A review of bovine fasciolosis and other trematode infections in Nigeria

Prevalence of Bovine Fasciolosis, Financial Losses and Risk Factors Associated with the Disease in Lira and Gulu Districts, Northern Uganda

Bovine fasciolosis (BF) is a parasitic disease of cattle that causes significant economic impacts to cattle farmers. The physical loses include weight loss, drop in productivity, liver condemnation and mortalities. This study assessed the prevalence, financial losses and risk factors associated with the disease in Lira and Gulu Districts, northern Uganda. A cross-sectional study of 720 slaughter cattle from the abattoirs was conducted by macroscopic examination of the animals and carcasses during routine slaughter. In the farms, 120 rectal faecal samples were taken to a laboratory for Fasciola egg detection by simple microscopy, while risk factors were assessed by administering a questionnaire to farm owners. Prevalence of BF was highest (38%) within cattle in the age group of 1-3 years and lowest (18%) in those over 5 years. The overall BF prevalence was 48% and 26% by postmortem examination and coprology, respectively. The cattle body condition had a significant association (p < 0.01) with prevalence of BF, in which emaciated cattle were most affected (59%), while fat ones had the least prevalence (15%). The annual financial loss due to BF infection was USD 89,099. The major risk factors associated with the disease at the farm level were communal grazing in swampy areas (82%) and watering cattle in swamps (71%). Farms where the source of drinking water was swamp water had higher chances (p < 0.05) of their cattle having BF. An integrated approach using routine deworming programs, improvement of cattle management practices and control of snail intermediate hosts is recommended to effectively control the spread of BF.

A Systematic Review and Meta-analysis on the Prevalence of Bovine Fascioliasis in Nigeria

OBJECTIVE

Bovine fascioliasis, a parasitic disease caused by Fasciola species, severely affects cattle health and agricultural productivity in tropical regions like Nigeria. It leads to economic losses through liver condemnations, decreased meat and milk production, and increased veterinary expenses. Despite its public health and economic significance, existing data on its prevalence and epidemiological patterns in Nigeria is limited.

METHODS

This systematic review and meta-analysis compiled findings from 40 studies conducted between 1980 and 2024 to evaluate the prevalence and distribution of bovine fascioliasis in Nigeria.

RESULTS

The analysis included 5,174,019 cattle and identified 120,678 infections, with a pooled prevalence of 29% (95% CI: 0.21, 0.38) using a random-effects model. A high level of heterogeneity was noted (I² = 100%, tau² = 0.0893). Subgroup analyses showed a higher prevalence in cross-sectional studies (33%, 95% CI: 0.25-0.42) compared to retrospective studies (18%, 95% CI: 0.04, 0.40). Diagnostic methods notably impacted prevalence estimates, with serological tests reporting 72%, versus 33% for microscopy and 22% for post-mortem examinations. Regional disparities were also evident, with the South-South zone exhibiting the highest prevalence in the country, underscoring the influence of environmental factors.

CONCLUSION

This study reveals the significant burden of bovine fascioliasis in Nigeria and highlights the need for region-specific, evidence-based control strategies. The findings also point to critical gaps in diagnostic standardization and surveillance, underscoring the necessity for improved diagnostic tools and integrated management practices to alleviate the effects of this parasitic disease.

Economic impact of fetal wastage and common diseases, along with their incidence rates and seasonal variations, at an abattoir in FCT, Nigeria

Infectious diseases and fetal wastage (FW) present major challenges in livestock management, particularly in sub-Saharan Africa, including Nigeria. This study assessed the season variations, incidence rate and economic impact of prevalent diseases and FW at the Kubwa (KB) abattoir in the Federal Capital Territory (FCT) of Abuja, Nigeria. Over a year-long period (January to December 2023), we analyzed 5,779 cattle through daily post-mortem inspections. Disease identification was based on morphological and gross lesions characteristic of the conditions studied. Economic losses from condemned organs and FW were calculated using the formula TEL = N × P × W. The results indicated statistically significant seasonal variations in the incidence of Fasciolosis (FS), Paramphistomosis (PP), and FW, with p-values of 2.52x10^-10, 3.33x10^-9, and 0.003, respectively. In contrast, Tuberculosis (TB), Contagious Bovine Pleuropneumonia (CBPP), Dermatophilosis (DM), Abscess (AB), and Moneziasis (MZ) did not show significant seasonal variation. The total economic impact of condemned organs and FW was 104,348 USD (equivalent to 99,130,600 NGN at the time of the study), representing a considerable threat to food security and substantial economic losses for farmers. Considering the zoonotic potential of some diseases, which can be transmitted to those handling the carcasses, there is a critical need for enhanced inspection protocols, continuous disease surveillance, and timely reporting in slaughterhouses. The notable economic losses from condemned organs also underscore the necessity of implementing pregnancy tests for female animals before slaughter to protect food security and support the nation's economy. These findings highlight the essential role of abattoirs in improving food security, detecting zoonotic diseases, and bolstering public health and economic stability in low-income countries.

Cholelithiasis in a goat associated with chronic fascioliosis in Bangladesh: A case report and review of literatures

The objective of the present study was to describe a very rare case of gallstone (cholelithiasis) in a goat associated with chronic fasciolosis. During a routine slaughterhouse-based survey, a two-and-half-year-old female Black Bengal Goat was found to be affected with severe chronic fascioliosis characterized by the massive damage in the liver. Through systemic dissection of liver, we isolated 94 adult Fasciola spp., and by PCR, we confirmed the fluke as Fasciola gigantica. The gallbladder of the goat was oedematous. On opening the gallbladder, we recovered 255 stones of variable sizes. Stones were whitish in colour and friable, and some of the fragile stones were attached to the wall of the gallbladder. To the authors' knowledge, this is the first report of the cholelithiasis in a goat associated with F. gigantica.

Infection Rates of Fasciola Intermediate Host Snail Species and Their Distribution in Africa: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis aimed to collate the infection rates of Fasciola spp. in intermediate host snails and their distribution in Africa. The overall infectivity prevalences of Galba truncatula, Radix natalensis, and Pseudosuccinea columella are 52%, 8%, and 3%, respectively. The intermediate host snails native to Africa (R. natalensis and G. truncatula) have been examined more than the invasive P. columella. The studies included in the review ranged from 1999 to 2022. North Africa has the highest prevalence of G. truncatula, with an infection rate of 52%. The review reveals that naturally infected intermediate host snails (G. truncatula, R. natalensis, and P. columella) are found in various regions of Africa. G. truncatula accounts for 22% (from three countries) of the studies included in the review and it was only found in the North African region with the highest overall infection rate of 52%. More studies on infection rate and distribution are needed to effectively control and prevent future transmissions.

Prevalence of Amphistomes and Fasciola in large ruminants reared by smallholders in Lampung and Banten Provinces, Indonesia

Background and Aim

Parasitic diseases, including trematode invasions, result in losses to livestock in Indonesia, hindering the government's efforts to achieve meat self-sufficiency. This study aimed to estimate the prevalence of Amphistomes and Fasciola in large ruminants reared by smallholder farmers.

Materials and Methods

Fecal samples from 199 buffalo and cattle were collected from the districts of East Lampung (Lampung Province) and Lebak (Banten Province). Fecal samples were examined for the presence of trematode eggs using a sedimentation technique.

Results

Parasite invasion rate was 48.2% (95% confidence interval [CI]: 41.3%-55.2%). Rate of invasion was 63.3% (95% CI: 52.7%-73.9%) in Lampung and 38.3% (95% CI: 29.6%-47.0%) in Lebak-Banten. The prevalence of multiple invasions of both Amphistomes and Fasciola was 20% in buffalo and local cattle, whereas invasion rate was 12.8% in crossbred cattle. Invasion rate of Amphistomes alone was 27.1%, and that of Fasciola was 4.5%. A higher invasion rate of Amphistomes (29.8%) occurred in crossbred animals. There were no significant differences between age groups for trematode invasion. The Chi-square test showed that the prevalence of trematode invasion in females was significantly higher than in males (51.5% and 30.0%, respectively). Amphistomes more commonly infected females than males (29.0% and 16.7%, respectively).

Conclusion

All breeds were vulnerable to invasion by both trematode species and single invasions with different invasion rates. These findings contribute to determining the magnitude of the disease and provide a basis for studies on prevention and treatment of trematode invasion.

Seroprevalence and risk factors of bovine fasciolosis in the municipalities of Colombia

Background and Aim

Bovine fasciolosis is a reemerging neglected disease with a worldwide distribution caused by the trematode Fasciola spp., which parasitize various hosts. Bovine fasciolosis is responsible for large economic losses in the bovine livestock sector. This study aimed to estimate the seroprevalence and risk factors of bovine fasciolosis in the municipalities of Colombia.

Materials and Methods

This was a descriptive cross-sectional study with simple random sampling conducted on 1140 cattle from the municipalities of Chiquinquirá, San Miguel de Sema, and Ubaté for a duration of 3 months. Serum samples were processed using the commercial Fasciola hepatica Antibody Test Kit IDEXX® Fasciolosis Verification (IDEXX, United States), which identified immunoglobulin G antibodies for gf2 antigen purified from Fasciola extracts. The f2 antigen is extremely immunogenic and highly specific for F. hepatica. An epidemiological survey was performed to record variables related to the sampled animals and herd management practices. Data were processed using the statistical program Epi Info® (Centers for Disease Control and Prevention; Atlanta, Georgia). The prevalence ratio was estimated to evaluate the association between fasciolosis and the hypothesized causal factors and the significance of this association using Pearson's Chi-square test. Finally, a logistic regression model was developed.

Results

The overall seroprevalence was 72.3%. The seroprevalence was 83.9% (323/385) in Chiquinquirá, 68.17% (257/377) in Ubaté, and 64.55% (244/378) in San Miguel de Sema. The seroprevalence was higher in male animals in Chiquinquirá and in female animals in San Miguel de Sema and Ubaté. Similarly, sex showed a statistically significant association with disease prevalence in Ubaté. The highest prevalence was found in cattle aged >2 years. The Holstein breed showed maximum seroprevalence in Chiquinquirá (p ≤ 0.05) and San Miguel de Sema, whereas crossbreed showed higher seroprevalence in Ubaté. Similarly, in Chiquinquirá, the association between the seroprevalence of fasciolosis and the presence of other species was statistically significant (95% confidence interval [CI]: 0.9601-3.4944; p = 0.0448). In Ubaté, the disease presentation was also associated with pasture rental (95% CI: 0.4047-1.0023; p = 0.003) and attendance to livestock expositions (95% CI: 0.2313-1.0636; p = 0.044). However, in San Miguel de Sema, water from the stream showed a statistically significant association with disease presentation (95% CI: 0.5209-1.0985; p = 0.00649785). Female sex and diarrhea occurrence were considered risk factors for fasciolosis.

Conclusion

A high seroprevalence of antibodies to Fasciola spp. was detected in cattle in the study municipalities, indicating a high parasite distribution in these areas. Female sex and diarrhea were established as risk factors associated with fasciolosis in Ubaté and San Miguel de Sema, respectively. Further, research is necessary to establish prevention and control programs against parasitosis.

Prevalence of flukes (Fasciola hepatica and paramphistomids) in cattle in south-eastern Mexico

The objective of this study was to determine the risk factors and prevalence of trematodes in south-eastern Mexico. The prevalence of trematodes was determined in 1010 bovines. The study was carried out from October 2018 (n=291) to December 2019 (n=719). Only in 2019 rumen and liver fluke eggs were differentiated. Faecal samples (n=311) were obtained from farms in southeast Mexico located in Tabasco, Chiapas and Campeche. In addition, the presence of flukes in liver and rumen from slaughtered cattle in abattoirs was recorded with a total of 408 samples. A logistic procedure was used to obtain the prevalence and the effect of main risk factors such as land physiography (flooded areas and hills), year, sex, animals' age and type of sample obtained (eggs in faeces and flukes). The general prevalence of flukes in cattle was 32.3 % in 2018 and 41.7 % in 2019. Prevalence of F. hepatica (liver fluke) was 18.6 % (134/719) and that of paramphistomids (rumen fluke) was 33.4 % (240/719). The infected cattle from the slaughterhouse indicated a lower prevalence of F. hepatica (1 %) and rumen fluke (26.7 %) than in farms detected by egg in faeces (41.8 % and 42.1 %, respectively). The physiographic zone was decisive in the presence of F. hepatica and rumen fluke, while sex did not represent a risk factor (P > 0.05). The environmental conditions of the Mexican southeast favour the presence of both liver and rumen fluke.

Human and Animal Fascioliasis: Origins and Worldwide Evolving Scenario

Fascioliasis is a plant- and waterborne zoonotic parasitic disease caused by two trematode species: (i) Fasciola hepatica in Europe, Asia, Africa, the Americas, and Oceania and (ii) F. gigantica, which is restricted to Africa and Asia. Fasciolid liver flukes infect mainly herbivores as ruminants, equids, and camelids but also omnivore mammals as humans and swine and are transmitted by freshwater Lymnaeidae snail vectors. Two phases may be distinguished in fasciolid evolution. The long predomestication period includes the F. gigantica origin in east-southern Africa around the mid-Miocene, the F. hepatica origin in the Near-Middle East of Asia around the latest Miocene to Early Pliocene, and their subsequent local spread. The short postdomestication period includes the worldwide spread by human-guided movements of animals in the last 12,000 years and the more recent transoceanic anthropogenic introductions of F. hepatica into the Americas and Oceania and of F. gigantica into several large islands of the Pacific with ships transporting livestock in the last 500 years. The routes and chronology of the spreading waves followed by both fasciolids into the five continents are redefined on the basis of recently generated knowledge of human-guided movements of domesticated hosts. No local, zonal, or regional situation showing disagreement with historical records was found, although in a few world zones the available knowledge is still insufficient. The anthropogenically accelerated evolution of fasciolids allows us to call them "peridomestic endoparasites." The multidisciplinary implications for crucial aspects of the disease should therefore lead the present baseline update to be taken into account in future research studies.

Body condition scores, fluke intensity, liver pathology, and carcass quality of different dairy cattle genotypes infected with Fasciola species at high throughput abattoirs in South Africa

Milk is an essential commodity whose demand far exceeds supply. However, dairy animal productivity is constantly hampered by parasitic diseases such as fasciolosis, affecting milk production. Despite the negative impact of liver fluke on milk production, there is little information on liver fluke infection and associated abattoir losses (body weight, condition score, liver pathology, and carcass quality) in culled dairy cattle. This study aimed to determine body condition scores, fluke intensity, liver pathology, and carcass quality of different cattle genotypes infected with Fasciola species at three commercial abattoirs. A longitudinal study was conducted from September 2019 to October 2020 to determine body condition score, liver fluke intensity, liver pathology in 3065 dairy cattle slaughtered in CA1, CA2, and CA3, of the Eastern Cape Province South Africa. Liver fluke intensity significantly increased with cattle age (P < 0.0001). Cattle ≥ 7 years old (59.93 ± 6.42) and those 4 to 6 years old (49.78 ± 9.98) had higher infection than those 2 to 3 years old (27.55 ± 13.68). The liver fluke infection was significantly (P < 0.001) the highest when sampling was conducted in summer, followed by autumn and winter, and least for spring. The differences in carcass weights or body condition scores decreased by 0.99 units (P < 0.0001) or 0.97 units (P < 0.0001) respectively. Therefore, this study suggests that fluke infection could be responsible for considerable economic and production losses mainly due to condemnation and weight loss in dairy cattle. This study recommended a combination of holistic and grazing management to control infection rates in dairy herds.

A large-scale epidemiological investigation on trematode infections in small ruminants in Bangladesh

BACKGROUND

The important trematode species in small ruminants: Paramphistomum sp., Fasciola spp. and Schistosoma spp. seriously affect the productivity of domestic ruminants in endemic areas.

METHODS

In the present study, we identified the potential risk factors associated with trematodes infections in small ruminants in seven topographic zones of Bangladesh using simple sedimentation and modified Stoll' ova counting technique.

RESULTS

A total of 2440 samples were examined, where 965 were found positive with one or more trematode species with an overall prevalence of 39.5% (95% CI, 37.6%-41.5%) and intensity of infection was 264.77 ± 9.86 egg per gram of faeces. Three trematode species were identified namely Paramphistomum sp. (34.1%, 32.2%-36.0%), Fasciola spp. (7.5%, 6.5%-8.6%) and Schistosoma spp. (2.7%, 2.1%-3.5%). Prevalence of co-infection was 4.8%. The spatial distribution of trematode infections varied from 29.5% to 53.6%. Univariate analysis revealed that physiological condition of females, body condition, farming system, deworming and season were significantly (p < 0.05) associated with trematodes infections in small ruminants. By multiple logistic regression model, three factors such as physiological condition of females (pregnant and lactating), poor body condition and animals without deworming were identified as potential risk factors for trematodes infection in small ruminants.

CONCLUSION

Trematode infections are prevalent in the study areas and Paramphistomum sp. is most common in different areas among the identified trematodes species. Government should take necessary action to appraise an effective control strategy of trematode infections in small ruminants.

Synergistic action of Viteselen with anti-Fasciola drug as a tool for improving fertility and hemato-biochemical biomarkers in Fasciola infected sheep

Fasciolosis causes public health problems and economic losses all over the world. The present study aimed to evaluate the synergistic action between Viteselen (anti-oxidant) and specific anti-Fasciola drug [Triclalbendazole (TCBZ)] for improving the body condition of F. gigantica naturally infected sheep with reference to some hematological and biochemical biomarkers in their sera. Animals were divided into five groups include G-1 as control non-infected animals, G-2 to G-5 are Fasciola naturally infected animals. G-2 are non-treated animals, G-3 treated with TCBZ, animals in G-4 were injected by Viteselen and those in G-5 were treated by both TCBZ and Viteselen. The results revealed a significant decrease in mean eggs in feces and F. gigantica circulating antigens (FCAg) in sera of TCBZ treated sheep after the 1st week post treatment. Complete disappearance of eggs from feces of drug treated groups was recorded at 21st d.p.t. While the value of FCAg decreased to negative at 14th d.p.t. The highest significant improvement (p < 0.05) in the estimated hematological parameters (RBCs, Hb and TLC), liver enzymes (AST and ALT), oxidative stress and anti-oxidant markers (TAC, MDA, SOD and GSH) and reproductive hormones (Progesterone and Estradiol) was recorded in animals in G-5 followed by G-3. While non-significant improvement was recorded in animals in G-4 in comparison with those in the control group. This improvement increased with increasing the time post treatment. In conclusion; using of Viteselen in association with specific anti-parasitic drug improved the general health parameters and reproductive performance of the investigated sheep.

Assessment of anthelmintic effectiveness to control Fasciola hepatica and paramphistome mixed infection in cattle in the humid tropics of Mexico

The objective of this study was to evaluate the effectiveness of the main anthelmintics used for the control of trematodes in cattle in an endemic area in the humid Mexican tropics. A diagnostic study was carried out in nine cattle farms to determine the prevalence of flukes through faecal examination. Only three farms with more than 20 cows positive to trematodes were chosen to determine the effectiveness of commercial anthelmintics (triclabendazole, TCBZ; ivermectin + closantel, (IVM + CLOS); IVM + clorsulon, (CLORS); nitroxynil, NITROX). The prevalence of Fasciola hepatica was 27.1% and 29.6% of paramphistomes. The faecal egg count of trematodes ranged from 0.0 to 12.2 eggs per gram of faeces. The highest effectiveness against F. hepatica was 96.7%, and 92.7% against paramphistomes. NITROX was the most effective in the control of trematodes, while other products, such as IVM + CLORS and TCBZ obtained values lower than 90%, which puts sustainable trematode control at risk. The presence of trematodes was observed on most farms, although the prevalence per herd was highly variable, which indicates that the trematodes F. hepatica and paramphistomes are endemic to the region and a suitable management programme is suggested to control infections caused by these parasites.

Efficacy of triclabendazole and albendazole against Fasciola spp. infection in cattle in Côte d'Ivoire: a randomised blinded trial

Triclabendazole is the anthelminthic of choice for the treatment of fascioliasis, however, it is only registered in a few countries. We investigated the efficacy of a single-dose of triclabendazole (12 mg/kg) or albendazole (15 mg/kg) against Fasciola spp. infection in cattle on farms in the northern part of Côte d'Ivoire in a randomized clinical trial. Faecal samples were obtained from 196 cattle, of which 155 (79.1%) were found positive for Fasciola spp. by the sedimentation technique. Cattle infected with Fasciola spp. were randomly allocated (3:3:1) to receive triclabendazole (n = 66), albendazole (n = 67) or left untreated to serve as control (n = 22). Follow-up faecal samples were collected on days 21, 28, 90 and 188 post-treatment. No adverse events were observed as reported by farmers in any of the treatment groups. The proportion of non-egg shedding cattle, assessed at day 21 (primary outcome), was significantly higher in cattle treated with triclabendazole (95.4%) compared to those receiving albendazole (70.3%; odds ratio [OR] 8.73, 95% confidence interval [CI] 2.43-31.28, p <0.001). The egg reduction rate (ERR) expressed as number of eggs per gram of faeces, a secondary endpoint assessed at day 21 post-treatment, was significantly higher in the triclabendazole arm (arithmetic mean (AM) ERR = 99.8%) than in the albendazole arm (AM ERR = 92.2%), with a difference of 7.6%-points (95% CI: 0.9-14.5%-points, p=0.026). This is the first report of efficacy of triclabendazole against Fasciola spp. in naturally infected cattle in Côte d'Ivoire. Our results confirm that triclabendazole is the most effective treatment of fascioliasis and therefore, should be considered for the control of livestock fascioliasis; if resources allow in combination with intermediate host snail control and raising farmers awareness of pasture and livestock management to avoid reinfection.

Prevalence of gastrointestinal helminths in ruminants in Ukraine: a 5-year meta-analysis

The production of environmentally friendly livestock products is currently receiving much attention, especially in the European Union. The problem of monitoring the quality and safety of meat and milk in modern conditions is relevant not only for Ukraine but also for the world community. The scientific substantiation of the methods of research on meat for sale subject to invasive diseases is especially important, as the product may pose risks to the consumer. One of the criteria for assessing the welfare of a herd is the prevalence of helminthiases in cattle. Ruminant parasitoses in Ukraine have always been and remain a separate, often significant, problem for veterinary specialists. Helminths have evolved to use a wide range of ecological niches. In this study, we tried to quantify the prevalence of helminthiases among ruminants (cattle, sheep and goats) in Ukraine. The relevant studies were searched for in the online databases. The meta-analysis included 15 publications from January 2015 to December 2020 which reported the spread of parasites in Ukraine. The research results show that the infestation of ruminants with gastrointestinal helminths on the territory of Ukraine is 56.7%. Egger’s regression test revealed no significant publication bias. During the period of pastured farming, stable parasitocenoses are formed in the body of ruminants. The parasitoses are caused by helminths (gastrointestinal strongyles, liver flukes, paramphistomas, dicrocelia). They are recorded in monoinvasions or mixed invasions. Ruminants, according to helminthological examination in different climatic zones, are constantly infested with trematodes. In Ukraine, the presence of three species of flukes has been confirmed in ruminants: Fasciola hepatica, Dicrocoelium dendriticum and Paramphistomum cervi. Parasitization by those species negatively affects the profitability of dairy farming. Trematodes cause significant economic losses: reduced milk productivity of cows, reduced live weight gain of young animals, negative impact on reproduction. At the same time, fascioliasis is socially significant and dangerous to humans. According to the analyzed literature sources, two types of cestodes have been registered in Ukraine: Moniezia benedeni and M. expansa. The epizootic situation regarding nematodes is just as fraught. That is the most numerous group of helminths, their fauna is represented by the following species: Strongyloides papillosus, Nematodirus spathiger, Bunostomum spp., Oesophagostomum radiatum, Haemonchus contortus, Toxocara vitulorum, Trichuris skrjabini, T. ovis and T. globulosa. It is proven that in cattle parasitocenoses are recorded more often than monoinvasions. The highest rates of prevalence of infection were observed when polyinvasion included gastrointestinal strongyles, namely from the order Strongylida. Strongyloides papillosus is the most common taxonomic representative, while Fasciola hepatica has the lowest prevalence of infection, especially in sheep. Updated data on helminthiasis will expand the screening strategy to maintain the health of farm ruminants and reduce economic losses.

The influence of liver fluke infection on production in sheep and cattle: a meta-analysis

Liver flukes (Fasciola spp.) are important parasites of ruminant livestock worldwide, causing profound damage to animal health and productivity. Many reviews have discussed the results of decades of research on the impact of fluke on livestock traits such as weight gain and milk production, but there have been no known attempts to collate previous research in a quantitative manner or to determine the factors that vary between studies that find substantial effects of fluke and others concluding that effects of fluke are negligible. Here, we use meta-analysis to provide quantitative "global" estimates of the impact of liver fluke on animal performance, and to identify elements of study design ("moderators") that influence variation between studies in their outcome. A literature search provided 233 comparisons of performance in fluke-infected and uninfected animals. We standardised these data as log response ratios and calculated effect size variances to weight studies by the accuracy of their estimates. We performed multi-level meta-analysis to estimate effects of fluke infection on daily weight gain, live weight, carcass weight, total weight gain and milk production. There were statistically-supported negative effects of fluke infection on daily weight gain, live weight and carcass weight (9%, 6% and 0.6% reductions, respectively), but not on total weight gain or milk production. A mixed-effects meta-analysis revealed that studies of younger animals found more severe effects of fluke on weight gain and that effects on live weight increased with time since infection. Limitations to the data that could be analysed, including a lack of statistical reporting in older papers and variation in the outcome variables measured, may have explained the relatively limited influence of modifiers that we detected. Our results provide, to our knowledge, the first quantitative estimate of the impact of liver fluke on performance across studies and highlight some elements of study design that can influence conclusions.

Economic impact assessment of small ruminant fasciolosis in Nigeria using pooled prevalence obtained from literature and field epidemiological data

Small ruminant fasciolosis (SRF) is a snail - borne disease, transmitted by tropical freshwater snail, Lymnaea (Radix) natalensis in Nigeria. Fasciolosis in small ruminants is often neglected and information on the prevalence and economic losses are scarce. The aim of this study was to evaluate the prevalence of SRF and provide estimated annual economic losses associated with the disease. Meta-analysis revealed pooled prevalence of 2.1% (95%CI: 0.0-5.8) in studies across Nigeria, while the distribution of L. natalensis was 13.2% (95%CI: 11.6-14.1) among collected snails. Approximately 29.4% livestock owners disagree with veterinary inspectors on the liver condemnation of their slaughtered animals in the abattoir during meat inspection. No significant difference (P > 0.05) was observed between SRF in sheep and goats. Mortality cost was estimated at US$ 55,671,620, while total liver condemnation was US$ 552,448. Direct losses were estimated at US$ 60,132,318 and indirect losses at US$ 17,807,706. The overall economic losses attributable to SRF in Nigeria was estimated at US$ 77,940,024 / annum (equivalent to 28.06 billion naira). Fasciolosis in small ruminant remains a major concern for Nigerian livestock industry. The present and future impact of the disease was further discussed. Considering the high economic burden of fasciolosis in small ruminants, improved disease surveillance and meat inspection, regular treatment and control campaigns are important to reduce infection rates and economic losses.

Prevalence and distribution of livestock schistosomiasis and fascioliasis in Côte d'Ivoire: results from a cross-sectional survey

BACKGROUND

Schistosoma and Fasciola are zoonotic parasites of public health and veterinary importance. However, while the epidemiology of schistosomiasis in humans is well studied, little is known about fascioliasis and schistosomiasis in livestock in Côte d'Ivoire. This study aimed to determine the prevalence and the distribution of livestock schistosomiasis and fascioliasis across Côte d'Ivoire. In 2018, we conducted a cross-sectional survey in abattoirs and farms in 13 departments of Côte d'Ivoire. In abattoirs, the mesenteric veins and livers of slaughtered cattle, sheep and goats were examined for adult Schistosoma and Fasciola flukes. Faeces from live cattle, goats and sheep were collected and examined for Schistosoma and Fasciola eggs using a sedimentation technique.

RESULTS

A total of 386 cattle, 174 goats and 151 sheep from abattoirs and 435 cattle, 22 goats and 176 sheep from farms were sampled. The observed prevalence of schistosomiasis was higher in slaughtered animals. Fascioliasis was more prevalent in farm animals. The prevalence of schistosomiasis in slaughtered cattle varied between 5.9% (95% confidence interval (CI): 0.7-19.7%) and 53.3% (95% CI: 37.9-68.3%) with the highest prevalence observed in Ouangolodougou in the North. Cattle from farms had a relatively low prevalence of schistosomiasis, with the highest prevalence found in Ouangolodougou (2.4%, 95% CI: 0.7-6.1%). The prevalence of fascioliasis varied considerably from one department to another, ranging from nil (95% CI: 0.0-18.5%) to 50.8% (95% CI: 43.4-58.2%), with the highest prevalence found in farm cattle in Dikodougou in the North. Sheep and goats had a lower prevalence of schistosomiasis and fascioliasis than cattle. In slaughtered animals, cattle aged 4 years and older were at highest risk for schistosomiasis (odds ratio (OR): 2.4; 95% CI: 1.0-5.6) and fascioliasis (OR: 2.1; 95% CI: 1.1-3.9). In farm animals, male cattle had higher odds of being infected with Schistosoma (OR: 4.3; 95% CI: 0.7-26.9) than females.

CONCLUSIONS

Our study confirms that schistosomiasis and fascioliasis are endemic in livestock across Côte d'Ivoire. A strategic control programme should be considered, especially for cattle, including providing drinking water in troughs to reduce faecal contamination of water sources by cattle.

Economic model of bovine fasciolosis in Nigeria: an update

Bovine fasciolosis is a zoonotic infection transmitted by infected freshwater snail-Lymnaea (Radix) natalensis-in tropical regions. The prevalence of bovine fasciolosis in Nigeria is overwhelming with huge financial cost. In the chronic form of the disease, hyperplastic cholangitis and calcification of bile ducts occur with severe liver damage. The aim of the study was to estimate annual economic losses of bovine fasciolosis in Nigeria. Disease prevalence was estimated at 18.3% (8.5-30.6), average annual disease incidence is maintained at 2.5%, an estimated mortality rate of 1.5%, a total liver condemnation rate of 11.1% were estimated from affected liver due to fasciolosis, annual slaughter rate of 10.5% and a total cattle population of 20 million. A total of 7.3% livestock owners consider fasciolosis as a threat, while only 4.3% have ever used molluscicide. Treatment cost of controlling fasciolosis is estimated at US$375,000, which puts the total annual loss due to fasciolosis at US$26.02 million. Both direct and indirect sources of production losses have an impact on the livestock industry in Nigeria. Bovine fasciolosis threatens food security in Nigeria; therefore, further awareness among livestock owners is needed on control strategies to improve the income base for small-scale livestock farmers.

Fasciola hepatica and Fasciola gigantica coexistence in domestic ruminants in Nigeria: application of a PCR-based tool

The distinction between Fasciola hepatica and Fasciola gigantica has been traditionally based on morphological criteria, although accurate recognition of the two flukes is usually difficult because of substantial variations in morphological features. The main aim of this study was to develop a PCR-based assay for discrimination between both species collected in sheep and cattle from Nigeria. A total of 47 animals, 33 cattle and 14 sheep, were sampled, and a single adult fluke was collected from each animal. DNA was extracted from flukes, and primers were designed based on mitochondrial DNA sequences to amplify a 304 bp fragment for the identification of F. hepatica and 752 bp for F. gigantica. PCR products from 12 flukes were sequenced for phylogenetic analysis. A total of 29 out of 47 flukes were identified as F. hepatica and 18 as F. gigantica. Within each host, the percentage of each fluke species was as follows: In cattle, 18/33 (54.5%) and 15/33 (45.5%) were F. hepatica and F. gigantica, respectively. In sheep, 11/14 (78.6%) were F. hepatica and 3/14 F. gigantica (21.4%). The phylogenetic analysis confirmed these results. Although the number of flukes collected in sheep was limited, it seems that F. hepatica is more prevalent in sheep than F. gigantica, whereas the percentage of each species was similar in cattle. This study confirms the presence of F. hepatica in Nigeria.

Genetic diversity and multiplicity of infection in Fasciola gigantica isolates of Pakistani livestock

Fasciola spp. are responsible for over 3 billion US dollars of production loss annually in livestock and cause widespread zoonotic disease. Nevertheless, understating of the emergence and spread of the trematode species is poor. The multiplicity of F. gigantica infection and its spread is potentially influenced by multiple factors, including the abundance of suitable intermediate hosts, climatic conditions favouring the completion of the parasite's lifecycle, and translocation of infected animals, or free-living parasite stages between regions. Here we describe the development of a 'tremabiome' metabarcoding sequencing method to explore the numbers of F. gigantica genotypes per infection and patterns of parasite spread, based on genetic characteristics of the mitochondrial NADH dehydrogenase 1 (mt-ND-1) locus. We collected F. gigantica from three abattoirs in the Punjab and Balochistan provinces of Pakistan, and our results show a high level of genetic diversity in 20 F. gigantica populations derived from small and large ruminants consigned to slaughter in both provinces. This implies that F. gigantica can reproduce in its definitive hosts through meiosis involving cross- and self-breeding, as described in the closely related species, Fasciola hepatica. The genetic diversity between the 20 populations derived from different locations also illustrates the impact of animal movements on gene flow. Our results demonstrate the predominance of single haplotypes, consistent with a single introduction of F. gigantica infection in 85% of the hosts from which the parasite populations were derived. This is consistent with clonal reproduction in the intermediate snail hosts.

Trematodiasis occurrence in cattle along the Progo River, Yogyakarta, Indonesia

AIM

This study aimed to measure the occurrence of trematodiasis in cattle along the Progo River, a district of Yogyakarta, Indonesia. The findings help to establish the magnitude of the disease and encourage prevention and treatment of this condition.

MATERIALS AND METHODS

Trematode eggs were extracted from 100 fecal samples collected from cattle. The eggs were examined using the sedimentation technique, and the method of Parfitt and Banks was used to differentiate Paramphistomum spp. eggs from Fasciola spp. eggs.

RESULTS

The infection rate of trematode parasites was 50%. Cattle experienced multiple infections of both Paramphistomum spp. and Fasciola spp., as well as single infections of one species or the other. All breeds were vulnerable to infections of both trematode species, although different cattle breeds, including Peranakan Ongole crossbreeds, Simmental crossbreeds, and Limousin crossbreeds, showed differences in infection rate. The highest rate of infection with Paramphistomum spp. (15.78%) occurred in the Simmental crossbreeds. The highest rate of infection (31.57%) with Fasciola spp. was in the Peranakan Ongole crossbreeds. Multiple infections of both Paramphistomum spp. and Fasciola spp. were highest in Simmental crossbreed cattle (28.97%).

CONCLUSION

The high infection rates of trematode parasites found in fecal samples, particularly of Fasciola spp., indicate that the cattle along the Progo River in Indonesia experience a high rate of trematodiasis disease.

Studies on the prevalence of fascioliasis among ruminant animals in northern Bauchi state, north-eastern Nigeria

A study of prevalence of ruminant fascioliasis was undertaken from May 2017 to April 2018. A set of 7640 stool and 7640 bile samples were collected from slaughtered cattles, sheeps and goats in seven local abattoirs located within the seven Local Government Areas making up northern Bauchi state. The Sample collection was demarcated into four sections of three months each corresponding into four local seasons. 1910 samples were collected from the beginning to the end of each of the four local seasons. Direct postmortem investigation to detect adult Fasciola spp. was employed. Stool samples were analyzed using formol-etha concentration technique. ANOVA (Analysis of variance) was conducted to examine the prevalence of fascioliasis in six communities of northern Bauchi state. The prevalence of infection was statistically different on different localities. The highest infection rates from the seven sampling sites was Jama'are (48.5%) followed by Zaki (46.9%) p = 0.05. Specie specific prevalence of fascioliasis between the host species was statistically different. Cattles were more infected than sheep and goat. Prevalence of fascioliasis on gender was statistically different, with bulls showing a higher prevalence rate and female sheep and goat recorded higher prevalence. Prevalence of fascioliasis based on estimated ages of animals sampled was statistically significant, animals above 5 years had higher prevalence of 64.5% followed by animals below the age of 1 with 41.3% (p = 0.05). Prevalence of fascioliasis among sampled ruminants based on seasonal variations was statistically significant. Higher prevalence percentages were observed during the early and late rainy season (47.2% and 58.4%) compared to early and late dry seasons (36.2% and 20.1%) p = 0.05. The study, therefore, recommends regular meat inspection alongside public awareness campaigns.

Epidemiology and economic loss of fasciolosis and dicrocoeliosis in Arak, Iran

Aim:

Fasciolosis and dicrocoeliosis are important parasitic diseases worldwide, causing significant financial losses due to decrease in production and viscera condemnation in animals. We performed the current research to assess the epidemiology of these infections and determine their significance from an economic perspective in Arak, Iran.

Materials and Methods:

In total, we evaluated 118,463 sheep, 207,652 goats, and 43,675 cattle through necropsic analysis at the slaughterhouses. The average weight of sheep, goat, and cattle liver was 1000, 900, and 5000 g, respectively. The average price of liver in the market was 8 USD/kg. Moreover, the elimination of fundamental nutrients and vitamins was evaluated in infected livers. The prevalence of fasciolosis and dicrocoeliosis was determined. Analysis of variance test was applied for the statistical analysis, and the significance level was <0.05.

Results:

In total, Fasciola hepatica and Dicrocoelium dendriticum were detected in 0.56% (confidence interval CI, 0.54-0.59) and 0.77% (CI, 0.75-0.81) of the animals, respectively (p=0.1). The annual economic loss attributed to fasciolosis and dicrocoeliosis was 26698.4 and 30479.2 USD, respectively. The total economic loss was 10,880, 9079.2, and 10,520 dollars in sheep, cattle, and goats, respectively. On the other hand, financial loss resulting from fasciolosis was 7160, 6098.4, and 13,440 dollars in sheep, goats, and cattle, respectively. In addition, economic loss due to dicroceliasis was 10,880, 9079.2, and 10,520 dollars, respectively.

Conclusion:

Overall, fasciolosis and dicrocoeliosis in Iran always remain common in sheep, goats, and cattle that afford major economic loss of all the country also exist in Arak province. The present study could provide basic information for further examination of liver fluke infections in Iran.