Epidemiological update of cystic echinococcosis in livestock and assessment of practices related to its control in the Mediterranean area

Cystic echinococcosis (CE), caused by the tapeworm Echinococcus granulosus, is a zoonotic parasitic disease that still represents a serious threat to human and animal health worldwide. The Mediterranean basin is recognized as one of the major hotspots of CE due to several factors, including the presence of diverse intermediate host species as well as socio-economic and cultural conditions of local communities. This study aims to take a closer look at epidemiological data on CE in the Mediterranean area and assess the knowledge attitudes and practices of shepherds towards this disease in four countries (Algeria, Greece, Italy and Tunisia), highly endemic for CE, with the final goal of identifying highly endemic risk areas and practices in use which might potentially allow the persistence of E. granulosus infection in these areas. To update the epidemiological scenario of CE in Mediterranean areas, a comprehensive review of peer-reviewed literature on CE prevalence data published during the 2017-2023 period was carried out and, through a geographical information system (GIS), a map displaying the current CE distribution in the Mediterranean area was generated. In addition, a questionnaire survey was conducted through in-depth interviews of the farmers to collect information on their management system as well as knowledge attitudes and practices towards CE. From the farmer-participatory survey some risky practices emerged including the non-regular deworming of dogs or the use of ineffective drugs or dosing, as well as the provision of uncooked animal viscera to dogs. Finally, lower levels of knowledge and awareness of the disease was observed among farmers from North Africa compared with those of European countries. In conclusion, the results obtained highlight that CE is still a very serious problem in Mediterranean areas and increased efforts are needed to promote awareness among farmers and to turn research results into policy in order to reduce the spread of this disease, according to the One Health perspective.

Baiting not-owned dogs against Echinococcus granulosus: innovative tools for integrated control

Cystic echinococcosis (CE), caused by the larval stage of the cestode Echinococcus granulosus, is one of the most widespread zoonoses in Mediterranean countries. Baiting not-owned dogs with praziquantel (PZQ), due to their key role in the maintaining the transmission of CE, currently appears to be the most effective way to limit the transmission of CE, as well as an important aspect to introduce for the control of this parasitic disease. Therefore, this study aims to test 3 types of PZQ-based baits by evaluating different parameters (integrity over time, attractiveness and palatability for dogs, and mechanical resistance after release to different altitudes) and the bait acceptance in field by target animals, i.e. not-owned dogs, by using camera traps. The double PZQ-laced baits (with a double layer of highly palatable chews) showed the greatest resistance in the environment while also preserving the attractiveness and palatability up to 10 days, also withstood heights of 25 m, thus resulting as the most suitable also for drone delivery. The results on the field showed that most of the baits were consumed by not-owned dogs (82.2%), while the remaining were consumed by wild boars (8.9%), foxes (6.7%), badgers (1.1%) and hedgehogs (1.1%), confirming the specific and high attractiveness of the double PZQ-laced baits for the target population and highlights how an anthelmintic baiting programme may be a viable tool for the management of E. granulosus among free-ranging dog populations in endemic rural areas.

An innovative strategy for deworming dogs in Mediterranean areas highly endemic for cystic echinococcosis

BACKGROUND

Cystic echinococcosis (CE), caused by the larval stage of Echinococcus granulosus sensu lato, is a zoonotic parasitic disease of economic and public health importance worldwide, especially in the Mediterranean area. Canids are the main definitive hosts of the adult cestode contaminating the environment with parasite eggs released with feces. In rural and peri-urban areas, the risk of transmission to livestock as well as humans is high because of the free-roaming behavior of owned/not owned dogs. Collecting data on animal movements and behavior using GPS dataloggers could be a milestone to contain the spread of this parasitosis. Thus, this study aims to develop a comprehensive control strategy, focused on deworming a dog population in a pilot area of southern Italy (Campania region) highly endemic for CE.

METHODS

Accordingly, five sheep farms, tested to be positive for CE, were selected. In each sheep farm, all shepherd dogs present were treated every 2 months with praziquantel. Furthermore, 15 GPS dataloggers were applied to sheep and dogs, and their movements were tracked for 1 month; the distances that they traveled and their respective home ranges were determined using minimum convex polygon (MCP) analysis with a convex hull geometry as output.

RESULTS

The results showed that the mean daily walking distances traveled by sheep and dogs did not significantly differ. Over 90% of the point locations collected by GPS fell within 1500 mt of the farm, and the longest distances were traveled between 10:00 and 17:00. In all the sheep farms monitored, the area traversed by the animals during their daily activities showed an extension of < 250 hectares. Based on the home range of the animals, the area with the highest risk of access from canids (minimum safe convex polygon) was estimated around the centroid of each farm, and a potential scheme for the delivery of praziquantel-laced baits for the treatment of not owned dogs gravitating around the grazing area was designed.

CONCLUSIONS

This study documents the usefulness of geospatial technology in supporting parasite control strategies to reduce disease transmission.

The genome-wide relationships of the critically endangered Quadricorna sheep in the Mediterranean region

Livestock European diffusion followed different human migration waves from the Fertile Crescent. In sheep, at least two diffusion waves have shaped the current breeds' biodiversity generating a complex genetic pattern composed by either primitive or fine-wool selected breeds. Nowadays most of the sheep European breeds derive from the second wave which is supposed to have largely replaced oldest genetic signatures, with the exception of several primitive breeds confined on the very edge of Northern Europe. Despite this, some populations also in the Mediterranean region are characterised by the presence of phenotypic traits considered ancestral such as the policeraty, large horns in the ram, short tail, and a moulting fleece. Italy is home of a large number of local breeds, albeit some are already extinct, others are listed as critically endangered, and among these there is the Quadricorna breed which is a four-horned sheep characterised by several traits considered as ancestral. In this context we genotyped 47 individuals belonging to the Quadricorna sheep breed, a relict and endangered breed, from Central and Southern Italy. In doing so we used the Illumina OvineSNP50K array in order to explore its genetic diversity and to compare it with other 41 breeds from the Mediterranean region and Middle-East, with the specific aim to reconstruct its origin. After retaining 32,862 SNPs following data filtering, the overall genomic architecture has been explored by using genetic diversity indices, Principal Component Analysis (PCA) and admixture analysis, while the genetic relationships and migration events have been inferred using a neighbor-joining tree based on Reynolds' distances and by the maximum likelihood tree as implemented in treemix. The Quadricorna breed exhibit genetic diversity indices comparable with those of most of the other analysed breeds, however, the two populations showed opposing patterns of genetic diversity suggesting different levels of genomic inbreeding and drift (FIS and FROH). In general, all the performed genome-wide analyses returned complementary results, indicating a westward longitudinal cline compatible with human migrations from the Middle-East and several additional genetic footprints which might mirror more recent historical events. Interestingly, among the Italian breeds, the original Quadricorna (QUAD_SA) first separated showing its own ancestral component. In addition, the admixture analysis does not suggest any signal of recent gene exchange with other Italian local breeds, highlighting a rather ancestral purity of this population. On the other hand, both the neighbor-joining tree and the treemix analysis seem to suggest a proximity of the Quadricorna populations to breeds of South-Eastern Mediterranean origin. Although our results do not support a robust link between the genetics of the first wave and the presence of primitive traits, the observed genetic uniqueness together with the inferred phylogeograpic reconstruction would suggest an ancient presence of the Quadricorna breed in the Italian Peninsula. Because of this singularity, urgent conservation actions are needed in order to keep the breed and all related cultural products alive.

The ancestral origin of the critically endangered Quadricorna sheep as revealed by genome-wide analysis

Livestock European diffusion followed different human migration waves from the Fertile Crescent. In sheep, at least two diffusion waves have shaped the current breeds' biodiversity generating a complex genetic pattern composed by either primitive or fine-wool selected breeds. Among primitive breeds, aside from sharing common ancestral genomic components, they also show several traits such as the policeraty, large horns in the ram, short tail, and a moulting fleece, considered as ancestral. Although most of the primitive breeds characterized by these traits are confined on the very edge of Northern Europe, several residual populations are also scattered in the Mediterranean region. In fact, although in Italy a large number of local breeds are already extinct, others are listed as critically endangered, and among these there is the Quadricorna breed which is a four-horned sheep characterized by several ancestral traits. In this context we genotyped 47 individuals belonging to the Quadricorna sheep breed, a relict and endangered breed, from Central and Southern Italy. In doing so we used the Illumina OvineSNP50K array in order to explore its genetic diversity and to compare it with other 33 primitive traits-related, Mediterranean and Middle-East breeds, with the specific aim to reconstruct its origin. After retaining 35,680 SNPs following data filtering, the overall genomic architecture has been explored by using genetic diversity indices, Principal Component Analysis (PCA) and admixture analysis, while the genetic relationships and migration events have been inferred using a neighbor-joining tree based on Reynolds' distances and by the maximum likelihood tree as implemented in treemix. Multiple convergent evidence from all our population genetics analyses, indicated that the two Quadricorna populations differ from all the other Italian breeds, while they resulted to be very close to the Middle Eastern and primitive European breeds. In addition, the genetic diversity indices highlighted values comparable with those of most of the other analyzed breeds, despite the two populations exhibit slightly different genetic indices suggesting different levels of genomic inbreeding and drift (FIS and FROH). The admixture analysis does not suggest any signal of recent gene exchange with other Italian local breeds, highlighting a rather ancestral purity of the two populations, while on the other hand the treemix analysis seems to suggest an ancient admixture with other primitive European breeds. Finally, all these evidences seem to trace back the residual Quadricorna sheep to an early Neolithic spread, probably following a Mediterranean route and that urgent conservation actions are needed in order to keep the breed and all related cultural products alive.

Anthelmintic Properties of Essential Oils to Control Gastrointestinal Nematodes in Sheep-In Vitro and In Vivo Studies

Herbal products such as essential oils may play a promising role in the treatment of infections caused by gastrointestinal nematodes (GINs). The aim of this study was to evaluate the in vitro potential of 11 essential oils (EOs) and one binary combination of isolated EO compounds, as well as the in vivo anthelmintic efficacy of two EO formulations. Four GIN genera were identified in the coproculture examination: Haemonchus, Trichostrongylus, Teladorsagia and Chabertia. The in vitro egg hatch test (EHT) was performed at six different concentrations (50, 12.5, 3.125, 0.781, 0.195 and 0.049 mg/mL) for each EO, whereas in the in vivo faecal egg count reduction test (FECRT), each EO sample was diluted in sunflower oil and orally administrated at a dose of 100 mg/kg to the different group of animals. In the EHT, the EOs of Origanum vulgare, Foeniculum vulgare, Satureja montana, Satureja hortensis and two types of Thymus vulgaris were the most effective. The dominant compounds of these EOs were carvacrol, thymol, anethol, p-cymene and γ-terpinene, indicating their importance for the anthelmintic activity. In the FECRT, both T. vulgaris EO type 1 and linalool:estragole combination show an anthelmintic potential with a mean effect on FECR of approximately 25%. The results suggest the possible role of tested EOs as anthelmintic agents in sheep farms, although further in vivo tests are needed.

A five-year retrospective study on ascarid infections in dogs in southern Italy

INTRODUCTION

A 5-year retrospective analysis of ascarid infections (Toxocara canis and Toxascaris leonina) in dogs from southern Italy was performed to update the epidemiological scenario of these parasites and to identify the risk factors which may favour these infections in animals in this study area. A total of 8,149 dogs, referred to our labs for copromicroscopic analysis using the FLOTAC technique, was considered. A sub-sample of 500 faecal samples were analysed also with the Mini-FLOTAC technique. Of the overall dog samples analysed, 9,2 % (95 % CI = 8,6-9,8) resulted positive for T. canis while 0,5 % (95 % CI = 0,4-0,7) resulted positive for T. leonina. Co-infections with T. canis and T. leonina were found in 0,1 % of dogs (95 % CI = 0,0-0,1). The results obtained by the FLOTAC and Mini-FLOTAC examinations showed a nearly perfect k agreement (k = 0,99, P < 0,001) between these two techniques. Chi-square test showed positivity to T. canis and T. leonina significantly (P < 0,001) associated with dogs housed outdoor (i.e., that lived in garden or in kennel). Moreover, the positivity for T. canis was significantly associated (P < 0,001) also with age (i.e., puppies), as shown by the logistic regression. The decreasing overall prevalence both for T. canis and T. leonina during the years of monitoring, showed that, as suggested by the European Scientific Counsel Companion Animal Parasites, the regular diagnosis could contribute to an efficient control of these parasites.

A 10-Year Surveillance of Eimeria spp. in Cattle and Buffaloes in a Mediterranean Area

Coccidiosis due to Eimeria spp. are widespread parasitic infections in cattle and water buffaloes and may impair health, welfare, and production of these livestock species. The aims of this study were (i) to investigate the prevalence and seasonal dynamics of eimeriosis and (ii) to characterize the Eimeria species in large ruminants in a Mediterranean area, in order to plan effective control strategies. Parasitological data were obtained from a 10-year surveillance program (2010–2019) on 3,631 farms (2,089 buffalo and 1,542 cattle farms) sampled in central and southern Italy. Pooled fecal samples were analyzed using the FLOTAC technique with an analytic sensitivity of 2 oocysts per gram of feces (OPG) utilizing a saturated sodium chloride flotation solution (specific gravity = 1.200). Eimeria species identification was performed by morphometric analysis after a one week incubation of oocysts in a 2.5% potassium dichromate solution. The results showed high prevalence of Eimeria (up to 100%) in both cattle and buffaloes in the 10 years of surveillance, even if a slight reduction was reported in the last three years. The overall prevalence of eimeriosis was 91.7% (95% confidence interval, 95% CI = 90.2–93.1) in cattle farms and 81.5% (95% CI = 79.8–83.1) in water buffalo farms. The mean OPG value was 66.8 (min = 2; max = 8,065) in cattle and 55.9 (min = 2; max = 15,415) in water buffaloes, but this difference was not statistically significant (p > 0.05). In total, nine species of Eimeria were found in cattle the most prevalent being Eimeria bovis, E. ellipsoidalis, E. cylindrica, and E. zuernii, whereas in water buffaloes eight species of Eimeria were found, the most prevalent being E. ellipsoidalis, E. auburnensis, E. bovis, and E. zuernii. Mixed infections were common in both ruminant species. The seasonal pattern showed a higher prevalence of eimeriosis in cattle in spring (86.9%) whereas in buffalo farms the prevalence was higher in winter (82.3%) and summer (82.4%). In conclusion, the 10-year surveillance program indicates that eimeriosis is common in cattle and water buffaloes and therefore continuous effective control strategies are needed.

Giardia and Cryptosporidium in water buffaloes (Bubalus bubalis)

A cross-sectional survey of Giardia duodenalis and Cryptosporidium parvum infection in the water buffalo (Bubalus bubalis) was carried out in central Italy. A geographical information system (GIS) was constructed utilizing as data-layers the topographic base map and the digital aerial photographs of the study area, as well as the geo-referenced points of all the buffalo farms. The survey was conducted on a sample of 90 farms, selected using a grid approach followed by proportional allocation. For this purpose, a grid representing quadrants of 5 x 5 km was overlaid on the study area within the GIS. As a result, the study area was divided in equal quadrants, and the number of farms sampled in each quadrant was proportional to the total number of study population in that quadrant. On each farm, faecal samples were collected per rectum from three to five asymptomatic buffalo calves, aged from 1 to 9 weeks. The total number of faecal samples collected was 347. Each faecal sample was tested for the presence of copro-antigens of G. duodenalis and of C. parvum using two commercially available enzyme-linked immunosorbent assays. Out of the 90 farms, 27 (30.0%) resulted positive for G. duodenalis and 22 (24.4%) for C. parvum. Co-infection was found in ten (11.1%) farms. With respect to animals, out of the 347 faecal samples, 63 (18.1%) were found to have antigens of G. duodenalis and 51 (14.7%) of C. parvum. Co-infection was found in ten buffalo calves (2.9%). The results of the logistic regression models showed a positive association between the positivity to G. duodenalis and the presence of sheep on farm and between the positivity to C. parvum and the high number of buffaloes on farms. No significant co-infection between the two protozoa was found. In conclusion, the findings of the present study, derived from a systematic territorial survey planned with GIS, are noteworthy because they provided additional data on C. parvum and the first evidence of G. duodenalis infection in water buffaloes.