). In addition, fragments of the genes coding for mitochondrial cytochrome c oxidase subunit 1 (CO1) and NADH dehydrogenase 1 (ND1) were sequenced. Two different genotypes of E. granulosus were unequivocally identified, the common sheep genotype, G1, and the common pig genotype, G7. The G1 genotype of E. granulosus has not been previously demonstrated in Mexico. Because of its recognized infectivity in humans, G1 genotype is a direct threat to human health and its presence in Mexico is consequently of immediate public health importance and epidemiological relevance.     

Cystic echinococcosis in Algeria: cattle act as reservoirs of a sheep strain and may contribute to human contamination

In Algeria, cystic echinococcosis (CE) is a serious economic and public health problem. The common sheep/dog cycle is usually considered as the major source of human contamination. But to date the main strain of Echinococcus granulosus involved in the human contamination and the role of other hosts are still unknown. This paper reports an original work performed in northern Algeria combining field observations and molecular analysis. In a first step, examination of 6237 carcasses in slaughterhouses showed high infection and fertility rates in cattle and dromedaries. Then, in a second step, we used a molecular biology approach to identify the E. granulosus strain(s) involved. Forty-six samples from various origins were collected. They were analysed using comparison of PCR-amplified DNA sequences with one genomic (BG 1/3) and two mitochondrial (COI and NDI) targets. Results show the presence of a "sheep" strain of E. granulosus in North Algeria circulating between cattle and ovines and infectious to humans, whereas in South Algeria, a "camel" strain and a "sheep" strain were found to circulate in camels and in sheep, respectively. This study also reports an ambiguous genotype which resembled the "sheep" strain genotype (Gl) on the basis of the partial COI gene sequence, whereas on the basis of the partial NDI gene sequence, it was similar either to the "sheep" strain (Gl) or to the "camel" strain (G6). Besides its basic interest, our study confirms the role of other hosts (mainly cattle) in leading to transmission to humans and suggests that control measures should not only target sheep.     

Variability in the Echinococcus granulosus cytochrome C oxidase 1 mitochondrial gene sequence from livestock in Turkey and a re-appraisal of the G1-3 genotype cluster

Investigations into the genetic strains of Echinococcus granulosus parasites occurring in sheep and cattle in Turkey were undertaken. A total of 112 hydatid cysts were investigated from sheep (100 isolates) derived from widely distributed sites within Turkey as well as from cattle (12 isolates) from the Turkish province of Kars. The parasite genotypes in these isolates were determined by DNA sequencing of part of the mitochondrial Cytochrome C oxidase 1 (cox1) gene. Haplotypes were identified which corresponded clearly to the previously described strain G1 in a total of 107 isolates, including 98 isolates from sheep and 9 isolates from cattle. Five isolates, including 2 sheep and 3 cattle, were determined to belong to the G3 genotype. Parasites of the G3 genotype were identified only in isolates derived from animals in the eastern regions of Turkey. While the majority of the isolates described here had haplotypes corresponding to the G1 genotype, none matched exactly the G1 sequence that was defined in previous studies. Analysis of all GenBank entries for E. granulosus cox1 sequences representing G1, G2 and G3 genotypes identified substantial microsequence variability. G1 and G3 could be distinguished as separate strains, however, the existence of G2 as a separate strain could not be supported. Rather, this can be regarded as a microsequence variation of G3.     

A canine purgation study and risk factor analysis for echinococcosis in a high endemic region of the Tibetan plateau

The Tibetan plateau of western China has been shown to have a very high prevalence of human cystic echinococcosis (CE) caused by Echinococcus granulosus and human alveolar echinococcosis (AE) caused by Echinococcus multilocularis. The domestic dog is suspected to be the primary definitive host for the transmission of both E. granulosus and E. multilocularis to humans in this locality. A purgation study of 371 dogs in Shiqu County, Sichuan Province during 2002-2003 resulted in an E. multilocularis prevalence of 12% and an E. granulosus prevalence of 8%. These crude prevalences were then adjusted, based on the known sensitivity of arecoline purgation for the detection of E. granulosus and a suggested sensitivity for the detection of E. multilocularis. In addition, it was assumed that some immature parasites of either species could be misidentified morphologically and wrongly assigned. This resulted in credible true prevalence intervals of between 13-33% for E. multilocularis and 8-19% for E. granulosus. Prevalences of other intestinal helminthes found on purgation were: Taenia spp. 31%, Dipylidium caninum 1%, and ascarids 8%. Risk factors associated with the acquisition of canine echinococcosis were evaluated based on responses to a questionnaire administered to dog owners. Male dogs were more likely to be infected with Echinococcus spp. than female dogs (P<0.05) and dogs allowed to roam were more likely to be infected with E. multilocularis (P<0.05).     

Detection of patent infections of Echinococcus granulosus ("sheep-strain", G1) in naturally infected dogs in Kosovo

A survey was carried out to assess the occurrence of canine echinococcosis in naturally infected dogs in Kosovo. Using the flotation-ovassay technique, taeniid eggs were found in 23 (7.5%) out of a total of 305 dogs. Eggs from other helminths were detected as well: hookworms 139 (45.5%), Trichuris sp. 87 (28.5%), Toxocara sp. 42 (13.7%), Toxascaris leonina 21 (6.8%) and Dipylidium caninum eight (2.6%). From 21 of the 305 samples (6.9%), taeniids eggs could be collected. Using PCR primers specific for Echinococcus granulosus ("sheep strain", G1), four of these samples (1.3%) resulted positive. The E. granulosus isolates originated from each one stray dog, hunting dog, sheepdog and pet dog. A semi-quantitative analysis showed low to moderate egg counts (2-10 per 1 g faeces) in dogs positive for E. granulosus ("sheep strain", G1) whereas specimens with high (11-20) or very high numbers (> 20) of taeniid eggs were negative in the E. granulosus PCR. Using specific primers for the detection of E. multilocularis, all samples containing taeniid eggs were negative. This is the first report on identification of E. granulosus in dogs from Kosovo where human cystic echinococcosis is a significant medical problem.     

Molecular epidemiology of Echinococcosis from food producing animals in north India

Echinococcosis is an important medical, veterinary and economic concern in India. Ten cysts were randomly selected from each intermediate host species (cattle, buffalo, sheep, goat and pigs). Either the germinal layer (sterile cysts) or protoscoleces (fertile cysts) were collected for molecular characterization. A 434 base pair fragment of the mitochondrial cytochrome oxidase-1 gene was amplified using PCR from each isolate. Ten representative samples (2 from each intermediate host species) were sequenced in both the directions from which readable sequences were obtained from nine for phylogenetic analysis (NCBI, Blast). Phylogenetic analysis of cytochrome oxidase I gene revealed that seven (77.7%) isolates, from cattle (2), pigs (2), buffaloes (1) and goat (2) were clustered with the Indian Buffalo (G3) strain of Echinococcus granulosus, while two (22.2%) isolates from sheep were clustered with the sheep strain (G1) of E. granulosus. Phylogenetic analysis of the cytochrome oxidase-1 gene revealed that the buffalo strain (G3) and common sheep strain (G1) are cycling among livestock in north India and that these strains are highly adapted to cattle, buffalo, sheep, goats and pigs.     

Molecular evidence of ovine (G1) and camel (G6) strains of Echinococcus granulosus in Tunisia and putative role of cattle in human contamination

Three hundred and seventy-two cysts coming from 50 humans, 166 cattle, 153 sheep and 3 camels were collected in order to establish some epidemiological molecular information in Tunisia for the first time. The analysis by PCR-RFLP of ITS1 sequence showed that all the human, ovine and bovine cysts were due to the common sheep strain of Echinococcus granulosus. The sequencing of the CO1 gene of 37 isolates confirm the G1 genotype of this strain. For seven of these isolates, we found the mutation C56T which is present in the three principal intermediate hosts: human (three cysts), cattle (three cysts) and sheep (one cyst). With regard to the G1 genotype, we identified three other point mutations. The camel strain G6 is uniquely found in the three camels isolates and not in the other intermediate hosts analysed. The fertility of the bovine cyst represents 48% that means that this host is involved in a bovine-dog cycle and consequently represents a reservoir of sheep strain in Tunisia. Our results confirm the importance of the prophylaxis measures in order to disrupt the cycle of transmission sheep-dog in Tunisia. Nevertheless, the supervision of bovine infection should be reinforced because this intermediate host may constitute an important link with the human contamination.     

In vitro and in vivo efficacy of epsiprantel against Echinococcus granulosus

In vitro, epsiprantel at a concentration of 10 micrograms ml-1 caused tegumental damage and death of protoscoleces, juveniles (seven-day-old) and adult (37-day-old) Echinococcus granulosus. Degenerative changes and death occurred more rapidly in the older parasites. Similarly, epsiprantel was more effective against adult (28-day-old) than seven-day-old experimental infections of E granulosus in dogs. Oral doses of 2.5, 5 and 7.5 mg kg-1 were greater than 96 per cent, 99.9 per cent and 99.99 per cent active, respectively, against mature worms, whereas in seven-day-old infections doses of 5, 7.5 and 10 mg kg-1 produced greater than 94 per cent, 90 per cent and 99.8 per cent reduction in worm burdens, respectively. No side effects from treatment were seen.     

Indirect fluorescent antibody test for the detection of antibodies to Echinococcus granulosus in experimentally infected pups

Adult parasites of Echinococcus granulosus of buffalo origin were used as antigen in the indirect fluorescent antibody test (IFA) for detection of antibodies to E. granulosus in experimentally infected pups. The technique permitted detection of antibodies on Day 5 post-infection (p.i.) and up to Day 80 p.i. in infected animals. The antigen-antibody reaction was characterized by the appearance of a specific brilliant greenish yellow fluorescence on the embryophore of mature eggs present within and outside the gravid segment of the cestode. A maximum antibody titre of 1:320 at Day 50 p.i. was observed in the infected pups, coinciding with maturation of adult worms in the intestine of the host.     

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.     

Evaluation of a serological test system for the diagnosis of natural Echinococcus granulosus infection in dogs using E. granulosus protoscolex and oncosphere antigens

Serum antibody responses in feral or domesticated dogs naturally infected with Echinococcus granulosus or/and other common helminths were examined in an enzyme-linked immunosorbent assay (ELISA) using antigens prepared from E. granulosus protoscoleces or oncospheres. The ELISA using the protoscolex antigen was optimised with serums from experimental dogs monospecifically infected with E. granulosus or other helminth parasites, and helminth-free dogs. Anti-protoscolex antibody was detected in 16 of 22 (72.7%) serums from feral dogs with E. granulosus burdens ranging from 300 to 302,600 worms per dog. Seven serums from feral dogs which did not harbour E. granulosus at autopsy but which originated from an endemic hydatid region were tested using protoscolex antigen, and 1 serum gave a positive reaction. One hundred and two serums from dogs known never to have been infected with E. granulosus all gave negative reactions to protoscolex antigen. The sensitivity of the ELISA test proved to be superior to that which has been achieved by arecoline purging as a method of diagnosis for E. granulosus infection in dogs. For use of the assay in hydatid control or eradication campaigns, its sensitivity can be increased by choosing a lower absorbance discrimination value above which serums are regarded as having positive reactions. However, this does introduce positive reactions of some serums from dogs infected with helminths other than E. granulosus. In further development of the assay, use of defined recombinant antigens may improve both sensitivity and specificity.(ABSTRACT TRUNCATED AT 250 WORDS)