Efficacy Of Anthelmintic Treatment Research Articles

An Insight into Practices Associated with the Control of Internal Parasites in the Dairy Goat Herds of Romania: A Questionnaire Survey.

The widespread and uncontrolled use of anthelmintic products has contributed to the emergence of anthelmintic resistance (AR). This phenomenon globally threatens the productivity and welfare of small ruminants. A questionnaire consisting of 34 questions was handed to 234 goat farmers across Romania to gain insight into control practices against internal parasites and the farmers' perception of the parasitic infections present in their herds and the efficacy of anthelmintic treatments. The majority of farmers (88.5%) admitted they had never submitted fecal samples for parasitological laboratory analysis, and 77.4% had treated the animals on their own. In general, the farmers dewormed their goats based on visual body weight estimation. Prophylactic anthelmintic treatment was practiced by more than 85% of the farmers. A traditional control approach based on treating the entire herd at fixed time intervals is widespread among Romanian goat and sheep farmers. The most commonly used anthelmintic drugs in the previous 3 years (2021-2023) were benzimidazoles (85.5%) and macrocyclic lactones (81.6%). Poor anthelmintic efficacy was suspected by 14.5% of farmers, and the minority (18.0%) considered internal parasites as a problem in their herds. Regarding the farmers' perception of the presence of parasites, there was a significant level of uncertainty. This is the first survey carried out in Romanian goat herds, and it provides up-to-date information on practices aimed at controlling internal parasites.

58 United States Department of Agriculture National Animal Health Monitoring System Goat 2019 study: Distribution of gastrointestinal nematodes

Abstract One objective of the United States Department of Agriculture National Animal Health Monitoring System Goat 2019 study was to describe practices producers use to control gastrointestinal nematodes (GIN) and reduce anthelmintic resistance through the examination of anthelmintic treatment efficacy via fecal egg count reduction tests and fecal cultures. The fecal cultures were used to determine what GIN were present across the areas of the US included in the study (September 2019-April 2020). Bulk cultures were processed from 318 operations in 24 states and results were consolidated into 4 regions: Northwest (3 states, 34 operations), Northeast (9 states, 89 operations), Southeast (9 states, 132 operations) and Southwest (3 states, 63 operations). GIN identification included Haemonchus, Trichostrongylus, Teladorsagia, Oesophagostomumand Nematodirus. In addition to GIN, lungworm presence was also noted. Haemonchus were found on 18.6% of the operations (Northwest, 27.0%; Northeast, 13.1%; Southeast, 15.9% and Southwest, 29.2%). Trichostrongylus were found on 97.2% of the operations (Northwest, 100%; Northeast, 98%; Southeast, 97.0% and Southwest, 95.7%). Teladorsagia were found on 80.3% of the operations (Northwest, 97.1%; Northeast, 71.6%; Southeast, 88.6% and Southwest (75.7%). Oesophagostomum were found on 38.2% of the operations (Northwest, 73.1%; Northeast, 39.6%, Southeast, 46.4% and Southwest, 15.5%). Nematodiruswere found on 7% of the operations (Northwest, 7%; Northeast, 5.2%, Southeast, 20.8% and Southwest, 0%). Lungworms were found on 35.4% of the operations (Northwest, 69.1%; Northeast, 52.2%, Southeast, 33.4% and Southwest, 8.3%). Due to sampling logistics, fecal collection was conducted during autumn through early spring which may have influenced number of more pathogenic GIN. This study provided valuable insight into regional prevalence of GIN in goats. In depth analyses continues and will be forthcoming.

Anthelmintic treatment follow up in a rural community in Camamu, Bahia, Brazil.

Enteroparasites are an important public health problem and the treatment seeks to cure and reduce transmission. The aim of this study was to evaluate the therapeutic efficacy of anthelmintic treatment in individuals living in a rural community area in Camamu, Bahia, Brazil. The parasitological diagnosis was performed by spontaneous sedimentation, Baermann-Moraes and Agar Plate Culture methods. A total of 212 individuals were evaluated. The most frequent helminth was Trichuris trichiura, 24.5% (52/212), followed by Ascaris lumbricoides, 21.2% (45/212), hookworms, 16.5% (35/212), and S. stercoralis, 4.7% (10/212). In the anthelmintic treatment follow up, T. trichiura infection presented the lowest parasitological cure rate, only 60.6% (20/33). Hookworm, Ascaris lumbricoides and Strongyloides stercoralis infections demonstrated cure rates of 70.5 (12/17), 78.1 (25/32) and 100% (5/5), respectively. Individuals who remained infected underwent a new drug therapy. The second parasitological cure rate for T. trichiura was 38.5% (5/13), and 66.7% (2/3) and 75% (3/4) for hookworms and Ascaris lumbricoides, respectively. Trichuris trichiura infection presented the lowest parasitological cure rate at this second evaluation. This reinforces the need to perform a follow-up of all treated individuals. The possibility of drug resistance denotes the necessity for studies to clarify the mechanisms and to evaluate new therapeutic approaches.

Parasite faecal egg counts in equine veterinary practice

SummaryWidespread occurrence of anthelmintic resistance in ascarid and strongylid parasites has led to recommendations of routine treatment efficacy screening with the faecal egg count reduction test. Furthermore, faecal egg counts are used for classifying mature horses into low, moderate and high strongylid egg shedders, and to monitor for ascarids in foals, weanlings and yearlings. The plethora of egg counting techniques is surrounded by confusion and misconception regarding their use, diagnostic performance and interpretation. This article aims to explain general concepts of evaluating and assessing faecal egg count test performance and address some of the most common misconceptions. The multiplication factor, which is used to convert the number of eggs counted under the microscope to eggs per gram of faeces, is a theoretically derived number, which does not reflect sensitivity. Accuracy and precision are quantitative performance parameters, which are not synonymous. Accuracy is a measure of how close a technique measures to the true count, and has implications for the classification of strongylid egg shedders, but will not affect anthelmintic treatment efficacy evaluation or ascarid monitoring. Precision is a measure of how close repeated counts are to each other, and affects anthelmintic efficacy estimates and strongylid shedding classification. Faecal egg counts do not correlate with worm burdens and do not inform on parasitic involvement in disease. Techniques using test tubes with cover slips placed on top tend to perform with low accuracy and precision in comparison to techniques using counting chambers. Veterinarians should consider the performance of the technique employed for determining faecal egg counts, whether they offer these in house or use a referral diagnostic service. Furthermore, they should consider the training and experience of personnel and protocols in place for diagnostic quality assurance.

Sheep nemabiome diversity and its response to anthelmintic treatment in Swedish sheep herds

BackgroundA novel way to study the species composition and diversity of nematode parasites in livestock is to perform deep sequencing on composite samples containing a mixture of different species. Herein we describe for the first time the nematode community structures (nemabiomes) inhabiting Swedish sheep and how these are/were affected by host age and recent anthelmintic treatments.MethodsA total of 158 fecal samples were collected (n = 35 in 2007 and n = 123 in 2013–2016) and cultured from groups of sheep on 61 commercial farms in the south-central part of the country where most animals are grazed. Among the samples, 2 × 44 (56%) were paired collections from the same groups pre- and post-treatment with anthelmintics such as macrocyclic lactones, benzimidazoles or levamisole. Samples were analyzed for their nemabiome using the PacBio platform followed by bioinformatic sequence analysis with SCATA. Species richness and diversity were calculated and analyzed in R.ResultsNematode ITS2 sequences were found in all larval culture samples except two, even though the fecal egg counts were below the McMaster threshold in 20 samples. Sequencing yielded, on average, 1008 sequences per sample. In total, 16 operational taxonomical units (OTU), all with ≥ 98 % identity to sequences in the NCBI database, were recognized. The OTUs found represented nematode species of which ten are commonly associated with sheep. Multiple species were identified in all pre-anthelmintic treatment larval culture samples. No effects on nematode diversity were found in relation to host age. On the other hand, recent anthelmintic treatment lowered species richness, especially after use of ivermectin and albendazole. Interestingly, despite zero egg counts after use of levamisole, these samples still contained nematode DNA and especially H. contortus.ConclusionsOur findings provide evidence that nemabiome analysis combined with diversity index analysis provides an objective methodology in the study of the efficacy of anthelmintic treatment as both high and low abundant species were detected.Graphical

Anthelmintic resistance in strongylids (Nematoda: Strongylidae) parasitizing wild and domestic equids in the Askania Nova Biosphere Reserve, Ukraine

Resistance of strongylids in domestic horses to benzimidazole anthelmintics (BZ) has been detected worldwide; however, information on the presence of BZ-resistance in wild equids has not been published to date. The purpose of this study was to analyze the manifestations of the BZ resistance in strongylids in domestic and wild equids kept in the Askania Nova Biosphere Reserve, Ukraine. Four species of equids: domestic horses and Shetland ponies (Equus caballus), donkeys (E. asinus), plains zebras (E. burchelli) and Grévy’s zebras (E. grevyi) kept under semi-free conditions were examined using the Fecal Egg Count Reduction Test (FECRT) in order to detect the presence of resistance to the BZ anthelmintics. Analysis of long-term data (2009–2019) revealed a decrease in the efficacy of BZ drugs against strongylids in these four species of equids from 97.6% in 2009 to <75% in 2019. The efficacy of anthelmintic treatments was low in all species of equids: in plains zebras – 69.4%, Grévy’s zebras – 72.7%, horses – 66.4%, ponies – 61.1% and donkeys – 45.2%. Ten species of cyathostomins (Cyathostomum catinatum, Cylicocyclus nassatus, C. ashworthi, C. leptostomus, Cylicostephanus calicatus, C. goldi, C. longibursatus, C. minutus, Coronocyclus labiatus, C. labratus) were found after horse deworming with albendazole. Our results are the first detection of BZ-resistance in strongylids of wild equids kept under semi-free conditions in the Reserve.

Behavioural assessment of sheep is sensitive to level of gastrointestinal parasite infection

Qualitative behavioural assessment (QBA) was applied to investigate the expressive behaviour of sheep with varying intestinal parasite burdens over two experiments. The expressive behaviour of sheep naturally infected with intestinal parasites was assessed from video footage collected in the paddock, and assessments were compared pre- and post-treatment with anthelmintic drench. The first experiment assessed sheep with a range of parasite burdens (n = 28), and the second compared sheep that expressed clinical symptoms of parasitism (Anaemic, n = 5) with those that did not (Non-anaemic, n = 5). Behavioural expression scores were validated against individual clinical evaluations (faecal egg counts – FEC, faecal consistency and anaemia scores), production parameters (body mass and body condition score), and quantitative locomotive measures (walking speed and return order to paddock). Twenty-two observers scored 28 video clips using QBA in experiment 1, and in the second experiment, 35 observers scored 20 video clips that depicted the 10 focal sheep pre- and post-treatment. QBA scores were analysed using Generalised Procrustes Analysis (GPA), and sheep scores on the main GPA dimensions were evaluated in relation to parasite burden using Spearman Rank correlations and repeated-measures ANOVA for experiment 1 and 2, respectively. In both experiments, observers reached significant (P < 0.001) consensus in their assessment of the behavioural expression of sheep. In experiment 1, sheep with higher FEC had lower anaemia scores (indicative of anaemia), poor body condition, lower body mass, walked slower, ranked lower in return order, and were scored by observers as more docile/at ease, and more assertive/motivated on GPA dimensions 1 and 3, respectively (P < 0.05). In experiment 2, observers scored Anaemic sheep as significantly more unsettled/apprehensive compared to Non-anaemic sheep on GPA dimension 1 (P < 0.05). In addition, observers consistently scored Non-anaemic sheep as more bright/observant following treatment on dimension 2 (P < 0.001). On dimension 3, all animals were scored by observers as less depressed/suspicious post-treatment (P < 0.05). An increase in average walking speed across all sheep was also identified post-treatment (P < 0.05). We conclude that under the conditions tested, QBA could provide information on the behavioural expression of sheep related to varying parasite burdens and the impact of treatment. The data presented herein offers proof of concept that assessments of behavioural expression could aid producers in the monitoring and management of parasitised sheep on-farm in terms of identification of individuals for treatment, and efficacy of anthelmintic treatment.

In Vivo and In Vitro Pharmacodynamics of Anthelmintic Medication Used in Sheep

Our research aimed to evaluate the efficacy of anthelmintic treatments in sheep, as well as the resistance occurrence risk for the most commonly used substances. Anthelmintic medication efficacy was evaluated on 30 animals from a private farm, located in Sânmihaiu Almaşului, Sălaj County. In vivo studies were performed by using Fecal Egg Count Reduction Test (FECRT) and testing an albendazole-based (ABZ) product. In vitro, we used Egg Hatch Assay (EHA) and Larval Development Assay (LDA) for albendazole (ABZ), mebendazole (MBZ), fenbendazole (FBZ), thiabendazole (TBZ) and ivermectin (IVM) (only for LDA). FECRT showed that intestinal nematodes developed resistance phenomena against the ABZ-based product, with an extensivity of 80% at seven days post therapy, an egg reduction percentage of 41.89% at seven days post-therapy and 43.9% at 14 days post-therapy. The in vitro EHA highlighted a superior efficacy of TBZ (egg hatch percentage at reference concentration being 51.21) compared to ABZ (71.89%), MBZ (84.46%) and FBZ (79.22%), with a minimum risk of anthelmintic resistance. The LDA test revealed the superior efficacy of FBZ (MIC 0.59 mcg/ml) and IVM (MIC 0.078 mcg/ml), with a minimal risk of inducing parasitic resistance. All in vivo and in vitro tests revealed a limited ABZ efficacy, recommending avoiding the therapy with this substance.

Field and Molecular Evaluation of Anthelmintic Resistance of Nematode Populations from Cattle and Sheep Naturally Infected Pastured on Mixed Grazing areas at Rio Grande do Sul, Brazil.

Reports of a lack of efficacy of most of the anthelmintic compounds for ruminants associated with the long-time necessity for creating new molecules have stressed the urgency to adopt alternative methods to control gastrointestinal parasites infection, such as strategies of sharing grazing areas. Therefore, this study aimed to evaluate nematode populations affecting cattle and sheep that share grazing areas before and after treatment with different anthelmintic compounds, and investigate the efficacy of anthelmintic treatment in these naturally infected ruminants at farms in the state of Rio Grande do Sul, Brazil. The presence of co-infections by Haemonchus species was investigated by polymerase chain reaction (PCR) for groups treated with a benzimidazole. Farms were selected by: farmers' consent, presence of 42-60 (or more) calves and sheep per farm with counts of ≥ 200 eggs per gram of feces (EPG), availability of calves and lambs aging from 6 to 9 months, absence of anthelmintic treatment for both species for 60 days before the experimental period, and shared grazing areas between this species on each farm. Animals were distributed into six treatment groups for each ruminant species per farm and treated with: ivermectin, doramectin, moxidectin, levamisole, albendazole, and closantel. Levamisol was the most effective anthelmintic compound for both ruminant species. In general, Cooperia spp., Haemonchus spp., and Trichostrongylus spp. were the genus present after tested treatments that were ineffective. PCR showed the presence of Haemonchus species co-infections between cattle and sheep. Therefore, this study demonstrated the similarity between nematode population, the presence of multi-resistant nematodes, and the presence of Haemonchus species co-infections affecting different ruminant species that share pastures.

Pixel by pixel: real-time observation and quantification of passive flotation speeds of three common equine endoparasite egg types

The efficacy of anthelmintic treatments against populations of endoparasites infecting livestock throughout the world is decreasing. To mitigate this, the use of fecal egg counts is recommended to determine both the necessity, and to ensure the appropriate choice, of anthelmintic treatment. Traditionally, and in order to facilitate easier identification and/or enumeration, samples are analysed after separating eggs from other fecal particulates by exposing them to a solution with a density higher than that of the eggs, but lower than the remaining fecal contents. While many parasite egg flotation protocols exist, little is known about the characteristics of these eggs with respect to their movement through a flotation solution. In this study, we have demonstrated a novel method for the observation and quantification of microscopic (65–100 µm) objects as they experience unassisted flotation. This also represents, to our knowledge for the first time, that the flotation of parasite eggs has been observed and their movement characteristics quantified as they float through solution. Particle tracking and video analysis software were utilised to automatically detect and track the movement of individual eggs as they floated. Three 30 s videos and one 2 min video of each egg type were analysed. If the first 30 s of video were discounted, the differences in mean flotation speed among all videos was statistically significant between egg types (P = 0.0004). Strongyle type eggs (n = 201) moved the fastest with a mean 51.08 µm/s (95% confidence interval: 47.54–54.62). This was followed by Parascaris spp. (n = 131) and Anoplocephala perfoliata eggs (n = 322), with mean speeds of 44.43 µm/s (95% confidence interval: 39.47–49.4) and 31.11 µm/s (95% confidence interval: 29.6–32.61), respectively. This method for evaluating the mean speed of passive flotation may represent a first step towards further optimizing fecal egg flotation and be of interest to parasitologists and veterinary practitioners.

Age affects antibody levels and anthelmintic treatment efficacy in a wild rodent.

The role of the host immune system in determining parasite burdens and mediating within-host parasite interactions has traditionally been studied in highly controlled laboratory conditions. This does, however, not reflect the diversity of individuals living in nature, which is often characterised by significant variation in host demography, such as host age, sex, and infection history. Whilst studies using wild hosts and parasites are beginning to give insights into the complex relationships between immunity, parasites and host demography, the cause-and-effect relationships often remain unknown due to a lack of high resolution, longitudinal data. We investigated the infection dynamics of two interacting gastrointestinal parasites of wild wood mice (Apodemus sylvaticus), the nematode Heligmosomoides polygyrus and the coccidian Eimeria hungaryensis, in order to assess the links between infection, coinfection, and the immunological dynamics of two antibodies (IgG1 and IgA). In an anthelmintic treatment experiment, mice were given a single oral dose of an anthelmintic treatment, or control dose, and then subsequently followed longitudinally over a period of 7–15 days to measure parasite burdens and antibody levels. Anthelmintic treatment successfully reduced burdens of H. polygyrus, but had no significant impact on E. hungaryensis. Treatment efficacy was driven by host age, with adult mice showing stronger reductions in burdens compared to younger mice. We also found that the relationship between H. polygyrus-specific IgG1 and nematode burden changed from positive in young mice to negative in adult mice. Our results highlight that a key host demographic factor like age could account for large parts of the variation in nematode burden and nematode-specific antibody levels observed in a naturally infected host population, possibly due to different immune responses in young vs. old animals. Given the variable success in community-wide de-worming programmes in animals and humans, accounting for the age-structure of a population could increase overall efficacy.

Anthelmintic efficacy against equine strongyles in the United States

Equine strongyle parasites are ubiquitous in grazing equids across the world. Anthelmintic resistance is widely developed in cyathostomin populations, but very few surveys have evaluated anthelmintic efficacy in equine populations in the United States, and most of these are over 15 years old. The present study was carried out as part of the National Animal Health Monitoring Systems (NAHMS) Equine 2015–2016 study. The aims were to investigate anthelmintic treatment efficacy by means of the fecal egg count reduction test (FECRT) and identify parameters associated with decreased efficacy. Data were collected from equine operations in 28 states via questionnaires and fecal samples submitted for fecal egg count analysis. Participants were instructed to collect samples from six equids at the day of anthelmintic treatments and 14 days later, and they were asked to include an empty syringe with a legible label of the anthelmintic product used in the shipment. Overall, dewormer treatment was effective for 76.3% of operations (84.6% of animals). Macrocyclic lactone use was effective for 88.7% of operations (95.0% of animals) while pyrimidine/benzimidazole use was effective for 21.4% of operations (43.5% of animals). Univariate analysis revealed that overall, macrocyclic lactones exhibited significantly higher efficacy than the pyrimidine and benzimidazole drug classes (p < 0.0001). There were no statistically significant differences observed between geographic regions (West, South Central, North East, and Southeast). Body weight (p = 0.0355), amount of anthelmintic administered (p = 0.0119), and operation size (p = 0.0162) were statistically associated with anthelmintic efficacy, while anthelmintic treatment frequency in the previous 12 months was not (p = 0.7081). Multiple, mixed-effect logistic regression revealed that anthelmintic drug class (p < 0.0001) was the most impactful factor in predicting anthelmintic efficacy, after accounting for operation size, region and clustering of equids at the operation level. Pasture rotation (p = 0.0129) also demonstrated a significant effect using this model. These data document widespread occurrence of reduced anthelmintic efficacy of benzimidazole and pyrimidine products against strongyle infections in equids in the United States. Anthelmintic efficacy patterns were relatively uniform between the four studied regions, and some epidemiological factors were identified to be associated with anthelmintic efficacy against strongyle infections. This information can be useful in devising sustainable parasite control strategies in the future.

Longitudinal study for anthelmintic efficacy against intestinal helminths in naturally exposed Lithuanian village dogs: critical analysis of feasibility and limitations

The efficacy of anthelmintic treatment at 1, 3, and 6month intervals was evaluated in a prospective controlled field study with naturally exposed Lithuanian village dogs by monthly coproscopy during 1year. A placebo-treated control group (C) (n = 202) and groups treated with two broad-spectrum anthelmintics, febantel/pyrantel-embonate/praziquantel (Drontal® Plus, Bayer) (D1, D3, D6; n = 113-117) and emodepside/praziquantel (Profender®, Bayer) (P1, P3, P6; n = 114-119), were included. At the beginning of the study, eggs of Toxocara canis (4.02%) and T. cati (0.44%) identified morphometrically and/or molecularly and eggs of taeniid- (0.78%) and Capillaria-like eggs (5.03%) were present in the feces without significant differences in prevalence between groups. Significant decreases in excretion of T. canis eggs was found 1month after the treatment with Drontal® Plus in February (D1) and with Profender® in October (P1), November (P1), December (P3), February (P1), and March (P1, P3), as compared to controls in the same months. The incidence of egg excretion per dog at least once a year was significantly lower in group P1 for T. canis (4.24%; p < 0.01) and in groups D1, P1 for taeniid eggs (0%; p < 0.01 and p < 0.001), when compared to controls (16.96 and 6.70%, respectively). A critical analyses of factors possibly responsible for intestinal passage of canine helminth eggs revealed that chained dogs excreted T. canis eggs more frequently 1month after treatment compared to dogs in pens, particularly from November to March (p = 0.01). The incidence of single detection of T. cati eggs was significantly increased in chained dogs (12.46%) as compared to fenced dogs (1.08%; p = 0.0001).

Comparison of Four Diagnostic Methods for Detection and Relative Quantification of Haemonchus contortus Eggs in Feces Samples.

We compared four methods for identification of Haemonchus contortus eggs. With increased trade in animals within and between countries and continents, it has become important to correctly identify H. contortus eggs in fecal samples. To validate the outcome of diagnostic tests, sheep feces (n = 38) were collected from naturally infected flocks in Sweden. Subsamples were analyzed with (a) McMaster egg counting; (b) differential counting of eggs after staining with peanut agglutinin (PNA); (c) detection of DNA following amplification by real-time quantitative polymerase chain reaction (qPCR); and (d) loop-mediated isothermal amplification (LAMP). Differences between similar tests (microscopic and molecular) and SD (±SD) were analyzed with Bland–Altman plots and Spearman rank correlation. Strongylid egg counts ranged from 200 to 12,100 eggs per gram (epg) (mean epg ± SD = 1,278 ± 2,049). Microscopy showed presence of H. contortus eggs in 27 (73%) unstained samples and in 28 (76%) samples stained with PNA, whereas 29 samples (78%) tested positive in LAMP and 34 (91%) in qPCR analysis. The cycle threshold (Ct) values with LAMP ranged between 13 and 38 (mean ± SD = 21 ± 7), and those in qPCR between 25 and 49 (mean ± SD = 33 ± 6). In the LAMP and qPCR analyses, seven (19%) and three (8%) samples, respectively, had a cycle threshold (Ct) >35, whereas no reactions were observed in eight (22%) and three (8%) samples, respectively. There was good agreement between the diagnostic tests based on microscopic examination and DNA detection, although the molecular tests were more sensitive. The bias between the microscopy methods (−4.2 ± 11) was smaller than for the molecular tests (−9.8 ± 10). The observed ranking in terms of test sensitivity was: McMaster counting by conventional microscopy < PNA < LAMP < qPCR. In conclusion, H. contortus can be identified by McMaster counting, without major mistakes regarding false positive results. However, molecular methods provide the capacity to diagnose H. contortus eggs with increased accuracy. This is essential when animals are investigated in quarantine or in studies evaluating anthelmintic treatment efficacy. These methods could also be applied to fecal samples from wildlife to investigate nematode transmission between wildlife and livestock.

A multiplex restriction enzyme-PCR for unequivocal identification and differentiation of Trichostrongylus species in human samples

Trichostrongylus species remain one of the major health challenges in the tropical and summer rainfall regions worldwide. Identification of strongylid species diagnostic methods is vital for obtaining a deep understanding of the epidemiology, population biology, anthelmintic treatment efficacy, and drug resistance in order to design effective parasite control strategies. We evaluated a multiplex RE-PCR for the diagnosis of key Trichostrongylus spp. Genomic DNA amplification of Trichostrongylus colubriformis, Trichostrongylus axei and Trichostrongylus vitrinus was achieved as standard sample using specific primers located in the second internal transcribed spacer (ITSII) of nuclear ribosomal DNA (rDNA). The mentioned method was based on isolation of Trichostrongylus ova from human fecal samples using Willis method, the extraction of ova genomic DNA samples, followed by rDNA ITSII PCR and one-step multiplex RE-PCR using three restriction enzymes of HinfI, DraI, and MseI. The multiplex RE-PCR technique provides a useful tool for discriminating all Trichostrongylus spp., being useful for diagnostic, epidemiological, ecological studies, and control programs. This method is rapid, especially when numerous restriction enzymes are required for species differentiation or identification.

Studies on prevalence of ascariasis in indigenous chickens in Gaibandha district and treatment by pineapple leaves extract

Ascariasis is very common in indigenous chicken causing retarded growth, low productivity and mortality. Considering the problem of Ascaridia galli in chickens, anthelmintic resistance, high cost and human health hazard of chemical anthelmintic the use of medicinal plant is an alternative choice. The study was conducted to determine the incidence of ascariasis in Polashbari upazilla of Gobindhaganj district during July to November 2012 and subsequently evaluated the efficacy of pineapple (Ananus comosus) leaves extract against ascariasis infected chickens. Out of 500 chickens examined for presence of A. galli infestation by faecal sample examination, 365 hens and 135 cocks. The 292 female (80%) and 119 male (88.15%) were found infected with A. galli. The highest infection rate 95.26% was found in 60 to 90 days of age group. Infected chickens were treated with pineapple leaves extract @ 1ml/kg body weight per OS for 7 consecutive days. The efficacy of anthelmintic treatment was evaluated by counting fecal egg per gram (EPG) compared with pretreatment values. Body weight and hematological changes of each chicken was recorded in pre and post treatment. In the untreated control chickens the average EPG increased from 300 ± 11.07 to 340 ± 13.96. The average EPG reduced from 300 ± 11.07 to 60 ± 7.40 within 28 days of pineapple treatment. The mean body weight gain in treated chicken was significantly (p&lt;0.01) higher than the control. Pineapple leaves extract increased the TEC, Hb and PCV and decreased TLC and ESR values of chickens. But in control group TEC, Hb and PCV decreased and TLC and ESR values increased. It may be concluded that pineapple leaves extract treatment effectively reduced the ascariasis load in chicken and improved body weight.Res. Agric., Livest. Fish.3(1): 157-163, April 2016

Efficacy of anthelmintic treatment in captive-reared black stilts (Himantopus novaezelandiae) released to the wild

AIMS: To assess the efficacy of praziquantel (PZQ) administered to control helminths in captive-reared critically endangered black stilts (Himantopus novaezelandiae) before their release into the wild and determine the effect on their survival shortly after release.METHODS: Of 77 captive black stilts, 37 were treated with PZQ prior to release into the wild in South Canterbury, New Zealand, in August and September 2007. Faecal helminth egg counts (FEC) were measured before and after anthelmintic treatment, and before and after release to the wild using modified faecal flotation and sedimentation methods. In addition, total helminth counts were determined in 11 of the birds that died following release, as well as four captive and 11 other wild stilts.RESULTS: The efficacy of PZQ against trematodes was 92% and against Capillaria spp. was 34%. No trematode or Capillaria spp. eggs were detected in treated birds 1 day after treatment, but FEC increased 3–5 days after treatment. There were no differences in the total helminth counts for trematodes, cestodes or Capillaria spp. in control or treated birds (p>0.2). Survival did not differ between treatment groups in the August or September releases (p>0.4). Of control and treated birds, 11/17 (65%) and 8/14 (57%) survived to 31 days, respectively, in the August release, and 16/20 (80%) and 10/15 (67%) survived to 84 days, respectively, in the September release.CONCLUSION: Overall, the results suggest that PZQ treatment may be an unnecessary cost and the risks of producing anthelmintic resistance, injuring the birds during processing or producing an unnecessary stress response at the time of release could exceed any likely benefits.CLINICAL RELEVANCE: It is recommended that pre-release anthelmintic treatment of black stilts should be used only if indicated by health screening. Any treatment should incorporate annual efficacy testing to monitor the emergence of anthelmintic resistance.

Equine tapeworm infections: Disease, diagnosis and control

SummaryEquine tapeworm infection has gained increasing attention over the past few decades and a number of research studies have already been published. These focus primarily on the most common of the 3 tapeworm species, Anoplocephala perfoliata, although some new information has also been generated for the other two species, Anoplocephala magna and Anoplocephaloides mamillana. The preponderance of research studies have focused on development and validation of diagnostic techniques for tapeworm detection and the role of these parasites in equine gastrointestinal disease. Several diagnostic techniques have been found useful for diagnosis of A. perfoliata but each has its strengths and weaknesses. Egg counting techniques have been modified to achieve acceptable to good diagnostic performance but the trade‐off is often a more time‐consuming method. Validation studies indicate that these methods can reliably detect tapeworm burdens above 10 worms. Several enzyme‐linked immunosorbent assays (ELISAs) have been developed and made commercially available. These can generate useful information about tapeworm exposure on the herd level but are less reliable for individual diagnosis. Unfortunately, none of the available diagnostic techniques are useful for evaluating anthelmintic treatment efficacy. Coproantigen testing may find use as a future diagnostic modality but further characterisation is required. The large body of scientific evidence supports an association between A. perfoliata infection and certain types of equine colic, although some discrepancy exists between studies. Tapeworm surveillance and control should be considered as part of the overall parasite control strategy. When properly used, the currently available diagnostic tools can guide the veterinarian to make strategic decisions regarding tapeworm control.

Helminth infections and type 2 diabetes: a cluster-randomized placebo controlled SUGARSPIN trial in Nangapanda, Flores, Indonesia.

BackgroundInsulin resistance is a strong predictor of the development of type 2 diabetes mellitus. Chronic helminth infections might protect against insulin resistance via a caloric restriction state and indirectly via T-helper-2 polarization of the immune system. Therefore the elimination of helminths might remove this beneficial effect on insulin resistance.Methods/DesignTo determine whether soil-transmitted helminth infections are associated with a better whole-body insulin sensitivity and whether this protection is reversible by anthelmintic treatment, a household-based cluster-randomized, double blind, placebo-controlled trial was conducted in the area of Nangapanda on Flores Island, Indonesia, an area endemic for soil-transmitted helminth infections. The trial incorporates three monthly treatment with albendazole or matching placebo for one year, whereby each treatment round consists of three consecutive days of supervised drug intake. The presence of soil-transmitted helminths will be evaluated in faeces using microscopy and/or PCR. The primary outcome of the study will be changes in insulin resistance as assessed by HOMA-IR, while the secondary outcomes will be changes in body mass index, waist circumference, fasting blood glucose, 2 h-glucose levels after oral glucose tolerance test, HbA1c, serum lipid levels, immunological parameters, and efficacy of anthelmintic treatment.DiscussionThe study will provide data on the effect of helminth infections on insulin resistance. It will assess the relationship between helminth infection status and immune responses as well as metabolic parameters, allowing the establishment of a link between inflammation and whole-body metabolic homeostasis. In addition, it will give information on anthelmintic treatment efficacy and effectiveness.Trial registrationThis study has been approved by the ethical committee of Faculty of Medicine Universitas Indonesia (ref: 549/H2.F1/ETIK/2013), and has been filed by the ethics committee of Leiden University Medical Center, clinical trial number: ISRCTN75636394. The study is reported in accordance with the CONSORT guidelines for cluster-randomised trials.

Trichostrongylus and Haemonchus anthelmintic resistance in naturally infected sheep from southern Brazil

The anthelmintic resistance in small ruminants is a common problem and concern worldwide. The aim of this study was to verify anthelmintic treatment efficacy in naturally infected sheep. This study was conducted on nine herds that used the same anthelmintic management for over a year. In each farm, the animals were divided into two groups: untreated control group (n = 5) and treated (n = 10) according to the number of eggs per gram of feces (EPG). The treatment effect was checked based on EPG results and larval culture performed before treatment and 10 days after treatment. Significant differences were not observed (P > 0.05) on EPG results between untreated and treated groups. The coproculture showed that the animals were infected primarily by Haemonchus spp., Trichostrongylus spp., Teladorsagia spp., Cooperia spp. and Oesophagostomum spp. In all farms, anthelmintic resistance by genera Haemonchus and Trichostrongylus was found, but this resistance varied greatly between farms. Haemonchus spp. showed resistance to closantel, levamisole, and albendazole. Trichostrongylus spp. was shown to be resistant to closantel, levamisole, and albendazole. The drugs tested showed to be efficient against the genera Teladorsagia, Cooperia, and Oesophagostomum. Based on these results, we conclude that the anthelmintic resistance to the tested drugs is a problem present in the farms evaluated.