A study of morphological aspects of cystic echinococcosis in sheep in Sardinia

Multiplex allele-specific polymerase chain reaction-based prevalence study of canine trapped neutrophil syndrome in Thailand

Background and Aim

Trapped neutrophil syndrome (TNS) is an autosomal recessive genetic disorder found in Border Collies and is characterized by peripheral neutropenia and myeloid hyperplasia of bone marrow. The underlying cause of TNS is associated with a 4-base pair deletion mutation in the vacuolar protein sorting 13 homolog B (VPS13B) gene. In this study, we proposed and validated a novel multiplex allele specific-polymerase chain reaction (MAS-PCR) technique to assess the prevalence of TNS using VPS13B genotypes of Border Collies and Thai Ridgebacks in Thailand.

Materials and Methods

We assessed the prevalence of TNS in 100 Border Collies and 30 Thai Ridgebacks using MAS-PCR-based allelic discrimination technique of the VPS13B gene. We then confirmed the VPS13B genotypes by direct DNA sequencing.

Results

A total of 130 samples were successfully genotyped using MAS-PCR assays. Of the two dog breeds examined, the VPS13B mutation was present in Border Collies, whereas Thai Ridgebacks were unaffected by this mutation. In Border Collies, 96% of dogs tested had an intact VPS13B genotype, whereas the remaining individuals had a heterozygous mutation genotype, with prevalence and mutated VPS13B allele frequencies of 4% and 2%, respectively.

Conclusion

Using a novel MAS-PCR assay targeting the VPS13B gene, this study demonstrates for the first time that carriers of TNS exist in Border Collies in Thailand. This assay is a reliable and cost-effective tool for diagnosing TNS based on VPS13B genotypes and is suitable for routine clinical practice.

The spatial distribution of cystic echinococcosis in Italian ruminant farms from routine surveillance data

Introduction

Cystic echinococcosis (CE) is a zoonotic parasite caused by the cestode Echinococcus granulosus sensu lato (s.l.) which predominantly affects livestock. The disease is endemic in central-southern and insular Italy, with CE particularly infecting sheep, goats, cattle, and water buffalo. The spatial distribution of CE in endemic regions is not widely understood, with surveillance efforts varying across the region.

Methods

In this study, we investigated the spatial distribution of CE in livestock using samples from farms across different livestock species using a Stochastic Partial Differential Equations (SPDE) model. Samples were collected during a survey conducted in the area of central-southern and insular Italy between the years 2019 – 2021.

Results

A total of 3141 animal samples (126 goats, 601 sheep and 2414 cattle and water buffalo) were inspected for Echinococcus s.l. cysts through routine surveillance in abattoirs by postmortem visual examination, palpation and incision of target organs. The geographic location of the farm of origin (a total of 2,878) for each sample was recorded. CE prevalence of 46.0% (1,323/2,878) was estimated at the farm level with 78.3% (462/590) of farms with sheep, 28.6% (36/126) of farms with goats, 36.5% (747/2,049) of farms with cattle, and 23.5% (102/434) of farms with water buffalo infected.

Discussion

The spatial model evaluated the probability of infection in farms across the sampled regions, with the distribution of CE showing high clustering of infected cattle farms in Sardinia and Sicily regions, and sheep farms in Salerno province (Campania region). The output of this study can be used to identify CE hot-spots and to improve surveillance and control programs in endemic areas of Italy.

Environmental Contamination by Echinococcus spp. Eggs as a Risk for Human Health in Educational Farms of Sardinia, Italy

Cystic Echinococcosis (CE) is a severe zoonosis caused by the larval stage of the tapeworm Echinococcus granulosus. These parasites are naturally transmitted between canid definitive hosts that harbour the adult stage in the intestine, and mainly ungulate intermediate hosts, with larval cysts developing in their internal organs. The close coexistence between dog and sheep with incorrect hygiene management are the most important factors for the persistence of this parasitic pathology. The Educational Farms (EF) are farms and agritourisms suitably equipped to carry out training activities for people interested in farm practices and agricultural processing, in particular student groups. Public attendance of farms represents a new potential risk factor for the zoonoses transmission. Consumption of contaminated food and water in combination with contact or playing with domestic dogs (Canis familiaris) are possible routes of zoonoses human infection. In fact, Echinococcus spp. eggs may persist in the environment up to several months at low temperatures and moist conditions, having the chance of contaminating different matrices and surfaces. The aim of this investigation was to study environmental contamination by parasitic elements as a risk for zoonoses, such as Echinococcus spp. A total of 116 samples (35 of water, 33 of soil, 23 of vegetables, 25 of dog faeces) were collected in 30 EF in Sardinia. Samples were subjected to biomolecular investigation for the research of specific gene sequences of Echinococcus granulosus, Echinococcus multilocularis and Taenia spp. The study allowed to identify eight positive EF due to the presence of Echinococcusgranulosus in eight dog faeces samples and one positive EF due to the presence of Taenia spp. in a water sample. The work has allowed to develop and harmonise the diagnostic methods and operating protocols essential for controlling the spread of the CE to create “One Health” intervention plans in high endemic areas through the implementation of SOP (standard operating procedures) for monitoring the pathology in animals, humans and environment.

Epidemiology and spatial distribution of Echinococcus granulosus in sheep and goats slaughtered in a hyperendemic European Mediterranean area

Background

Cystic echinococcosis (CE) is a worldwide parasitic zoonosis caused by the larval stage of Echinococcus granulosus sensu lato affecting livestock, particularly sheep and goats. However, often this parasitosis is underestimated. For this reason, this study aimed to evaluate the epidemiological features and spatial distribution of CE in sheep and goats slaughtered in a hyperendemic Mediterranean area.

Methods

A survey was conducted in the Basilicata region (southern Italy) from 2014 to 2019. A total of 1454 animals (1265 sheep and 189 goats) from 824 farms were examined for hydatid cyst detection by visual inspection, palpation and incision of target organs. All the CE cysts were counted and classified into five morphostructural types (unilocular, multiseptate, calcified, caseous and hyperlaminated). Molecular analysis was performed on 353 cysts. For spatial analysis, a kriging interpolation method was used to create risk maps, while clustering was assessed by Moran’s I test.

Results

CE prevalence of 72.2% (595/824) and 58.4% (849/1454) was observed at the farm and animal levels, respectively, with higher values in sheep (62.9%) than goats (28.0%). The liver and lungs were the most frequently infected organs in both sheep and goats. Most of recovered cysts were of the calcified and multiseptate morphotypes. All the isolates were identified as E. granulosus sensu stricto (genotypes G1–G3). Spatial distribution showed a moderate clustering of positive animals.

Conclusion

The findings of this study can be used to better understand the eco-epidemiology of echinococcosis and to improve CE surveillance and prevention programs in regions highly endemic for CE.

Graphical abstract

Degree of calcification and cyst activity in hepatic cystic echinococcosis in humans

To evaluate the relationship between cyst activity and calcification degree in cystic echinococcosis (CE) in humans, 99 hepatic cysts at successive stages of involution, surgically excised from 72 Sardinian patients, have been analyzed. Cysts were classified into 4 groups according to calcification extent: CALC 0 (no calcification); CALC 1 (scattered punctate calcifications); CALC 2 (large coarse segmental/partial calcifications); CALC 3 (complete or nearly complete circumferential ring of calcification up to thick wall of osseous consistency/calcified content of cyst). In addition the possible correlation with antibody response has been explored analyzing IgG1, IgG4 and IgE produced against somatic PSCAg. Results showed that calcification is not restricted to the inactive WHO cyst types CE4 and CE5, but occurs to a varying extent in all morphotypes of metacestode, from active classic unilocular or multivesicular cysts to the more complicated and highly degenerate stages, where cyst wall appears massively calcified. Prevalence of calcification increases with progression of cyst degenerative process, but is not synonymous with parasite inactivity and can be misleading as signs of calcification may coexist with still metabolically active cysts. On the contrary, detection of entirely firmly solidified content seems a reliable indication of cyst inactivity. IgG4 is the dominant isotype associated particularly with the evolutive phase. Positive rates and OD levels, higher in active vs inactive stages, are stable or increase slightly in weakly and moderately calcified cysts (CALC 1/CALC 2), compared to non-calcified ones (CALC 0), strongly decreasing in highly calcified forms (CALC 3). In conclusion, evaluation of calcification extent may be pertinent for staging CE, and immunological tests, particularly for IgG4, and IgE may help to better define cyst activity.