Bovine fasciolosis: prevalence, effects of treatment on productivity and cost benefit analysis in five districts of Punjab, Pakistan

Molecular Characterization and Phylogenetic Analysis of Fasciola gigantica Based on ITS-1 Genetic Marker and copro-epidemiological Survey from Ruminants of Pakistan

PURPOSE

Fascioliasis is a zoonotic parasitic disease spread by genus Fasciola that causes considerable health and economic losses to both humans and livestock. Pakistan is an endemic region for fascioliasis and only a few molecular studies have been conducted to describe the etiology of disease in the country.

METHODS

Current study involved the molecular characterization of adult fluke specimens (n = 31) through ITS-1 region of rDNA collected from four host species (sheep, goats, cattle and buffaloes) of district Sargodha. Moreover, coprology based epidemiology (n = 28620) and association of different risk factors with disease prevalence was also determined. Additionally, an overview of prevalence of fascioliasis in Pakistan, including molecular studies in the four provinces and livestock species, was also carried out.

RESULTS

The phylogenetic analysis revealed that Fasciola gigantica was the main etiological agent infecting the livestock species of this region. The coprological survey revealed an overall prevalence of 30.18% among the livestock species (sheep = 32.31%, goats = 30.67%, cattle = 31.01%, buffaloes = 25.23%). It was inferred that females were slightly more susceptible to infection (32.59%) and that the older age group had higher infection rate (34.01%) in all the host species.

CONCLUSION

The current study suggests that fascioliasis is a disease of primary concern indicating its status as one of the prevalent diseases affecting livestock in this region. It was also concluded that both Fasciola gigantica and Fasciola hepatica existed among the infected animals in addition to presence of hybrid/intermediate form in Pakistan with F. gigantica as dominant species in Punjab province.

Prevalence and risk factors of fasciolosis in a bovine population from farms in Taiping, Malaysia

Fasciolosis is a zoonotic disease, considered an emerging neglected tropical disease threatening ruminant productivity and causing economic losses. Controlling fasciolosis is challenging due to the complex life cycle of Fasciola, which involves snail intermediate hosts. The high rainfall status in Taiping makes it an optimal region for snail abundance, which increases the opportunity to complete Fasciola's life cycle. Previous studies showed that liver condemnation caused by fasciolosis was highly prevalent in the Taiping abattoir compared to other investigated main abattoirs of Peninsular Malaysia. Therefore, the present study determined the prevalence of bovine fasciolosis and risk factors in farms from Larut and Matang (Taiping), Malaysia. Sampling was carried out from February until August 2020. In this cross-sectional study, a total of 371 fecal samples from bovines (dairy cattle, beef cattle, buffalo) were examined from 23 farms selected based on location, farmer consent, and history of anthelmintic usage. Animal's intrinsic and farm management details were recorded, and interview sessions were conducted with farmers to collect information on the potential risk factors. Individual fecal samples were examined for the presence of Fasciola egg using Flukefinder® sedimentation. There was moderate prevalence of bovine fasciolosis in Taiping (36.9%, n = 137/371). Significant risk factors (p < 0.05) were observed, which include buffalo group (OR = 9.5, 95% CI: 9.44-9.55), age of >3 years (OR = 5.5, 95% CI: 5.43-5.57), thinner animals with body condition score of 1 to 4 (OR = 1.2-14.9, 95% CI: 1.09-15.08), and larger grazing area (OR = 1.3, 95% CI: 1.30-1.31). Additional risk factors include the presence of more than one ruminant species in the same farm (OR = 2.0-2.1, 95% CI: 2.00-2.22), extensive housing system (OR = 4.0, 95% CI: 3.77-4.23), farm age (OR = 1.2, 95% CI: 1.20-1.21), and also co-infection with Paramphistomes (OR = 1.4, 95% CI: 1.10-1.71). The present study underscores the importance of local bovine fasciolosis epidemiology, which could be used to conduct future veterinary and public health programmes to inform effective parasitic management aimed at reducing the prevalence of fasciolosis.

Diversity, prevalence and risk factors associated to gastrointestinal tract parasites in wild and domestic animals from Pakistan

The gastrointestinal tract (GIT) of animals contains various helminth parasites, responsible for subclinical and clinical parasitism. The health situation of animals is seriously affected by these parasites and leads massive financial losses for the livestock trade. The present study was conducted to determine the prevalence and associated risk factors of GIT parasites in small and large ruminants of Mardan district and zoo animals of Golden Life Safari Park Khyber Pakhtunkhwa. A total of 419 fecal samples were collected including 117 from goats, 110 from cattle, 80 from sheep, 66 from buffaloes, 40 from birds, four from deer, and two from leopards. The fecal samples were subjected to sedimentation and floatation to identify parasite eggs. Of a total of 419 fecal samples, 215 (51.31%) were found positive for GIT parasites eggs. The prevalence of GIT parasites was high in sheep (65%), followed by goats (62.39%), cattle (42.70%), and buffaloes (37.87%). In birds, GIT parasite eggs were identified in 11 (45.83%) and 7 (43.75%) fecal samples of Pheasant and Peacock, respectively. However, an absence of infection was noted in fecal samples from deer and leopards. Eggs of GIT Parasites belonging to one superfamily and four different genera were recognized in fecal samples of domestic animals and buffaloes, which were Trichostrongyloidea (19.81%), Strongyloides (9.31%), Trichuris (7.77%), Monezia (6.44%), and Fasciola (4.53%). For bird, the coccidia group comprises the highest representation of parasites (2.63%), followed by the Trichuris genus (1.67%). Settlement, management system, anthelminthic medications and body condition score were significantly associated with the occurrence of GIT parasites in feces (P < 0.05). Animals from rural settlements, rearing under poor management systems, with thin (poor) body condition and under warmed were more affected by GIT parasites. The diversity and the high prevalence of GIT parasites reported in this study highlights the urgent need for intervention through treatment and modification of management practices in the investigated areas of Pakistan.

Molecular Characterization of Fasciola hepatica in Sheep Based on DNA Sequences of Ribosomal ITS-1

Introduction

World Health Organization (WHO) considers Fascioliasis as a neglected tropical disease that requires global efforts for disease control. Data from the genetic characterization of Fasciola population shed light on the spread of infections among animals which could help in the development of effective parasite control. The aim of the present work was to genetically characterize Fasciola adult worms isolated from sheep in Saudi Arabia by sequence analysis of ITS-1 region.

Methods

A total of 12,653 slaughtered sheep in Jeddah city, Saudi Arabia were examined for the presence of Fasciola spp. adult worms. The ITS-1 region of all parasites was amplified and sequenced.

Results

Overall, 12 variants DNA sequences were obtained. The variance of isolates ranged from 0.00771 to 0.34405. BLAST search showed that all obtained sequences were Fasciola hepatica and had >99.3% similarity with F. hepatica isolates from Spain and USA (from different hosts other than sheep). Phylogenetic analysis showed that Fasciola isolates were closely related to isolates from different countries.

Discussion

The current study showed that F. hepatica was the only spp. isolated from sheep in Jeddah. Further studies from different localities in Saudi Arabia are needed to help in the development of disease control.

Study on Cattle Trematodiasis and Related Risk Factors in Damot Sore District, Wolaita Zone, Southern Ethiopia

Trematodes are chronic, debilitating diseases in livestock, causing significant economic losses worldwide. From mid-December 2021 to May 2022, a cross-sectional study was carried out in the Damot Sore District to estimate the prevalence of trematode infections in cattle and associated risk factors. Trematode eggs were found in 100 of the 384 faecal samples tested, with an overall prevalence of 26.04% (95% CI: 21.88-30.69%). The prevalence for Fasciola, Paramphistome, and Schistosoma species were 12.50%, 5.21%, and 0, respectively. Moreover, the infection rate with two parasites was 8.33%. The data were then examined further using univariable and multivariable logistic regression analysis. As a result, age was the only potential predictor identified to influence trematode infections in cattle among the potential predictors considered. Furthermore, old cattle were more likely to be infected with trematodiasis nearly 12 times (OR = 11.5) that of young cattle, and this difference was statistically significant (p < 0.05), whereas other risk factors considered were statistically insignificant (p > 0.05). According to the findings of this study, cattle trematodiasis is a moderately common disease in the study area. As a result, additional research on the meteorological conditions of snail infection was forwarded, along with other points to reduce the disease problem in livestock production.

Fasciolosis in the Mediterranean island of Corsica (France): Insights from epidemiological and malacological investigations

Fasciolosis is a re-emergent parasitic disease of worldwide significance with a major global impact on livestock health and production. In the French Mediterranean island of Corsica, fasciolosis has been recognized for a long time but little is known about its dynamic as the main investigations are outdated. Three compartments - definitive domestic hosts, intermediate hosts and environment - involved in fasciolosis transmission were studied by applying an integrative and extensive approach: (1) farm and abattoir surveys, (2) snail sampling, identification and infection prospection, and (3) snail habitat analysis; and (4) a questionnaire-based survey to inquire about husbandry practices and environmental risks. Our results indicate a significant circulation of the liver flukes in Corsican livestock, with 90% (252/279) of the sampled farms testing positive for anti-F. hepatica antibodies. At the abattoir, 46% (67/149) of cattle were positive for F. hepatica antibodies and eggs were present in the bile of 19% (26/139) bovines. In addition, high prevalence of Dicrocoelium dendriticum (69%) was observed in slaughtered cattle. Malacological surveys registered the occurrence of several lymnaeid species in a variety of habitats throughout the island. In particular, we report for the first time the presence of the invasive lymnaeid snail Pseudosuccinea columella in Corsica, a potential intermediate host for F. hepatica. We also found that the presence of Galba truncatula and, to a lesser extent, that of Peregriana peregra, is associated with altitude. Fasciola hepatica DNA was detected in the latter species occurring at two different sites. Finally, a questionnaire-based study revealed risky management practices among Corsican farmers, low perception of transmission and a suboptimal use of flukicide treatments as main control strategy. Our results show that animal fasciolosis in Corsica is characterised by a significant circulation and a favourable epidemiological scenario for transmission to occur.

Copromicroscopic study of gastrointestinal parasites in captive mammals at Central Zoo, Lalitpur, Nepal

BACKGROUND

Zoological gardens (Zoo) provide abode to various threatened animals or trafficked animals seized by the authorities, and injured and orphaned animals. Captive animals are more susceptible to infection as they are under significant stress due to diet and space which further dwindle their resistance to parasitic infections.

OBJECTIVES

This study was conducted to determine the prevalence and burden of gastrointestinal parasites in captive mammals housed at Central Zoo.

METHODS

Fresh faecal samples from three orders of mammals including carnivora (n = 24), rodentia (n = 28) and artiodactyla (n = 35) were examined by direct smear, faecal floatation and sedimentation techniques, and the McMaster technique was applied to quantify parasite eggs per gram (EPG)/oocysts per gram (OPG) of a faecal sample.

RESULTS

One or more parasite taxa were detected in 19.54% of the examined samples and five types of GIPs including one protozoon (Eimeria spp.) and four helminths (Strongyloides spp., Haemonchus spp. and Trichostrongylus spp. and hookworm) were recorded. The protozoan prevalence (6.89 %) was lower than helminths (12.64%). The Eimeria spp. was the most prevalent parasite (6.89%) with the highest OPG (427.77 ± 25.45SD) in spotted deer (Axis axis), and the highest prevalence was noticed among artiodactyla (34.28%) followed by carnivora (12.5%) and rodentia (7.14%). Artiodactyla had both single infection (25.71%) and double (8.57%) infection. The percentage of single infection (16.09%) was found to be higher than double infection (3.44%) among the captive mammals. The wild boar (Sus scrofa) had the highest EPG of 383.33 ± 76.37SD (Strongyloides spp.), while the spotted deer had the lowest EPG of 216.66 ± 76.37SD (hookworm).

CONCLUSIONS

Despite careful management practices, the parasitic infection may be attributed to the narrow enclosure, group housing and environmental contamination. The present finding provides baseline information on the parasitic infection in captive mammals, and can be used by zoo managers for the better life of captive animals.

Prevalence of Fascioliasis in Livestock and Humans in Pakistan: A Systematic Review and Meta-Analysis

Fascioliasis is a parasitic infection that affects both livestock and humans. Understanding the distribution of Fasciola spp. can help the development of preventive measures to control fascioliasis. This systematic review and meta-analysis aimed to estimate the status of fascioliasis among livestock and humans in Pakistan between 2000 and 2020. Based on the selection criteria, 25 articles were selected from Google Scholar, PubMed, and Scopus. This review included 76,099 animals, including 13,738 that were positive for fascioliasis. The overall prevalence was 18.1%; it was 0.3% in humans and 20.1% in livestock. Among animal hosts, the prevalence was highest in sheep (53.5%), followed by the goats (44.9%), cows (21.3%), buffaloes (16.8%), cattle (12.7%), and humans (0.3%). Sindh had the highest prevalence at 42.7%, followed by Baluchistan (25.2%), Punjab (17.7%), Khyber Pakhtunkhwa (10.7%), and Islamabad capital territory (1.5%). In the Punjab province, sheep had the highest prevalence (65.7%); in Khyber Pakhtunkhwa, it was buffalo (15.9%); and in Baluchistan, it was cows (28.5%). The prevalence of Fasciola spp. was higher in Sindh and Baluchistan than in the other provinces. The presented results are essential for developing preventive approaches for the management of human health and minimizing economic loss in the livestock industry in Pakistan. Preventive-curative treatments two times a year followed by a prophylactic treatment at the end of the dry season are crucial throughout the areas of Pakistan that serve as hotspots for infection by Fasciola sp. For humans, regular, prioritized surveys must be performed for high-risk populations so that the real situation can be assessed and addressed in a timely manner.

Risk factor analysis for the prevalence of gastrointestinal parasites found in large ruminants in Lower Dir Khyber Pakhtunkhwa Pakistan

The present study was designed to investigate the prevalence of gastrointestinal (GI) parasites in cattle and buffaloes of Lower Dir Khyber Pakhtunkhwa, Pakistan. The presence of the eggs, cysts, and oocysts of GI parasites in fecal samples were detected using direct smear methods and concentration techniques including floatation, centrifugation, and sedimentation. Identification of recovered fecal stages were determined by morphology using size and appearance of the recovered eggs, cysts, and oocysts. A total of 314 fecal samples were collected from the different Tehsils (Administrative Districts) and analyzed through microscopy. A higher prevalence was observed in the buffalo than the cow population. A total of 184 samples were positive for GI parasites of which 109/196 (55.61%) were from cattle, whereas 75/118 (63.55%) were from buffaloes. The minimum number of strongyle eggs detected in all the samples were 136.39 eggs/g (EPG). The mean EPG in cattle was 143.30 and 122.56 in buffaloes. The open-source water prevalence of GI parasites was higher than the other sources in cattle and the second highest after tap water in buffaloes. The seasonal prevalence of GI parasites ranged from 32.39% (23/71), in spring to 68.8% (86/125) in summer in cattle. In was For buffaloes the infection prevalence was 52.94% (27/51) and 71.64% (48/67) in spring and summer, respectively. Gastrointestinal parasites are a serious problem in cattle and buffaloes in the lower district of Dir Khyber Pakhtunkhwa Pakistan. In general, the burden of parasitic infection was low in most animals that received previous anti-parasitic treatment.

High-throughput sequencing of Fasciola spp. shows co-infection and intermediate forms in Balochistan, but only Fasciola gigantica in the Punjab province of Pakistan

Fasciola gigantica and Fasciola hepatica are digenetic trematodes causing fasciolosis in ruminants. The host and geographical distribution of both Fasciola species are influenced by environmental and climatic conditions favouring survival and development of free-living stages and intermediate hosts, and livestock management practices. The aim of the present study was to describe the host distribution of the two Fasciola species in buffalo, cattle, goats, and sheep in the Balochistan and Punjab provinces of Pakistan. 359 flukes were collected from a total of 32 livers from the four livestock species. Deep amplicon sequencing of the internal transcribed spacer region 2 of ribosomal DNA (rDNA ITS-2) and mitochondrial nicotinamide adenine dinucleotide dehydrogenase 1 (mtDNA ND-1) loci confirmed co-infection of F. hepatica and F. gigantica in Balochistan and single species F. gigantica infection in Punjab. In Balochistan, co-infections and hybrids of both Fasciola species were identified in cattle, with more F. hepatica detected than F. gigantica. However, F. hepatica was the only species identified in goats, and F. gigantica was the only species identified in buffalo. In Punjab, all flukes were confirmed as F. gigantica in each of the four livestock species. Overall, the results indicate differences in the host and geographical distribution of F. gigantica and F. hepatica, and provide useful knowledge for the development of control strategies for livestock and humans.

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.

Milk As a New Diagnostic Tool for Rapid Detection of Fascioliasis in Dairy Goats Using Excretory/Secretory Antigen

PURPOSE

Fascioliasis is a serious livestock illness of particular importance for dairy goats; the objectives of this study were to describe effects of F. gigantica on milk composition and to use this information to estimate economic damages linked with Fasciola spp. infections. Furthermore, the study sought to standardize the use of milk instead of serum for early diagnosis of fascioliasis in dairy goats.

METHODS

One-hundred samples of goat milk along with corresponding blood samples were obtained at random from flocks in Cairo and Giza Governorates. The ELISA and DOT-ELISA were performed in both serum and milk of dairy goats.

RESULTS

Total mesophilic count (mean value) was 2.12 × 10⁶ ± 1.63 × 10⁵ CFU/ml in enzyme-linked immunosorbent assay (ELISA) positive samples and 1.46 × 10⁴ ± 8.58 × 10² CFU/ml in ELISA-negative samples. The mean values were significantly different (P < 0.05). The mean values of percentages of fat, SNF, protein, salts, lactose, pH, and MSCC/ml in ELISA-positive samples were 2.3 ± 0.17, 8.21 ± 0.63, 3.08 ± 0.18, 0.90 ± 0.06, 3.64 ± 0.28, 6.93 + 0.53, and 1.18 × 10⁶ ± 9.07 × 10⁴ cells/ml, respectively. A significant difference (P < 0.05) between the mean values of two composition parameters, i.e., percent of fat and MSCC/ml in ELISA-positive and -negative samples, for Fasciola gigantica was observed. The antigen used for the diagnosis of F. gigantica was excretory/secretory (E/S) antigen. The dilutions of (E/S) concentrations after checkerboard titration for indirect ELISA were 20 μg/ml protein and for dot-ELISA, 300 ng/μl. Sera dilution was 1:100 in the two tests, and milk dilution was 1:50 for indirect ELISA, and 1:25 for dot-ELISA. The two tests were performed using known F. gigantica positive and negative goat sera and known rat hyper immunized negative and positive sera against E/S antigen of F. gigantica as well as known sera for paramphistomes without F. gigantica infection. The cutoff values in indirect ELISA were 0.45 for sera and 0.35 for milk.

CONCLUSION

The application of different serological technique in goat farms reveals a good test in rapid diagnosis of fascioliasis especially the uses of dot ELISA when using the milk instead of the serum.

The First Report of Ruminant Fascioliasis in Sabah, East Malaysia

Ruminant fascioliasis is a neglected yet important tropical zoonotic disease that affects both the livestock and humans. The disease has a worldwide distribution, and Malaysia is one of the countries that face problems related to this parasite. These retrospective studies were conducted in Makmal Diagnosa Veterinar Kota Kinabalu (MDVKK) and Sabah Meat Technology Centre (SMTC), Kinarut over a period of eleven years (2008–2018). For MDVKK, the overall occurrence of fascioliasis was 24.9%. Out of 769 cattle's and buffaloes' faecal samples submitted, Fasciola spp ova were detected in 189 of the samples. A total of 2297 cattle, buffaloes, and goats were slaughtered at SMTC over that period, and 21 livers were condemned due to fascioliasis, giving the total occurrence of 0.91%. This investigation provides information on the occurrence of ruminant fascioliasis in Sabah, East Malaysia. The results from this study highlight the alarming incidence of fascioliasis and the urgent need for action to control this neglected tropical disease in East Malaysia.

Towards the comprehension of fasciolosis (re-)emergence: an integrative overview

The increasing distribution and prevalence of fasciolosis in both human and livestock are concerning. Here, we examine the various types of factors influencing fasciolosis transmission and burden and the interrelations that may exist between them. We present the arsenal of molecules, 'adjusting' capabilities and parasitic strategies of Fasciola to infect. Such features define the high adaptability of Fasciola species for parasitism that facilitate their transmission. We discuss current environmental perturbations (increase of livestock and land use, climate change, introduction of alien species and biodiversity loss) in relation to fasciolosis dynamics. As Fasciola infection is directly and ultimately linked to livestock management, living conditions and cultural habits, which are also changing under the pressure of globalization and climate change, the social component of transmission is also discussed. Lastly, we examine the implication of increasing scientific and political awareness in highlighting the current circulation of fasciolosis and boosting epidemiological surveys and novel diagnostic techniques. From a joint perspective, it becomes clear that factors weight differently at each place and moment, depending on the biological, environmental, social and political interrelating contexts. Therefore, the analyses of a disease as complex as fasciolosis should be as integrative as possible to dissect the realities featuring each epidemiological scenario. Such a comprehensive appraisal is presented in this review and constitutes its main asset to serve as a fresh integrative understanding of fasciolosis.

Prevalence of Fascioliasis and Associated Economic Losses in Cattle Slaughtered at Lira Municipality Abattoir in Northern Uganda

Fascioliasis (liver fluke infestation) is one of the most important parasitic diseases affecting cattle, other ruminant animals and humans. Fascioliasis causes large, but usually neglected, economic losses to cattle farmers and traders. The objectives of this study were to assess the prevalence and associated risks for fascioliasis in slaughter cattle and estimate the financial losses due to liver condemnation at the Lira Municipal abattoir in Uganda. A total of 216 cattle were sampled during the study period. Animal breed and sex were determined by observing the phenotypic characteristics of the animals. Age was determined by assessing the eruption and wearing of permanent teeth. After slaughter, the liver was examined for presence of Fasciola spp. (liver flukes) by visual inspection, palpation, and incisions. The bile ducts and gall bladder were similarly examined for presence of mature Fasciola spp. The gross weight and amount of liver trimmed-off due to fluke infestation were determined. Of the 216 liver examined, 65.7% (n = 142) were infested with Fasciola spp. Cattle that were aged 4-5 years old at the time of slaughter had significantly greater odds (OR = 5.84; CI [2.79-12.22]) of being infested with Fasciola spp. compared to those that were younger than 3.5 years old. In contrast, cattle that had a body condition score of 3.5 or 4 had lower odds (OR= 0.42; CI [0.21-0.88] and OR = 0.22; CI [0.04-1.10]) of fascioliasis than those with a BCS of 3. Other tested variables including animal origin, breed, sex, and gross weight of the liver had no significant effect on the prevalence of fascioliasis. This study also revealed that the abattoir loses an estimated 38 million UGX annually due to condemnation of Fasciola-infested liver (one UGX= 0.00027 USD; July 2016). Our study showed that the prevalence of fascioliasis was high in Lira District, Uganda, which results in a large amount of liver being condemned and destroyed, leading to financial losses for affected farmers in the area. Therefore, there is a need to take the necessary preventive measures to control the disease and increase awareness among farmers and medical personnel in the area due to the zoonotic nature of fascioliasis.

Selective flukicide treatment of non-lactating cows and the corresponding production impact of Fasciola hepatica in dairy herds in Sweden

A control strategy against Fasciola hepatica infection based on selective treatment of non-lactating animals was evaluated in four Swedish dairy herds. The study was conducted over the course of two consecutive seasons in moderately to highly F. hepatica infected herds with robotic milking, where heifers and dry cows received an oral drench with albendazole (10 mg/kg) during three visits in January, February and March in both 2017 and 2018. This resulted in an anthelmintic coverage between 38 % and 58 % of the animals. Furthermore, on each visit, the infection status of all dewormed animals along with 15 randomly selected milking cows were monitored by detection of F. hepatica coproantigens. Individual milk samples were also collected quarterly from the whole herds for measurements of individual antibody levels against the parasite using milk ELISA. In addition, individual data on milk yield and quality were collected on a monthly basis between 2016 and 2018. To further study the impact of the infection on milk production, truly F. hepatica positive and negative cows in the first lactation were identified based on the results from coproantigen and milk ELISA assays. Total F. hepatica coproantigen prevalence in the herds varied between 28 % and 85 % in the first year, and between 27 % and 68 % in the second year of the study. We found that two years of treatments resulted in a significant decrease of coproantigen-positivity especially on the two most heavily infected farms. These results were confirmed by a similar drop in within-herd prevalences obtained by milk ELISA results. The infection had a significant negative impact on milk yields in untreated F. hepatica positive cows. No consistent long-term effect was observed at the herd level probably due to the influx of animals infected before puberty and/or adult animals that were re-infected at dry-off. This is the first study of the effects of F. hepatica infection on milk yield and quality in dairy herds in Sweden.

Economic impact of the liver condemnation of cattle infected with Fasciola hepatica in the Peruvian Andes

Fasciolosis is a zoonotic food- and waterborne infection related to great economic losses on ruminant production. In order to determine the prevalence of bovine liver condemnations due to fasciolosis in an abattoir at the Central Andes of Peru, we evaluated the records of an authorized slaughterhouse in Huancayo, at 3300 m above sea level, over 16 months. Subsequently, the average weights of condemned viscera and carcasses were also estimated to determine the direct and indirect economic losses. Fasciolosis was the main cause of liver condemnation, with a prevalence of 55.72% (3926/7046; CI 95%: 56.88-54.56%). The livers infected were more than double the amount of livers supplied to markets in this period. Although the average price of liver in the Peruvian Andes is very cheap, approximately 16.45 tons of livers were destroyed, estimating a direct economic loss of US$ 35,080 (CI 95%: US$ 29,178-40,938). The indirect loss due to decreased body weight gain (calculated using 10% of the average weight of a healthy animal carcass) was estimated at US$ 354,570 (CI 95%: US$ 387,908-US$ 321,227). Fasciolosis is an important zoonotic disease that threatens food security in the Andean region, with major repercussions on the income of the livestock industry and the availability of cheap protein sources.

Prevalence of Bovine Fasciolosis and Its Economic Loss due to Liver Condemnation at Wolaita Sodo Municipal Abattair, Ethiopia

Fasciolosis is a serious animal health problem in Ethiopia where cattle raising is very important to the local economy. A cross sectional study was carried out from November 2018 to February 2019 to estimate the prevalence of bovine fasciolosis and its associated risk factors as well as financial losses due to liver condemnation. A total of 247 cattle consisting of 219 males and 28 females were randomly selected and fecal sample collection for Fasciola egg detection and postmortem liver inspection for adult liver flukes, were done. From the total of 247 cattle examined, the overall prevalence of bovine fasciolosis in the study area was 16.6% and 20.24% by coprological and postmortem examinations, respectively. The livers and bile ducts were examined for the adult flukes and the result showed that F. hepatica was frequently detected Fasciola sp. (72%) than F. gigantica (28%). In the study area, the prevalence of bovine fasciolosis between sex was significantly different (p < 0.05) with higher prevalence was recorded in female (57.1%) than male (15.5%). There was also significant association (p < 0.05) among different age groups for the prevalence of bovine fasciolosis with the highest prevalence in older (40.1%) than younger (18.8%) age groups. But, regarding origin and body condition the prevalence of bovine fasciolosis was not significantly associated (p > 0.05). The annual direct financial losses incurred due to fasciolosis were estimated around 1,505, 856 ETB ($43, 024.458). In conclusion, bovine fasciolosis is prevalent and economically important disease in the study area. Therefore, implementation of control and prevention strategy like, grazing managements, reducing the population of the intermediate host, diagnosis and treating sick animals using anthelmintic, is mandatory.

High prevalence, potential economic impact, and risk factors of Fasciola hepatica in dairy herds in tropical, dry and temperate climate regions in Mexico

The aims of this study were to determine the prevalence of fasciolosis in cattle herds and its influence on production in order to identify potential risk factors in different climate regions and risk indices in three states of Mexico. The levels of anti-F. hepatica IgG1 antibodies were determined using an indirect ELISA. A total of 837 farm owners or managers answered the questionnaire. The total prevalence of the parasite over the period of January to March 2017 was 63.56%. The highest percentages of positive herds for the categories were found in Hidalgo state (88.33%), the no-risk classification (69.55%) and the temperate climate (76.53%). Overall, the production losses were approximately 0.51 to 1.00 kg of milk per parasitized cow per day. The annual costs of milk production loss per farm were estimated to range from US$2218.39 to US$6424.51, followed by anthelmintic treatment for young stock (US$67.68) and adult cows (US$209.47). Using multivariate logistic regression analysis, six final models were constructed for potential association with the ELISA results and were supported by the climatic, environmental and management factors. The results indicate that different factors were significantly associated with an increased risk of infection for each model.

Cross-sectional prevalence of Fasciola gigantica infections in beef cattle in Botswana

A cross-sectional study was carried out to determine the prevalence and distribution of Fasciola gigantica infections in communally grazed and ranch-grazed beef cattle through coprological examination. A total of 8646 cattle (4618 adults, 2843 weaners and 1185 calves) faecal samples were collected during the 24 months of study. Results from this study indicated that only 64 (0.74%; 95% CI 0.57, 0.94%) of the samples were positive for F. gigantica eggs. The positive samples were detected in one (Central) of the six study districts and was restricted to the Tuli Block (commercial) farms in Machaneng village in eastern Botswana. The prevalence of fluke eggs was significantly higher in adult cattle (12.85%; 95% CI 9.72, 16.54%) than weaners (6.49%; 95% CI 3.40, 11.06%) and calves (0.79%; 95% CI 0.02, 4.31%), (χ²(2) = 19.01, p < 0.001). Thus, adults (OR = 18.57; 95% CI 2.54, 135.81%) were approximately 20 times more likely to be infected than calves. By taking liver inspection as a gold standard for diagnosis of fasciolosis, the sensitivity of the sedimentation technique was found to be 72.41% and the specificity 100%, with moderate relationship (κ = 0.53; 95% CI 0.31-0.75) between the two methods. This study has demonstrated that infection of cattle from Botswana, with F. gigantica, was low and distribution of the fluke appeared to be linked to suitable environmental conditions for the intermediate host snail. However, detailed surveillance studies, involving more cattle and areas, are required to verify the true prevalence. Such information would assist in the design of appropriate, strategic and effective fluke control programmes.

Domestic water buffaloes: Access to surface water, disease prevalence and associated economic losses

Given the shortage and non-availability of freshwater in Pakistan, wastewater is being used for bathing water buffaloes; however, this has a negative impact on animal welfare. Although there is a vast literature on indirect linkages between wastewater and animal productivity, studies focusing on the direct impacts of water buffaloes bathing in wastewater on animal productivity and economic losses are rare. Therefore, using 360 domestic water buffalo farms, this study examines the expenditure and production losses associated with bathing (in wastewater and freshwater) and non-bathing water buffaloes by employing partial budgeting and resource adjustment component techniques. Furthermore, it investigates the prevalence of animal diseases and associated economic effects using correlation analysis and propensity score matching techniques, respectively. The findings reveal that compared to their counterparts (freshwater bathing and non-bathing water buffaloes), buffaloes bathing in wastewater are at increased risk of clinical mastitis, foot and mouth disease (FMD) and tick infestation. Moreover, the use of wastewater for bathing buffaloes also leads to higher economic and production losses by affecting milk productivity, causing premature culling, and reducing slaughter value. The findings of the double-log model show that economic losses are higher if buffaloes bathe in wastewater within 30 min after milking, as there are more chances that those buffaloes would be exposed to bacterial penetration in the teat ducts, which may result in intramammary infection. According to the propensity score matching method, the higher economic damages per month are associated with buffaloes bathing in wastewater and freshwater, 155 and 110 USD per farm, respectively. The study findings reference the need for policies to restrict wastewater access by water buffaloes, and a regular check of and access to cool clean water wallows for bathing during hot summer days, to reduce excess heat and economic losses, and thus improve animal welfare.

Trematode infections in farm animals and their vector snails in Saint Martin's Island, the southeastern offshore area of Bangladesh in the Bay of Bengal

The prevalence of snail-borne trematode (SBT) infections in farm animals on the offshore Saint (St.) Martin’s Island of Bangladesh were 68.9% for cattle, 76.7% for buffaloes, 56.3% for goats, respectively. Examination of fecal samples showed that paramphistomes infection was the most common at 50.5% followed by schistosomes at 23.7% and Fasciola at 2.3%. Fasciola infection was found in cattle (1.9%) and buffaloes (16.7%) but not in goats. Schistosome infection in cattle, buffaloes and goats were 31.1, 6.7 and 17.5%, respectively. Prevalence of SBTs was higher in older animals. Thiara tuberculata (Melanoides tuberculata) were found to serve as vector for paramphistomes and Indoplanorbis exustus for schistosomes and paramphistomes, respectively. Our results suggest that SBT and their vector snails are highly endemic on St. Martin’s Island of Bangladesh, and proper attention is needed to control these infections.

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).

Anthelmintic Drugs: Their Efficacy and Cost-Effectiveness in Different Parity Cattle

Gastrointestinal nematodes are responsible for economic losses in bovines and are characterized by reduced milk production, decreased working efficiency, and even death. In our study, the effect of different anthelmintic treatments on nematode control in different parity cattle (Friesian crossbreds) at calving and their effect on milk yield were evaluated. The economics of anthelmintics and farm benefits in terms of increased milk production after deworming was also calculated. We screened cattle of first and second parity for nematodes. Animals were randomly selected in each group. In first parity animals, there were 23 positive cattle found, which were divided into 3 different groups, while in second parity animals there were 20 positive cattle which were also divided into 3 groups. For treatment of gastrointestinal nematodes, we used albendazole (velbazine) at 10 mg/kg body weight and levamisole (Nilverm®) at 7.5 mg/kg. In this study, both drugs were found effective in controlling nematode infections in cattle. Percentage reduction of eggs per gram (EPG) by albendazole was 48.20, 85.34, and 93.90% and 51.54, 81.43, 91.74% on day 7, 14, and 21 in first and second parity animals, respectively. Percentage reduction of EPG by levamisole was 44.45, 76.92, and 88.03% and 46.60, 73.78, 85.43% on day 7, 14, and 21 in first and second parity animals, respectively. The average increase in milk production in albendazole-treated groups was 0.39 and 0.92 L per day while increases in levamisole treated groups were 0.27 and 0.55 L per day in first and second parity cattle, respectively. After treatment, albendazole increased the milk fat by 0.07 and 0.1% while levamisole decreased by 0.02 and 0.05% in first and second parity cattle, respectively. It is concluded that anthelmintic treatments of recently calved cattle have a significant effect on milk production due to the nematode control. Milk production increased significantly in second parity cattle following anthelmintic treatment as compared to first parity animals. Levamisole had a negative effect on fat concentration in cattle while albendazole-treated cattle showed a positive effect. Albendazole has been found more efficient in reducing EPG of helminths in both parity animals as compared to levamisole-treated animals while the cost-benefit ratio of levamisole was greater than albendazole.

Epidemiology of bovine fascioliasis in the Nile Delta region of Egypt: Its prevalence, evaluation of risk factors, and its economic significance

Aim

This study focuses on the risk factors associated with the prevalence of Fasciola affecting cattle population in three provinces belonging to the Nile Delta of Egypt and to estimate the economic losses as a result of fascioliasis.

Materials and Methods

From January 2015 to end of December 2015, records of 21 farms (4976 cattle) were analyzed to screen the prevalence of fascioliasis among cattle farms, to identify its associated risk factors and its economic impacts on Nile Delta region of Egypt.

Results

The overall prevalence of fascioliasis in the Nile Delta region of Egypt was 9.77%. The prevalence of fascioliasis was found to be statistically significantly associated with age, sex, breed, and type of farms. The highest prevalence was observed in <2 age group (10.91%), and the lowest was >3 age groups (8.35%). In terms of body condition scores, cattle with medium and poor conditions were associated with fascioliasis more than those with good body condition. Besides, cattle raised in organic farms were associated with lower risk of fascioliasis than those in conventional farms. The prevalence of fascioliasis was noted more prominent in districts with moderate temperatures and with relative humidity (>60%). The annual overall costs for fascioliasis were estimated to be 221.2 USD/cow due to the significant reduction in body weight, reduction in milk production, and the treatment costs for fascioliasis.

Conclusion

The results provided could be helpful for improving the control and preventive strategies.

Environmental factors associated with Dictyocaulus viviparus and Fasciola hepatica prevalence in dairy herds from Costa Rica

Dictyocaulosis and fasciolosis are parasitic diseases that cause considerable economic losses for owners of farm animals worldwide, with special relevance on fasciolosis because it is an emerging zoonosis. Indirect diagnosis of these diseases through analyses of bulk milk tank samples has allowed carrying out large-scale prevalence studies, while the use of geographical information systems has helped to visualize and determine those variables that affect distribution of these pathogens. This study is intended to describe the spatial distribution of Dictyocaulus viviparus and Fasciola hepatica in dairy herds from Costa Rica, as well as their associated environmental factors. Bulk milk tank samples from 526 dairy herds in the three most important dairy regions of Costa Rica were analyzed using enzyme immunoassays. Results from the farms were subjected to spatial analyses using Holdridge's life zones, relief and soil type environmental layers. Of the total bulk milk tank samples analyzed, 3.8% (n=20) and 3.6% (n=19) were positive for D. viviparus and F. hepatica, respectively. Moran's I analysis revealed the existence of potential cluster (Moran's I=1.789, z=12.726 p<0.05) for D. viviparus. Consequently, Getis-Ord General G analysis showed that the spatial distribution of positive farms in the dataset was clustered (Observed General G=0.015, variance=0.000001, z=12.823, p<0.05). No significant positive spatial autocorrelation (Moran's I=0.038, z=0.286, p>0.0.5) was observed for F. hepatica. Furthermore, a significant difference was detected in the spatial locations of both parasites (latitude p<0.05, longitude p<0.05), and about the spatial distribution of both D. viviparus negative and positive farms (latitude p<0.05, longitude p<0.05), as well as in F. hepatica negative and positive farms regarding on latitude (p<0.05), but not on longitude (p>0.05). In the case of environmental factors, significant differences were found for D. viviparus and F. hepatica with respect to types of soil, precipitation, altitudinal belts, life zones, biotemperature, and elevation.

Bovine fascioliasis risk factors and space-time clusters in Mymensingh, Bangladesh

A hospital-based case-control study was undertaken to identify risk factors for - and space-time clusters of - bovine fascioliasis in Mymensingh, Bangladesh. Fascioliasis cases diagnosed using fecal sample test between January 2006 and December 2015 (n=593) at the Bangladesh Agricultural University Veterinary Teaching Hospital (BAUVTH) and three controls per case (n=1563) were selected. Data on date of report, location, age, breed, sex and body weight were extracted from the hospital records. A mixed multivariable logistic regression model with location as a random effect was built to identify risk factors for fascioliasis. The scan statistic (Bernoulli model) was used to identify space-time clusters. Compared to cattle ≤1year of age, the odds of fascioliasis were 5.2- (95% confidence interval [CI]: 3.6-7.4), 6.1- (95% CI: 4.2-8.7) and 10.7-times (95% CI: 6.9-16.6) greater in cattle aged >1-3, >3-8 and >8years, respectively. The odds of fascioliasis were 1.4- (95% CI: 1.03-1.99) and 1.5-times (95% CI: 1.13-2.11) greater in post-monsoon and monsoon seasons, respectively, compared to winter. Five significant (P<0.05) clusters (7-13 locations each) were identified, lasting from six months to 5years. Six locations - Bhangnamari, Deuhakhola, Gauripur, Ishwarganj, Nandail and Rasulpur - appeared to be at more risk for fascioliasis: these locations were part of at least 3 significant clusters. Anthelmintic treatment should focus on high risk age groups (>1year, especially those >8years). Importantly, we have demonstrated high-risk periods (monsoon and post-monsoon) and disease hotspots of bovine fascioliasis. Focusing disease control efforts in time and space offers an opportunity to more effectively control bovine fascioliasis in Bangladesh and in other similar geo-climatic zones throughout the world.

The use of wastewater in livestock production and its socioeconomic and welfare implications

Although epidemiological studies have found a significant amount of toxins in surface water, a complex link between animals' access to wastewater and associated animal and human welfare losses needs to be explored. The scarcity of safe water has put stress on the utilization of wastewater for crops and livestock production. The access of animals to wastewater is related to the emergence of dangerous animal's diseases, hampering productivity, increasing economic losses, and risking human health along the food chain. This review explores use of wastewater for agriculture, epidemiological evidence of microbial contamination in wastewater, and animal and human welfare disruption due to the use of wastewater for crop and livestock production. More specifically, the review delves into animals exposure to wastewater for bathing, drinking, or grazing on a pasture irrigated with contaminated water and related animal and human welfare losses. We included some scientific articles and reviews published from 1970 to 2017 to support our rational discussions. The selected articles dealt exclusively with animals direct access to wastewater via bathing and indirect access via grazing on pasture irrigated with contaminated wastewater and their implication for animal and human welfare losses. The study also identified that some policy options such as wastewater treatments, constructing wastewater stabilization ponds, controlling animal access to wastewater, and dissemination of necessary information to ultimate consumers related to the source of agricultural produce and wastewater use in animal and crop production are required to protect the human and animal health and welfare.

A review on epidemiology, global prevalence and economical losses of fasciolosis in ruminants

Fasciolosis is an important plant borne trematode zoonosis in ruminants caused by the Fasciola hepatica and Fasciola gigentica, It is classified as a neglected tropical disease and found in more than 50 countries especially where sheep and cattle are reared. Fasciolosis is a serious animal health problems in many rural and urban areas of world, causing significant financial losses due to decrease in production and viscera condemnation in animals. Accurate diagnosis of fasciolosis is always remained a challenging task for the field practitioners. There is no comprehensive summary on the occurrence and distribution of the infection at international level. Therefore, we intended to provide a complete overview on the prevalence and epidemiology of fasciolosis in farm animals from a global prospective. It includes to map the global distribution of fasciolosis in different areas of the world to identify the endemic regions which may be a source of potential disease outbreak. The financial liability related to fasciolosis on the livestock production has also been addressed. For this purpose, the published data during 2000-2015 (15 years) on fasciolosis was reviewed and collected by electronic literature search of four databases including Google, PubMed, Science Direct, and Web of Science. Data presented are contemplated to enhance our current understanding of the parasite's geographical distribution, host range, and economic losses. Information provided would be useful for the application of more effective control strategies against fasciolosis in different geo-economics regions of the world.

Associations between fasciolosis and milk production, and the impact of anthelmintic treatment in dairy herds

Liver fluke is a ubiquitous parasite that causes extensive production losses in cattle and is a zoonosis. The aims of this study were to determine the prevalence of fasciolosis in 178 dairy cattle herds in Styria (federal state of Austria) and its influence on production, to detect the risk factors for infection, and to explore effective strategies in management and control. A questionnaire on farm management, prophylaxis, and therapy was developed and applied. Furthermore, production parameters (milk yield, milk protein content, butter fat content, non-return rate 90, calving to conception interval, service period) were recorded for 2014 and 2015, and a commercial ELISA for detection of Fasciola hepatica antibodies was applied in bulk tank milk in March 2014 and March 2015. Analysis of bulk tank milk samples showed a prevalence of 61.3% in 2014 and 45.5% in 2015. No associations could be found between F. hepatica exposure and farm structure or pasture management. Farms with highly positive (optical density ratio (ODR) ≥ 0.6 and lying above the upper interquartile range) antibody levels had a significantly lower annual milk yield of 438 kg per cow per year (p = 0.045), butterfat content of 0.091% (p = 0.004), and milk protein content of 0.046% (p = 0.024). However, fertility parameters were not significantly associated with liver fluke exposure. Anthelmintic treatment led to significantly lower antibody levels in the subsequent year (p = 0.042) and had a significant influence on protein content in milk (p = 0.003). This study highlighted the importance of fasciolosis in Austria and its influence on milk production and the need for veterinary advice regarding prophylactic measures to reduce economic losses.

Fascioliasis risk factors and space-time clusters in domestic ruminants in Bangladesh

Background

A retrospective observational study was conducted to identify fascioliasis hotspots, clusters, potential risk factors and to map fascioliasis risk in domestic ruminants in Bangladesh. Cases of fascioliasis in cattle, buffalo, sheep and goats from all districts in Bangladesh between 2011 and 2013 were identified via secondary surveillance data from the Department of Livestock Services’ Epidemiology Unit. From each case report, date of report, species affected and district data were extracted. The total number of domestic ruminants in each district was used to calculate fascioliasis cases per ten thousand animals at risk per district, and this was used for cluster and hotspot analysis. Clustering was assessed with Moran’s spatial autocorrelation statistic, hotspots with the local indicator of spatial association (LISA) statistic and space-time clusters with the scan statistic (Poisson model). The association between district fascioliasis prevalence and climate (temperature, precipitation), elevation, land cover and water bodies was investigated using a spatial regression model.

Results

A total of 1,723,971 cases of fascioliasis were reported in the three-year study period in cattle (1,164,560), goats (424,314), buffalo (88,924) and sheep (46,173). A total of nine hotspots were identified; one of these persisted in each of the three years. Only two local clusters were found. Five space-time clusters located within 22 districts were also identified. Annual risk maps of fascioliasis cases correlated with the hotspots and clusters detected. Cultivated and managed (P < 0.001) and artificial surface (P = 0.04) land cover areas, and elevation (P = 0.003) were positively and negatively associated with fascioliasis in Bangladesh, respectively.

Conclusions

Results indicate that due to land use characteristics some areas of Bangladesh are at greater risk of fascioliasis. The potential risk factors, hot spots and clusters identified in this study can be used to guide science-based treatment and control decisions for fascioliasis in Bangladesh and in other similar geo-climatic zones throughout the world.

Direct and indirect effects of wastewater use and herd environment on the occurrence of animal diseases and animal health in Pakistan

The use of wastewater for rearing domestic animals is a common phenomenon in most of the developing countries like Pakistan that face a serious shortage of freshwater resources. However, most of the literature has only focused on the indirect effects of wastewater use on animal health or productivity, and literature on the direct effects of wastewater use is rare. Therefore, this study aims to investigate the direct and indirect effects of wastewater usage on the prevalence of animal diseases and animal health in Pakistan. The study is based on a household-level survey of 360 domestic water buffalo herds collected from 12 districts of Punjab Province, Pakistan. We tested the prevalence of the animal's diseases, animal's health, and wastewater-use preference with various econometric tools, such as the Poisson, negative binomial, and logistic regressions. The findings of the study show that the majority of the farmers use wastewater for buffalo bathing due to the shortage of freshwater resources. Results explore the prevalence of diseases such as clinical mastitis, tick infestation, and foot and mouth disease at the farm level significantly associated with buffalo bathing in the wastewater. Moreover, bathing in wastewater pre- and post-milking also plays a role in the occurrence of diseases. Particularly, if the buffalo's access to wastewater for bathing is within 60 min after milking, the probability of the animals being exposed to mastitis is higher. Furthermore, on investigation, a number of factors are found, such as the distance to the water source, power shortage, groundwater availability, and the education of farmers that influence farmers' behavior of letting their animals take a bath in wastewater. Moreover, the use of different preventive measures improves the animal's health.

Epidemiology and impact of Fasciola hepatica exposure in high-yielding dairy herds

The liver fluke Fasciola hepatica is a trematode parasite with a worldwide distribution and is the cause of important production losses in the dairy industry. The aim of this observational study was to assess the prevalence of exposure to F. hepatica in a group of high yielding dairy herds, to determine the risk factors and investigate their associations with production and fertility parameters. Bulk milk tank samples from 606 herds that supply a single retailer with liquid milk were tested with an antibody ELISA for F. hepatica. Multivariable linear regression was used to investigate the effect of farm management and environmental risk factors on F. hepatica exposure. Higher rainfall, grazing boggy pasture, presence of beef cattle on farm, access to a stream or pond and smaller herd size were associated with an increased risk of exposure. Univariable regression was used to look for associations between fluke exposure and production-related variables including milk yield, composition, somatic cell count and calving index. Although causation cannot be assumed, a significant (p<0.001) negative association was seen between F. hepatica exposure and estimated milk yield at the herd level, representing a 15% decrease in yield for an increase in F. hepatica exposure from the 25th to the 75th percentile. This remained significant when fertility, farm management and environmental factors were controlled for. No associations were found between F. hepatica exposure and any of the other production, disease or fertility variables.

Serological and coprological analyses for the diagnosis of Fasciolagigantica infections in bovine hosts from Sargodha, Pakistan

A serological and coprological survey of fasciolosis was conducted in bovine hosts from the Sargodha district, Pakistan using excretory–secretory (ES) antigens of Fasciola gigantica from cattle and buffaloes. Livers, faecal and blood samples of 146 cattle and 184 buffaloes were collected from slaughterhouses and examined for the presence of any Fasciola in bile ducts and ova in faeces. Serum was separated. ES antigens were prepared by incubating adult Fasciola in phosphate-buffered saline for 6–8 h and then filtering using a 0.22-μm syringe filter. Checkerboard titration was performed and optimum concentrations of antigen and serum were determined. Sero-prevalence was found to be 50.00 and 38.35% in buffalo and cattle, respectively. Using liver examination as the gold standard, enzyme-linked immunosorbent assay (ELISA) sensitivity was found to be 100% in both buffalo and cattle as compared with that of coprological examination in buffalo (61.79%) and cattle (54.54%). This indigenous ELISA was also highly specific, with values of 96.84 and 98.90% in buffalo and cattle, respectively. Positive predictive values were calculated as 96.74 and 98.21% in buffalo and cattle, respectively, while negative predictive values were 100%. For the validation of indigenous ELISA in field surveys, faecal and blood samples were collected from six sub-districts (tehsils) in the district of Sargodha. Sera were screened for the presence of anti-fasciola antibodies using both the indigenous and commercial ELISA kits. While both kits were equally sensitive, the indigenous ELISA was found to be more specific. The highest prevalence of fasciolosis was found in December, as ascertained using both serological and coprological examination. Significant differences were found in prevalences of fasciolosis in different sub-districts and age groups, together with feeding and watering systems.

Study on prevalence of Fasciolosis in buffaloes at Anand and Ahmedabad districts, Gujarat, India

Aim:

This study was undertaken to derive the prevalence rate of Fasciolosis in buffaloes by a collection of fecal and liver samples from Anand and Ahmedabad districts’ local slaughter houses.

Materials and Methods:

Fecal and liver samples were collected during ante- and post-mortem examination, respectively, and brought to the department laboratory preserved in 10% formalin for further processing. Fecal samples were processed with qualitative examination viz.; sedimentation technique for identification of the ova. Liver samples were also examined for the presence of gross parasites.

Results:

The highest prevalence rate was observed in the month of December (25.97% fecal and 33.33% liver samples) and lowest in the month of May (10.71% fecal and 11.76% liver samples) at Anand district. In the area of Ahmedabad district, the highest prevalence rate was recorded in the month of October and February (26.98%) and lowest in the month of May (10.34%) for the fecal and highest prevalence was observed in the month of February (26.98%) and lowest in May (11.11%) for the liver samples.

Conclusion:

It can be concluded that the heavy infection is present in Anand and Ahmedabad districts, especially in the month of winter followed by monsoon and the least in summer.

Molecular evidence shows that the liver fluke Fasciola gigantica is the predominant Fasciola species in ruminants from Pakistan

Fascioliasis is an important disease affecting livestock, with great costs to producers worldwide. It has also become a serious issue for human populations in some endemic areas as an emerging zoonotic infection. There are two Fasciola species of liver fluke responsible for this disease, which occur worldwide, Fasciola hepatica and Fasciola gigantica. Identifying these two species on the basis of adult or egg morphology requires specialist knowledge due to the similarity of characters, and may misidentify putative intermediate or hybrid forms. In this study we sequenced the internal transcribed spacer 2 (ITS-2) rDNA of liver flukes collected from multiple species of hosts from seven localities in the Punjab and Baluchistan provinces of Pakistan, to determine the distribution of these two species. All 46 flukes processed in this study, collected from seven sites, showed the rDNA ITS-2 genotype corresponding to F. gigantica, contradicting previous reports, based on adult and egg morphology, that both species are present in Pakistan, with F. hepatica being the more common.

In vitro tegumental alterations on adult Fasciola gigantica caused by mefloquine

Emergence of drug-resistant Fasciola strains has drawn the attention of many authors to alternative drugs. The purpose of this study is to explore the in vitro effect of the antimalarial mefloquine against adult Fasciola gigantica. Light and scanning electron microscopic observations could be used to determine the target of the drug following 6 and 12 h of incubation in medium containing mefloquine at three different concentrations 10, 20 and 30 μg/mL, as morphological changes could be observed. These changes occurred in definite sequences in response to mefloquine, and were consisted of swelling, vacuolization that was later disrupted, leading to desquamation of the tegument, resulting in exposure and disruption of basal lamina and the dislodging of spines. It is concluded that mefloquine presented itself as a drug that might become important in trematode chemotherapy, with the tegument being an important drug target.

Distribution of bovine fasciolosis and associated factors in south Espírito Santo, Brazil: an update

The geographical distribution and factors associated with bovine fasciolosis in the south of Espírito Santo were updated and the prevalences of this disease and of snails of the genus Lymnaea in the municipality of Jerônimo Monteiro were calculated. In the first stage, fecal samples were collected from 10% of the herds of 115 farms in 23 municipalities and interviews were conducted with owners. Generalized linear mixed models were used. In the second stage, in Jerônimo Monteiro municipality, feces and mollusks were collected from all farms registered in the milk cooperatives in the region. The mollusks were identified and examined for infection by Fasciola hepatica. Fasciolosis was diagnosed in 18 (78%) of the 23 municipalities. Of the 1157 fecal samples examined, 19.01% were positive for eggs of F. hepatica. The final model shows statistical evidence of associations between positive farms and previous cases of fasciolosis and concomitant grazing of cattle with other definitive hosts. In the evaluated farms from the studied municipality the prevalence of fasciolosis and Lymnaea was of 66.7% and 23.8%, respectively. Mollusks were found in flooded areas and the animals' drinking water troughs. The wide geographical distribution of bovine fasciolosis in the south of Espírito Santo requires control measures to prevent its expansion towards the north of this state and other places characterized as F. hepatica free-infection.

Diversity of flora used for the cure of equine diseases in selected peri-urban areas of Punjab, Pakistan

BACKGROUND

Plants have widely been used and documented for their therapeutic potential in many parts of the world. There are, however, few reports on the use of plants for the treatment of diseases of equines. To this end, participatory epidemiology and rapid rural appraisal techniques were used to document the plants having pharmacotherapeutic significance against different ailments of equines in selected population of Punjab, Pakistan.

METHODS

A survey was conducted to interview a total of 450 respondents (150 from each of the districts of Faisalabad, Lahore and Sargodha of Pakistan) to collect information about disease recognition of the equines and their treatment on a well - structured questionnaire. A total of 60 plants belonging to 40 families were documented. An inventory was developed depicting detailed information of plants used in treatment of different conditions of equines.

RESULTS

The top ten species of plants used were: Allium cepa, Zingiber officinale, Vernonia anthelmintica, Capsicum annum, Brassica campestris, Trachyspermum ammi, Anethum graveolens, Picrorhiza kurroa, Azadirachta indica, and Citrullus colocynthis. Seeds were the most frequently used (n = 16/60) parts, followed by leaves (n = 12/60) and fruits (n = 11/60) of plants. Based on the combination of different parts of plants used in different ratios and variation in their dose or mode of preparation led to a large number of recipes/remedies against wounds, lameness, bronchitis, colic, anorexia, dermatitis, weakness, parasitism (internal and external), fever, heat stress, urine retention, swelling, toxemia, and indigestion.

CONCLUSIONS

This study generated lot of data on phytomedicinal approach for the treatment of ailments in the equines in some selected areas. It would, therefore, be imperative to expand similar studies in other parts of Pakistan and elsewhere. Moreover, use of the documented plants may be validated employing standard scientific procedures, which may have their application in the drug discovery/development by the pharmaceutical industry.

Phenotypes of intermediate forms of Fasciola hepatica and F. gigantica in buffaloes from Central Punjab, Pakistan

Fascioliasis is an important food-borne parasitic disease caused by the two trematode species, Fasciola hepatica and Fasciola gigantica. The phenotypic features of fasciolid adults and eggs infecting buffaloes inhabiting the Central Punjab area, Pakistan, have been studied to characterize fasciolid populations involved. Morphometric analyses were made with a computer image analysis system (CIAS) applied on the basis of standardized measurements. Since it is the first study of this kind undertaken in Pakistan, the results are compared to pure fasciolid populations: (a) F. hepatica from the European Mediterranean area; and (b) F. gigantica from Burkina Faso; i.e. geographical areas where both species do not co-exist. Only parasites obtained from bovines were used. The multivariate analysis showed that the characteristics, including egg morphometrics, of fasciolids from Central Punjab, Pakistan, are between F. hepatica and F. gigantica standard populations. Similarly, the morphometric measurements of fasciolid eggs from Central Punjab are also between F. hepatica and F. gigantica standard populations. These results demonstrate the existence of fasciolid intermediate forms in endemic areas in Pakistan.

The global burden of fasciolosis in domestic animals with an outlook on the contribution of new approaches for diagnosis and control

Fasciolosis is an economically important disease for livestock, as well as being zoonotic. Recent figures on the prevalence of this disease have caused alarm concerning its potential for an increased prevalence in the future. The prevalence of fascioliosis has been documented from different regions of the world, helping us identify areas where future research needs to be focused. This manuscript is a review of the current status of the disease, the pathogenic species involved, diagnostic techniques (with new modifications and comparative specificity, sensitivity, and rapidity of these tests), chemotherapy, and vaccination. This also encompasses inaccurate reports on vaccination and drug development as well as the latest technologies to find promising candidates for drugs and vaccines. Drugs with lower efficacy have been used on some farms which lead to exacerbation of the clinical disease, presumably due to the development of drug resistance. Future studies should be focused on (1) the use of the most reliable diagnostic tests for periodic monitoring of the disease, (2) insights of the ecobiology and transmission dynamics of the snail intermediate host and the best possible methods of their control, (3) in vitro and in vivo testing of chemotherapeutic compounds using sensitive methods, and (4) the identification of novel drug and vaccine candidates using modern molecular markers. This approach may help increase the reliability of chemotherapeutic agents and control nuisance, ultimately reducing the economic losses attributable to the livestock industry around the world.

Investigating the impact of fasciolosis on cattle carcase performance

Liver fluke is a manifestation of bovine fasciolosis and its presence is compulsorily investigated as part of routine official abattoir inspections. It is known that the presence of fasciolosis negatively influences beef production, interfering with weight gain and fertility. Recent reports suggest increased occurrence of this parasite worldwide. This paper aims to investigate the impact of fasciolosis on beef cattle performance by examining the association of liver fluke with carcase characteristics and its value. Cattle slaughtered between 2005 and 2010 (328, 137 cattle (of which 12.6% were positive to liver fluke) sourced from 2278 farms) are analysed adjusting for the effect of gender, age, breed, season and year. Carcases with liver fluke have lower cold weight than those carcases free of fluke, estimated coefficient -0.63 kg (95% confidence intervals (CI) -0.93, -0.33). Carcases with liver fluke have lower price than those carcases free of fluke, estimated coefficient -£1.5 (95% CI -2.24, -0.74). The presence of liver fluke is associated with lower carcase conformation scores compared to carcases with fluke absence, proportional odds ratio (POR) 0.89 (95% CI 0.87-0.91). Similarly, the presence of liver fluke is associated with lower levels of fat in the carcase compared to carcases with fluke absence, POR 0.97 (95% CI 0.95-0.99). These results indicate a potential negative effect of the parasitism on carcase performance. The downgrading of the carcase impacts its value and therefore the price paid to the farmer. Both farmers and abattoir operators share a common interest in the control of fasciolosis in order to optimise the profitability of beef production. This study shows the utility of abattoir post-mortem inspection as a tool to monitoring animal health and production.

Prevalence of Fasciola in cattle and of its intermediate host Lymnaea snails in central Vietnam

The aims of this study were to investigate the prevalence of natural Fasciola infections in both the definitive hosts (cattle) and the intermediate hosts (Lymnaea snails) in central Vietnam. A total of 1,075 fecal samples, randomly collected from cattle in Binh Dinh, Khanh Hoa, and Phu Yen provinces, were examined for Fasciola eggs by a sedimentation method. The overall prevalence of Fasciola was 45.3 %. A subset of the animals (235) was also screened for antibodies against Fasciola by an enzyme-linked immunosorbent assay. Overall, 46.3 % of these animals were shedding Fasciola eggs while 87.2 % were Fasciola seropositive. A lower prevalence of Fasciola was observed in calves ≤ 2 years of age (37.6 %) compared to that in cattle >2 years of age (53.7 %) (p < 0.05). The prevalence in the rainy season (50.8 %) was significantly different to that in the dry season (38.1 %) (p < 0.05). Of the 3.269 Lymnaea viridis and 1.128 Lymnaea swinhoei examined, 31 (0.95 %) and seven (0.62 %), respectively, were found to be infected with Fasciola. This appears to be the first epidemiological survey of the prevalence of Fasciola in cattle and snails in these three provinces in central Vietnam.

Estimating the total cost of bovine fasciolosis in Turkey

The aim of this study was to estimate the total cost of bovine fasciolosis under three different scenarios (expected, optimistic and pessimistic scenarios) in Turkey. The weighted mean prevalence of infection was calculated as 1·9% and the financial losses were estimated in US$ at 2010 current prices. The total costs of bovine fasciolosis per infected beef cattle and dairy cow were estimated as 223·7 US$ (201·3-246·1, under optimistic-pessimistic scenarios) and 430·7 US$ (387·6-473·7), respectively. Total cost of the disease was estimated as 7·4 million US$ (6·1-8·8) for beef cattle and 35·4 million US$ (28·9-42·6) for dairy cows. The nation-wide total cost of the disease in Turkey for 2010 was estimated to be 42·8 million US$ (35·1-51·4). Most of the losses arise from reduced meat yield, fertility and milk yield, and smaller losses are due to condemnation of livers and disease control expenditures. As a result, the quantity of these losses may help the farmers and policy makers to give the better decision for controlling and eradication of the animal diseases in Turkey.

Point prevalence of bovine fascioliasis and the influence of chemotherapy on the milk yield in a lactating bovine population from the district of Toba Tek Singh, Pakistan

This paper provides an estimation of the point prevalence of fascioliasis and its economic impact in terms of increased milk yield after chemotherapy of a bovine population from the district of Toba Tek Singh, Punjab, Pakistan. A total of 2400 cattle and buffaloes were examined quantitatively using the McMaster egg-counting technique. Infected cattle and buffaloes (50 of each) were randomly selected and each divided into two groups of 25 animals. Groups A (buffaloes) and C (cattle) were treated with oxyclozanide (orally, 16.6 mg kg− 1 body weight). Groups B and D served as negative controls for buffaloes and cattle, respectively. Pre- and post-treatment milk yield was recorded to determine if there were any changes in milk yield after treatment. Of 2400 faecal samples analysed, 654 (27.25%) were positive for Fasciola spp. with a mean number of eggs per gram (EPG) of 503.2. The point prevalence and worm burden of fascioliasis was significantly higher (OR = 2.13; P < 0.05) in buffaloes (34.58%; 415/1200; mean EPG maximum likelihood = 521.4) as compared to that of cattle (19.92%; 239/1200; mean EPG maximum likelihood = 415.8). Among the parasite species, F. gigantica (19.88%; 477/2400) was predominant (OR = 3.12; P < 0.05) as compared to F. hepatica (7.38%; 177/2400). An average daily increase of 0.67 and 0.87 litres of milk, with 0.41% and 0.37% more fat per animal, was observed in oxyclozanide-treated buffaloes and cattle, respectively. The economic value of reduced production of infected animals was estimated as US$0.33 and 0.32 per animal per day for cattle and buffaloes, respectively.