Risk factors and geospatial modelling for the presence of Fasciola hepatica infection in sheep and goat farms in the Greek temperate Mediterranean environment

An insight into the epidemiology of foodborne zoonotic fascioliasis in small ruminants in northwestern region of Bangladesh

Fascioliasis is one of the most common foodborne zoonotic infection of ruminants in Bangladesh. To estimate the prevalence and associated risk factors of fascioliasis and extent of liver damage, 825 livers of sheep and goats were randomly inspected during onsite slaughterhouse visiting in Naogaon, Natore, Rajshahi and Joypurhat districts. The overall prevalence of fascioliasis was 25.09% and significantly (P = 0.008) higher in goats (26.11%) than sheep (24.00%). During gross inspection, Fasciola infected livers were increased in size, fibrosed, fatty, multiple white or reddish necrotic foci on the parietal surface, hard to cut, calcified, and numerous mature and immature flukes were also observed. In histoarchitecture, inflammatory cell infiltration in the hepatic parenchyma and periportal area, fibrous connective tissue proliferation around necrotic area, hyperplastic bile duct, congestion, and primary biliary cirrhosis were seen in acute and chronic fascioliasis. Epidemiological investigations revealed that fascioliasis was higher in goats than sheep. Age, sex, BCS and season were found to have statistically significant associations with fascioliasis in goats. In case of sheep, age (OR = 5.8671; 95% CI: 2.9482-11.6757, P < 0.0001), sex (OR = 3.7317; 95% CI: 1.9052-7.3094, p < 0.0001), BCS (OR = 6.0346; 95% CI: 1.7986-20.2472, p < .0001), and season (OR = 8.2308; 95% CI: 3.9922-16.9693, p =  < .0001) were also found to have statistically significant associations with fascioliasis. Results of the study can help for molecular epidemiology of fascioliasis in small ruminants to plan fluke control programs for safe food production.

Spatial analysis and risk mapping of Fasciola hepatica infection in dairy cattle at the Peruvian central highlands

This study aimed to develop maps for Fasciola hepatica infection occurrence in dairy cattle in the districts of Matahuasi and Baños in the Peruvian central highlands. For this, a model based on the correlation between environmental variables and the prevalence of infection was constructed. Flukefinder® coprological test were performed in samples from dairy cattle from 8 herds, during both the rainy and wet season. Grazing plots were geo-referenced to obtain information on environmental variables. Monthly temperature, monthly rainfall, elevation, slope, normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), normalized difference water index (NDWI), distance to rivers, urban areas and roads were obtained by using remote sensor images and ArcGIS®. Multilayer perceptron Artificial Neural Networks modeling were applied to construct a predictive model for the occurrence of fasciolosis, based on the relationship between environmental variables and level of infection. Kappa coefficient (k > 0.6) was used to evaluate concordance between observed and forecasted risk by the model. Coprological results demonstrated an average prevalence from 20% to 100%, in Matahuasi, and between 0 and 87.5%, in Baños. A model with a high level of concordance between predicted and observed infection risk (k = 0.77) was obtained, having as major predicting variables: slope, NDWI, NDVI and EVI. Fasciolosis risk was categorized as low (p < 20%), medium (20% < p < 50%) and high (p ≥ 50%) level. Using ArcGIS 10.4.1, risk maps were developed for each risk level of fasciolosis. Maps of fasciolosis occurrence showed that 87.2% of Matahuasi area presented a high risk for bovine fasciolosis during the dry season, and 76.6% in the wet season. In contrast, 21.9% of Baños area had a high risk of infection during the dry season and 12.1% during the wet season. In conclusion, our model showed areas with high risk for fasciolosis occurrence in both districts during both dry and rainy periods. Slope, NDWI, NDVI and EVI were the major predictors for fasciolosis occurrence.

Prevalence of gastrointestinal parasites and molecular identification of beta-tubulin mutations associated with benzimidazole resistance in Haemonchus contortus in goats from selected districts of Uganda

Gastrointestinal parasites are among the most economically important pathogens of small ruminants causing serious economic losses and animal welfare problems for the livestock industry worldwide. The emergence of anthelmintic resistant H. contortus in small ruminants is a serious problem because it undermines effective helminth control and results in reduced productivity. Little is known about resistance to benzimidazoles (BZ) in Haemonchus in goats and sheep in Uganda. The objective of this study was to determine the prevalence of gastrointestinal parasites and to identify the presence of benzimidazole resistance associated mutations in the β-tubulin isotype 1 gene of Haemonchus contortus in goats from selected districts of Uganda. A total of 200 goats from 10 districts of Uganda slaughtered at Kalerwe abattoir in Kampala were sampled for H. contortus adult worms. Faecal samples were also collected to detect other intestinal parasites. Faecal microscopy and analysis were performed using flotation and sedimentation techniques. DNA was extracted from adult worms and PCR and sequencing of the ITS- 2 region and β-tubulin isotype 1 gene performed to identify H. contortus species and to determine the presence of mutations associated with anthelmintic resistance respectively. Faecal microscopy showed that the most prevalent intestinal parasites were coccidia (98%), strongyles (97.5%), Strongyloides (82%), Paramphistomum (74.5%), Moniezia (46%), Fasciola (1.5%) and Trichuris (1%). Most goats had a high intestinal burden of coccidia (≥ 5000 oocyst per gram) and strongyles (≥ 1000 egg per gram), 65% and 67.5%, respectively. The prevalence of H. contortus adult worms was 63% (126/200). Sequencing of the partial β-tubulin isotype 1 gene of 54 Haemonchus contortus adult male isolates revealed the presence of mutations associated with anthelmintic resistance. The F200Y mutation was the most common mutation (13% of samples with good beta-tubulin sequences) followed by the E198A and E198K mutations, both found in 9% of sequenced samples. Mutation F167Y was not identified in any of the samples and there were no heterozygous individuals for any of the SNPS associated with BZ resistance that were identified in this study. These findings highlight the need for controlled use of anthelmintics especially benzimidazoles, to enable sustainable control of H. contortus in Uganda, and a need for further investigation to understand the resistance of other parasites identified in this study.

Prevalence of Human and Animal Fasciolosis in Butajira and Gilgel Gibe Health Demographic Surveillance System Sites in Ethiopia

Fasciolosis is regarded as a major challenge to livestock productivity worldwide, but the burden of disease in humans has only started to receive some attention in the past three decades. The aim of this study was to determine the prevalence of human and animal fasciolosis and its determinant factors in the Gilgel Gibe and Butajira Health and Demographic Surveillance System (HDSS) sites in Ethiopia. A study was undertaken among 389 households across the two sites. Face-to-face interviews were conducted to investigate the knowledge, attitudes and practices of households with regard to fasciolosis. Stools from 377 children aged 7–15 years, and 775 animals (cattle, goats and sheep) were analyzed using a proprietary Fasciola hepatica (F. hepatica) coproantigen ELISA kit. The prevalence of fasciolosis in children was 0.5% and 1% in Butajira and Gilgel Gibe HDSS sites, respectively. The overall prevalence of animal fasciolosis was 29%, 29.2%, and 6% among cattle, sheep, and goats, respectively. More than half of the respondents from Gilgel Gibe (59%, n = 115) did not know that humans can be infected with F. hepatica. The majority of respondents in Gilgel Gibe (n = 124, 64%) and Butajira (n = 95, 50%) did not know the transmission route for fasciolosis. Grazing animals were 7 times more likely to be infected with fasciolosis than animals in cut-and-carry production systems (adjusted odds ratio [AOR] = 7.2; 95% confidence interval [CI]: 3.91–13.17). The findings indicated a lack of knowledge amongst local populations about fasciolosis. Thus, there is a need for public health awareness campaigns about fasciolosis in the study areas.

Fasciolosis in sheep and goats slaughtered at abattoirs in Central Ethiopia and associated financial losses

Fasciolosis is a serious animal health problem in Ethiopia where livestock is crucial for the domestic economy. A study was conducted in two Ethiopian abattoirs to estimate the prevalence of Fasciola infection in goats and sheep, and the monetary losses resulting from liver condemnation. Post-mortem examination of 925 animals (424 sheep and 501 goats) were examined by incision of the liver parenchyma for presence of the liver fluke, Fasciola. The direct financial losses were calculated based on the estimated prevalence, the market price of the liver, and the average number of sheep and goats slaughtered annually. The overall prevalence of fasciolosis was 10.4% (20.7% sheep and 1.6% goats). Among the studied variables, species of the study animal and age in sheep showed a statistically significant association with infection (p < 0.05). Based on the annual average of 89,054 sheep and 76,374 goats slaughtered, the annual average economic loss due to the condemned liver was estimated at 3700 US$ (185,232 ETH Birr) for sheep and 245 US$ (12,220 ETH Birr) for goats.

This study revealed that the prevalence of fasciolosis was higher in sheep than in goats, and substantial economic losses occur for the sheep and goat industry. Hence, considering the irrigations schemes in the country, strategic control programs targeting Fasciola infection and intermediate hosts are warranted.

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20.7% of 424 sheep and 1.6% of 501 goats were infected with fasciolosis.

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Young sheep were more commonly affected than adults.

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Sheep and goat livers condemned annually were valued at $3700 US and $245 US, respectively.

Rumen and Liver Fluke Infections in Sheep and Goats in Northern and Southern Germany

Simple Summary

Little is known about the distribution of rumen and liver flukes in sheep and goats in Germany or about the occurring rumen fluke species. These fluke infections can be detected by the parasite’s eggs in the host animal’s feces. Therefore, fecal samples from 223 sheep farms and 143 goat farms from northern and southern Germany were examined. The eggs of rumen flukes were detected on 2.2% of the samples, the eggs of common liver flukes on 2.7%, and the eggs of small liver flukes on 21.1% of the examined sheep farms. The rumen flukes were identified as the emerging species Calicophoron daubneyi. No rumen fluke eggs were detected on any of the goat farm samples, but common and small liver fluke eggs were detected in 5.6% and 7.0% of the goat herds, respectively. Differences in the geographical distribution of rumen and liver flukes between and within the two regions were identified. Rumen flukes were more frequently found in the north, while the two liver fluke species were more frequently found in the south of Germany. Sheep sharing the pasture with other ruminants were more likely to be infected with rumen flukes.

Abstract

Paramphistomidosis has recently been identified as an emerging parasitosis in Europe. This study estimated the prevalence of rumen flukes, Fasciola hepatica and Dicrocoelium dendriticum, in small ruminants in Germany and identified occurring rumen fluke species and potential predictors for fluke infections. Pooled fecal samples from 223 sheep farms and 143 goat farms in northern and southern Germany were examined by the sedimentation technique, and molecular species identification was performed on rumen-fluke-positive samples. In sheep, a flock prevalence of 2.2% was detected for rumen flukes. Calicophoron daubneyi was identified on four of five positive farms, while species identification failed in one flock. No rumen fluke eggs were detected in the examined goat herds. F. hepatica eggs were detected in 2.7% of the sheep flocks, while the herd prevalence was 5.6% in goats. Higher prevalence values of 21.1% (sheep) and 7.0% (goats) were observed for D. dendriticum. Mixed grazing with other ruminants and previously identified infections with rumen flukes and/or F. hepatica were identified as predictors for paramphistomidosis. The distribution of the three trematode species followed a geographical pattern associated with conditions favoring the relevant intermediate hosts. C. daubneyi is an established parasite in German sheep at a currently low prevalence.

Occurrence and Distribution of Fasciolosis in a Cohort of Ovine Livestock Restricted to a Mountain Plateau in Central Portugal

Simple Summary

Fasciola hepatica is a parasite that affects ruminants. This study evaluated the occurrence of fasciolosis in ovine livestock from central Portugal during a 2-year period. Positive animals were found in most locations and in both years (19.6% and 18.5% seropositive in the first year and second year, respectively). Correct anthelmintic treatment could further reduce egg elimination and pasture contamination.

Abstract

Fasciola hepatica is a parasite that is widespread in Europe, having been reported in ruminants of several European countries and causing an important economic impact. This study ascertained the occurrence and distribution of fasciolosis in Portuguese ovine livestock by assessing F. hepatica IgG antibodies in a cohort of confined sheep from a high-altitude region of central Portugal in a 2-year period. Positive animals were found in most locations and in both years, with 18 of the 92 animals (19.6% [95% confidence interval CI: 12.03–19.15]) and 17 of the same 92 animals (18.5% [95% CI: 11.15–27.93]) showing to be seropositive in the first year and second year, respectively (p = 0.85). Pasture contamination by F. hepatica eggs could be reduced by thorough anthelmintic treatments.

Current Status for Controlling the Overlooked Caprine Fasciolosis

The disease fasciolosis is caused by the liver flukes Fasciola hepatica and F. gigantica, which infect a wide range of mammals and production livestock, including goats. These flatworm parasites are globally distributed and predicted to cost the livestock industry a now conservative USD 3 billion per year in treatment and lowered on-farm productivity. Infection poses a risk to animal welfare and results in lowered fertility rates and reduced production yields of meat, milk and wool. This zoonotic disease is estimated to infect over 600 million animals and up to 2.4 million humans. Current and future control is threatened with the global emergence of flukes resistant to anthelmintics. Drug resistance calls for immediate on-farm parasite management to ensure treatments are effective and re-infection rates are kept low, while a sustainable long-term control method, such as a vaccine, is being developed. Despite the recent expansion of the goat industry, particularly in developing countries, there are limited studies on goat-focused vaccine control studies and the effectiveness of drug treatments. There is a requirement to collate caprine-specific fasciolosis knowledge. This review will present the current status of liver fluke caprine infections and potential control methods for application in goat farming.

Prevalence of Fasciola hepatica in Goats and Sheep by Using ELISA in Sera and Milk in Duhok, Iraq

An indirect ELISA technique was used to determine the prevalence of infection in sera and milk samples among goats and sheepin Duhok, Kurdistan Region, Iraq. Results of the present study shows that the prevalence of infection was higher in sera compared to milk samples among goats and sheep as follow: (6.3, 4.2%) and (8.9, 5.6%) respectively and there was no statistical significance difference in goats at P value =0.42, also there was no statistically differences at P value= 0.22. ELISA results also shows that the prevalence according to the age among goats and sheep were higher in animal aged > 2 years in both sera and milk samples were (7.5, 5.3%) and (11.3, 7%) respectively and there was no significant difference between age groups of goats and sheep by ELISA. The present study is the first study done to determine the prevalence of F. hepatica in both sera and milk samples among local goats and sheep. Continuously screening of sheep and goats for Fascioliasis and using of anthelmintic to control the infection in small ruminants is necessary

A holistic model to assess risk factors of fasciolosis in Ankole cattle

In recent decades, remote sensing (RS) technology and geographical information systems (GIS) were increasingly used as tools for epidemiological studies and the control of zoonotic diseases. Fasciolosis, a zoonotic disease caused by a trematode parasite (Fasciola spp.), is a good candidate for the application of RS and GIS in epidemiology because it is strongly influenced by the environment, i.e. the habitat of the intermediate host. In this study, we examined variables which may increase the fasciolosis risk of Ankole cattle in the degraded and overgrazed Mutara rangelands of north-eastern Rwanda. The risk variables considered included three environmental variables (normalized difference vegetation index, NDVI; normalized difference moisture index, NDMI; normalized difference water index, NDWI), two landscape metric variables (rangeland proportion, building density), two geological variables (poorly-drained soil proportion, elevation) and three animal husbandry variables (herd size, adult proportion and the body condition score). Fasciola spp. prevalence was used as the dependent variable, sampling season as a fixed factor and four principal components (PCs, condensed from the ten risk variables) as covariates in a univariate General Linear Model. Fasciola spp. prevalence was positively correlated to rangeland proportion, cattle herd size in rural areas, adult proportion and individual body condition. Moreover, high Fasciola spp. prevalence was found in densely vegetated areas with high moisture (high values of NDVI and NDMI), in combination with large proportions of poorly-drained soil at low elevations. Future investigations should focus on increased sampling across the Mutara rangelands to prepare a predictive, spatial fasciolosis risk map that would help to further improve sustainable land-use management.

Fasciola hepatica infection in cattle and the use of simulation models for endemic areas

Fasciolosis is a food-borne disease that causes great distress to a range of hosts, including humans. The objectives of this study were to (1) evaluate the liver damage and carcass weight of cattle naturally infected with Fasciola hepatica from the state of Rio Grande do Sul (RS), Brazil, and to (2) determine the distribution of adult flukes in 12,236 cattle liver from RS. The data from these experiments were used to calculate the overall economic loss due to F. hepatica infection. Eighteen adult Polled Hereford cows were divided into a triclabendazole (TbG) and a F. hepatica-positive group (FhG). For Experiment 1, a generalized linear mixed model revealed a statistical difference in carcass weight (49.8 kg) between TbG and FhG. The Monte Carlo analysis also revealed that the animals' weight differences were due to the disease. For Experiment 2, the prevalence of infected livers was above 16% (1904/12,236), mostly (20.1%) from the south-west region of RS. The Susceptible-infected-recovered (SIR) epidemic model revealed the evolution of the infection using a high infectivity and low recovery rate. Other distinctive scenarios that occur in RS were also established with different rates of infectivity. The economic assessment showed a potential loss of US$45 million to the beef cattle industry of RS, with an overall State cost of US$90.3 million. These novel findings reveal the importance of fasciolosis infection, which can cause a significant health condition and poor animal welfare.

Bulk tank milk ELISA to detect IgG1 prevalence and clustering to determine spatial distribution and risk factors of Fasciola hepatica-infected herds in Mexico

Fasciola hepatica is a helminth parasite that causes huge economic losses to the livestock industry worldwide. Fasciolosis is an emerging foodborne zoonotic disease that affects both humans and grazing animals. This study investigated the associations between climatic/environmental factors (derived from satellite data) and management factors affecting the spatial distribution of this liver fluke in cattle herds across different climate zones in three Mexican states. A bulk-tank milk (BTM) IgG1 enzyme-linked immunosorbent assay (ELISA) test was used to detect F. hepatica infection levels of 717 cattle herds between January and April 2015. Management data were collected from the farms by questionnaire. The parasite's overall herd prevalence and mean optical density ratio (ODR) were 62.76% and 0.67, respectively. The presence of clustered F. hepatica infections was studied using the spatial scan statistic. Three marked clusters in the spatial distribution of the parasite were observed. Logistic regression was used to test three models of potential statistical association from the ELISA results using climatic, environmental and management variables. The final model based on climatic/environmental and management variables included the following factors: rainfall, elevation, proportion of grazed grass in the diet, contact with other herds, herd size, parasite control use and education level as significant predictors. Geostatistical kriging was applied to generate a risk map for the presence of parasites in dairy herds in Mexico. In conclusion, the spatial distribution of F. hepatica in Mexican cattle herds is influenced by multifactorial effects and should be considered in developing regionally adapted control measures.

Bulk tank milk prevalence and production losses, spatial analysis, and predictive risk mapping of Ostertagia ostertagi infections in Mexican cattle herds

This study investigated the prevalence, production losses, spatial clustering, and predictive risk mapping in different climate zones in five states of Mexico. The bulk tank milk samples obtained between January and April 2015 were analyzed for antibodies against Ostertagia ostertagi using the Svanovir ELISA. A total of 1204 farm owners or managers answered the questionnaire. The overall herd prevalence and mean optical density ratio (ODR) of parasite were 61.96% and 0.55, respectively. Overall, the production loss was approximately 0.542 kg of milk per parasited cow per day (mean ODR = 0.92, 142 farms, 11.79%). The spatial disease cluster analysis using SatScan software indicated that two high-risk clusters were observed. In the multivariable analysis, three models were tested for potential association with the ELISA results supported by climatic, environmental, and management factors. The final logistic regression model based on both climatic/environmental and management variables included the factors rainfall, elevation, land surface temperature (LST) day, and parasite control program that were significantly associated with an increased risk of infection. Geostatistical kriging was applied to generate a risk map for the presence of parasite in dairy cattle herds in Mexico. The results indicate that climatic and meteorological factors had a higher potential impact on the spatial distribution of O. ostertagi than the management factors.

Prevalence of liver flukes infections and hydatidosis in slaughtered sheep and goats in Nishapour, Khorasan Razavi, Iran

Background:

Food-borne trematode infections and hydatidosis are endemic diseases caused by helminths in Iran that are responsible for great economic loss and getting public health at risk.

Aim:

Aim of this study was to determine the prevalence of fasciolosis, dicrocoeliasis, and hydatidosis infections in slaughtered sheep and goats in Nishapour, Khorasan Razavi province of Iran.

Materials and Methods:

A survey was implemented on 130,107 sheep and goats slaughtered at an abattoir in Nishapour (Neyshbur) city, north central Khorasan Razavi Province, Iran, to determine the prevalence of fascioliasis, dicrocoeliosis and presence of hydatidosis.

Results:

During a 1-year period of study, among 130,107 of sheep and goats slaughtered at Nishapour abattoir, 1064 and 7124 livers were condemned totally and partially, respectively. A total of 255 (0.19%), 181 (0.12 %), and 7751 (5.95%) of livers were condemned due to cysts of Echinococcus granulosus, flukes of Fasciola spp., and Dicrocoelium dendriticum, respectively. Totally, 1932 (1.48%) lungs were condemned due to hydatidosis. The significant seasonal pattern was seen for fasciolosis, dicrocoeliosis, and hydatidosis, statistically (p<0.01).

Conclusion:

According to this study, it seems that Neyshabour is considered as an endemic region for Fasciola spp. and D. dendriticum infections and D. dendriticum is the most widespread liver fluke found in sheep and goats.

Fasciola hepatica infection in water buffalo Bubalus bubalis in three provinces of the Nile Delta, Egypt: a cross-sectional study

A cross-sectional study was conducted to estimate the prevalence of Fasciola hepatica (F. hepatica) infection in water buffalo (Bubalus bubalis) in Alexandria, Beheira, and Kafr el-Sheikh governorates (provinces) of the Nile Delta in Egypt and to identify the underlying risk factors associated with the infection. A total of 29 farms (10 in Alexandria, 10 in Beheira, and 9 in Kafr el-Sheikh) were randomly selected and all the buffaloes that resided on these farms from 21 February 2015 to 20 February 2016 were included in the study. The sampling approach was target-based where all the buffaloes were examined and screened for clinical signs of Fasciola infection. All suspected buffaloes were then subjected to fecal examination, and those positive for Fasciola eggs underwent antibody testing using indirect hemagglutination test. Consequently, data on 3,356 buffaloes from 29 farms in these governorates was analyzed using a multiple logistic regression model. The final model showed that the age and body condition score of the buffalo, location and type of the farm, application of prophylactic treatment, and temperature and relative humidity of the farm’s location significantly affected the rate of infection. The highest prevalence was observed in buffaloes from Alexandria governorate (19.6%), followed by Beheira and Kafr el-Sheikh governorates (15.5 and 9.1%, respectively).

A retrospective survey of liver flukes in livestock based on abattoir data in Kermanshah, west of Iran

A retrospective study was carried from 2008 to 2013 to estimate the prevalence of liver flukes in ruminants slaughtered at the abattoir of Kermanshah province, west of Iran. A total of 663,633 animals slaughtered in the 5-year period and totally 1.95 % of livers were condemned due to liver flukes. Fasciolosis were responsible for 0.8, 0.7 and 1.5 % of liver condemnations, whereas 1, 0.8 and 1 % of liver were condemned because of Dicrocoelium dendriticum infection in the sheep, goats and cattle, respectively. A significant difference in the prevalence of liver flukes were observed among studied animals (p < 0.001) and the highest and lowest prevalence were detected in cattle and goats, respectively. Data showed significant seasonal pattern for distomatosis in sheep and goat (p < 0.001). Liver condemnations due to fasciolosis were prevalent in sheep and goats and cattle slaughtered during winter, summer and autumn, respectively, whereas dicrocoeliosis were common in autumn season for sheep and cattle and in winter for goats. This survey provides baseline data for the future monitoring of these potentially important parasitic infections in the region.

An analysis of seroprevalence and risk factors for parasitic infections of economic importance in small ruminants in Greece

A cross-sectional serological survey was carried out to screen the small ruminants of Thessaly, Greece, for infection with Haemonchus contortus, lungworms (i.e. Cystocaulus ocreatus, Muellerius capillaris, Protostrongylus rufescens and Neostrongylus linearis) as a group, and for Cysticercus tenuicolis, Linguatula serrata and Oestrus ovis. A second objective was to determine the risk factors related to herd characteristics, management practices, farmer status and bioclimatic variables associated with these parasitic infections. A total of 361 sheep and 179 goat serum samples were examined. The seroprevalences were 33.9%, 41.5%, 14.1%, 4.6% and 1.4% for H. contortus, lungworms, L. serrata, C. tenuicolis and O. ovis, respectively. The final logistic regression model showed that farm location and temperature were associated with H. contortus, lungworm and L. serrata infections. Anthelmintic treatment, class of anthelmintic and rotation of grazing were associated with H. contortus and lungworm infections, while grazing with other herds was associated with lungworm and L. serrata infections; rain was associated with H. contortus and L. serrata infections. Farm type and age of farmer were associated with H. contortus infections and elevation was associated with lungworm infection. The results may help to formulate appropriate control strategies in Greece and other areas with similar climatic conditions in order to channel limited resources to mitigate only those risk factors which are significant to protect the profitability of the livestock industry.

Seroprevalence and GIS-supported risk factor analysis of Fasciola hepatica infections in dairy herds in Germany

A total of 20 749 bulk tank milk (BTM) samples was collected in November 2008 from all over Germany, corresponding to 20·9% of all German dairy herds. The BTM samples were analysed for antibodies against Fasciola hepatica using the excretory–secretory (ES) ELISA. A geospatial map was drawn to show herd prevalences per postal code area. Various spatial risk factors were tested for potential statistical associations with the ELISA results in logistic regression supported by a geographical information system (GIS). The mean seroprevalence was 23·6% and prevalences in different German federal states varied between 2·6% and 38·4%. GIS analysis revealed statistically significant positive associations between the proportion of grassed area and water bodies per postal code area and positive BTM ELISA results. This can be explained by the biology of the intermediate host, the amphibious snail Galba (Lymnea) truncatula and the pasture-borne nature of fasciolosis. The full logistic regression model had a Pseudo-R2 of 22%, while the final model obtained by controlled stepwise model building revealed a Pseudo-R2 of 14%, indicating that additional, unrecorded factors and random effects contributed substantially to the occurrence of positive ELISA results. Considering the high seroprevalences in some areas and the economic impact of fasciolosis, farmers and veterinarians should be strongly advised to implement effective liver fluke control programmes.