Bioclimatic analysis and spatial distribution of fascioliasis causative agents by assessment of Lymnaeidae snails in northwestern provinces of Iran.

BACKGROUND: Snails of the Lymnaeidae family are the intermediate hosts of Fasciola species, the causative agents of fascioliasis. The purpose of this study was to determine the prevalence of Fasciola species in lymnaeid snails and to investigate the association of geoclimatic factors and Fasciola species distribution in northwestern provinces of Iran using geographical information system (GIS) data. METHODS: A total of 2000 lymnaeid snails were collected from 33 permanent and seasonal habitats in northwestern Iran during the period from June to November 2021. After identification by standard morphological keys, they were subjected to shedding and crushing methods. Different stages of Fasciola obtained from these snails were subjected to the ITS1 polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for species identification. The associations of weather temperature, rainfall, humidity, evaporation, air pressure, wind speed, elevation, and land cover with the distribution of Fasciola species were investigated. Geographical and statistical analysis was performed using ArcMap and SPSS software, respectively, to determine factors related to Fasciola species distribution. RESULTS: Of the 2000 snails collected, 19 were infected with Fasciola hepatica (0.09%), six with F. gigantica (0.03%), and 13 with other trematodes. Among geoclimatic and environmental factors, mean humidity, maximum humidity, and wind speed were significantly higher in areas where F. hepatica was more common than F. gigantica. The altitude of F. hepatica-prevalent areas was generally lower than F. gigantica areas. No significant relationship was observed between other investigated geoclimatic factors and the distribution of infected snails. CONCLUSIONS: The present study showed the relationship of humidity and wind speed with the distribution of snails infected with F. hepatica or F. gigantica in the northwestern regions of Iran. In contrast to F. gigantica, F. hepatica was more prevalent in low-altitude areas. Further research is recommended to elucidate the relationship between geoclimatic factors and the presence of intermediate hosts of the two Fasciola species.

Prevalence and associated risk factors assessment of bovine fasciolosis in the Imbo Region, Burundi.

Fasciolosis is a zoonosis that limits the productivity of ruminants worldwide, but there is a lack of information on its occurrence in Burundi. Therefore, this study aimed to fill the information gap by determining the prevalence and risk factors associated with bovine fasciolosis in the Imbo Region of Burundi. Two prevalence studies were conducted in parallel in the five communes of the five provinces in the Imbo region. In the first study, a total of 426 fecal samples were collected from randomly selected cattle farms and microscopically examined to determine Fasciola egg burden. Survey data on cattle husbandry were collected from owners of these cattle and analyzed to determine the risk factors for bovine fasciolosis. In the second study, 467 cattle were randomly selected in abattoirs and their livers were examined postmortem to determine liver fluke burdens. Data were entered separately into Microsoft Excel and analyzed using R software. The overall prevalence of bovine fasciolosis was 47.7% (42.9-52.4, 95% CI) for microscopic examination and 33.2% (28.9-37.5, 95% CI) for postmortem examinations. The majority of positive cattle (60.6%) had light intensity infections as determined by eggs per gram of feces (epg). Postmortem examinations corroborated these results and indicated that 80% of cattle had light intensity infections. Chi-square analysis showed a statistical association with the presence of bovine fasciolosis and the age, sex, and origin of cattle and the practices of cattle owners (P < 0.05).

Assessment of Fasciola and Paramphistomes co-infection in large ruminants through faecal egg counts around Taiping, Malaysia.

Emerging cases of Fasciola and Paramphistomes co-infection have been reported, especially in tropical regions. Thisis due to Fasciola and Paramphistomes sharing biological factors which influence the pattern of transmission, especially in faecal egg shedding due to interaction and competition in the definitive host. Most reports surveyed the occurrence of fasciolosis in ruminants with a lack of observation of faecal egg distribution. Therefore, present study is aimed to assess the distribution of Fasciola and Paramphistomes faecal egg count (fec) in co-infected large ruminants in Larut, Matang, and Selama areas (Taiping). A total of 371 faecal samples were collected at random from 23 ruminant herds. Flukefinder® sedimentation was used to quantify the Fasciola and Paramphistomes eggs. Descriptive analyses were performed to determine the prevalence of co-infections, and Spearman correlation analysis was used to correlate the fec. Overall, the prevalence of Fasciola and Paramphistomes co-infection was 23.7% (n=89/371) in Taiping. Prevalence of paramphistomosis was always higher than fasciolosis in overall and single infection, with 46.9% (n=174/371) and 22.9% (n=85/371) compared to 36.9% (n=137/371) and 12.9% (n=48/371) respectively. Egg per gram (epg) of both parasites were positively skewed with a median of 1.5 epg in fasciolosis and 10.5 epg in paramphistomosis. Spearman correlation analysis of the epg in co-infected bovine was found to have a moderately positive correlation with rs=0.39 (p-value<0.01). The recent study observed a moderate prevalence of Fasciola and Paramphistomes coinfection in a large ruminant population from Taiping, with the prevalence of paramphistomosis being higher than fasciolosis. Hence, this suggests that infection with one of these parasites increases the chance of infection with another. There is a need to integrate fec in parasite surveillance to monitor the trend of parasite transmission. Findings in the present study could tailor control strategies, especially for fasciolosis to limit the economic loss and prevent zoonotic transmission.

Assessment of genetic markers for multilocus sequence typing (MLST) of Fasciola isolates from Iran.

BACKGROUND: Several markers have been described to characterise the population structure and genetic diversity of Fasciola species (Fasciola hepatica (F. hepatica) and Fasciola gigantica (F. gigantica). However, sequence analysis of a single genomic locus cannot provide sufficient resolution for the genetic diversity of the Fasciola parasite whose genomes are ∼1.3 GB in size. OBJECTIVES: To gain a better understanding of the gene diversity of Fasciola isolates from western Iran and to identify the most informative markers as candidates for epidemiological studies, five housekeeping genes were evaluated using a multilocus sequence typing (MLST) approach. METHODS: MLST analysis was developed based on five genes (ND1, Pepck, Pold, Cyt b and HSP70) after genomic DNA extraction, amplification and sequencing. Nucleotide diversity and phylogeny analysis were conducted on both concatenated MLST loci and each individual locus. A median joining haplotype network was created to examine the haplotypes relationship among Fasciola isolates. RESULTS: Thirty-three Fasciola isolates (19 F. hepatica and 14 F. gigantica) were included in the study. A total of 2971 bp was analysed for each isolate and 31 sequence types (STs) were identified among the 33 isolates (19 for F. hepatica and 14 for F. gigantica isolates). The STs produced 44 and 42 polymorphic sites and 17 and 14 haplotypes for F. hepatica and F. gigantica, respectively. Haplotype diversity was 0.982 ± 0.026 and 1.000 ± 0.027 and nucleotide diversity was 0.00200 and 0.00353 ± 0.00088 for F. hepatica and F. gigantica, respectively. There was a high degree of genetic diversity with a Simpson's index of diversity of 0.98 and 1 for F. hepatica and F. gigantica, respectively. While HSP70 and Pold haplotypes from Fasciola species were separated by one to three mutational steps, the haplotype networks of ND1 and Cyt b were more complex and numerous mutational steps were found, likely due to recombination. CONCLUSIONS: Although HSP70 and Pold genes from F. gigantica were invariant over the entire region of sequence coverage, MLST was useful for investigating the phylogenetic relationship of Fasciola species. The present study also provided insight into markers more suitable for phylogenetic studies and the genetic structure of Fasciola parasites.

Fasciolosis prevalence, risk factors and economic losses due to bovine liver condemnation in abattoirs in Mexico.

This study investigated the prevalence of bovine liver condemnation due to Fasciola hepatica in abattoirs and its influence on livestock productivity. It also explored risk factors such as season, breed, age and sex in the states of Puebla and Veracruz, Mexico. A total of 5281 cattle livers were inspected in two abattoirs. The overall prevalence of the parasite in cattle throughout 2020 was 24.9% (1313 out of 5281). The highest prevalence was found in Veracruz (28.5%; tropical climate), followed by Puebla (18.4%; temperate climate). The prevalence of fluke infection during the wet season was 19.0% and 25.8% in the states of Puebla and Veracruz, respectively; during the dry season, this was 18.0% and 30.2% respectively. The annual loss caused by condemnation of the liver for both abattoirs was estimated to be US$7502. Using multivariate logistic regression analysis, two models were constructed for potential association with the prevalence of condemned livers, using season, breed, age and sex as risk factors. The results indicate that season, age and sex were significantly associated with an increased risk of parasitic infection. Cattle age was the variable most strongly associated with F. hepatica infection, with the highest prevalence in cattle over three years of age as compared to younger animals, both in the states of Veracruz with a tropical climate (OR 6.443; 95% CI: 4.487-9.251) and in Puebla with a temperate climate (OR 2.854; 95% CI: 1.531-5.321). The results indicate that different factors were significantly associated with the prevalence of condemned livers, and it highlights the importance of continuous monitoring programmes for F. hepatica infection and preventing economic losses in cattle production.

Stunting in pre-school and school-age children in the Peruvian highlands and its association with Fasciola infection and demographic factors.

Fascioliasis is a zoonotic trematode infection that is endemic in the highlands of Peru. Chronic fascioliasis can be asymptomatic and remain undiagnosed for years. Chronic malnutrition in children, as manifested by stunting, leads to delayed cognitive development and lost productivity. We hypothesized that fascioliasis is among the factors associated with stunting in children from endemic areas. We conducted a cross-sectional study among children attending pre-school and school in 26 communities in the Anta province in the Cusco region of Peru. We conducted interviews to collect information on demographic, socioeconomic, and medical history. Blood was collected and tested for complete cell count and FAS2 ELISA for Fasciola antibodies. Three stool samples per participant were tested for parasites by Kato-Katz and Lumbreras rapid sedimentation methods. Chronic fascioliasis was determined by the presence of ova in stool. Children's height, weight, and age were recorded and used to calculate height for age Z scores (HAZ). Three thousand children participated in the study. Nine percent (264) of children had at least one positive test for Fasciola infection, 6% (164) had chronic fascioliasis, and 3% (102) had only positive antibody tests. The median HAZ was -1.41 (IQR: -2.03 to -0.81) and was similar in males and females. Twenty six percent (776) of children had stunting with HAZ < -2. Children with chronic fascioliasis had a lower median HAZ than children without Fasciola (-1.54 vs. -1.4, p = 0.014). History of treatment for malnutrition, history of treatment for anemia, having other helminths in stool, lower socioeconomic score, living at a higher elevation, and fewer years of schooling of both parents were associated with a lower HAZ score. In a multiple regression analysis, older age and a lower socioeconomic score were associated with a lower HAZ score. While fascioliasis and other helminths were associated with lower HAZ, they were not independent of the socioeconomic score.

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.

Evaluation of zoonotic platyhelminthe infections identified in slaughtered livestock in Iran, 2015-2019.

BACKGROUND: Platyhelminth infections of livestock can result in considerable economic losses. This study aims to evaluate the spatial frequency of cystic echinococcosis (CE), dicrocoeliasis, and fascioliasis in livestock slaughtered in Iran during the years 2015-2019 and estimate direct costs associated with organ condemnation due to these parasites. METHODS: Abattoir data from 413 abattoirs representing all 31 Iranian provinces were collected from the Iran Veterinary Organization. Infection prevalence was calculated per year at the province level. The Local Moran's I statistic was performed to evaluate spatial autocorrelation of animals positive at slaughter for the years 2015-2019. Direct costs associated with condemned livers were calculated for each parasitic condition, with costs associated with condemned lungs also included for CE. RESULTS: Overall prevalence values for the study timeframe were as follows: sheep and goat fascioliasis 1.56% (95% CI: 1.56-1.56%), cattle fascioliasis 3.86% (95% CI: 3.85-3.88%), sheep and goat dicrocoeliasis 4.63% (95% CI: 4.62-4.63%), cattle dicrocoeliasis 3.08% (95% CI: 3.07-3.09%), sheep and goat CE 5.32% (95% CI: 5.32-5.33%), and cattle CE 7.26% (95% CI: 7.24-7.28%). Northwest Iran had the highest prevalence of CE and fascioliasis. High infection areas for Dicrocoelium spp. included the provinces of Zanjan, Gilan, Qazvin, and Tehran, which are located in northern Iran. Direct economic losses for sheep and goat fascioliasis, dicrocoeliasis, and CE for the study period were US$13,842,759, US$41,771,377, and US$22,801,054, respectively. Direct economic losses for cattle fascioliasis, dicrocoeliasis, and CE for the study period were US$1,989,200, US$1,668,986, and US$2,656,568, respectively. CONCLUSION: Our findings provide valuable data for future monitoring of these important parasitic diseases in Iranian livestock. Disease control strategies are required to reduce the economic and public health impact of these platyhelminths.

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.

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

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

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.

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.

Liver fluke in Irish sheep: prevalence and associations with management practices and co-infection with rumen fluke.

BACKGROUND: The present study aimed to identify the national prevalence of Fasciola hepatica in Irish sheep and to conduct a risk analysis assessment based on management and treatment practices in participating flocks. Also, co-infection with rumen fluke was quantified and its association with liver fluke and management practices was assessed. METHODS: A total of 305 sheep flocks were selected ensuring even national representation of the sheep population. Participating farms were asked to complete a survey questionnaire on farm management practices and submit faecal samples during the winter of 2014-2015. Pooled faecal samples were analysed for the presence of F. hepatica and co-infection with rumen fluke. Apparent and true prevalence were calculated, additionally, the rate of co-infection with rumen fluke was also obtained. Correlation and regression analyses were used for assessing associations between management practices, liver fluke infection and co-infection with rumen fluke. RESULTS: The national true prevalence of F. hepatica was 50.4% (n = 305). Regional prevalence varied from 41% in the east to 52% in the south. Co-infection with rumen fluke was observed in 40% of the studied population and correlated with increased F. hepatica egg counts (OR = 2.9; P ≤ 0.001). Predominant breeds were Suffolk, Texel and Horned Mountain breeds. Beef cattle were the most frequent type of other livestock present on farms and mixed species grazing was frequently reported (73%). More than half of the flocks reported a mid-to-late lambing period (March-April). Use of mountain land for grazing was of 32%. Flukicides were most commonly used twice over the autumn-winter period. Regression analyses highlighted significant association of F. hepatica status, with the presence of other livestock on farm, frequency of flukicides used during the winter and clinical presentation of liver fluke. A significant increase in eggs per gram of faeces was observed in Charollais sheep in comparison with all other breeds. Co-infection with F. hepatica and Calicophoron daubneyi was also significantly associated with the presence of other livestock on the farm, type of flukicide used and clinical fasciolosis. CONCLUSIONS: The present study provides up-to-date information on the prevalence of F. hepatica in Irish sheep and adds insight to the epidemiology of the disease. These findings will be useful for designing new holistic control measures for F. hepatica infection.

A socio-economic study of Fasciola infections in cattle and sheep at the Etoudi slaughterhouse, Yaoundé, Cameroon.

A cross-sectional socio-economic study of fascioliasis in livestock was carried out at the Livestock Development Cooperation (SODEPA) slaughterhouse in Etoudi, Yaoundé during the periods covering the beginning and late dry season in the northern and eastern regions of Cameroon. A total of 768 cattle and 267 sheep were inspected for the presence of Fasciola species. The overall infection rate in cattle and sheep was 18% (n = 767) and 27% (n = 267), respectively. For the animals that were Fasciola positive, a total of 267.86 kg of liver in cattle was condemned, resulting in a loss of US$1124, while a total of 57 kg of liver was condemned from the sheep population, amounting to a loss of US$114. A total of US$76,097 was determined as losses incurred from condemnation of liver for both cattle and sheep per annum based on the total number slaughtered each year. The findings indicate that fascioliasis is present in cattle and sheep slaughtered in Cameroon and that it causes great economic losses due to condemnation of liver. The local climatic conditions, husbandry systems and the presence of snails (intermediate hosts) are probably the main factors influencing the incidence of the disease and may account for the epidemiological significance found in this study.

Liver fluke (Fasciola hepatica) co-infection with bovine tuberculosis in cattle: A prospective herd-level assessment of herd bTB risk in dairy enterprises.

Co-infection of tuberculosis (TB) and helminths is recognized as a significant problem in regions where such pathogens are endemic and chronic cases exist. Co-infection can modulate the immune system leading to interference with diagnostic tests, increased pathological impacts and pathogen persistence. However, research has found that such interactions between pathogens can be context and species specific. Recent studies have suggested that liver fluke, Fasciola hepatica, infection may impact on immunological responses and diagnostics for bovine tuberculosis (bTB; caused by Mycobacterium bovis) in cattle. Where evidence of such interaction exists, there would be an onus on policy makers to adjust eradication programs to minimize impacts. We assessed the association between herd-level bTB breakdown risk and seasonal variation in liver fluke exposure based on 5,753 bulk tank milk (BTM) samples from 1,494 dairy herds across Northern Ireland. BTM was tested by an IDEXX antibody specific enzyme-linked immunosorbent assay (ELISA) using the 'f2' antigen as a detection agent. The ELISA determined the result based on a sample to (known) positive ratio (S/P%) from which binary status and categories of exposure were derived. Associations were tested using multivariable random effects models. Models predicting bTB risk were not improved with the inclusion of liver fluke exposure levels. Variations in modelling liver fluke exposure (S/P%, binary, categories of exposure) and bTB risk (skin test breakdowns, post-mortem confirmed breakdowns, breakdown size and lag effects) also failed to support associations (neither positive nor negative) between the pathogens at herd-level. These results, along with previously published animal-level data from Northern Ireland, suggest that the nexus between bTB and F. hepatica may have small size effects at the population-level. However, our results also highlight the high prevalence of F. hepatica in cattle in our study population, and therefore we cannot fully discount the potential hypothesis of population-level depression of immune response to M. bovis due to co-infection.

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.

Prevalence of bovine fascioliasis and economic impact associated with liver condemnation in abattoirs in Mongu district of Zambia.

BACKGROUND: Fascioliasis is a trematode zoonotic snail-borne disease of public health and economic importance. The disease causes liver damage and is hardly recognized by medical personnel hence, is rarely considered as the differential diagnosis. In animals, the disease leads to mortalities, growth retardation, drop in livestock production and condemnation of the infected livers during meat inspection. The cross-sectional study was conducted from 2013 to 2017 in abattoirs in Mongu district, Western province of Zambia. Each selected carcass was examined macroscopically for bovine fascioliasis by dissecting the liver and checking for adult liver flukes. Infested and condemned livers were weighed and incinerated. RESULTS: A total of 69,152 carcasses with their livers was examined at the abattoirs for adult Fasciola worms and 44,511 (64.4%) were positive. According to the intensity of pathological lesions, 55.3% constituted severely affected livers, 30.3% were moderately affected livers and 14.4% were lightly affected livers. Our observation revealed that the most prevalent liver fluke identified was Fasciola gigantica (56.1%) and it mostly affected the poor body conditioned animals (71.4%). The study also indicated that 164,600 kg liver was condemned and destroyed. This reduced the income base for small-scale livestock farmers to about ZMW 7,407,000.00, which was equivalent to 592,560 USD. CONCLUSION: In conclusion, our study suggests that the prevalence of bovine fascioliasis was high resulting in a large amount of liver being condemned and destroyed, leading to economic losses for affected livestock farmers in the area. Consequently, there is a need to take the necessary measures to control the disease and create awareness among medical personnel to consider it as a differential diagnosis in all functional liver deficiencies due to the zoonotic nature of the disease.

Liver fluke (Fasciola hepatica) co-infection with bovine tuberculosis (bTB) in cattle: A retrospective animal-level assessment of bTB risk in dairy and beef cattle.

Bovine tuberculosis (bTB), caused by Mycobacterium bovis, remains a persistent problem for cattle industries in endemic countries. The frequency, quality, and performance of tests, and the presence of wildlife reservoirs, have been identified as impediments to eradication. Recently, exposure to helminth infection (Fasciola hepatica) has been associated negatively with the disclosure of bTB. Here, for the first time, we assess impact of concurrent infections of Fasciola hepatica and the disclosure of bTB at the animal-level using large surveillance datasets. We utilized a dataset of 138,566 animal records from an abattoir from Northern Ireland (2011-2013). The presence of F. hepatica infection was assessed from macroscopic tissue inspection at abattoir. Multivariable models were developed to assess co-infection associations with bTB status based on: Single Intradermal Comparative Tuberculin Test (SICTT), lesion, bacteriological confirmation, including either all animals, or only skin-test negative animals (lesions at routine slaughter; LRS; confirmed nonreactors at routine slaughter; cNRs) or positive (reactors) animals alone, respectively. The relationship between skin tuberculin reaction sizes and fluke status was also explored for a subset of animals with field recordings (n = 24,680). Controlling for known risk factors (e.g., climatic, herd, and individual level characteristics), we did not find significant associations between the SICTT (standard or severe interpretation), lesion, nor confirmation status of animals and their liver fluke status. The only exception was a negative association between liver fluke positivity, and LRS or cNRs, respectively; though effect-sizes were small (e.g., LRS Odds-Ratio: 0.87; 95% CI: 0.76-1.00). There was limited evidence of a relationship between tuberculin reaction sizes during SICTT testing and liver fluke infection status. These data do not support the contention that the detection of bTB using skin-tests or reactor postmortem follow-up may be compromised by co-infection at a population level, but the relationship with lesion formation (pathogenesis) may indicate an impact for postmortem surveillance.

Socioeconomic Factors Associated with Fasciola hepatica Infection Among Children from 26 Communities of the Cusco Region of Peru.

Fasciola hepatica is the most widely distributed trematode-affecting humans. The Andes Mountains are highly endemic for fascioliasis. We report results of a cross-sectional study evaluating the epidemiology of Fasciola among children in 26 agricultural communities in the Cusco region of Peru. Children 3 to 16 years old were enrolled in preschools and schools. Blood from participants was tested for complete blood counts, transaminases, and Fasciola antibodies. Stool samples were tested for Fasciola and other parasites. A total of 2,515 children were included in the analysis and the mean age was 9.6 years (±3.6). Ten percent (253) of the children had at least one positive test for Fasciola, 6% had chronic infection, and 0.4% acute infection. The rest of the subjects had only antibodies against Fasciola. The prevalence of infection varied from 0% to 20% between communities. Children with evidence of Fasciola exposure were older, lived at higher altitudes, and had a lower socioeconomic status than children without infection. The logistic regression analysis showed that children from Ancahuasi district, older children, and children with higher measures of poverty were more likely to have Fasciola exposure. Fascioliasis is common in the Cusco region and associated with poverty. However, the distribution varies markedly between communities.