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.     

Cystic echinococcosis in slaughtered sheep in Sardinia (Italy)

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

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.     

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.     

A survey of Taenia multiceps coenurosis in Sardinian sheep

A survey was carried out to assess the occurrence of Coenurus cerebralis infection in Sardinian sheep. A prevalence of 0.35% was observed when 566 regularly slaughtered sheep were examined. However, in 120 sheep with suspected symptoms of coenurosis examined from November 2001 to October 2002, a total of 299 cerebral coenurosis lesions were observed with an incidence of 1% per year. Lesions were classified as migratory, cystic and secondary. Most migratory lesions were found in sheep aged 3-6 months. Cavitary lesions containing cysts in different developing stages were found with high incidence per year in sheep aged 7-12 months. Secondary lesions due to the development of Coenurus were most frequent in sheep aged 19-36 months. Most sheep were found infected in spring and in early summer, between March and June. Most lesions were located in the cortex. The mean number of protoscolices per cyst was 149 (range 10-370).     

Human outbreak of trichinellosis in the Mediterranean island of Sardinia, Italy

Trichinella sp. infection has been documented in both humans and animals in most Mediterranean countries, yet in the past 60 years no infections have been reported on the Mediterranean islands. We describe the first outbreak of Trichinella sp. infection to have been reported on the island of Sardinia. The outbreak occurred in two villages in 2005 and involved 11 persons who had eaten raw sausages made from the same free-ranging sow. All 11 persons developed signs and symptoms of trichinellosis and seroconverted within 48 days of consuming the infected meat. The etiological agent was Trichinella britovi. Sardinia, like all Mediterranean islands, had been considered to be Trichinella-free. The present report, together with a recent report of T. britovi infection in animals on the nearby island of Corsica (France), raises questions as to the validity of the concept of Trichinella-free areas or regions.     

Cystic echinococcosis in Europe and in Italy

Cystic Echinococcosis remains a public health problem especially in the Mediterranean Region and the economic impact of Echinococcosis is great despite efforts to control it. In this review, an attempt is made to assess the present epidemiological situation of Echinococcosis in Europe and Italy.     

Cystic Echinococcosis in Water Buffaloes from the Campania Region of Southern Italy

Veterinary Research Communications -     

Efficacy of epsiprantel against Echinococcus granulosus infections in dogs

Dogs with 41-day-old experimental infections of Echinococcus granulosus were treated orally with epsiprantel. Single doses of 2.5 mg kg-1, 5.0 mg kg-1 or 7.5 mg kg-1 were effective in removing more than 99 per cent of these parasites, but total clearances of worms only occurred in dogs given the highest dose.