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IntroductionEchinococcus granulosus, known as cystic echinococcosis, is a prominent zoonotic parasitic disease of significant global concern. The definitive hosts serves as the primary reservoir for the transmission of echinococcosis, as well as a main factor in the prevention and control of the disease. Unfortunately, there is currently no commercially available vaccine for these hosts. Nevertheless, DNA vaccines show potential as a feasible strategy for the control and management of parasitic diseases.MethodsIn this study, the EgM123 antigen was selected for its well-documented immunogenic properties to develop a DNA vaccine aimed at combating E. granulosus infection in canines.ResultsThe results showed a marked increase in IgG levels in the group vaccinated with pVAX1-EgM123 DNA compared to the PBS group. Additionally, the cytokines IL-1, IFN-γ, IL-4, and IL-6 were significantly upregulated in the pVAX1-EgM123 DNA vaccine group. Furthermore, in comparison to the PBS control group, the EgM123 DNA vaccine group exhibited a notable 87.85% reduction in worm burden and a 65.00% inhibition in segment development.DiscussionThese findings indicate that the pVAX1-EgM123 DNA vaccine shows promising immunogenicity, successfully eliciting a targeted immune response in canines. Moreover, it significantly diminishes the worm burden and hinders the progression of tapeworms in the pVAX1-EgM123 DNA vaccine group. These findings suggest that the pVAX1-EgM123 DNA vaccine holds promise as a potential candidate vaccine for combating E. granulosus infection in dogs.

Trichinella spiralis (T. spiralis), a nematode parasite, is the major cause of Trichinellosis, a zoonotic disease. A key role of MAPR in the reproductive system is to maintain pregnancy. Previous studies found that antihormone drug design and vaccine therapy of recombinant protein (rTs-MAPRC2) control T. spiralis infection. The current study investigates the inhibitory effects of different ratios of antibodies against Ts-MAPRC2 on the development of muscle larvae (ML) and newborn larvae (NBL). First, we performed indirect immunofluorescence assays and examined the effects of rTs-MAPRC2-Ab on ML and NBL in vitro as well as in vivo. Afterward, siRNA-Ts-MAPRC2 was transfected into T. spiralis muscle larvae. Following that, Ts-MAPRC2 protein was detected by Western Blotting, and mRNA levels were determined by qPCR. We also assessed whether siRNA-treated NBLs were infective by analyzing muscle larvae burden (MLs). Our results showed that rTs-MAPRC2-Ab greatly inhibited the activity of the Ts-MAPRC2 in ML and NBL of T. spiralis and rTs-MAPRC2-Ab reduced larval infectivity and survival in the host in a dose-dependent manner (1:50, 1:200, 1:800 dilutions). Furthermore, siRNA-Ts-MAPRC2 effectively silenced the Ts-MAPRC2 gene in muscle larvae (ML) in vitro, as well as in newborn larvae (NBL) of T. spiralis in vivo. In addition, siRNA-Ts-MAPRC2 (siRNA180, siRNA419, siRNA559) reduced host larval survival and infectivity significantly. This study, therefore, suggests that Ts-MAPRC2 might be a novel molecular target useful in the development of vaccines against T. spiralis infection. [ABSTRACT FROM AUTHOR]

Trichinella spiralis (T. spiralis), a nematode parasite, is the major cause of Trichinellosis, a zoonotic disease. A key role of MAPR in the reproductive system is to maintain pregnancy. Previous studies found that antihormone drug design and vaccine therapy of recombinant protein (rTs-MAPRC2) control T. spiralis infection. The current study investigates the inhibitory effects of different ratios of antibodies against Ts-MAPRC2 on the development of muscle larvae (ML) and newborn larvae (NBL). First, we performed indirect immunofluorescence assays and examined the effects of rTs-MAPRC2-Ab on ML and NBL in vitro as well as in vivo. Afterward, siRNA-Ts-MAPRC2 was transfected into T. spiralis muscle larvae. Following that, Ts-MAPRC2 protein was detected by Western Blotting, and mRNA levels were determined by qPCR. We also assessed whether siRNA-treated NBLs were infective by analyzing muscle larvae burden (MLs). Our results showed that rTs-MAPRC2-Ab greatly inhibited the activity of the Ts-MAPRC2 in ML and NBL of T. spiralis and rTs-MAPRC2-Ab reduced larval infectivity and survival in the host in a dose-dependent manner (1:50, 1:200, 1:800 dilutions). Furthermore, siRNA-Ts-MAPRC2 effectively silenced the Ts-MAPRC2 gene in muscle larvae (ML) in vitro, as well as in newborn larvae (NBL) of T. spiralis in vivo. In addition, siRNA-Ts-MAPRC2 (siRNA180, siRNA419, siRNA559) reduced host larval survival and infectivity significantly. This study, therefore, suggests that Ts-MAPRC2 might be a novel molecular target useful in the development of vaccines against T. spiralis infection.

Abstract Background Sibship reconstruction is a form of parentage analysis that can be used to identify the number of helminth parental genotypes infecting individual hosts using genetic data on only their offspring. This has the potential to be used for estimating individual worm burdens when adult parasites are otherwise inaccessible, the case for many of the most globally important human helminthiases and neglected tropical diseases. Yet methods of inferring worm burdens from sibship reconstruction data on numbers of unique parental genotypes are lacking, limiting the method’s scope of application. Results We developed a novel statistical method for estimating female worm burdens from data on the number of unique female parental genotypes derived from sibship reconstruction. We illustrate the approach using genotypic data on Schistosoma mansoni (miracidial) offspring collected from schoolchildren in Tanzania. We show how the bias and precision of worm burden estimates critically depends on the number of sampled offspring and we discuss strategies for obtaining sufficient sample sizes and for incorporating judiciously formulated prior information to improve the accuracy of estimates. Conclusions This work provides a novel approach for estimating individual-level worm burdens using genetic data on helminth offspring. This represents a step towards a wider scope of application of parentage analysis techniques. We discuss how the method could be used to assist in the interpretation of monitoring and evaluation data collected during mass drug administration programmes targeting human helminthiases and to help resolve outstanding questions on key population biological processes that govern the transmission dynamics of these neglected tropical diseases.

This study was carried out to evaluate the effect of drug treatments and enzymes level on the worm burden in an experimental Schistosoma haematobium infected guinea pig. Eggs of S. haematobium were collected from the urine of infected persons and hatched into miracidia. Fresh water Snail species Bulinus truncatus were exposed to miracidia and allowed for five weeks to establish infection and develop to cercaria. Guinea pigs were exposed to S. haematobium cercaraie by subcutaneous injection. The infected guinea pigs were divided into four groups, designated as 7, 28, 90 days post infection and controls. The guinea pigs were treated singly and in combination with different doses of Praziquantel (PZQ), Artemether (ART) and Artequine (ARQ). The efficacy of the different drugs on worm burden were assessed. Blood samples were collected from the guinea pigs before and after treatment for determination of Alkaline Phosphatase (ALP), Alanine Aminotransferase (ALT) and Aspartate Aminotransferase (AST). Result showed that treatment with higher doses of PZQ/ART (100/200mg/kg) and PZQ/ARQ (100/200mg/kg) resulted in total worm reduction rate of 58 and a percentage efficacy of 98.3%. ARQ (300 mg/kg) had the highest percentage efficacy of 89.8% amongst the single drugs used with respect to higher doses. There were observed alteration in the levels of the enzymes after S. haematobium infection. The serum level of ALP, AST and ALT after infection generally decreased. There were various activities in the level of ALP AST and ALT after treatment with different drug regimen at different stages of S. haematobium infection. ARQ alone and in combination with PZQ had anti schistosomal effect and could be promising in controlling schistosomiasis. [ABSTRACT FROM AUTHOR]

Background: Clonorchiasis is endemic in East and Southeast Asian countries. For a preventive strategy against infectious diseases, vaccination is the most effective. Here, we evaluated the molecular characteristics and immune responses of CsAg17 protein from Clonorchis sinensis, and investigated its protective effects against C. sinensis challenge. Methods: A cDNA clone encoding CsAg17 protein and containing a secretory signal peptide at the N-terminus was retrieved from the C. sinensis transcriptome bank. Recombinant CsAg17 B-cell epitope protein and cDNA vaccines were produced and their immune responses were evaluated in FVB mice. The proportional changes of CD3+/CD4+ and CD3+/CD8+ T cells were detected by flow cytometry, and immune effectors were measured by ELISA. Results: The CsAg17 mRNA was transcribed at a higher level in C. sinensis adults than in metacercariae. The CsAg17 protein was distributed in the sperms, oral and ventral suckers, and mesenchymal tissues of C. sinensis adults. In mice challenged with C. sinensis metacercariae, vaccination with CsAg17 protein and cDNA resulted in a reduction to 64% and 69% in worm burden, respectively. Both CsAg17 protein and cDNA vaccines increased the proportion of CD3+/CD4+ and CD3+/CD8+ T cells and stimulated the production of Th1 type cytokines such as interleukin (IL)-2, IL-12, and interferon-γ, while maintaining minimum levels of Th2 cytokines. The levels of IgG specific to CsAg17 protein steeply increased in the two vaccinated groups from 2 weeks after immunization. The liver tissue retained good morphology in the mice vaccinated with CsAg17 protein or cDNA, whereas severe inflammation and large serous cysts were observed in the liver of the unvaccinated mice. Conclusions: Vaccination with CsAg17 protein and cDNA reduced the pathological changes in the bile duct and liver, and ameliorated the worm burden via cellular and humoral immune responses. Thus, they may serve as good vaccine candidates against C. sinensis infections. [ABSTRACT FROM AUTHOR]

The study was carried out to estimate the prevalence, species composition and worm burden of abomasal nematodes of small ruminants (sheep and goats) slaughtered in Hawassa, southern Ethiopia from November 2007 through March 2008. During this period, visceral organs (abomasums) were collected from 237 animals (125 sheep and 112 goats) slaughtered in restaurants located in Hawassa. Of these, 224 small ruminants were male and the remaining 13 were females. All the carcasses examined were from adult animals. Out of the 237 organs examined, the majority (196) were collected during the dry season and the rest were collected during the wet season. Worm recovery, species identification and determination of worm burden were carried out according to standard procedures. The results showed that the overall prevalence of abomasal nematode infections in sheep and goats was 90.4% and 77.7%, respectively. Haemonchus contortus and Trichostrongylus axei were the only worms recovered in the abomasum of the slaughtered sheep and goats. In sheep, the prevalence of H. contortus and T. axei was 80% and 79.2%, respectively. In the goats, the prevalence of H. contortus and T. axei was 67.7% and 62.6%, respectively. Significant differences (P>0.05) in prevalence were not found between sex of animal, months and seasons. However, there was significant difference (P<0.05) in prevalence between animal species. Regarding the worm burden, there were significant differences (P<0.05) between months and seasons. However, there were no significant differences (P>0.05) in the monthly mean worm counts between animal species and sex. In general, the findings of this study showed high prevalence and worm burden of H. contortus and T. axei which could potentially be among the most important nematodes affecting the productivity of small ruminants in the area. Further, molecular epidemiology and immunological studies are recommended to understand the transmission dynamics of these parasites and their larval ecology including associated factors. [ABSTRACT FROM AUTHOR]

This study involved a national cross-sectional survey of gastrointestinal nematodes (GINs) of alpacas in Australia. A total of 1545 fresh faecal samples were collected from both sexes of alpacas and processed for faecal egg counts (FEC) and molecular identification of nematodes using the multiplexed tandem PCR assay. Based on egg morphology, the overall prevalence of GINs was 66% while that for strongyles was 59%. The overall mean FEC was 276 eggs per gram (EPG) of faeces, with the highest count of 17,415 EPG. Male alpacas had a higher prevalence (68%, 334/490) as well as mean FEC (328 ± 60 EPG) of GINs than females (63%, 602/954; 227 ± 26, respectively). Weaners had the highest prevalence (80%) whereas tuis had the highest FEC (402 EPG) of nematodes. The highest prevalence (77%, 293/383) and FEC (630 EPG) of GINs were observed in the summer rainfall zone followed by the Mediterranean-type rainfall, non-seasonal rainfall and winter rainfall zones. The characterisation of nematode DNA isolated from faeces revealed the occurrence of seven different GINs, including Camelostrongylus mentulatus, Cooperia spp., Haemonchus spp., Oesophagostomum spp., Ostertagia ostertagi, Teladorsagia circumcincta and Trichostrongylus spp. Besides, Nematodirus spp. and Trichuris spp. were also found during FECs. The prevalence of Haemonchus spp. was highest in the summer rainfall zone while that of C. mentulatus was highest in the Mediterranean-type rainfall, non-seasonal rainfall and winter rainfall zones. The findings of this study revealed that alpacas harbour many of the same nematodes as sheep and cattle. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the prevalence and worm burden of gastrointestinal parasites in Thai indigenous chickens (Gallus gallus domesticus) kept under extensive backyard conditions in Northern Thailand. A total of 211 male (N = 98) and female (N = 113) chickens from 11 smallholder farms were selected randomly between December 2016 and May 2017. At slaughter, fecal samples were collected to estimate fecal egg counts (presented as eggs per gram of feces) and oocyst counts (oocyst per gram of feces). The gastrointestinal tract of each animal was examined for the presence of parasites. The percentage of FEC- and FOC-positive samples was 33.7 and 55.4%, respectively. On average, 111 ± 328 ascarid eggs and 2,983 ± 11,641 coccidian oocysts were found. From the post mortem examination, 3 nematode species and cestodes were recovered. A total of 156 (73.9%) of the sampled chickens were infected with at least 1 helminth species. Average worm burden per chicken was 46.7 (SD = 50.9, median = 30). The most prevalent species were the nematodes Heterakis gallinarum (70.6%) followed by Ascaridia galli (60.2%) and Capillaria spp. (44.1%). The overall prevalence of cestodes was 27.7%. Apart from A. galli with higher prevalence in males than in females (P ≤ 0.05), gender did neither affect prevalence nor worm burden (P > 0.05). Growth performance was not negatively affected by helminth infections. In conclusion, the vast majority of Thai native chickens are subclinically infected with at least 1 helminth species under the studied backyard conditions. [ABSTRACT FROM AUTHOR]

Schistosomiasis is the third most devastating tropical disease worldwide caused by blood flukes of the genus Schistosoma. Praziquantel (PZQ) is the drug of choice for treating all species of schistosomes. However, PZQ kills only adult Schistosoma worms, not immature stages. The inability of PZQ to abort early infection or prevent re-infection, and the lack of prophylactic effect prompt the need for novel drugs and strategies for the prevention of schistosomiasis. Tumor burden can be developed in Schistosoma-infected patients. The present study aimed to determine the host responses to mutual interaction between cancer, represented by Ehrlich ascites, and infection, represented by Schistosomiasis. Mice infected with Schistosoma and challenged with tumor 4-5 weeks later showed the same anti-schistosomal (worm and egg burden) and antitumor (total tumor cell count and mouse survival) parameters when compared to mice infected with Schistosoma alone or challenged with tumor cells alone. As expected, combinatorial treatment with PZQ and cisplatin of Schistosoma-infected mice that were challenged with tumor cell line decreased the tumor burden as well as the worm and egg burden after treatment as compared to the non-treated controls; while the worm burden and egg counts were significantly decreased (P <0.001) in treated group (VI) treated with cisplatin (0.5 mg/kg), group (VII) treated with cisplatin (2 mg/kg), group (VIII) treated with PZQ/cisplatin (0.5 mg/kg) and group (IX) treated with PZQ / cisplatin (2 mg/kg) by 44.55%, 74%, 100% and 97.8% in worm burden, and by 47%, 78.7%, 96% and 97% in liver egg count, respectively than that of group (II) non treated S. mansoni infected alone and (IV) non treated S. mansoni/EAC alone. Also, Group IX caused a significant reduction (P <0.05) in worm burden than that of group VI. Also, total ascetic volume and the tumor cell counts in Ehrlich's ascites carcinoma (EAC)-cells were significantly decreased (P <0.001) in groups VIII and IX than that of the group (III) non-treated (EAC) inoculated alone. There was no mutual interaction between schistosomiasis infection and tumor burden. Also, whereas, PZQ did not affect on the antitumor parameters, cisplatin even at low doses had anti-schistosomal effects. [ABSTRACT FROM AUTHOR]

Worldwide approximately 68 million people are infected with lymphatic filariasis (Lf), provoked by Wuchereria bancrofti, Brugia malayi and Brugia timori. This disease can lead to massive swelling of the limbs (elephantiasis) and disfigurement of the male genitalia (hydrocele). Filarial induced immune regulation is characterised by dominant type 2 helper T cell and regulatory immune responses. In vitro studies have provided evidence that signalling via Toll-like receptor-mediated pathways is triggered by filarial associated factors. Nevertheless, until now, less is known about the role of the adapter molecule TRIF during in vivo infections. Here, we used the rodent-specific nematode Litomosoides sigmodontis to investigate the role of TLR signalling and the corresponding downstream adapter and regulatory molecules TRIF, MyD88, IRF1 and IRF3 during an ongoing infection in semi-susceptible C57BL/6 mice. Interestingly, lack of the central adapter molecule TRIF led to higher worm burden and reduced overall absolute cell numbers in the thoracic cavity (the site of infection) 30 days post-infection. In addition, frequencies of macrophages and lymphocytes in the TC were increased in infected TRIF−/− C57BL/6 mice, whereas frequencies of eosinophils, CD4+ and CD8+ T cells were reduced. Nevertheless, cytokine levels and regulatory T cell populations remained comparable between TRIF-deficient and wildtype C57BL/6 mice upon 30 days of L. sigmodontis infection. In summary, this study revealed a crucial role of the adapter molecule TRIF on worm recovery and immune cell recruitment into the site of infection 30 days upon L. sigmodontis infection in C57BL/6 mice. [ABSTRACT FROM AUTHOR]

Abstract Coprological analysis is the most widely used diagnostic tool for helminth infection in both domestic and wild mammals. Evaluation of the efficacy of this technique is rare, due to the lack of availability of adult worm burden. Where information is available the majority of studies are in small ruminants and seldom in a wild host. This study of 289 wild badgers is the first to report the relationship between faecal egg/larval counts and adult worm burden in badgers whilst also evaluating the reliability of coprological analysis as a diagnostic tool for hookworm (Uncinaria criniformis) and lungworm (Aelurostrongylus falciformis) infection. The prevalence of hookworm and lungworm infection, as assessed through adult worm burden was 59.2% and 20.8% respectively. For both species of helminth, infection was consistently under-reported by coprological analysis compared to adult worm burden with a reported 41% sensitivity for hookworm and 10% for lungworm. A significant positive relationship was found between faecal counts and adult worm burden for both species of helminths. Additionally the density –dependent relationship often reported in helminth infection appears to be weak or non-existent in this study, up to the observed worm intensity of 500. Graphical abstract Image 1 Highlights • Hookworm infection is endemic within the Irish badger population. • Lungworm infection is also common in Irish badgers. • Coprological analysis has a low sensitivity for diagnosing infection compared to adult worm burden. • Faecal is a reliable indicator of intensity of infection. • Density-dependence is weak, or non-existent up to the observed intensity of 500 worms. [ABSTRACT FROM AUTHOR]

Abstract Background It is the aim of the World Health Organisation to eliminate soil-transmitted helminths (STH) as a health problem in children. To this end, the goal is to increase anthelmintic treatment coverage for soil transmitted helminths to reach 75 % in pre-school aged and school aged children by 2020 in endemic countries. In this paper, we use mathematical models to investigate the impact of achieving this goal on the burdens of Ascaris lumbricoides, Trichuris trichuria and hookworm. Methods We employ a deterministic fully age-structured model of STH transmission and mass drug administration to examine the changes in worm burden in response to the known and projected coverage trends in children up to 2020 and beyond. Parameters are estimated from worm expulsion data and age intensity profiles before treatment using maximum likelihood methods. Model validation is performed using reinfection studies for Ascaris and analyses are conducted to assess the sensitivity of the predicted outcomes to variation in parameter estimates including transmission intensity (R0), children’s contributions to the pool of infective stages and drug coverage levels. Results The impact of the required increase in coverage trends are quite different across the three species. Ascaris burdens are reduced dramatically by 2020 with elimination predicted within studied the setting a further 10 years. For Trichuris and hookworm, however, impact is more limited, due to issues of drug efficacy (Trichuris) and distribution of worms in the population (hookworm). Sensitivity analysis indicates that results are largely robust. However, validation against Ascaris data indicates that assumptions concerning re-infection among children may have to be revised. Conclusions The 2020 coverage target is predicted to have a major impact on Ascaris levels by 2020. However, there is evidence from model validation that Ascaris in children is more resilient to treatment than currently assumed in the model. Broader coverage across all age classes is required to break transmission for hookworm and alternative dual drug treatment approaches are needed for Trichuris.

Soil-transmitted helminths (STHs) are endemic in more than half of the world’s countries. The World Health Organization has advocated targeted preventive chemotherapy (PC) to control STH infections by distributing albendazole or mebendazole to at-risk populations. While the overall impact and sustainability of this strategy is disputed, a decrease in moderate and heavy STH infections can be largely attributed to a scale-up of drug distribution. Two factors might jeopardise the success of PC programs. First, the benzimidazoles possess unsatisfactory efficacy against Trichuris trichiura infections. Second, increased drug distributions might trigger anthelmintic resistance. This review presents an overview of the burden of STH infections, the evolution of PC along with its success and challenges, recent estimates of the efficacy of recommended drugs, and alternative treatment options. [ABSTRACT FROM AUTHOR]

Patient-side test kits for detecting antigenemia in dogs associated with sexually mature female heartworms ( Dirofilaria immitis ) have been available for three decades, and these tests are continually updated and improved. To define the sensitivity (Se) and specificity (Sp) of contemporary antigen detection tests against cardiopulmonary D. immitis burden, we evaluated five patient-side kits—Anigen Rapid One Step ® (Bio note), SNAP ® 4Dx Plus Test Kit (IDEXX), WITNESS ® Heartworm Canine Heartworm Antigen Test Kit (Zoetis), VetScan ® Canine Heartworm Rapid Test (Abaxis), and Solo Step ® CH Canine Heartworm Antigen Test (Heska), and one microplate ELISA (DiroCHEK ® ; Zoetis), using archived canine sera divided into five subclasses of female worms (0, 1–5, 6–20, 21–40, and >40). The patient-side tests were performed once, side-by-side according to each manufacturer’s protocol by personnel blinded to the D. immitis status of each dog. The overall Se and Sp of the patient-side kits was ≥97.5 and =94.0%, respectively. For samples from dogs with 1–5, 6–20, and 21–40 D. immitis , the Se was between 96 and 100%, with a slight increase in Se in dogs with ≥41 worms. The agreement between tests for all subclasses of D. immitis burden was between 99 and 100%. The Se and Sp for the ELISA compared with the necropsy results of dogs was 99 and 96%, respectively. Agreement between each patient-side test and the ELISA was between 97 and 100%. All commercially available tests can give practitioners excellent patient-side information, allowing them to make informed decisions on the need for additional diagnostic work-up before instituting new or continuing D. immitis prophylaxis. [ABSTRACT FROM AUTHOR]

1. A cross-sectional study was conducted from September 2015 to July 2016 in South Tyrol, Northern Italy to examine the prevalence of gastrointestinal helminths in free-range laying hens under mountain farming production conditions. 2. A total of 280 laying hens from 14 free-range mountain farms (4 organic, 10 conventional) were randomly collected at the end of the laying period. Faecal samples were taken to analyse faecal egg counts (FEC) and faecal oocyst counts (FOC). The gastrointestinal tracts were removedpost mortemand examined for the presence of helminths. 3. In faeces, FEC values averaged 258 eggs per g of faeces, which were dominated byAscaridia galliandHeterakis gallinarum. Mean FOC was 80 oocysts/g. In the gastrointestinal tract, at least one nematode species was found in 99.3% of the examined hens.H. gallinarumwas the most prevalent nematode (95.7%), followed byCapillariaspp. (66.8%) andA. galli(63.6%). Thirty per cent of the chickens were infected with cestodes (tapeworms). Correlation coefficients between worm counts ofH. gallinarum, Capillariaspp. andA. galliranged from 0.41 to 0.51. 5. The helminth prevalence did not differ between conventional and organic farms, whereas total worm burden was higher in organic compared with conventional farms (318.9 vs. 112.0). Prevalence and infection intensity did not differ between farms that used anthelmintic treatments and those that did not. 6. In conclusion, free-range laying hens under the studied mountain farming conditions are at high risk of nematode infection, especially in organic systems. The vast majority of hens are subclinical infected with at least one helminth species. [ABSTRACT FROM AUTHOR]

The French heartworm Angiostongylus vasorum is found in European red fox ( Vulpes vulpes ) and dog populations, where it appears to be spreading geographically. Once introduced into new areas, it establishes in local fox populations, typically to over 50% prevalence in a few years. High susceptibility and constant excretion of first stage larvae (L1) by the definitive hosts are prerequisites for sustaining high parasite biomass in a particular habitat. The present study explores the hypothesis that repeated ingestion of gastropods in nature will result in accumulation of adult worms and elevated excretion of L1 in feces. Experimentally infected foxes were subsequently inoculated via stomach tube once (9 weeks post initial inoculation) or twice (9 and 13 weeks post inoculation (wpi)) with 100 third stage A. vasorum larvae (L3) previously isolated from aquatic snails infected with L1 from a naturally infected dog. Despite large variation in fecal larval excretion for the individual animals within the groups, excretion of L1 was significantly higher in foxes twice inoculated as compared to foxes inoculated only once. With an outlier in the once inoculated group removed, excretion became significantly higher in the three times inoculated group. Establishment of adult worms varied and only a trend to higher worm burdens was found in the group of foxes inoculated three times. However, this became significant with the same single outlier removed. Overall, it appears that protective immunity to A. vasorum does not appear to occur in V. vulpes with animals exhibiting high infection intensities without obvious clinical signs. The increasing larval excretion in foxes being repeatedly exposed to A. vasorum L3 support the hypothesis that foxes under natural conditions may repeatedly ingest infected gastropods and remain a source of environmental contamination for several months, potentially contributing to the establishment of endemic foci through increasing L1 excretion. [ABSTRACT FROM AUTHOR]

Abstract Background Gastrointestinal nematodes cause significant economic losses in the sheep industry, with frequent reports of anthelmintic resistance. Therefore, alternative methods to control these parasites are necessary. Thus, the aim of the present study was to assess the effect of treatment with selenium and copper on the protein profile of sheep that were experimentally infected with Haemonchus contortus. Methods Twenty-eight lambs were experimentally infected with H. contortus and divided into four experimental groups as follow: G1 - untreated animals; G2 - treated with sodium selenite; G3 - treated with copper; G4 - treated with sodium selenite and copper. The serum protein, body weight and egg count per gram of feces (EPG) were assessed at the baseline and after 20, 40, 60 and 80 days. The parasite burden was assessed 80 days after the beginning of the experiment. Results Higher levels of total protein and gamma globulin were observed in the lambs treated with sodium selenite and copper on D80. Copper acted as a growth promoter. The copper-supplemented groups exhibited higher daily and total weight gain. The association of selenium and copper altered the protein profile of sheep. Copper and selenium supplementation reduced EPG and worm burden at the end of the experiment. To the best of our knowledge, this is the first study to demonstrate the positive effect of the combined parenteral supplementation of Se and Cu on H. contortus infection. Conclusions This injectable supplementation could be used as an auxiliary method to control H. contortus in sheep.

Abstract In a Letter to the Editor, Eberhard et al. question the validity of our model of skin snip sensitivity and argue against the use of skin snips to evaluate onchocerciasis elimination by mass drug administration. Here we discuss their arguments and compare model predictions with observed data to assess the validity of our model.

A dual drug repurposing/nanotechnological approach was used to develop an alternative oral treatment for schistosomiasis mansoni using miltefosine (MFS), an anticancer alkylphosphocholine, and lipid nanocapsules (LNCs) as oral nanovectors. We demonstrated earlier that MFS possesses significant activity against different developmental stages of Schistosoma mansoni in the mouse model using 5 successive 20 mg/kg/day oral doses. Moreover, an effective single dose (20 mg/kg) oral treatment against the adult stage of S. mansoni in mice was developed using LNCs, particularly modified with CTAB, a positive charge imparting agent (MFS-LNC-CTAB + ), or oleic acid as membrane permeabilizer (MFS-LNC-OA). Efficacy enhancement involved, at least in part, targeting of the worm tegument with MFS-LNCs as a new therapeutic entity. As the tegument surface charge and composition may differ in pre-patent stages of the parasite, it was of importance in the present study to assess the efficacy of a single oral dose of the two MFS-LNC formulations against invasive and immature stages for potential advantage relative to praziquantel. Results indicated potent schistosomicidal effects against both invasive and immature stages of S. mansoni in infected mice, efficacy being both formulation and developmental stage dependent. This was indicated by the significant reduction in the total worm burden of the invasive stage by 91.6% and 76.8% and the immature stage by 82.7% and 96.7% for MFS-LNC-CTAB+ and MFS-LNC-OA, respectively. Histopathological findings indicated amelioration of hepatic pathology with regression of the granulomatous inflammatory reaction and reduction in granulomas number and size, verifying marked improvement in architecture of hepatic lobules. From a clinical perspective, MFS-LNCs offer potential as an alternative single oral dose nanomedicine with a wide therapeutic profile for the mass chemotherapy of schistosomiasis mansoni. [ABSTRACT FROM AUTHOR]