Adipose and skin distribution of African trypanosomes in natural animal infections.

BACKGROUND: Animal African trypanosomiasis, which is caused by different species of African trypanosomes, is a deadly disease in livestock. Although African trypanosomes are often described as blood-borne parasites, there have been recent reappraisals of the ability of these parasites to reside in a wide range of tissues. However, the majority of those studies were conducted on non-natural hosts infected with only one species of trypanosome, and it is unclear whether a similar phenomenon occurs during natural animal infections, where multiple species of these parasites may be present. METHODS: The infective trypanosome species in the blood and other tissues (adipose and skin) of a natural host (cows, goats and sheep) were determined using a polymerase chain reaction-based diagnostic. RESULTS: The animals were found to harbour multiple species of trypanosomes. Different patterns of distribution were observed within the host tissues; for instance, in some animals, the blood was positive for the DNA of one species of trypanosome and the skin and adipose were positive for the DNA of another species. Moreover, the rate of detection of trypanosome DNA was highest for skin adipose and lowest for the blood. CONCLUSIONS: The findings reported here emphasise the complexity of trypanosome infections in a natural setting, and may indicate different tissue tropisms between the different parasite species. The results also highlight the need to include adipose and skin tissues in future diagnostic and treatment strategies.

Intra- and interspecies variation and population dynamics of Fasciola gigantica among ruminants in Sudan.

Fasciola gigantica is a widespread parasite that causes neglected disease in livestock worldwide. Its high transmissibility and dispersion are attributed to its ability to infect intermediate snail hosts and adapt to various mammalian definitive hosts. This study investigated the variation and population dynamics of F. gigantica in cattle, sheep, and goats from three states in Sudan. Mitochondrial cytochrome c oxidase subunit I (COI) and NADH dehydrogenase subunit 1 (ND1) genes were sequenced successfully to examine intra and interspecific differences. ND1 exhibited higher diversity than COI, with 15 haplotypes and 10 haplotypes, respectively. Both genes had high haplotype diversity but low nucleotide diversity, with 21 and 11 polymorphic sites for ND1 and COI, respectively. Mismatch distribution analysis and neutrality tests revealed that F. gigantica from different host species was in a state of population expansion. Maximum likelihood phylogenetic trees and median networks revealed that F. gigantica in Sudan and other African countries had host-specific and country-specific lineages for both genes. The study also indicated that F. gigantica-infected small ruminants were evolutionarily distant, suggesting deep and historical interspecies adaptation.

Predicting and reducing potential parasite infection between migratory livestock and resident Asiatic ibex of Pin valley, India.

Disease cross-transmission between wild and domestic ungulates can negatively impact livelihoods and wildlife conservation. In Pin valley, migratory sheep and goats share pastures seasonally with the resident Asiatic ibex (Capra sibirica), leading to potential disease cross-transmission. Focussing on gastro-intestinal nematodes (GINs) as determinants of health in ungulates, we hypothesized that infection on pastures would increase over summer from contamination by migrating livestock. Consequently, interventions in livestock that are well-timed should reduce infection pressure for ibex. Using a parasite life-cycle model, that predicts infective larval availability, we investigated GIN transmission dynamics and evaluated potential interventions. Migratory livestock were predicted to contribute most infective larvae onto shared pastures due to higher density and parasite levels, driving infections in both livestock and ibex. The model predicted a c.30-day antiparasitic intervention towards the end of the livestock's time in Pin would be most effective at reducing GINs in both hosts. Albeit with the caveats of not being able to provide evidence of interspecific parasite transmission due to the inability to identify parasite species, this case demonstrates the usefulness of our predictive model for investigating parasite transmission in landscapes where domestic and wild ungulates share pastures. Additionally, it suggests management options for further investigation.

Complete Mitochondrial Genome for Lucilia cuprina dorsalis (Diptera: Calliphoridae) from the Northern Territory, Australia.

The Australian sheep blowfly, Lucilia cuprina dorsalis, is a major sheep ectoparasite causing subcutaneous myiasis (flystrike), which can lead to reduced livestock productivity and, in severe instances, death of the affected animals. It is also a primary colonizer of carrion, an efficient pollinator, and used in maggot debridement therapy and forensic investigations. In this study, we report the complete mitochondrial (mt) genome of L. c. dorsalis from the Northern Territory (NT), Australia, where sheep are prohibited animals, unlike the rest of Australia. The mt genome is 15,943 bp in length, comprising 13 protein-coding genes (PCGs), two ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs), and a non-coding control region. The gene order of the current mt genome is consistent with the previously published L. cuprina mt genomes. Nucleotide composition revealed an AT bias, accounting for 77.5% of total mt genome nucleotides. Phylogenetic analyses of 56 species/taxa of dipterans indicated that L. c. dorsalis and L. sericata are the closest among all sibling species of the genus Lucilia, which helps to explain species evolution within the family Luciliinae. This study provides the first complete mt genome sequence for L. c. dorsalis derived from the NT, Australia to facilitate species identification and the examination of the evolutionary history of these blowflies.

Prevalence and seasonal aspects of parasitism by Oestrus ovis (Diptera: Oestridae) in sheep from Mato Grosso State, Brazil.

Oestrus ovis larvae are obligate parasites of vertebrates and cause cavitary myiasis (oestrosis) in sheep and goats. It is also reported as a zoonosis causing ophthalmomyiasis and nasopharyngeal myiasis. Despite being relatively common in Brazil, epidemiological studies on O. ovis are scarce. Considering that the infestation is influenced by the climate and biomes of the studied region, we aimed to investigate the seasonal prevalence of O. ovis among slaughtered sheep in the northern region of the state of Mato Grosso, Brazil. The heads of sheep (n=697) slaughtered at a slaughterhouse in the municipality of Terra Nova do Norte (November 2011 to November 2013) were collected to count, catalog, and identify the larvae found in the upper respiratory tract. Overall, 45.77% (319/697) of the animals were infested with 2,412 recovered larvae, 96.89% (2,337/2,412) of which were identified at the species level as O. ovis. Seasonal variations in prevalence ranged from 41% (spring) to 56% (summer); however, no correlation was observed between prevalence and season, mean humidity, or temperature. In conclusion, parasitism by O. ovis in sheep in the studied area, occurs year-round, considering the occurrence of larvae (L1, L2, and L3) throughout the year, probably because of the area's environmental conditions.

Validation of deep amplicon sequencing of Dicrocoelium in small ruminants from Northern regions of Pakistan.

Dicrocoelium lancet flukes cause significant production loss in ruminant livestock. Although co-infection with multiple Dicrocoelium species within a host is common, techniques for studying the composition of these complex parasite communities are lacking. The pathogenicity, epidemiology, and therapeutic susceptibility of different helminth species vary, and little is known about the interactions that take place between co-infecting species and their hosts. Here, we describe the first applicationof metabarcoding deep amplicon sequencing method to studythe Dicrocoelium species in sheep and goats. First, rDNA ITS-2 sequences of four Dicrocoelium species (Dicrocoelium dendriticum, Dicrocoelium hospes, Dicrocoelium orientalis, and Dicrocoelium chinensis) were extracted from the NCBI public database. Phylogenetic analysis revealed separate clades of Dicrocoelium species; hence, molecular differentiation between each species is possible in co-infections. Second, 202 flukes belonging to seventeen host populations (morphologically verified as belonging to the Dicrocoelium genus) were evaluated to determine the deep amplicon sequencing read threshold of an individual fluke for each of the four species. The accuracy of the method in proportional quantification of samples collected from single hosts was further assessed. Overall, 198 (98.01%) flukes were confirmed as D. dendriticum and 1.98% produced no reads. The comparison of genetic distances between rDNA ITS-2 revealed 86% to 98% identity between the Dicrocoelium species. Phylogenetic analysis demonstrated a distinct clustering of species, apart from D. orientalis and D. chinensis, which sit very close to each other in a single large clade whereas D. hospes and D. dendriticum are separated into their own clade. In conclusion each sample was identified as D. dendriticum based on the proportion of MiSeq reads and validated the presence of this group of parasites in the Gilgit Baltistan and Khyber Pakhtunkhwa provinces of Pakistan. The metabarcoding deep amplicon sequencing technology and bioinformatics pathway have several potential applications, including species interactions during co-infections, identifying the host and geographical distribution of Dicrocoelium in livestock, drug therapy response evaluation and understanding of the emergence and spread of drug resistance.

Refugia or reservoir? Feral goats and their role in the maintenance and circulation of benzimidazole-resistant gastrointestinal nematodes on shared pastures.

Gastrointestinal nematodes threaten the productivity of grazing livestock and anthelmintic resistance has emerged globally. It is broadly understood that wild ruminants living in sympatry with livestock act as a positive source of refugia for anthelmintic-susceptible nematodes. However, they might also act as reservoirs of anthelmintic-resistant nematodes, contributing to the spread of anthelmintic resistance at a regional scale. Here, we sampled managed sheep and cattle together with feral goats within the same property in New South Wales, Australia. Internal transcribed spacer 2 (ITS-2) nemabiome metabarcoding identified 12 gastrointestinal nematodes (Cooperia oncophora, Cooperia punctata, Haemonchus contortus, Haemonchus placei, Nematodirus spathiger, Ostertagia ostertagi, Teladorsagia circumcincta, Oesophagostomum radiatum, Oesophagostomum venulosum, Trichostrongylus axei, Trichostrongylus colubriformis and Trichostrongylus rugatus). Isotype-1 ß-tubulin metabarcoding targeting benzimidazole resistance polymorphisms identified 6 of these nematode species (C. oncophora, C. punctata, H. contortus, H. placei, O. ostertagi and T. circumcincta), with the remaining 3 genera unable to be identified to the species level (Nematodirus, Oesophagostomum, Trichostrongylus). Both ITS-2 and ß-tubulin metabarcoding showed the presence of a cryptic species of T. circumcincta, known from domestic goats in France. Of the gastrointestinal nematodes detected via ß-tubulin metabarcoding, H. contortus, T. circumcincta, Nematodirus and Trichostrongylus exhibited the presence of at least one resistance genotype. We found that generalist gastrointestinal nematodes in untreated feral goats had a similarly high frequency of the benzimidazole-resistant F200Y polymorphism as those nematodes in sheep and cattle. This suggests cross-transmission and maintenance of the resistant genotype within the wild ruminant population, affirming that wild ruminants should be considered potential reservoirs of anthelmintic resistance.

Pharmacopuncture with a low dosage of B complex vitamins in the Da Zhui acupoint (Governing Vessel 14) for controlling gastrointestinal parasitism in periparturient ewes / Farmacopuntura com dose baixa de vitaminas do complexo B no acuponto Da Zhui (Vaso Governador 14) para o controle da parasitose gastrintestinal em ovelhas no periparto

Gastrointestinal parasites are a significant challenge in sheep farming, and periparturient ewes are one of the most susceptible categories in sheep flocks. This study aimed to verify whether the injection of B vitamins at the acupuncture point governing vessel 14 (GV14) can influence the parasitic load or host-parasite interaction in naturally infected ewes during the peripartum period. Four weeks before parturition, 25 ewes were divided into five treatment groups: (1) Dose Control: 0.2 mL of B complex via IM; (2) Drug Control: 2 mL Complex B via IM; (3) Acupoint Control: 0.2 mL of Water at GV14 point; (4) Control; (5) Test group: 0.2 mL of B complex at the GV14 point. Treatments were performed at weeks -3, -1, 2, 4, and 6 about the parturition time. Fecal samples to estimate the parasitic load by fecal egg counts (FEC) and total blood samples for hemogram examination were performed seven days after the treatment, coinciding with weeks -2, 3, 5, and 7 about the parturition time. The number of peripheral eosinophils was higher in group 3 than in group 1 (p <0.05). Although groups 3 and 5 had lower mean values of FEC and higher hematological values at the time of weaning, these differences were not statistically significant (p> 0.05) according to the F test. However, all animals in groups 3 and 5 maintained low parasitism levels until the end of the experiment. Further studies should be performed with larger sample sizes and minor changes to the experimental protocol to elucidate the role of GV14 acupoint stimulation in the host-parasite relationship.(AU)

A parasitose gastrointestinal é o principal desafio sanitário para a criação de ovinos a pasto, e as ovelhas no periparto são uma das categorias mais susceptíveis a esta infeção no rebanho. O objetivo deste trabalho foi verificar se a injeção de vitaminas do complexo B no acuponto Vaso Governador 14 (VG14) poderia influenciar a carga parasitária ou modular a interação hospedeiro-parasito em ovelhas naturalmente infectadas no período de periparto. Quatro semanas antes da data prevista para o parto, 25 ovelhas foram divididas em cinco grupos de tratamento (1) Controle da dose: 0,2 mL de vitaminas do complexo B via IM; (2) Controle do fármaco: 2mL complexo B via IM; (3) Controle do Ponto: 0,2 mL de água destilada no ponto VG14; (4) Controle sem tratamento; (5) Grupo teste: 0,2 mL de complexo B no pontoVG14. Estes tratamentos foram realizados nas semanas -3; -1; 2; 4 e 6 em relação à data do parto. Amostras de fezes para contagem de ovos por grama de fezes (OPG), assim como amostras de sangue para realizar o hemograma, foram obtidas dos animais sete dias após os tratamentos, coincidindo com as semanas -2, 3, 5 e 7 do parto. O número de eosinófilos periféricos foi superior no grupo 3 se comparado ao grupo 1 (p <0,05). Os animais dos grupos 3 e 5 tiveram menores valores de OPG e maior hematócrito, mas estas diferenças não foram consideradas significativas pelo teste F (p> 0,05). No entanto, todas as ovelhas dos grupos 3 e 5 se mantiveram com níveis baixos de parasitismo durante todo o experimento. Sugere-se que novos estudos sejam realizados com algumas modificações deste protocolo a fim de aprofundar o conhecimento do potencial imunomodulador do acuponto VG14.(AU)

Relationship between FAMACHA© scores and zootechnical indicators of a sheep production system / Relação entre os graus FAMACHA© e indicadores zootécnicos de um sistema de produção de ovinos

In Brazil, lamb producers face challenges raising their animals because of high anthelmintic resistance and loss of productivity due to parasites. It is well known that parasitic infections can reduce the performance of sheep. However, until the publication of this work, no research was found that quantified the effects that anemia reflected by FAMACHA© scores can exert on other zootechnical indicators in a lamb production system. The objective of this study was to use the FAMACHA© scores to quantify the impacts of anemia in ewes at breeding and lambing on the productive and reproductive performance of a meat sheep flock. The variables evaluated were i) FAMACHA© score of ewes at breeding and lambing, ii) body condition score of ewes at breeding and at lambing, iii) average daily gain of lambs until weaning, iv) ewe's age, v) birth weights per individual lamb and litter, vi) weaning weight, vii) ewe's weight, viii) litter size and ix) pre-weaning survival. The treatments evaluated corresponded to the FAMACHA© score of the ewes during breeding and lambing. Quantitative responses were submitted to analyses of variance and compared by Duncan's test. In contrast, qualitative or discrete responses were evaluated by the Kruskal & Wallis test and compared to Dunn's test. The Wilcoxon test was performed to compare the FAMACHA©scores of ewes at breeding and lambing. All statistical analyzes were performed using the R-Studio software version 4.2.0 at a 5% significance level. The FAMACHA© score of breeding ewes was related to the body condition score at breeding, ewe weight, pre-weaning survival, ewe age, litter size, and birth weight. Furthermore, the FAMACHA© score of ewes at lambing was related to the body condition score at lambing, ewe weight, pre-weaning survival, birth weight per lamb and litter, pre-weaning average daily gain, weaning weight, and age of the ewe. There was no significant difference between the test times of the FAMACHA© scores of the ewes, indicating that an ewe will present a similar score at both stages. It was concluded that ewes with FAMACHA© scores of 4 and 5 and their offspring showed the worst productive and reproductive performances. Conversely, the ewes with FAMACHA© 1 obtained the opposite result, demonstrating better technical performance.(AU)

No Brasil, produtores de cordeiros enfrentam desafios na criação de seus animais devido à alta resistência anti-helmíntica e perda de produtividade devido a parasitoses. Sabe-se que as infecções parasitárias podem reduzir o desempenho de matrizes ovinas, contudo, até a elaboração desse trabalho não foram encontradas pesquisas que mensuraram os efeitos que a anemia refletida pelos graus FAMACHA© podem exercer sobre outros indicadores zootécnicos em um sistema de produção de cordeiros. Sendo assim, o objetivo desse estudo foi quantificar os impactos das verminoses em matrizes ovinas, representadas pelo grau FAMACHA©, durante a estação de monta e a parição, no desempenho produtivo e reprodutivo de um rebanho ovino de corte. As variáveis avaliadas foram: i) grau FAMACHA© das matrizes à monta e ao parto, ii) escore de condição corporal das matrizes à monta e ao parto, iii) ganho médio diário até o desmame, iv) idade da matriz, v) pesos dos cordeiros ao nascer individual e por parto, vi) peso ao desmame, vii) peso da matriz, viii) prolificidade e ix) sobrevivência pré-desmame. Os tratamentos avaliados corresponderam ao grau FAMACHA© das matrizes durante a monta e parto. As respostas quantitativas foram submetidas à análise de variância e comparadas pelo teste de Duncan, já as respostas qualitativas ou discretas foram avaliadas pelo teste de Kruskal & Wallis e comparadas pelo teste de Dunn. Realizou-se o teste de Wilcoxon para comparar os graus FAMACHA© das matrizes nos momentos de monta e parto. Todas as análises estatísticas foram realizadas no software R-Studio versão 4.2.0 ao nível de 5% de significância. O grau FAMACHA© das matrizes à monta foi relativo ao escore de condição corporal à monta, peso da matriz, sobrevivência pré-desmame, idade da matriz, prolificidade e peso ao nascer coletivo por parto. Já o grau FAMACHA© das matrizes ao parto foi relativo ao escore de condição corporal ao parto, peso da matriz, sobrevivência pré-desmame, pesos ao nascer individual e coletivo por parto, ganho médio diário pré-desmame, peso ao desmame e idade da matriz. Não houve diferença significativa entre os momentos dos graus FAMACHA© das matrizes, indicando que uma ovelha manterá um grau FAMACHA© similar em ambas as fases. Conclui-se que ovelhas com graus FAMACHA© 4 e 5, assim como suas crias, apresentaram os piores desempenhos produtivos e reprodutivos. Em contrapartida, as matrizes com FAMACHA©1 obtiveram o resultado oposto, mostrando indicadores zootécnicos com valores mais eficientes ao sistema de produção.(AU)

The detection and phylogenetic analysis of Anaplasma phagocytophilum-like 1, A. ovis and A. capra in sheep: A. capra divides into two genogroups.

In this study, the presence, prevalence, and genotypes of Anaplasma phagocytophilum, A. ovis, and A. capra in sheep were investigated based on 16 S SSU rRNA, groEL, and gtlA gene-specific polymerase chain reaction (PCR), respectively. The sequences of the genes were used for detection of the phylogenetic position of the species. Additionally, a restriction fragment length polymorphism (RFLP) were carried out for discrimination of A. phagocytophilum and related variants (A. phagocytophilum-like 1 and 2). The prevalence of Anaplasma spp. was found as 25.8% (101/391), while it was found that A. ovis, A. phagocytophilum-like 1, and A. capra are circulating in the sheep herds in Kyrgyzstan, according to the PCRs, RFLP and the partial DNA sequencing results. The positivity rates of A. phagocytophilum-like 1, A. ovis, and A. capra genotype-1 were 6.9, 22.5, and 5.3%, respectively. A total of 32 (8.2%) sheep were found to be mix infected. Moreover, phylogenetic analyses and sequence comparison with those available in the GenBank showed that A. capra formed two distinct genetic groups (A. capra genotype-1 and A. capra genotype-2). Considering the zoonotic potential of these species, it may be necessary to make changes in the interpretation of anaplasmosis cases in animals and there is a need for further studies to determine the pathogenicity of the species/genotypes circulating in animals.

Morphological identification and molecular characterization of economically important ticks (Acari: Ixodidae) from North and North-Western Egypt.

Ticks represent a major source of growing economic and public health concern, especially in the tropics and sub-tropics. Towards evidencing ticks' invasion in the North and North-Western parts of Egypt, the present study aimed to investigate the morpho-molecular aspects of those ectoparasites using stereomicroscopy, scanning electron microscopy (SEM) and sequencing of the mitochondrial 16S ribosomal DNA gene (rDNA) and nuclear second internal transcribed spacer (ITS2). Our analysis confirmed the presence and well-distribution of Rhipicephalus sanguineus s.l. infesting dogs and sheep (Alexandria governorate), Rhipicephalus annulatus infesting cattle (Beheira governorate), and Hyalomma dromedarii infesting camels (Marsa Matruh governorate) from North/North-Western Egypt. 16S rDNA and ITS2 sequences of the ticks were amplified using universal and gene-specific sets of primers, sequenced and analyzed. Lengths of amplified 16S rDNA sequences in all examined tick species were found to be similar in size (approximately 460 bp); however, they differed in base pair constitutions, whereas ITS2 lengths were 1,500 bp, 1,550 bp, and 1,800 bp for Rh. annulatus, Rh. sanguineus s.l., and Hy. dromedarii, respectively. Phylogenetically, based on the 16S rDNA results, Rh. sanguineus s.l. ticks clustered with the southeastern Europe lineage from Romania and Greece, Rh. annulatus ticks were similar to Turkish populations, and Hy. dromedarii were close to the isolates from Tunisia. Similarly, based on ITS2 sequences, Rh. sanguineus s.l. from dogs were showing 99% similarity to Nigerian populations; however, those collected from sheep were closer to Iranian populations with 4.1% nucleotide divergence between the two populations of different hosts. Rh. annulatus ticks were identical to a population from Romania, whereas Hy. dromedarii was close by 99.7% similarity to a population from Kenya. This is the first study reporting nucleotide sequences of 16S rDNA and ITS2 in integration with morphological identification of ticks from this part of Egypt.

Functionally distinct T-helper cell phenotypes predict resistance to different types of parasites in a wild mammal.

The adaptive immune system is critical to an effective response to infection in vertebrates, with T-helper (Th) cells pivotal in orchestrating these responses. In natural populations where co-infections are the norm, different Th responses are likely to play an important role in maintaining host health and fitness, a relationship which remains poorly understood in wild animals. In this study, we characterised variation in functionally distinct Th responses in a wild population of Soay sheep by enumerating cells expressing Th-subset specific transcription factors and quantifying Th-associated cytokines. We tested the prediction that raised Th1 and Th2 responses should predict reduced apicomplexan and helminth parasite burdens, respectively. All measures of Th-associated cytokine production increased with age, while Th17- and regulatory Th-associated cytokine production increased more rapidly with age in males than females. Independent of age, sex, and each other, IL-4 and Gata3 negatively predicted gastro-intestinal nematode faecal egg count, while IFN-γ negatively predicted coccidian faecal oocyst count. Our results provide important support from outside the laboratory that Th1 and Th2 responses predict resistance to different kinds of parasites, and illustrate how harnessing specific reagents and tools from laboratory immunology will illuminate our understanding of host-parasite interactions in the wild.

Economic impact of gastrointestinal nematodes in Morada Nova sheep in Brazil / Impacto econômico de nematódeos gastrintestinais em ovinos Morada Nova no Brasil

Abstract This study evaluated the economic impact of gastrointestinal nematode (GIN) infection in Morada Nova lambs under different parasite chemical control conditions. For this, 246 lambs, in the rainy and dry season, were randomized into groups according to their anthelmintic treatment with levamisole: control (CT: no treatment); routine treatment (RT: treated every 42 days); and targeted selective treatment (TST: treated according to the average daily weight gain, DWG). From 63 days of age (D63) to D210, the lambs were weighed and monitored for GIN infection parameters. Spending on anthelmintics in the production system was 1.3% of the total economic result. The economic result per animal (R$ 5.00 = US$ 1.00) was higher in the RT group, amounting to US$ 6.60 in the rainy and US$ 5.69 in the dry season, due to higher DWG. Thus, RT presented economic results 14.4% and 10.9% higher than CT, and 7.2% and 1.9% higher than TST, in the rainy and dry season, respectively. However, fast development of resistance made RT unfeasible. Here, the economic impact of GIN infection on a national scale is discussed, demonstrating its importance and the impossibility of profitable and sustainable sheep production without adequate control.

Resumo Este estudo avaliou o impacto econômico da infecção por nematoides gastrintestinais (NGI), em cordeiros Morada Nova, sob diferentes condições de controle químico dos parasitas. Para isso, 246 cordeiros, na estação chuvosa e seca, foram randomizados em grupos de acordo com o tratamento com levamisol: controle (TC: sem tratamento); tratamento rotineiro (TR: tratado a cada 42 dias); e tratamento seletivo direcionado (TST: tratado de acordo com o ganho de peso médio diário, GMD). Dos 63 dias de idade (D63) ao D210, os cordeiros foram pesados ​​e monitorados quanto aos parâmetros de infecção por NGI. O gasto com anti-helmínticos no sistema produtivo foi de 1,3% do resultado econômico total. O resultado econômico por animal (R$ 5,00 = US$ 1,00) foi maior no grupo RT, totalizando US$ 6,60 na estação chuvosa e US$ 5,69 na seca, devido ao maior GMD. Assim, o RT apresentou resultados econômicos 14,4% e 10,9% superiores ao TC, e 7,2% e 1,9% superiores ao TST, no período chuvoso e seco, respectivamente. Entretanto o rápido desenvolvimento de resistência inviabiliza o TR. O impacto econômico da infecção por NGI em escala nacional são aqui discutidos, demonstrando sua importância e a impossibilidade de uma ovinocultura lucrativa e sustentável sem o controle adequado.

Natural infection of Trypanosoma sp. in domestic sheep from Ecuador / Infecção natural do Trypanosoma sp. em ovelhas domésticas do Equador

Trypanosomosis in sheep is a hemoparasitic disease of worldwide interest due to its effects on the health of animals and the economic impact on producers, is caused by the protozoan Trypanosoma sp. In the present study, the occurrence of Trypanosoma sp. in sheep from the urban-rural area of the canton Salitre was determined, through an applied study with a qualitative descriptive prospective cross-sectional approach, carried out between October 1, 2019, and February 19, 2020. Blood samples were extracted from the jugular vein and analyzed by the blood smear method using the Giemsa and Diff-Quick staining techniques. Previously, in a first study realized between 2018 and 2019, 2 cases (2%) of Trypanosoma sp., 1 case of Babesia sp. (1%), and 4 cases of Anaplasma marginale (4%) were identified, but without the presence of symptoms of the disease. However, in this new research study, of 170 animals sampled from 5 herds and aged between 3 and 8 years, 34 (20%) were positive for Trypanosoma sp., 6 for Babesia sp. (3.52%) and 6 for A. marginale (3.52%) with coinfection between them. In this research, deteriorated clinical aspects and low hematological values were also determined in positive animals; besides of the total of positive cases, 25 presented symptoms of hemoparasitic disease, 3 sheep had abortions and 8 died. The results of this study showed that Trypanosoma sp. could already become an endemic parasitosis in sheep in the country, representing a serious problem of animal health.

A tripanossomose em ovinos é uma doença hemoparasitária de interesse mundial devido a seus efeitos sobre a saúde dos animais e o impacto econômico sobre os produtores, Esta doença é causada pelo protozoário Trypanosoma sp. No presente estudo, foi determinada a ocorrência de Trypanosoma sp. em ovelhas da área urbano-rural do Cantão Salitre, através de um estudo aplicado com uma abordagem transversal descritiva qualitativa prospectiva, realizado entre dia primeiro de outubro de 2019, à 19 de fevereiro de 2020. Amostras de sangue foram extraídas da veia jugular e analisadas pelo método de esfregaço de sangue usando as técnicas de coloração Giemsa e Diff-Quick. Anteriormente, em um primeiro estudo realizado entre 2018 e 2019, dois casos (2%) de Trypanosoma sp., foram identificados um caso de Babesia sp. (1%), e quatro casos de Anaplasma marginale (4%), mas sem a presença de sintomas da doença. Entretanto, neste novo estudo de pesquisa, de 170 animais amostrados de cinco rebanhos e com idades entre três e oito anos, 34 (20%) foram positivos para Trypanosoma sp., seis para Babesia sp. (3,52%) e seis para A. marginale (3,52%) com coinfecção entre eles. Nesta pesquisa, aspectos clínicos deteriorados e baixos valores hematológicos também foram determinados em animais positivos; além do total de casos positivos, 25 apresentaram sintomas de doença hemoparasítica, três ovelhas tiveram abortos e oito morreram. Os resultados deste estudo mostram que o Trypanosoma sp. já poderia se tornar uma parasitose endêmica em ovinos no país, representando um grave problema de saúde animal.

Trichostrongyloid nematodes in ruminants of northern Iran: prevalence and molecular analysis.

BACKGROUND: This study was carried out to investigate the prevalence and analyze the molecular characteristics based on the internal transcribed spacer (ITS) 2 region of the ribosomal RNA (RNA) gene of trichostrongylid nematodes in different ruminants from Guilan province, northern of Iran. METHODS: The gastrointestinal tracts of 144 ruminants including 72 cattle, 59 sheep, and 13 goats were collected from an abattoir in Guilan province during July to September 2018. After isolation the helminths, male specimens were identified based on morphological parameters. PCR and partial sequencing of the ITS2 fragment were conducted. After phylogenetic analysis, the intraspecific and interspecific differences were calculated. RESULTS: The prevalence of total infections with the nematodes was 38.9, 74.6 and 84.6% among cattle, sheep and goats, respectively. Eleven species of trichostrongylid nematodes including Haemonchus contortus, Marshallagia marshalli, Trichostrongylus axei, T. colubriformis, T. vitrinus, Ostertagia trifurcata, Teladorsagia circumcincta, Marshallagia occidentalis, O. lyrata, O. ostertagi, and Cooperia punctate were recovered from the ruminants. The most prevalent trichostrongyloid nematodes in cattle, sheep and goats were O. ostertagi (26.4%), M. marshalli (64.4%) and T. circumcincta (69.2%), respectively. Phylogenetic tree was discriminative for Trichostrongylidae family, while phylogenetic analysis of the ITS2 gene represented low variations and no species identification of Haemonchidae and Cooperiidae families. CONCLUSIONS: This study suggests the high prevalence and species diversity of trichostrongyloid nematodes in different ruminants, indicating the importance of implement antiparasitic strategies in north regions of Iran. As well, this study showed that the ITS2 fragment is not a discriminative marker for Haemonchidae and Cooperiidae families, and investigation of other genetic markers such as mitochondrial genes would be more valuable for better understanding of their phylogenetic relationships.

Spillover, hybridization, and persistence in schistosome transmission dynamics at the human-animal interface.

Zoonotic spillover and hybridization of parasites are major emerging public and veterinary health concerns at the interface of infectious disease biology, evolution, and control. Schistosomiasis is a neglected tropical disease of global importance caused by parasites of the Schistosoma genus, and the Schistosoma spp. system within Africa represents a key example of a system where spillover of animal parasites into human populations has enabled formation of hybrids. Combining model-based approaches and analyses of parasitological, molecular, and epidemiological data from northern Senegal, a region with a high prevalence of schistosome hybrids, we aimed to unravel the transmission dynamics of this complex multihost, multiparasite system. Using Bayesian methods and by estimating the basic reproduction number (R0 ), we evaluate the frequency of zoonotic spillover of Schistosoma bovis from livestock and the potential for onward transmission of hybrid S. bovis × S. haematobium offspring within human populations. We estimate R0 of hybrid schistosomes to be greater than the critical threshold of one (1.76; 95% CI 1.59 to 1.99), demonstrating the potential for hybridization to facilitate spread and establishment of schistosomiasis beyond its original geographical boundaries. We estimate R0 for S. bovis to be greater than one in cattle (1.43; 95% CI 1.24 to 1.85) but not in other ruminants, confirming cattle as the primary zoonotic reservoir. Through longitudinal simulations, we also show that where S. bovis and S. haematobium are coendemic (in livestock and humans respectively), the relative importance of zoonotic transmission is predicted to increase as the disease in humans nears elimination.

First hemispheric report of invasive tick species Haemaphysalis punctata, first state report of Haemaphysalis longicornis, and range expansion of native tick species in Rhode Island, USA.

BACKGROUND: Invasive arthropod vectors and the range expansions of native vectors can lead to public and veterinary health concerns, as these vectors may introduce novel pathogens or spread endemic pathogens to new locations. Recent tick invasions and range expansion in the USA has been attributed to climate and land use change, an increase in global travel, and importations of exotic animals. METHODS: A 10-year surveillance study was conducted on Block Island, Rhode Island, from 2010 to 2020 including sampling ticks from small mammal and avian hosts. RESULTS: We report the discovery and establishment of the red sheep tick (Haemaphysalis punctata) for the first time in the western hemisphere and in the US. This invasive species was first collected in 2010 on Block Island, was collected continuously throughout the study, and was collected from an avian host. We document the first report of the invasive Asian longhorned tick (Haemaphysalis longicornis) in the state of Rhode Island, first observed at our sites in 2018. Finally, we present data on the range expansion and establishment of two native tick species, the lone star tick and the rabbit tick, on Block Island. CONCLUSION: This study emphasized the importance of long-term surveillance to detect changes in tick host communities, including invasive and expanding native vectors of potential significance to humans and wildlife.

Epidemiology and spatial distribution of Echinococcus granulosus in sheep and goats slaughtered in a hyperendemic European Mediterranean area.

BACKGROUND: Cystic echinococcosis (CE) is a worldwide parasitic zoonosis caused by the larval stage of Echinococcus granulosus sensu lato affecting livestock, particularly sheep and goats. However, often this parasitosis is underestimated. For this reason, this study aimed to evaluate the epidemiological features and spatial distribution of CE in sheep and goats slaughtered in a hyperendemic Mediterranean area. METHODS: A survey was conducted in the Basilicata region (southern Italy) from 2014 to 2019. A total of 1454 animals (1265 sheep and 189 goats) from 824 farms were examined for hydatid cyst detection by visual inspection, palpation and incision of target organs. All the CE cysts were counted and classified into five morphostructural types (unilocular, multiseptate, calcified, caseous and hyperlaminated). Molecular analysis was performed on 353 cysts. For spatial analysis, a kriging interpolation method was used to create risk maps, while clustering was assessed by Moran's I test. RESULTS: CE prevalence of 72.2% (595/824) and 58.4% (849/1454) was observed at the farm and animal levels, respectively, with higher values in sheep (62.9%) than goats (28.0%). The liver and lungs were the most frequently infected organs in both sheep and goats. Most of recovered cysts were of the calcified and multiseptate morphotypes. All the isolates were identified as E. granulosus sensu stricto (genotypes G1-G3). Spatial distribution showed a moderate clustering of positive animals. CONCLUSION: The findings of this study can be used to better understand the eco-epidemiology of echinococcosis and to improve CE surveillance and prevention programs in regions highly endemic for CE.

First description of Sarcocystis species infecting Barbary sheep (Ammotragus lervia).

Barbary sheep (Ammotragus lervia) is a North African native wild Caprinae, introduced in the 1970s in new territories such as Spain, the USA, and Mexico. Here, we describe Sarcocystis species in Barbary sheep. Sarcocysts were found in 19 out of 56 adult A. lervia in Southern Spain and characterized morphologically and molecularly. By light microscopy, sarcocysts had thin (< 1 µm) or thick (> 2 µm) walls. By transmission electron microscopy, sarcocysts with thick walls had Type 14 villar protrusions corresponding to S. tenella/S. capracanis of domestic sheep (Ovis aries) or goats (Capra hircus). Sarcocysts with thin walls had Type 7b villar protrusions that corresponded to S. arieticanis/S. hircicanis of domestic sheep or goats. Molecular analyses allowed the identification of only thick-walled Sarcocystis species. Six sarcocysts were assigned to S. tenella (99.2-100% and 95.6-100% sequence similarity within 18S rRNA and COI, respectively) and 19 sarcocysts were assigned to S. capracanis (98.5-99.8% and 97.9-99.0% sequence similarity within 18S rRNA and COI, respectively). Further studies are needed for taxonomic identification of sarcocysts in Barbary sheep because Sarcocystis species in sheep and goats are not cross transmissible despite morphological similarities.