Parasitic helminths of the pig: factors influencing transmission and infection levels

Effects of season, age and parasite management practices on gastro - intestinal parasites in pigs kept outdoors in Ireland

Outdoor farming offers pigs considerable behavioural freedom and better consumer acceptance than intensive, indoor systems. However, gastro - intestinal (GI) parasites pose a significant health and welfare challenge for pigs reared outdoors. The aim of this study was to ascertain effects of management, season and animal factors such as age, on a range of different GI parasites in Irish pigs farmed outdoors. Sixty-five pig faecal samples (a mix from at least 2-4 animals per paddock) were collected from 65 paddocks across 20 outdoor pig farms, over two visits (1st visit - February/May-December 2023, n = 37, 2nd visit- July/October 2023, n = 28). Samples were collected and mixed thoroughly to achieve a paddock level sample. Data were also collected related to pig characteristics (grower/fatteners or sows and boars), anthelmintic usage (Yes/No) and paddock rotation (Yes/No) and categorized at paddock level. Samples were analysed using the McMaster floatation method, faecal egg count (FEC) was calculated, and GI parasites were identified by morphology. Generalized linear mixed models were used to analyse the effect of season, age, anthelmintic usage and paddock rotation on FEC. Four parasite taxa were identified (Eimeria/Isospora spp., strongyles, Ascaris suum and Trichuris suis). Infection rates were > 80% for Eimeria/Isospora spp. and strongyles, 31% for A. suum and 9% for T. suis for both visits. Eimeria/Isospora spp. FEC was higher at the 2nd visit (P < 0.001) and strongyles FEC was higher at the 1st visit (P < 0.05). Fattener pigs had higher FEC for Eimeria/Isospora spp. (P < 0.01) and sows/boars had higher strongyle counts (P < 0.05). Strongyle count was lower with anthelmintic use (P < 0.05) and Eimeria/Isospora spp. count was lower (P = 0.05) with paddock rotation when anthelmintics were used. Lower winter temperatures may have influenced the seasonal variation in strongyle FEC. This study provides a comprehensive picture of GI parasites in outdoor pig farms in Ireland in terms of the taxa, their prevalence and risk factors.

Abattoir monitoring of liver lesions caused by Ascaris suum larvae: A longitudinal study conducted in northern Italy

INTRODUCTION

Data supplied by the abattoir monitoring system offer a useful tool both for tracing the prevalence of Ascaris suum milk spot lesions and for conducting large-scale epidemiological studies.

MATERIALS

In this study, livers of 754833 slaughtered pigs from 5835 batches and 399 farms located in northern Italy, were evaluated in one of the largest national abattoirs during a year of survey. From each farm data concerning the breeding region and province, the season of post-mortem inspection, the farm size and the type of farm production were collected and the probability of finding a positive animal, i.e. with at least one milk spot lesion, in relation to these factors was estimated by a generalised linear mixed model (GLMM).

RESULTS

368 out of 399 farms tested positive (92.2 %), out of 5835 batches of animals, 4395 (75.3 %) had at least one positive pig, and out of 754833 carcasses, 198964 showed milk spots, with an overall prevalence of 26.4 %. The breeding province and the season of post-mortem inspection were two significant risk factors: a higher risk of finding animals with milk spots was recorded in some Italian provinces and in spring.

CONCLUSIONS

This study provides data on the prevalence of milk spots caused by A. suum migrating larvae in an area characterised by a high density of pig farms. Given the high prevalence recorded, it is necessary to promote effective communication between abattoir, veterinarians and farmers, monitoring the circulation of A. suum, developing specific control plans and enhancing animal health surveillance.

Roles of helminth extracellular vesicle-derived let-7 in host-parasite crosstalk

Helminth infections are a major public health problem as they can cause long-term chronic infections in their hosts for which there is no effective vaccine. During the long-term interaction between helminths and their hosts, helminth-derived extracellular vesicles (EVs) can participate in host immunomodulatory processes by secreting bioactive molecules (BMAs). Growing data suggests that microRNAs (miRNAs) in helminth EVs have a significant impact on the host's immune system. The let-7 family is highly conserved among helminth EVs and highly homologous in the host, and its function in host-parasite crosstalk may reflect active selection for compatibility with the host miRNA machinery. In-depth studies targeting this aspect may better elucidate the mechanism of parasite-host interactions. Hence, this review summarizes the current studies on the cross-species involvement of helminth EV-derived let-7 in host immune regulation and discusses the barriers to related research and potential applications of helminth EVs.

Gastrointestinal nematodes in German outdoor-reared pigs based on faecal egg count and next-generation sequencing nemabiome data

BACKGROUND

There is a higher risk for nematode infections associated with outdoor-reared pigs. Next to Ascaris suum, Oesophagostomum dentatum and Trichuris suis, there is the potential of infections with other nodular worm species, Hyostrongylus rubidus, Stongyloides ransomi and Metastrongylus spp. lungworms. Next-generation sequencing methods describing the nemabiome have not yet been established for porcine nematodes.

METHODS

FLOTAC was used for faecal egg counts of porcine gastrointestinal nematodes and lungworms in piglets, fatteners and adults individually. A nemabiome analyses based on ITS-2 gene region metabarcoding was used to differentiate strongyle species. Additionally, questionnaire data was analysed using mixed-effect regression to identify potential risk factors associated with parasite occurrences and egg shedding intensity.

RESULTS

On 15 of 17 farms nematode eggs were detected. Ascaris suum, strongyles and T. suis were detected on 82%, 70% and 35% of the 17 farms, respectively. Lungworms were detected on one out of four farms with access to pasture. Strongyloides ransomi was not detected. 32% (CI 28-36%), 27% (24-31%), 5% (4-7%) and 3% (0.9-8%) of the samples where tested positive for strongyles, A. suum, T. suis and lungworms, respectively. The nemabiome analysis revealed three different strongyle species, with O. dentatum being the most common (mean 93.9%), followed by O. quadrispinulatum (5.9%) and the hookworm Globocephalus urosubulatus (0.1%). The bivariate and multivariate risk factor analyses showed among others that cleaning once a week compared to twice a week increased the odds significantly for being infected with A. suum (OR 78.60) and strongyles (2077.59). Access to pasture was associated with higher odds for A. suum (43.83) and strongyles (14.21). Compared to shallow litter systems, deep litter and free range systems resulted in significant higher odds for strongyles (85.74, 215.59, respectively) and T. suis (200.33, 623.08).

CONCLUSIONS

Infections with A. suum, O. dentatum, O. quadrispinulatum, T. suis, Metastrongylus spp. and G. urosubulatus are present in German outdoor-reared pigs. This is the first report of G. urosubulatus in domestic pigs in Europe. Metabarcoding based on the ITS-2 region is a suitable tool to analyse the porcine nemabiome. Furthermore, management practices have the potential of reducing the risk of parasite infections.

Prevalence of gastrointestinal parasitism in pigs of Tripura, India

Pigs breeds are an important livestock species mostly reared by economically lower incomesection of people in India. Within North-Eastern (NE) states, pig husbandry is very much popular hence maintain the livelihood of the rural native population. Gastrointentinal (GI) parasitic infectionisone of the major constraint in profitable pig production in this area. In the present study, the GI parasitism was investigated in 388 pigs in the three districts of Tripura, NE State of India. The examination of faecal samples revealed 61.65% overall prevalence of parasitic infestation, precisely6 GI parasitic species; including 4 nematodes and 2 protozoa, while 46.91% were the mixed infections.Metastrongylus spp. (17.53%), Strongyloids spp. (19.33%),Trichuris spp. (15.98%), Coccidia spp. (12.37%), and Balantidium coli (10.82%), were detected, however, Ascaris spp. was the most prevalentrecording 32.47%. The epidemiological factors including: age, sex, season, breed, area and farming system wise when considered as markers of study showed the highest prevalence of GI parasites in grower(6-12 months) stage, female, monsoon season, non-descript breeds, Khowai district and free range farming system, recorded 71.52%, 67.27%, 65.78%, 65.71%, 64.57%, and 69.44%, respectively. Overall, our study provides a baseline data for further investigation and formulation of strategies for control of GI parasitism in pigs in Tripura.

Hepatobiliary Ascariasis in a Piglet

PURPOSE

Ascariasis caused by the helminth Ascaris suum is the most common parasitosis of swine worldwide and it may involve all age categories of pigs. The present study reports an unusual localization of A. suum worms in the biliary system of a piglet slaughtered for human consumption.

METHODS

The liver was subjected to ultrasound scan and pathological examination. The isolated worms were morphologically examined and the DNA was extracted for the molecular identification of the species involved.

RESULTS

A total of 43 preadult nematodes were found within the gallbladder and the bile ducts. Parasites were morphologically identified as belonging to the genus Ascaris and molecularly as A. suum. At gross examination, the liver was moderately enlarged, with the bile ducts severely dilated. A chronic inflammatory infiltrate was noted, often centered around ectatic bile ducts (up to 5 mm in diameter), lined by hyperplastic epithelium and filled with sections of nematodes. The worm sections showed smooth cuticle, coelomyarian musculature, and an intestinal tract lined by columnar, uninucleated cells within a pseudocoelom. The ex vivo ultrasonographic examination of the liver allowed the visualization of several nematodes in the bile duct lumen and could be suggested for in vivo diagnosis. Unfortunately, the absence of the intestine did not allow to define the pathogenesis of the infection.

CONCLUSION

Although, given the unusual nature of this finding, it is difficult to identify predisposing factors for this A. suum localization, it suggests that ascariasis should be considered in the differential diagnosis of pigs with hepatobiliary disease.

INTESTINAL PARASITES IN PECARI TAJACU AND SUS SCROFA DOMESTICUS IN THE CAATINGA FROM SOUTHEASTERN PIAUÍ, BRAZIL

This study identifies gastrointestinal parasites in the feces of Pecari tajacu (caititu) and Sus scrofa domesticus (domestic pig) in southeastern Piauí, Brazil. The region covers 2 protected areas, Serra da Capivara National Park and Serra das Confusões National Park, and surrounding communities. Fecal samples from 64 animals, 42 from domestic swine and 22 from caititu, collected between 1985 and 2013, were analyzed by optical microscopy. Helminths and/or protozoa were found in 64% of the domestic pig samples and 27% of the caititu samples, totaling 18 morphospecies: Nematoda, Spirurida (2 morphospecies), Trichostrongyloidea, Eimeriidae, Aspidodera sp., Bertiella sp., Metastrongylus sp., Trichostrongylus sp., Moniezia sp., Gongylonema sp., Trichuris suis, Spirocerca lupi, Macracanthorhyncus hirudinaceus, Globocephalus urosubulatus, Strongyloides cf ransomi, Balantioides coli, and Eimeria cf scabra. The highest parasite diversity was obtained in the pig samples, totaling 15 morphospecies, compared to only 6 in caititus, with S. cf ransomi, G. urosubulatus, and S. lupi present in both hosts. We discuss the presence of parasites associated with domestic animals around the Protected Areas and potentially zoonotic parasites close to human communities, which raise concerns about the conservation of wildlife, human health, and livestock in the region.

Intestinal roundworm infection in organic and alternative swine farms in the USA

Swine parasites are a challenge for organic and alternative pig farmers and represent suboptimal animal health because use of chemical prophylaxis is not recommended. There is no comprehensive study of how prevalent gastrointestinal parasites are in organic or alternative pig farms across the USA. This study investigates prevalence, abundance, and intensity measures for three intestinal roundworm parasites (Ascaris suum, Oesophagostomum spp. and Trichuris suis) on organic and alternative swine farms by quantifying their eggs in pig feces, pastured soil, and bedding. Nine farms raising pigs in bedded facilities across four states (Iowa, Minnesota, Pennsylvania, and Wisconsin) were sampled, and analysis of parasite egg counts from feces indicate that 88.9%, 55.5%, and 44.4% of farms were infected with A. suum, Oesophagostomum spp. and T. suis, respectively. Prevalence, mean abundance, and mean intensity of eggs per gram (EPG) in feces for A. suum and T. suis were higher in growing and finishing pigs, whereas they were higher for Oesophagostomum spp. in finishing pigs and sows. Prevalence and abundance with A. suum eggs in feces were higher in organic certified farms, whereas abundance of Oesophagostomum spp. and T. suis was lower than those in alternative farms. Fewer eggs were recovered from soils than bedding samples, but their presence in both substrates confirmed that dispersal stages occur in farms. Overall, our results indicate that intestinal parasite infection across organic and alternative swine farms in the USA is common, and not surprising given that few options to control infection within organic regulations are available.

Modulation of the porcine intestinal microbiota in the course of Ascaris suum infection

Background

The porcine roundworm Ascaris suum impairs feed conversion and weight gain, but its effects on intestinal microbiota remain largely unexplored.

Methods

Modulation of the intestinal microbiota was assessed in pigs that were infected once with 10,000 A. suum eggs and pigs that received a trickle infection (1000 eggs/day over 10 days), compared with a non-infected control group. Six pigs each were sacrificed per group at days 21, 35 and 49 post-infection (p.i.). Faecal samples taken weekly until slaughter and ingesta samples from different intestinal compartments were subjected to next-generation sequencing of the bacterial 16S rRNA gene.

Results

The results revealed marked differences between the single- and the trickle-infected group. Single infection caused a remarkable but transient decrease in microbial diversity in the caecum, which was not observed in the trickle-infected group. However, an increase in short-chain fatty acid-producing genera in the caecum on day 21 p.i., which shifted to a decrease on day 35 p.i., was common to both groups, possibly related to changes in excretory–secretory products following the parasite’s final moult. Faecal microbial interaction networks were more similar between the single-infected and control group than the trickle-infected group. In addition, a lower degree of similarity over time indicated that A. suum trickle infection prevented microbiota stabilization.

Conclusions

These different patterns may have important implications regarding the comparability of experimental infections with natural scenarios characterized by continuous exposure, and should be confirmed by further studies.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05535-w.

Advances in diagnosis of gastrointestinal nematodes in livestock and companion animals

Diagnosis of gastrointestinal nematodes in livestock and companion animals has been neglected for years and there has been an historical underinvestment in the development and improvement of diagnostic tools, undermining the undoubted utility of surveillance and control programmes. However, a new impetus by the scientific community and the quickening pace of technological innovations, are promoting a renaissance of interest in developing diagnostic capacity for nematode infections in veterinary parasitology. A cross-cutting priority for diagnostic tools is the development of pen-side tests and associated decision support tools that rapidly inform on the levels of infection and morbidity. This includes development of scalable, parasite detection using artificial intelligence for automated counting of parasitic elements and research towards establishing biomarkers using innovative molecular and proteomic methods. The aim of this review is to assess the state-of-the-art in the diagnosis of helminth infections in livestock and companion animals and presents the current advances of diagnostic methods for intestinal parasites harnessing (i) automated methods for copromicroscopy based on artificial intelligence, (ii) immunodiagnosis, and (iii) molecular- and proteome-based approaches. Regardless of the method used, multiple factors need to be considered before diagnostics test results can be interpreted in terms of control decisions. Guidelines on how to apply diagnostics and how to interpret test results in different animal species are increasingly requested and some were recently made available in veterinary parasitology for the different domestic species.

Family-Run Pig Farms: Research and Extension Activities for Parasite Control in a Municipality in the State of Rio de Janeiro, Brazil

The parasites infesting pigs and pig farmers on family farms in Rio de Janeiro city, Brazil, were analyzed, and extension activities were carried out to impart information about parasites. Between 2020 and 2021, fecal samples were collected from 180 pigs as well as ear scrapings from 142 pigs. In addition, 34 stool specimens from farmers and their families were analyzed. The collected material was processed by parasitological techniques. Parasites were detected in 86.1% of the pigs, forms of phylum Ciliophora (70.5%), strongylids (56.7%), Strongyloides ransomi (44.4%), coccidia (38.3%) and Ascaris suum (32.2%). Sarcoptes scabiei var. suis were identified in 3.5% of the pigs. An analysis of infections by age group revealed that the general frequency of phylum Ciliophora and strongylid parasites was statistically significant. Other factors also associated with the frequency of the parasites included the type of food fed to the pigs, cleaning of the facilities, care of piglets and type of facility. The frequency of intestinal parasites of farmers themselves was low; however, the high rate of parasite infections detected in pigs highlighted the precarious conditions of hygiene of the farms. Lastly, the farmers’ participation in extension activities was a step forward in actions to improve their farm management.

Prevalence of Swine Gastrointestinal Parasites in Two Free-Range Farms from Nord-West Region of Romania

Parasitic diseases cause significant economic losses in swine, including free-range swine farms, the number of which in Romania has increased in the last decades. The current study aimed to identify the parasitic profile of swine raised on two free-range (low-input) farms from Transylvania. Nine hundred sixty samples collected from weaners, fatteners, and sows were investigated by flotation, centrifugal sedimentation, modified Ziehl-Neelsen stained fecal smear, modified Blagg technique, and oocyst/egg cultures. The number of oocysts (OPG), cysts (CPG), and eggs (EPG) were counted per gram of fecal matter. The examination revealed parasitic infections with Balantidium coli, Eimeria spp., Ascaris suum, Trichuris suis, Oesophagostomum spp., Strongyloides ransomi and Cryptosporidium spp. Prevalence (P) and the mean intensity (MI) of the infections varied according to age, swine category, farm, and season. The overall prevalence in both free-range farms according to the age category was 63.2%—Eimeria spp., 70.31%—B. coli, 9.38%—Oesophagostomum spp., 3.75% S. ransomi, and 18.12% Cryptosporidium spp. in weaners. In fatteners Eimeria spp. revealed a prevalence of 50.93%, B. coli—72.5 %, A. suum—63.13%, T. suis—39.06%, and in sows Eimeria spp.—39.06%, B. coli—62.19%, A. suum—34.06%, Oesophagostomum spp.—27.19%, S. ransomi—1.56% and Cryptosporidium spp.—9.38%. The study revealed statistically significant (p < 0.05) differences between age groups, seasons, and farms for all diagnosed parasites. Further research is required to better understand the epidemiology of these infections in swine from Transylvania.

Occurrence of Intestinal Parasites and Its Impact on Growth Performance and Carcass Traits of Pigs Raised Under Near-Organic Conditions

Parasite infection is a common problem in organic pig production, which can compromise health and growth of pigs, threaten food safety of pork products, and cause economic losses to organic farmers. To develop management strategies for controlling parasites, we evaluated intestinal parasite infection in pigs at different ages and of different sexes, and investigated whether parasite infection influences growth performance and carcass traits in a cross-sectional study. Fecal samples were collected from pigs (n = 298) raised under near-organic standards during nursery, growing, finishing, and gestating phases for analysis of fecal egg counts (FEC) of Ascaris suum, Trichuris suis, and Oesophagostomum spp. Ascaris suum eggs were not detected in the feces of nursery pigs. Eggs of Ascaris suum were found in 45%, 74%, and 0% of fecal samples of growing pigs, finishing pigs, and gestating sows, respectively, after false-positive adjustment (P < 0.001). Mean FEC of Ascaris suum was higher in infected finishing pigs than in infected growing pigs [2,502 vs. 724 eggs per gram (epg), P < 0.001]. No differences in percent of Ascaris suum positive samples or FEC of Ascaris suum were detected between sexes. Growth performance and carcass traits were not different between non-infected pigs and those infected with Ascaris suum. All pigs (n = 32) examined at slaughter had white spots on the liver, and 78% harbored Ascaris suum worms. Trichuris suis eggs were not detected in any fecal samples. Eggs of Oesophagostomum spp. were found in 7%, 0%, 1%, and 9% of fecal samples of nursery pigs, growing pigs, finishing pigs, and gestating sows, respectively, with a maximum FEC of 40 epg in all age groups. These results indicate Ascaris suum was the predominant parasite infecting growing and finishing pigs in the herds studied. To control A. suum infection, future research should investigate the efficacy of treating pigs with organically approved anthelmintics during the growing phase of production.

Cytochrome c oxidase subunit 1 gene reveals species composition and phylogenetic relationships of Oesophagostomum spp. infecting pigs in northeastern Brazil

Helminths of the genus Oesophagostomum cause enteric diseases and affect domestic animals such as pigs. The aim of this study was to explore the species composition and genetic diversity of Oesophagostomum spp. infecting pigs in close contact with humans in the state of Piauí, Brazil. Eighty-seven fecal samples were collected for parasitological tests and molecular analysis. Through microscopy, the overall positivity rate for strongyliform eggs was 81.6% among the pigs studied. Forty-two strongyliform egg samples were subjected to PCR and six cox1 sequences (637 bp) were identified for the genus Oesophagostomum. The sequences were identified as Oesophagostomum dentatum, O. quadrispinulatum and O. columbianum. In the phylogenetic tree and haplotype network, 89 sequences were separated into seven clusters, which also included reference sequences from GenBank. Oesophagostomum dentatum and O. quadrispinulatum were seen to be closely related species and formed a monophyletic group related to O. aculeatum. Oesophagostomum columbianum showed similarity with sequences from parasites infecting small ruminants and the clade was positioned closer to O. bifurcum. High interspecific diversity was found and intraspecific diversity varied according to the species. This was the first study to characterize Oesophagostomum DNA sequences obtained from pigs in Brazil.

Comparison of different detection methods for Ascaris suum infection on Austrian swine farms

Background

Ascaris suum, the large roundworm of pigs, is one of the economically most important pig parasites worldwide. In Austria it is commonly diagnosed by monitoring livers for milk spots at the slaughterhouse and intravital diagnosis (flotation for detection of fecal egg shedding). Recently, serological diagnosis based on the detection of specific antibodies with an ELISA (SERASCA®) with high sensitivity has been developed. To introduce and evaluate serology for A. suum screening in Austrian pigs, blood (for serology) (n = 177) and feces (for copromicroscopy) (n = 177) were taken from randomly selected slaughter pig batches from 18 farms at a slaughterhouse in Lower Austria. In addition, livers presented at slaughter (n = 844; max. 70/farm) were evaluated for milk spots.

Results

Overall, 19% of the livers were milk spot-positive (22% of those with complete diagnostic evaluations). Thirteen percent of the fecal samples contained A. suum eggs, while 69% of the blood samples were serologically positive. Despite we did not determine the sensitivity of the ELISA specifically, results ouf our study confirmed the high sensitivity of the ELISA, which was claimed by the manufacturer prior to our work (sensitivity: liver assessment: 23.5–27.0%; copromicroscopy: 8.5–9.0%; ELISA: 99.5%), and a high percentage of A. suum infections that remained undetected by standard liver assessment.

Conclusions

This suggests that the current method of roundworm diagnostics is insufficient and antibody detection at the end of the fattening period should be established as the standard procedure.

Macracanthorhynchus hirudinaceus in expanding wild boar (Sus scrofa) populations in Eastern Spain

Prevalence and temporal evolution of the infection by the acanthocephalan Macracanthorhynchus hirudinaceus is studied in the Valencian Community (Eastern Spain), a region only recently fully colonized by the expanding native Eurasian wild boar (Sus scrofa). For 8 years, a total of 1486 wild boars were sampled in order to look for the parasite. The mean prevalence was 20.7% (95% CI, 18.6-22.8; 307/1486). We observed an increasing trend through time, both in the number of wild boars and affected districts. The prevalence of M. hirudinaceus rose in parallel to the annual capture of wild boars, and its presence has been expanding towards the East. A hotspot of M. hirudinaceus is located to the west of the study area, in Muela de Cortes Game Reserve, where 89.6% of the wild boars were positive for the infection, constituting one of the world's highest known prevalence areas.

Prevalence of Swine Gastrointestinal Parasites in Nyagatare District, Rwanda

While pig farming has been growing rapidly in Rwanda, its potential contribution to the prevalence of zoonotic infections is not well known. Pig production is usually affected by gastrointestinal parasites, some of which are zoonotic and can threaten human health. The knowledge about the status of such infections is essential for policy decisions and interventions. We aimed to investigate the prevalence of swine gastrointestinal parasites in Nyagatare district, Rwanda. A cross-sectional study involved collecting 104 faecal samples from apparently healthy pigs. The floatation technique was used to identify the parasites and frequency distribution analysis, and Pearson chi-square tests of association were conducted for this study data. Overall, the prevalence of swine gastrointestinal parasites was 84.6%, and the predominant species were Strongyle-type helminths representing 70.2%, followed by coccidia (55.8%), Strongyloides ransomi (39.4%), and Ascaris suum (10.6%). Of all parasitized pigs (n = 88), 84.1% developed coinfections involving 2, 3, or 4 different parasite species. The results showed a statistically significant correlation between the location of pigs and parasitic infections and that some prevalent parasites are zoonotic. Interventions among pig farmers in Nyagatare should aim to improve awareness and to provide information on the negative impacts of swine gastrointestinal parasites on pig production and human health.

Evidence for mitochondrial pseudogenes (numts) as a source of contamination in the phylogeny of human whipworms

Trichuris trichiura and T. suis are whipworms of humans and pigs, respectively, but it has recently been suggested that humans may be infected with multiple genotypes or species of Trichuris and cross-infection with Trichuris of pig origin has also been reported. In addition, the species status of Trichuris in non-human primates is unsettled and it is unknown how many whipworm species we share with other primates. Herein, we inferred the phylogeny of Trichuris collected from human, baboon and pig based on nuclear (18S and beta-tubulin) and mitochondrial (cox1) genes and evaluated the use of three PCR linked restriction fragment length polymorphism (PCR-RFLP) to identify worms. We found that all baboon worms clustered with human worms and that all these primate worms are different from T. suis. In general, there was an agreement between the phylogeny established based on the nuclear and mtDNA genes. However, we found evidence for non-targeted cox1 gene amplification for a subset of the human worms and suggest the presence of mitochondrial pseudogenes (numts) of pig cox1 gene in the human Trichuris genome. In conclusion, phylogenetic characterization of human whipworm based on the cox1 gene alone may be problematic without suitable preceded measures to avoid the numts amplification.

Research and extension action for parasitic control in pig breeding families located in Tanguá, Rio de Janeiro

ABSTRACT: This study aimed to analyze the parasites infesting pigs and their producers on family farms in Tanguá, RJ, Brazil, and to conduct extension activities between 2018 and 2019. Fecal samples were collected from 132 pigs, as well as, skin scrapings from the ears of 125 animals. In addition, 36 stool specimens from farmers and their families were analyzed. The collected material was processed by direct examination, sedimentation and flotation techniques. Gastrointestinal parasites were detected in 88.6% of the pigs, especially coccidia (71.8%), Balantioides coli (55%), strongyles (40.2%) and Strongyloides ransomi (31.6%) which showed statistically significance (p<0.05). Ectoparasites were identified in 16% of the pigs, mostly Sarcoptes scabiei var. suis (76.2%). Parasites were detected in 19.4% of the humans, including, Entamoeba coli (19.4%), Ascaris lumbricoides (8.3%) and Trichuris trichiura (5.5%). The frequency of B. coli and S. scabiei var. suis (p<0.05) were statistically significant, when analyzing the age group of the animals, having been more detected in the older years, fatterners phase. The pig farmers participated in these activities extension, which included lecture and “field day”, aimed at imparting information about parasites and their prophylaxis. The situation in Tanguá pig farms reinforces the need to carry out programs that provide technical support to these farmers, whose livelihood depends on pig farming.

Prevalence and Risk Factors of Intestinal Parasite Infections in Greek Swine Farrow-To-Finish Farms

Intestinal parasites, helminths, and protozoa challenge health and welfare of pigs and deteriorate the sustainability of swine farms leading to monetary losses. A multicentric survey was conducted for approximately one year. Overall, 1150 fecal samples were collected from eight intensive farms in Greece at regular intervals and examined by flotation and Ziehl-Neelsen techniques. Age, season, and time of last recorded antiparasitic treatment were assessed as possible risk factors using binary regression models. The overall prevalence of intestinal parasitism in pigs was 44.7%. The most frequently detected parasites in the studied population were the protozoa Balantidium coli (37.8%), followed by Entamoeba spp. (8.3%), Cystoisospora suis (6.0%), and the nematodes Ascaris suum (3.7%), Trichuris suis (2.5%), and Oesophagostomum spp. (1.4%). Distribution of intestinal parasites in different age groups was as expected. In autumn, the prevalence of Balantidium coli infection enhanced whereas the prevalence of Entamoeba spp. and Cystoisospora suis infections increased in spring. Time of last recorded antiparasitic treatment influenced Balantidium coli and Trichuris suis infection levels. Our results demonstrated that swine intestinal parasitism in intensive farms of Greece seems to be relatively common and highlighted the importance of proper laboratory examinations, as well as the need for tailored made control programs.

Effects of surface materials of self-draining beds on cattle behavior in a temperate climate

Objective

The objective of the present experiment was to construct self-draining beds to keep surface bedding materials clean and dry for beef cattle comfort in a temperate climate.

Methods

In Experiment 1, a self-draining bed was covered with sand at depths of 10 cm (S-10a), 15 cm (S-15), and 20 cm (S-20) respectively. In Experiment 2, self-draining beds of different sizes were covered with 10 cm of sand (S-10b) and wood shavings (WS) at depths of 15 cm and 20 cm (WS-15 and WS-20). Fifteen cattle were engaged to evaluate the comfort of self-draining beds covered with different bedding materials.

Results

No cattle lay in the feed alley and cattle spent more time lying on S-10a than S-15 or S-20 in Experiment 1 (p<0.01). No difference in lying time was detected between S-15 and S-20 (p>0.05). In Experiment 2, no cattle selected the feed alley as the lying area. Cattle preferred WS-15 as the lying area and time spent lying on WS-20 was slightly higher than on S-10b (p<0.05). Feces weight was higher in the feed alley than in the different bedding areas in both Experiments 1 and 2 (p<0.01).

Conclusion

Sand-bedding depth at 10 cm and WSs at 15 cm above the self-draining bed can provide for the lying comfort of beef cattle. Design of a special feed alley to hold most of the feces to keep bedding materials clean and dry is desirable for organic beef cattle in a loose barn.

The 'breakpoint' of soil-transmitted helminths with infected human migration

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Novel analytic understanding of STH transmission dynamics near the breakpoint.

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New models of infected human migration are developed and analysed.

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An approximate Markovian process description is shown to describe migration well.

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Migration rates greater than the death rate of infectious stages are critical.

Building on past research, we here develop an analytic framework for describing the dynamics of the transmission of soil-transmitted helminth (STH) parasitic infections near the transmission breakpoint and equilibria of endemic infection and disease extinction, while allowing for perturbations in the infectious reservoir of the parasite within a defined location. This perturbation provides a model for the effect of infected human movement between villages with differing degrees of parasite control induced by mass drug administration (MDA). Analysing the dynamical behaviour around the unstable equilibrium, known as the transmission ‘breakpoint’, we illustrate how slowly-varying the dynamics are and develop an understanding of how discrete ‘pulses’ in the release of transmission stages (eggs or larvae, depending on the species of STH), due to infected human migration between villages, can lead to perturbations in the deterministic transmission dynamics. Such perturbations are found to have the potential to undermine targets for parasite elimination as a result of MDA and/or improvements in water and sanitation provision. We extend our analysis by developing a simple stochastic model and analytically investigate the uncertainty this induces in the dynamics. Where appropriate, all analytical results are supported by numerical analyses.

First detection of ivermectin resistance in oesophagostomum dentatum in pigs

In 2016 suspected reduced ivermectin (IVM) efficacy in Oesophagostomum species in pigs was reported in England. Following this initial report, APHA raised awareness amongst private pig veterinary practitioners of the need to monitor the efficacy of the worm control on pig units. In 2017 another veterinary practitioner highlighted a potential in-field lack of IVM efficacy in treating Oesophagostomum species in sows on another breeder-finisher unit. In this trial, the efficacy of IVM against Oesophagostomum species worms has been investigated to determine whether suspected reduced efficacy (52% reduction in mean faecal egg count 14 days post ivermectin administration) on a mixed indoor and outdoor breeder-finisher pig farm in England reflected true IVM resistance under controlled experimental conditions. On days 0 and 40 of the trial, twenty helminth-naive pigs were artificially infected per os with 5000 Oesophagostomum L3 obtained from the farm under investigation. The pigs were allocated to treatment or control groups (n = 10 per group). Treatment group pigs received IVM (0.3 mg kg body weight) by sub-cutaneous injection as per manufacturer's instructions on day 44. Control group animals were left untreated. Faecal worm egg counts were monitored throughout the trial from day 15 post infection to determine time to patency. On day 50 all pigs were euthanased to assess the worm burdens. Resistance to IVM was confirmed in Oesophagostomum dentatum based on the results of a faecal egg count reduction test (FECRT) and a controlled efficacy test (CET). Efficacy based on mean reduction in faecal egg count of IVM-treated pigs compared to untreated control pigs was 86%. Mean reduction in IVM-treated pig worm burdens was 5% against an adult worm population and 94% against an L3/L4 population. The apparent discrepancy between FECRT and CET efficacy results appears to be due to egg development and/or oviposition suppression in IVM-treated female worms. The detection of IVM resistance in Oesophagostomum species worms for the first time in UK pigs is particularly important considering the global situation where resistance to pyrantel, levamisole and benzimidazole anthelmintics in Oesophagostomum species in pigs have already been reported. The results also provide an opportunity to discuss the wider issue of anthelmintic usage and efficacy on pig farms and highlight the need for wider surveillance for the occurrence of anthelmintic resistance in pigs.

Prevalence of gastrointestinal helminths and parasites in smallholder pigs reared in the central Free State Province

Pigs are kept by farmers as a source of livelihood and food. Unfortunately, helminthiasis and other internal parasites are major setbacks to profitable pig production in Africa. There is a lack of information on the prevalence and intensity of gastrointestinal helminths and parasites plaguing resource-poor pig farmers in the Free State. Knowledge of these endemic parasites can be used as baseline data to help design future intervention plans. The aim of this study was to identify and quantify the types of gastrointestinal helminths and parasites prevalent in smallholder pigs reared in the central Free State Province. Faecal samples were randomly collected from 77 pigs and parasitologically analysed. Quantification was done using the McMaster counting technique. Farming system, age, gender and health status were the risk factors considered. The study was conducted between January and March 2016. Overall, results showed that 61 samples (79.2%) tested positive for one or more gastrointestinal parasites, which were observed as single or mixed infections. Amongst the positive samples, 44.5% were infected with Ascaris suum, 50.6% with Trichuris suis, 26.0% and 72.7% were infected with Oesophagostomum dentatum and coccidia, respectively. There were significant differences (p < 0.05) between the rate of infection in the intensive and semi-intensive systems and between the dewormed and non-dewormed pigs. Piglets and female pigs recorded a higher prevalence in their categories. Pigs excreted mostly low (eggs per gram [EPG] ≤ 100) to moderate (EPG > 100 < 500) levels of helminth eggs. It is concluded that different species of gastrointestinal parasites are present in most pigs reared by smallholder farmers in this study area.

Keywords: gastrointestinal helminths and parasites; smallholder pig farmers; pigs; prevalence; Central Free State Province.

Effect of strategic deworming on Ascaris suum exposure and technical performance parameters in fattening pigs

The aim of this study was to investigate the effect of a strategic deworming program on Ascaris suum infection levels and technical performance parameters in fattening pigs. Eighteen fattening stables were selected and divided into two groups. Group 1 consisted of 9 stables in which the fattening pigs tested seropositive for Ascaris, indicative for the presence of Ascaris eggs in the stable, whereas group 2 consisted of 9 stables in which the fattening pigs tested seronegative for Ascaris, indicating of a low or absent environmental contamination with Ascaris eggs. The production in each stable was monitored for a period of 7 consecutive fattening rounds. The first of these 7 fattening rounds (i.e. round 0), during which no intervention took place in the deworming strategy applied in the stable, served as a historical control. A deworming program using 200 mg/ml fenbendazole oral suspension in drinking water for 2 days every 6 weeks was implemented for a period of 6 consecutive fattening rounds. For each fattening round and for each stable, technical performance parameters including average daily growth, feed conversion ratio, days in fattening and the percentage of affected livers were obtained from the producers. Blood was collected from 10 randomly selected animals per stable at the end of each fattening round and evaluated for the presence of anti-Ascaris antibodies using 2 different serological tests, namely the AsHb- and the L3-Lung ELISA. The serological results obtained indicated a lower exposure of the animals to Ascaris after the implementation of a strategic deworming program. A significant decline in anti-Ascaris antibody levels was detectable in the stables that originally tested positive for Ascaris and was already visible after one treatment round. The outcomes of hierarchical linear mixed models indicated that the level of L3-Lung antibody reactivity was a significant predictor of decreased ADG, increased FCR and prolonged DIF for the Ascaris-positive herds, indicating an effect of Ascaris infections on productivity.

Exploration of extracellular vesicles from Ascaris suum provides evidence of parasite-host cross talk

The prevalent porcine helminth, Ascaris suum, compromises pig health and reduces farm productivity worldwide. The closely related human parasite, A. lumbricoides, infects more than 800 million people representing a disease burden of 1.31 million disability-adjusted life years. The infections are often chronic in nature, and the parasites have a profound ability to modulate their hosts' immune responses. This study provides the first in-depth characterisation of extracellular vesicles (EVs) from different developmental stages and body parts of A. suum and proposes the role of these vesicles in the host-parasite interplay. The release of EVs from the third- (L3) and fourth-stage (L4) larvae and adults was demonstrated by transmission electron microscopy (TEM), and sequencing of EV-derived RNA identified a number of microRNAs (miRNAs) and transcripts of potential host immune targets, such as IL-13, IL-25 and IL-33, were identified. Furthermore, proteomics of EVs identified several proteins with immunomodulatory properties and other proteins previously shown to be associated with parasite EVs. Taken together, these results suggest that A. suum EVs and their cargo may play a role in host-parasite interactions. This knowledge may pave the way to novel strategies for helminth infection control and knowledge of their immune modulatory potential.

Internal Parasites of Pigs and Worm Control Practices in Bamboutos, Western Highlands of Cameroon

Internal parasites are limiting factors to successful, sustainable livestock production. Knowledge on how they are dealt with is important to prevent resistance to anthelmintics. The aim of this study was to describe the internal parasitism of indoor pigs in Bamboutos Division in Cameroon, as well as the attendant worm control practices. Thus, 324 pigs from 50 small scale farms were sampled for feces which were qualitatively and quantitatively examined for parasite eggs, cysts, or oocysts. Data on worm control practices were also collected. The overall prevalence was 74.7% (95 % Confidence Interval (CI): 69.6–79.3%) and the overall mean egg/oocyst per gram of feces (epg/opg) was 304.1±1218.0. The following parasites were found: Strongylid parasites (58.6%; epg= 105.0±134.7); Coccidia (26.9; opg=517.2± 1862.1); Strongyloides ransomi (25.9%; epg=61.9± 40.8); A. suum (3.7%. epg=50±0); Metastrongylus sp (0.9%; epg=50±0); Trichuris suis (0.9%; epg=50±0); and Macracanthorhynchus hirudinaceus (0.62%; epg=50±0). Single to septuple infestations occurred. The majority of farmers resorted to modern veterinary services (64%) and mostly used conventional drugs (88%). Internal parasitism was associated with the person in charge of animal health, the implementation of a prophylaxis program on the farm, and the annual deworming frequency. The implementation of a prophylaxis program significantly reduced the overall egg/oocyst load while high treatment frequency (more than thrice a year) did not, indicating that prophylaxis measures such as general hygiene must be reinforced in pig herds in the country, and the treatment frequency reduced as much as possible to prevent the selection of anthelmintic resistance.

Effectiveness of an integrated intervention in the control of endo- and ectoparasites of pigs kept by smallholder farmers in Mbeya rural and Mbozi districts, Tanzania

This study was conducted to evaluate effectiveness of an integrated management intervention in the control of endo- and ectoparasites of pigs kept by smallholder farmers in Mbeya Rural and Mbozi districts of southern highlands of Tanzania. A repeated cross-sectional group randomization design was employed, with 10 villages in the intervention group and six villages in the control group. The intervention consisted of improving pig confinement, feeds and feeding practices, and strategic anthelmintic treatment of pigs with oxfendazole, to primarily control Taenia solium (porcine) cysticercosis and nematodes; and with ivermectin to control ectoparasites and nematodes. Blood and faecal samples, ectoparasite specimens and skin scrapings were collected at baseline and two follow-up rounds, at an interval of seven months. A total of 482, 460 and 421 pigs were sampled in 221, 196 and 139 households at baseline, first and second follow-up visits respectively. Sero-prevalence of PC, prevalence and burden of gastrointestinal (GI) nematodes and prevalence of ectoparasites were determined using Ag-ELISA, McMaster faecal egg counting technique and body searches/skin scrapings, respectively. Mann Whitney test was used to measure intervention effect by comparing changes from baseline values of prevalence and faecal egg counts between the two groups. No significant difference (p > 0.05) was observed between the two groups, in changes from baseline of sero-prevalence of PC. The intervention significantly reduced prevalence of Trichuris suis (p = 0.044) and mean faecal egg counts of Ascaris suum (p = 0.02) from baseline to first follow-up. The intervention showed a substantial effect on the prevalence of ectoparasites as it significantly reduced overall prevalence of ectoparasites (p = 0.026), lice (p = 0.045), ticks (p = 0.049) and mites (p = 0.013) from baseline to first follow-up, and prevalence of ectoparasites, lice and mites from baseline to second follow-up (p = 0.052, p = 0.03, p = 0.017 respectively). This study has demonstrated a moderate effect of the intervention on controlling GI nematodes and ectoparasites, but no effect on sero-prevalence of PC. The reported ineffectiveness of the intervention against PC is probably an underestimation because serology is not able to provide quantitative data. It may also be a result of reduced compliance as this was a field study. Nevertheless, further studies are needed to better understand transmission dynamics of PC and explore One Health approaches including treatment of the human population against taeniosis to better secure public health.

Occurrence of Intestinal Parasites in Pigs in Poland - the Influence of Factors Related to the Production System

Introduction

The aim of study was to estimate the prevalence and intensity of intestinal parasite infections in pigs in Poland and evaluate the influence of factors related to the production system on the infection intensity.

Material and Methods

A total of 70 pig farms of all Polish provinces, differing in the herd size and production system, were selected for the study. Fresh faecal samples were collected from all age groups: suckling piglets, weaners, fatteners, and lactating sows. Moreover, data were obtained regarding the size of the herd, the use of paddock and all-in/all-out system, the presence of diarrhoea, and the type of flooring.

Results

Parasite eggs or oocysts were detected in 57 of the 70 examined pig farms. Oesphagostomum spp. eggs were found in the largest number of farms (68.6%). Moreover, coccidia (42.9%), Ascaris suum(28.6%), Trichuris suis (21.4%), and Strongyloides spp. (11.4%) were detected. The highest prevalence of coccidia and Strongyloides spp. was found in suckling piglets, A. suum and T. suis in fatteners, and Oesphagostomum spp. in sows. Higher prevalence of parasites was detected in small farms than in medium and large farms, except the prevalence of coccidia, which was the highest in medium farms. Simultaneous infection with several parasites was more often detected than with one parasite. Odds ratio of parasites occurrence was higher in farms with paddock and litter floor and in farms which do not use all-in/all-out system.

Conclusion

Relatively high prevalence of intestinal parasites was found in pigs in Poland. Moreover, specific distribution of parasites in different age groups and farms of different size was observed. Influence of breeding factors on parasite prevalence was identified.

Research trends in outdoor pig production - A review

Since the industrialization of swine production in the late 1900s, swine farms in the United States, as well as in Europe, have largely become consolidated. Pig farms became larger in size but fewer in number, with 91% of market pigs being produced by large operations with 5,000 or more pigs on-site in the US, and only 3% of the total utilized agricultural land representing organic farming. Such change in the market made it difficult for small farmers to stay competitive, forcing them to find alternative ways to reduce the cost of production and increase profit using the outdoor production system. In contrast to the indoor confinement system, outdoor production system uses pasture-based units and/or deep-bedded hoop structures that promote animal welfare and environmental sustainability with a lower capital investment. In accord with the growing concern for animal and environmental welfare and food safety by the consumers, small farmers practicing an outdoor production system are seeing increased opportunities for marketing their products in the pork niche market. Unlike the general belief that the reproductive and growth performance measures of the outdoor sows and piglets are poorer in comparison with the animals reared indoors, studies showed that there was no significant difference in the performance measures, and some traits were even better in outdoor animals. Improved reproductive and production traits can increase the sustainability of outdoor farming. Present study reviewed the recent studies comparing the performance measures, meat quality and health of indoor and outdoor animals, as well as the efforts to improve the outdoor production system through changes in management such as hut types and breed of animals.

Benchmarking of pluck lesions at slaughter as a health monitoring tool for pigs slaughtered at 170kg (heavy pigs)

Abattoir post-mortem inspections offer a useful tool for the development and monitoring of animal health plans and a source of data for epidemiological investigation. The aim of the present work was to develop an abattoir benchmarking system which provides feedback on the prevalence and severity of lesions of the pluck (lung, pleura and liver) in batches of pigs to inform individual producers and their veterinarians of the occurrence of pathological conditions affecting their herds. The weekly collection of data throughout a year (from September 2014 to September 2015) supported the further aim of providing benchmark values for the prevalence of lesions and their seasonality in Italian heavy pig production. Finally, correlations and redundancies among different lesions were evaluated. In total, 727 batches of heavy pigs (around 165kg live weight and 9 months of age) derived from 272 intensive commercial farms located in Northern Italy were monitored. Within each batch, an average number of 100 plucks was individually scored, assigning a value for lesions of lungs (0-24), pleura (0-4) and liver (1-3). Presence of lung scars, abscesses, consolidations, lobular/chessboard pattern lesions and pleural sequestra was also recorded. Statistical analysis showed a strong farm effect (36-68% of variation depending of the lesion) and a seasonal effect on all lesions. Winter showed the lowest percentage of severe lung and pleural lesions (P<0.001 and P=0.005), whereas lung scars from older lesions (P=0.003), as well as severe hepatic lesions (P<0.001), were reduced in autumn. In order to allow effective benchmarking of each farm in a determined health class, scores for each quartile of the population are reported. Whilst such a benchmarking scheme provides useful data for herd health management, challenges of repeatability of scoring and cost of implementation need to be overcome.

Whipworms in humans and pigs: origins and demography

Background

Trichuris suis and T. trichiura are two different whipworm species that infect pigs and humans, respectively. T. suis is found in pigs worldwide while T. trichiura is responsible for nearly 460 million infections in people, mainly in areas of poor sanitation in tropical and subtropical areas. The evolutionary relationship and the historical factors responsible for this worldwide distribution are poorly understood. In this study, we aimed to reconstruct the demographic history of Trichuris in humans and pigs, the evolutionary origin of Trichuris in these hosts and factors responsible for parasite dispersal globally.

Methods

Parts of the mitochondrial nad1 and rrnL genes were sequenced followed by population genetic and phylogenetic analyses. Populations of Trichuris examined were recovered from humans (n = 31), pigs (n = 58) and non-human primates (n = 49) in different countries on different continents, namely Denmark, USA, Uganda, Ecuador, China and St. Kitts (Caribbean). Additional sequences available from GenBank were incorporated into the analyses.

Results

We found no differentiation between human-derived Trichuris in Uganda and the majority of the Trichuris samples from non-human primates suggesting a common African origin of the parasite, which then was transmitted to Asia and further to South America. On the other hand, there was no differentiation between pig-derived Trichuris from Europe and the New World suggesting dispersal relates to human activities by transporting pigs and their parasites through colonisation and trade. Evidence for recent pig transport from China to Ecuador and from Europe to Uganda was also observed from their parasites. In contrast, there was high genetic differentiation between the pig Trichuris in Denmark and China in concordance with the host genetics.

Conclusions

We found evidence for an African origin of T. trichiura which were then transmitted with human ancestors to Asia and further to South America. A host shift to pigs may have occurred in Asia from where T. suis seems to have been transmitted globally by a combination of natural host dispersal and anthropogenic factors.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-016-1325-8) contains supplementary material, which is available to authorized users.

Case-control study of pathogens involved in piglet diarrhea

Background

Diarrhea in piglets directly affects commercial swine production. The disease results from the interaction of pathogens with the host immune system and is also affected by management procedures. Several pathogenic agents such as Campylobacter spp., Clostridium perfringens, Escherichia coli, Salmonella spp., group A rotavirus (RV-A), coronaviruses (transmissible gastroenteritis virus; porcine epidemic diarrhea virus), as well as nematode and protozoan parasites, can be associated with disease cases.

Results

All bacterial, viral, protozoan, and parasitic agents here investigated, with the exception of Salmonella spp. as well as both coronaviruses, were detected in varying proportions in piglet fecal samples, and positive animals were equally distributed between case and control groups. A statistically significant difference between case and control groups was found only for Cystoisospora suis (p = 0.034) and Eimeria spp. (p = 0.047). When co-infections were evaluated, a statistically significant difference was found only for C. perfringens β2 and C. suis (p = 0.014).

Conclusions

The presence of pathogens in piglets alone does not determine the occurrence of diarrhea episodes. Thus, the indiscriminate use of antibiotic and anthelminthic medication should be re-evaluated. This study also reinforces the importance of laboratory diagnosis and correct interpretation of results as well as the relevance of control and prophylactic measures.

Determining geographical variations in Ascaris suum isolated from different regions in northwest China through sequences of three mitochondrial genes

The sequence diversities in three mitochondrial DNA (mtDNA) regions, namely portions of NADH dehydrogenase subunit 1 (pnad1), cytochrome c oxidase subunit 1 (pcox1), and NADH dehydrogenase subunit 4 (pnad4), were investigated in all Ascaris suum samples isolated from four regions in northwestern China. Those genes were amplified by PCR method and the lengths of pnad1, pcox1, and pnad4 were 419 bp, 711 bp, and 723 bp, respectively. The intraspecific sequence variations within A. suum samples were 0-2.9% for pnad1, 0-2.1% for pcox1, and 0-3.1% for pnad4. Phylogenetic analysis combined with three sequences of mtDNA fragments showed that all A. suum samples were monophyletic groups, but samples from the same geographical origin did not always cluster together. The results suggested that the three mtDNA fragments could not be used as molecular markers to identify the A. suum isolates from four regions, and have important implications for studying molecular epidemiology and population genetics of A. suum.

Gastrointestinal parasites of swine raised in different management systems in the State of Rio de Janeiro, Brazil

Abstract: From 2012 to 2013 were surveyed gastrointestinal parasites from pig farms located in different municpaliyies in the state of Rio de Janeiro. Fecal samples from 790 pigs were collected from the rectum on 88 family farms and 702 farms with industrial production. The samples were subjected to Faust et al., Sheather, Ritchie, Lutz and direct examination faecal techniques. The estimated parasite prevalence was 93.1% in family farms and 59.1% in industrial farms. Balantidium coli, coccidia and Entamoeba sp. were the parasites with the highest frequencies, and the male and female reproductive categories and fatteners pigs the most infected (p<0.05). Trophozoites of B. coli were most evident in stool samples from semi-solid followed by solid and diarrheal consistencies. Strongyles eggs and Trichuris suis have been detected exclusively in family farms. Ascaris suum eggs and Strongyloides ransomi showed low frequency. The high degree of parasitism, especially protozoa, indicates the need to reassess the management of pigs in both types of production.

The influence of endoparasites on selected production parameters in pigs in various housing systems

The aim of the study was to determine the level of lean meat content and daily gains of 400 fatteners infected by endoparasites and kept in two systems (shallow and deep litter). Slaughter evaluation of the pigs was conducted according to the EUROP carcass classification. In order to evaluate the average daily gains (g) during finishing period, body weights were investigated twice: at the beginning and at the end of the finishing period. The housing system affected the presence of Ascaris suum and Oesophagostomum spp. Infestation was found to be higher on shallow than on deep litter, and it significantly affected selected fattening and slaughter parameters of the fatteners. Infected animals were characterized by gains approximately 60 g lower than those of uninfected ones, while meatiness was higher in fatteners which were not infected at the end of the fattening period compared to animals with parasites (55.2% vs. 52.0%).

Studies on gastrointestinal parasites of pigs in Shimoga region of Karnataka

The study was conducted to ascertain the actual status of gastro-intestinal parasites in pigs maintained under different rearing systems in Shimoga region, Karnataka state. A total of 150 Pigs fecal samples were examined, which includes 50 from organized piggery farm, Veterinary College Shimoga, 50 from private piggery farm of Shimoga and 50 from free range desi pigs of Shimoga city. The fecal samples were processed and examined by direct and sedimentation method. Out of 50 fecal samples examined from organized piggery farm, 19 were found positive for different parasitic eggs, Out of 50 fecal samples screened form private farm, 28 harbored different parasites, whereas from 50 free range desi pigs fecal samples examined, all showed one and other parasitic eggs/ova. The percent prevalence of parasitic infection is more in free range desi pigs compared to Yorkshire breeds maintained under stall fed condition.

New insights in cysticercosis transmission

Taenia solium infection causes severe neurological disease in humans. Even though infection and exposure to swine cysticercosis is scattered throughout endemic villages, location of the tapeworm only explains some of the nearby infections and is not related to location of seropositive pigs. Other players might be involved in cysticercosis transmission. In this study we hypothesize that pigs that carry nematodes specific to dung beetles are associated with cysticercosis infection and/or exposure. We carried out a cross-sectional study of six villages in an endemic region in northern Peru. We euthanized all pigs (326) in the villages and performed necropsies to diagnose cysticercosis. For each pig, we counted cysticerci; measured anti-cysticercus antibodies; identified intestinal nematodes; tabulated distance to nearest human tapeworm infection; and recorded age, sex, productive stage, and geographic reference. For the purpose of this paper, we defined cysticercosis infection as the presence of at least one cysticercus in pig muscles, and cysticercosis exposure as seropositivity to anti-cysticercus antibodies with the presence of 0–5 cysticerci. Compared to pigs without nematode infections, those pigs infected with the nematode Ascarops strongylina were significantly associated with the presence of cysticerci (OR: 4.30, 95%CI: 1.83–10.09). Similarly, pigs infected with the nematode Physocephalus sexalatus were more likely to have cysticercosis exposure (OR: 2.21, 95%CI: 1.50–3.28). In conclusion, our results suggest that there appears to be a strong positive association between the presence of nematodes and both cysticercosis infection and exposure in pigs. The role of dung beetles in cysticercosis dynamics should be further investigated.

In endemic areas, pigs acquire cysticercosis when ingesting Taenia solium eggs that have been released into the environment in the feces of a person infected with T. solium. The present study has found evidence that players, such as dung beetles, might be involved in further dissemination of the parasite into the environment. Specifically, we found an association between helminths, for whom dung beetles act as an intermediate host, and porcine cysticercosis infection and exposure after adjusting for other porcine cysticercosis predictors such as distance to tapeworm carrier and age. Although the study does not evaluate dung beetles directly, parasites specific to dung beetles serve as a novel proxy to evidence the potential role of dung beetles in the epidemiology of cysticercosis. Therefore, it is important that further studies elucidate the role of other players in cysticercosis transmission in order to better explain the reemergence and persistence of cysticercosis after elimination and control efforts. In addition, vector populations could potentially be used as markers for cysticercosis in the communities.

Prevalence of porcine cysticercosis in the Lake Kyoga Basin, Uganda

Background

Taenia solium is a zoonotic helminth with the potential to cause life threatening epilepsy in people through the aberrant larval infection of the brain called Neurocysticercosis (NCC). The pig is the intermediate host for T. solium where the larval form, cysticercus cellulosae, normally develops after the pig eats eggs of the parasite. Humans are the definitive host where the adult tapeworm develops and are infected through the consumption of poorly cooked, infected meat. T. solium has been acknowledged by the World Health Organization (WHO), Food and Agriculture Organization (FAO) and UK Department for International Development (DFID) as being a neglected zoonotic disease, and was recently included in the WHO roadmap for control of neglected tropical diseases. This neglect encompasses a lack of epidemiological data and a lack of validated, effective control strategies being adopted. Understanding the epidemiology of this parasite in the intermediate host is the first step towards designing suitable intervention strategies for the improvement of public health. This study was undertaken to provide an accurate and up-to-date estimate for the prevalence of porcine cysticercosis in the Lake Kyoga basin.

Results

Sera from 378 pigs were analysed with the HP10 Antigen Enzyme Linked Immunosorbant Assay (ELISA) and the prevalence was found to be 25.7% (95% confidence interval 21.0% to 30.0%). Previous sero- surveillance in this region, using the B158/B60 Ag Elisa had indicated a prevalence of 8.6% in 2005 indicating a dramatic increase in prevalence (J. Parasitol Res, Article ID 375493, 2009) within a 6 year period.

Conclusion

This increasing prevalence in the disease indicates to us that there is currently no effective control of this parasite and that in this region of Uganda at least; cysticercosis remains a neglected zoonotic disease.

Internal parasites and health management of pigs in Burayu District, Oromia Regional State, Ethiopia

The study determined the prevalence and major types of gastrointestinal parasites in pigs and assessed the health management practices on farms in Burayu District in West Shoa Zone of Oromia Regional State, Ethiopia. The study was performed from November 2007 to April 2008 using standard coprological examination and a well-organised questionnaire survey. Of the 272 pigs examined for the presence of gastrointestinal parasites, 36 (13.2%) were infected with one or more types of parasite. Neither age nor management system proved to be a statistically significant factor in the prevalence of parasites. The highest prevalence of parasites was recorded in December, January and April, whereas the lowest was observed in February. Significant variation in the prevalence of parasites was noticed amongst study months. The majority of farmers did not use acaricides to treat and control external parasites. Anthelmintics were not used by any of the farmers. Some 76.1% of the farmers never used any type of treatment for sick pigs; 21.7% of the farmers used modern treatment and 2.2% of the farmers used traditional medicines. More than 95.0% of pigs were kept on soil floors and only 10.9% of the housing systems had good ventilation. Dung was removed at least every three days, with the majority of farmers (91.2%) removing it every morning. This study provided evidence for the occurrence of internal parasites in pigs kept in Burayu District in Oromia. Further epidemiological studies are needed to determine the zoonotic and economic importance of pig parasites in other parts of Ethiopia.

Animal Health and Welfare Issues Facing Organic Production Systems

Simple Summary

The demand for organically grown, animal derived produce is increasing due to a growing desire for consumer products that have minimal chemical inputs and high animal welfare standards. Evaluation of the scientific literature suggests that a major challenge facing organic animal production systems is the management and treatment of health-related issues. However, implementation of effective management practices can help organic animal producers achieve and maintain high standards of health and welfare, which is necessary to assure consumers that organic animal-based food and fibre has not only been produced with minimal or no chemical input, but under high standards of animal welfare.

Abstract

The demand for organically-grown produce is increasing worldwide, with one of the drivers being an expectation among consumers that animals have been farmed to a high standard of animal welfare. This review evaluates whether this expectation is in fact being met, by describing the current level of science-based knowledge of animal health and welfare in organic systems. The primary welfare risk in organic production systems appears to be related to animal health. Organic farms use a combination of management practices, alternative and complementary remedies and convenional medicines to manage the health of their animals and in many cases these are at least as effective as management practices employed by non-organic producers. However, in contrast to non-organic systems, there is still a lack of scientifically evaluated, organically acceptable therapeutic treatments that organic animal producers can use when current management practices are not sufficient to maintain the health of their animals. The development of such treatments are necessary to assure consumers that organic animal-based food and fibre has not only been produced with minimal or no chemical input, but under high standards of animal welfare.