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This study was carried out to estimate the minimal number of eggs present in adult E. coelomaticum uterus. Samples were collected during post-mortem inspection and were submitted to light microscopy (bright field). The length, width, the total area of the parasite, uterus, and eggs were measured. The ImageJ software was used to calculate the area of the different parameters analyzed in this study. It was possible to observe that the uterus corresponds on average to 51.9 % of the total area of the parasite (ranging from 45 to 64 %). The number of eggs present in the uterus of parasites ranged from 5,946 to 15,813. To estimate the number of eggs three scenarios were considered, where the first taken into account the number of whole eggs observed in the image. In the second way to estimate the number of eggs, all the structures were considered (whole eggs and fractions that could be delimited) and compared with manual counting. Finally, in the last scenario, was considered an occupancy rate of 100 % of the uterine area per eggs, since there are overlapping eggs and these cannot be correctly delimited and accounted for. This study describes an important tool for quantifying eggs in a nondestructive manner and aggregate information until then is not explained by other works.

Polycystic echinococcosis, caused by the larval stage (metacestode) of the small-sized tapeworm, Echinococcus vogeli, is an emerging parasitic zoonosis of great public health concern in the humid tropical rainforests of South and Central America. Because morphological and morphometric characteristics of the metacestode are not well known, hydatid cysts from the liver and the mesentery were examined from patients following surgical procedures. Whole mounts of protoscoleces with rostellar hooks were examined under light and confocal laser scanning microscopy. Measurements were made of both large and small hooks, including the total area, total length, total width, blade area, blade length, blade width, handle area, handle length and handle width. The results confirmed the 1:1 arrangement of hooks in the rostellar pad and indicated, for the first time, that the morphometry of large and small rostellar hooks varies depending upon the site of infection. Light and confocal microscopy images displayed clusters of calcareous corpuscles in the protoscoleces. In conclusion, morphological features of large and small rostellar hooks of E. vogeli are adapted to a varied environment within the vertebrate host and such morphological changes in calcareous corpuscles occur at different stages in the maturation of metacestodes. [ABSTRACT FROM AUTHOR]

Infected hosts progressively decrease egg output during the chronic phase of Schistosoma mansoni infection. Ageing may be a factor that results in a progressive decrease in the ability to reproduce. This study was performed to gain insight into the effects of ageing on adult schistosomes, using confocal laser scanning microscopy. Adult worms were recovered from experimentally infected Nectomys squamipes (water rat). Viable eggs were voided in the faeces for 65 weeks and, thereafter, only unviable eggs were eliminated. The rat died after 70 weeks in captivity. Recovered worms (six males and one female) were prepared for confocal microscopy and images were obtained with an LSM 510-ZETA laser confocal microscope. The overall morphology of the adult worms (suckers and tegument) and reproductive organs were the focus of this work. The suckers, ovary, vitellaria and oocytes appeared to be apparently normal. The ootype was formed by flattened cells and unclear nuclei, suggesting that the mechanism for eggshell production by the ootype during organogenesis might have been impaired. Testicular lobes showed empty areas around the germinative cells. Male adult worms showed flaccid musculature of the dorsal surface. Taken together, the present results provided several indications of infertility in older male and female schistosomes. [ABSTRACT FROM AUTHOR]

A prevalência das enteroparasitoses foi verificada através de inquérito coproparasitológico realizado de março de 1990 a outubro de 1991, em 1.381 pré-escolares provenientes de quatro comunidades faveladas da cidade do Rio de Janeiro, Brasil. Por meio da técnica de Blagg et al. (1955), foi encontrada uma positividade geral de 54,5. Os parasitos mais freqüentes foram Giardia lamblia e Ascaris lumbricoides, em cerca de 25,0% das crianças investigadas. Correlação estatisticamente significativa foi observada entre idade e positividade nas crianças menores de três anos. Sugerimos que tratamento antiparasitário e modificações ambientais sejam implementados para o controle das infecções parasitárias nesta população.

Echinococcus granulosus sensu lato (s.l.) is a species complex with the potential to cause cystic echinococcosis (CE). Contact with the feces of domestic dogs (Canis familiaris) fed with raw viscera of intermediate livestock hosts is a risk factor for this infection in the southern region of Brazil. Although the region has been considered endemic to CE for many years, molecular data regarding the species of the complex causing CE in humans are scarce. This study aimed to perform a molecular analysis of the biological fluid from a human liver cyst to investigate the species responsible for CE. Genetic material obtained from the hydatid fluid of a hepatic cyst from a human with CE was subjected to PCR to amplify mitochondrial and nuclear DNA sequences. The phylogenetic analysis confirmed the human infection by Echinococcus canadensis G7 in the state of Paraná, Brazil. This is the first molecular record of E. canadensis G7 infecting a human in Brazil, and it is important to reiterate the risk of human CE caused by this species in South America, as reported by a previous study in Patagonia, Argentina. From the epidemiological point of view, this finding is of great relevance for the southern region of Brazil, since this parasite has previously only been detected in pigs in the state of Rio Grande do Sul, neighboring Paraná. The finding points to the importance of this identification in the molecular epidemiology of E. granulosus s.l., especially in South America., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

With the increasing concomitant demands for Brazilian beef and in particular high-quality beef, there is a need for observational studies of the effects of pre- and post-slaughter practices on beef carcass traits. We hypothesized in our case study that pre-slaughter transport of bovines over significant distances would induce stress in animals, and that this would reduce carcass quality because of higher pH resulting from long-distance transportation. To test this hypothesis, 30,230 Nellore carcasses from a private slaughterhouse were evaluated 24 h postmortem . Analysis showed correlations between animal maturity, ultimate pH, distance, and carcass weight. More precisely, there was a slight positive correlation between ultimate pH and weight (but not with transportation distance) and a slight positive correlation between maturity and weight. A linear regression model ( R 2  = 0.016) failed to show distance having a significant effect on ultimate pH ( P  = 0.63), while carcass weight significantly affected ultimate pH ( P  < 0.001) with a low coefficient of 0.0003. Maturity negatively affected ultimate pH also ( P  < 0.001) but with also a small effect (-0.0008). Results (from 95% confidence intervals of variance of the random effects and of the random errors) showed that the variability within farms was higher than between farms. The linear mixed model showed that maturity had a significant effect on carcass weight value ( P  < 0.001) with a large coefficient of 2.90. The R 2 of the linear mixed model was 46.03%. In conclusion, while weight and maturity both affect ultimate pH, long distances did not significantly impact ultimate pH and therefore the beef quality from Nellore cattle. This could be because of low stress during transport, as well as the physical characteristics of the Nellore breed that favor greater resistance to tropical climatic conditions., (© The Author(s) 2023. Published by Oxford University Press on behalf of the American Society of Animal Science.)

The coproparasitological examination of dogs (n=278) from two Brazilian biomes (Amazon [AZ] and Atlantic Forest [AF]) by centrifugal flotation demonstrated positivity values of 54.2% (AF) and 48.5% (AZ). The most prevalent parasites in AF were hookworms (81.0% - 47/58), Toxocara sp. (17.3% - 10/58) and Trichuris vulpis (12.1% - 7/58); while in AZ they were hookworms (86.7% - 72/83), Toxocara sp. (18.1% - 15/83), Dipylidium caninum (13.3% - 11/83) and T. vulpis (10.8% - 9/83). PCR was performed using the partial mitochondrial genes cytochrome c oxidase subunit 1 (pcox1) and NADH dehydrogenase 1 (pnad1) in 25 fecal samples positive for Toxocara sp. eggs and found one sample positive for pcox1 and six positives for pnad1. The sequencing of these samples was unsuccessful due to the difficulties inherent in copro-PCR+sequencing. The sequencing of 14 samples of T. canis adult helminths retrieved 11 sequences of 414 bp for pcox1 and nine sequences of 358 bp for pnad1. The phylogenetic trees of these sequences confirmed the species T. canis. Intraspecific genetic variation was only observed for pnad1. This is the second study involving molecular analysis of T. canis in dogs from Brazil and adds new information through the use of pnad1.

Human polycystic echinococcosis is a parasitic infection caused by the larval stage of Echinococcus vogeli, which occurs in rural areas of Central and South America. Until now, little information on the genetic variability of E. vogeli is available. Here, 32 samples from human-excised E. vogeli cysts had a 396-bp sequence of the mitochondrial cytochrome oxidase I (COI) gene sequenced and compared to another 17 COI sequences representing nine Echinococcus species. A Bayesian COI tree revealed that all E. vogeli sequences formed a monophyletic and well-supported clade with an E. vogeli reference sequence. The occurrence of geographically restricted E. vogeli COI haplotypes suggests retention of ancestral polymorphisms with little migration in Acre, Brazil.

The aim of this study was to evaluate the effect of increasing concentrate supplementation levels on the intake, nutrient digestibility, and performance of crossbred steers during the dry period of the year. The experiment was developed on Princesa do Mateiro farm, in the municipality of Ribeirão do Largo, located in the southwest region of Bahia State, Brazil. Forty uncastrated male crossbred (½ Holstein-Zebu) steers with an average body weight (BW) of 232.55 ± 24.97 kg were distributed into four treatments in a completely randomized design with ten replicates. The animals were managed in an experimental area formed by Brachiaria brizantha cv. Marandu, in an intermittent grazing system. Treatments consisted of the following supplementation levels: 0.2% BW, with 60% crude protein (CP); 0.3% BW, with 40% CP; 0.4% BW, with 30% CP; and 0.5% BW, with 24% CP. The intakes of forage dry matter in kg/day and %BW and neutral detergent fiber corrected for ash and protein (NDFap) in %BW decreased linearly, whereas the intake of non-fibrous carbohydrates corrected for ash and protein in kg/day and average daily gain increased linearly. Therefore, the use of supplementation at 0.5% BW (24% crude protein) to provide gains of up to 0.500 kg/day is recommended for grazing steers during the post-weaning period in the dry season of the year.

This study was carried out to estimate the minimal number of eggs present in adult E. coelomaticum uterus. Samples were collected during post-mortem inspection and were submitted to light microscopy (bright field). The length, width, the total area of the parasite, uterus, and eggs were measured. The ImageJ software was used to calculate the area of the different parameters analyzed in this study. It was possible to observe that the uterus corresponds on average to 51.9 % of the total area of the parasite (ranging from 45 to 64 %). The number of eggs present in the uterus of parasites ranged from 5,946 to 15,813. To estimate the number of eggs three scenarios were considered, where the first taken into account the number of whole eggs observed in the image. In the second way to estimate the number of eggs, all the structures were considered (whole eggs and fractions that could be delimited) and compared with manual counting. Finally, in the last scenario, was considered an occupancy rate of 100 % of the uterine area per eggs, since there are overlapping eggs and these cannot be correctly delimited and accounted for. This study describes an important tool for quantifying eggs in a nondestructive manner and aggregate information until then is not explained by other works., Competing Interests: Conflict of Interest The authors declare that there are no conflicts of interest regarding the publication of this article., (© 2018 F. A. Da Silva Júnior, C. Monteiro Da Silva, F. B. De Almeida, R. Rodrigues-Silva Published by Sciendo.)

Although sheep farming has grown in the state of Acre over the past four decades, little is known about occurrences of helminthiases in the herds of this region. The objective of the study was to assess the occurrences of non-intestinal helminthiasis among sheep slaughtered in Rio Branco. A total of 110 sheep livers were inspected from two slaughter batches (july 2014 and march 2015) in a slaughterhouse in Rio Branco. Livers with macroscopic lesions were photographed and were then subjected to histopathological analysis under an optical microscope. The macroscopic lesions showed small nodes with inflammatory characteristics and areas of fibrosis, which appeared to be calcified, thus suggesting a granulomatous reaction. Of the 110 evaluated livers, we noticed 110 nodules in total; these nodules have an average size of 0.5 cm. The histopathological analysis showed alterations to the architecture of the hepatic lobe, with multiple foci of necrosis and polymorphonuclear cells. Two samples revealed the presence of helminths from Nematode class and Capillaria sp. eggs identified by the typical morphology and morphometry. This seems to be the first report of Capillaria sp. in sheep livers in Brazil, and it serves as an important alert regarding animal health surveillance and control and regarding the Capillaria sp. zoonotic role in humans.

Polycystic echinococcosis (PE) is caused by Echinococcus vogeli metacestodes (larval stage) in Neotropical countries. E. vogeli is trophically-transmitted between predators bush dogs (Speothos venaticus) and prey pacas (Cuniculus paca). In Brazil, reported PE cases are restricted to the Amazon biome. In this study, metacestodes from a paca hunted in Mato Grosso do Sul state (Cerrado biome) were identified morphological and histopathological techniques and further confirmed by molecular testing (sequencing of cytochrome C oxidase subunit I (cox1) gene) for the first time. Images of the whole liver showed superficial bubble-like hepatic masses. The parasitological analysis revealed large hooks (41.3 ± 1.2 μm length/12.8 ± 0.8 μm width) and small hooks (33.0 ± 1.5 μm length/11.1 ± 1.2 μm width), consistent with E. vogeli. Microscopically, the liver showed protoscoleces, a thick laminated layer, fibrosis, and inflammatory infiltrate in the adventitial layer. The DNA sequencing confirmed E. vogeli with 99% homology with sequences deposited in the GenBank. In addition, this finding greatly extends the geographic range of animal polycystic echinococcosis into the Cerrado. It is likely to occur in new biomes, where bush dogs and pacas share a given area in a trophic relationship., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Fasciola hepatica is a trematode showing genetic variation among isolates from different regions of the world. The objective of this work was to characterize for the first time F. hepatica isolates circulating in different regions of Argentina. Twenty-two adult flukes were collected from naturally infected bovine livers in different areas from Argentina and used for DNA extraction. We carried out PCR amplification and sequence analysis of the ribosomal internal transcribed spacer 1 (ITS1), mitochondrial nicotinamide adenine dinucleotide dehydrogenase subunits 4 and 5 (nad4 and nad5) and mitochondrial cytochrome c oxidase subunit I (cox1) genes as genetic markers. Phylogenies were reconstructed using maximum parsimony algorithm. A total of 6 haplotypes were found for cox1, 4 haplotypes for nad4 and 3 haplotypes for nad5. The sequenced ITS1 fragment was identical in all samples. The analyzed cox1 gene fragment is the most variable marker and is recommended for future analyses. No geographic association was found in the Argentinean samples., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Chemotherapy of food-borne trematodes relies on two drugs, praziquantel and tricabendazole, and there is growing interest in finding alternative therapies. Plant oil extracts have long been used in traditional Chinese medicine as sources of bioactive compounds with antiparasitic activity. Species of the genus Echinostoma are used as good models to test effective compounds against food-borne trematodes. This study evaluated the anthelmintic activity of crude artesunate extracts in vitro on newly excysted metacercariae of Echinostoma paraensei by light and scanning electron microscopy (SEM). The flukes were incubated with 1 μg/mL, 10 μg/mL, 25 μg/mL, 50 μg/mL and 100 μg/mL of artesunate for 4, 12, 24, 48 and 72 h. When the exposure time and concentration of artesunate increased, there were changes in motor activity, tegument damage and death. Blebs and swelling were the most common damages quantified on the tegument. The in vitro study reproduced results described for other immature flukes incubated with artemisinin derivatives. Excysted metacercariae of E. paraensei constitute a good model to study in vitro drug effects., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Echinococcus granulosus (sensu lato) (s.l.) and Echinococcus vogeli are causative agents of chronic zoonotic diseases such as cystic and polycystic echinococcosis, respectively. In Brazil, polycystic echinococcosis has a restricted geographical distribution in the North Region, while cystic echinococcosis is observed in the South Region. Domestic dogs (Canis familiaris) fed with raw viscera represent a risk factor for E. granulosus (s.l.) infection in the South Region. Although this practice is frequent, it remains unclear whether domestic dogs are infected with E. vogeli in the state of Acre, located in the Amazon basin in the North Region of Brazil. The aim of this study was to investigate this gap in the polycystic echinococcosis epidemiology., Methods: Sixty-five fecal samples were collected from the ground in five municipalities (Sena Madureira, n = 14; Rio Branco, n = 06; Bujari, n = 06; Xapuri, n = 30; and Epitaciolândia, n = 09) located in the state of Acre, northern Brazil. The samples were screened for parasites by copro-PCR using the cox1 gene associated with automated sequencing., Results: Echinococcus vogeli was molecularly confirmed in a sample from Sena Madureira and E. granulosus (sensu stricto) (s.s.) (G1) in a sample from Rio Branco., Conclusions: These findings indicate that molecular assays are useful in typing Echinococcus taxa from fecal samples of dogs in northern Brazil. The present study is the first molecular record of E. vogeli in domestic dogs found in the state of Acre, reinforcing their role as a source of infection for humans. Because E. granulosus (s.s.) (G1) was detected for the first time in the North Region, from the epidemiological standpoint this finding is highly relevant, because it expands the known geographical distribution, which was previously restricted to the South Region of Brazil.

Cutaneous leishmaniasis (CL) is a chronic inflammatory disease caused by dermotropic Leishmania species belonging to the Viannia subgenera, with Leishmania (V.) braziliensis considered the main agent in Brazil. After infection, a local inflammatory process is initiated, inducing the expression of several cytokine/chemokine genes. We evaluated the immunity to CL of patients living in the indigenous community Xakriabá, Minas Gerais state, Brazil, by performing detailed analyses of the mRNA expression of different cytokines and chemokines in CL lesions, considering the time evolution (recent or late). We also studied the profile of the inflammatory infiltrate by histopathological analysis. The histopathological features of recent CL lesions showed an intense inflammatory reaction, characterized by the presence of both mononuclear and polymorphonuclear cells, whereas late CL lesions exhibited a predominance of mononuclear leukocytes. The gene expression of cytokines/chemokines in skin biopsies from the CL group showed higher transcript levels of modulatory (IL10 and TGFB1), anti-inflammatory (IL4), and pro-inflammatory (TNF, IFNG, IL12B, CCL2, CCL3, CCL5, CXCL10) biomarkers in recent lesions than in late lesions. Our findings suggest that differential gene expression of cytokines and chemokines found in skin lesions from CL patients is associated with time evolution of lesions., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

The helminth fauna of Agouti paca (Linnaeus, 1766) has seldom been studied. In this paper, we report an unusual mixed infection of Echinococcus vogeli Rausch & Bernstein, 1972 and Calodium hepaticum (syn. Capillaria hepatica Bancroft, 1863) in free-ranging paca from a forested region in Acre (Brazil). Gross morphological examination revealed that paca liver contained multiple spherical to subspherical white or translucent lesions, which were isolated or frequently contiguous and partially covered by Glisson's capsule. Microscopic examination revealed unilocular cystic structures that contained abundant brood capsules in which numerous protoscolices budded from the inner surface. The protoscolices possessed rostellar hooks (33-41 μm in length), a morphological characteristic of the blade and calcareous corpuscles that is consistent with the metacestode E. vogeli. The diagnosis of C. hepaticum infection was based on the morphology and morphometry of the egg-shaped ellipsoids with bipolar plugs (44.8 ± 1.9 μm (length) × 24.4 ± 2.0 μm (width)) and liver histopathology. This finding expands the known range of C. hepaticum hosts in South America and, to the best of our knowledge, it is the first case of a mixed infection of E. vogeli and C. hepaticum. Furthermore, our data provide evidence that wild animal meat may be a source of C. hepaticum infection.

Our work represents the first case report of polycystic echinococcosis co-infection with HIV, hepatitis C virus (HCV), and hepatitis B virus (HBV). Structural liver alterations were found to be related to parasitic structures and necroinflammatory foci (karyopyknosis, karyorrhexis, and karyolysis), consistent with Echinococcus vogeli. Visceral adipose tissue and intrahepatic triglyceride droplets (macrovesicular and microvesicular steatosis) indicated abnormal fat anabolism, which probably resulted from both viral-induced hepatopathy and drug-related toxicity. In summary, our results suggest that the observed liver abnormalities reflected the coincident exposure to hepatotropic viruses and parasites causing polycystic echinococcosis and were not indicative of opportunistic relationships among these pathogens., (Copyright © 2013 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

The lack of knowledge regarding polycystic hydatid disease results in delayed or even incorrect diagnosis. The lack of systematic information regarding treatment also makes it difficult to assess the results and prognosis in patients with peritoneal and hepatic lesions caused by Echinococcus vogeli. Here we describe the clinical features of patients, propose a radiological classification protocol and describe a therapeutic option for the treatment of hydatid disease that previously had only been used for cases of cystic echinococcosis (Echinococcus granulosus). A prospective cohort study was initiated in 1999 and by 2009 the study included 60 patients. These patients were classified according to the PNM classification (parasite lesion, neighbouring organ invasion and metastases) and placed in one of three therapeutic modalities: (i) chemotherapy with albendazole at a dose of 10 mg/kg/day, (ii) surgical removal of cysts or (iii) percutaneous puncture of the cysts via puncture, aspiration, injection and re-aspiration (PAIR). The results were stratified according to therapeutic outcome: "cure", "clinical improvement", "no improvement", "death" or "no information". The PNM classification was useful in indicating the appropriate therapy in cases of polycystic hydatid disease. In conclusion, surgical therapy produced the best clinical results of all the therapies studied based on "cure" and "clinical improvement" outcomes. The use of PAIR for treatment requires additional study.

The therapeutic effects of praziquantel (PZQ) against a Schistosoma mansoni isolate derived from Nectomys squamipes (isolate R) and a susceptible isolate (BH) were analyzed in Swiss mice by fecal egg counting, adult worm reduction and oogram pattern. Infected mice were orally administrated with 62.5mg/kg (group 1), 125mg/kg (group 2), 250mg/kg (group 3) and 500mg/kg (group 4), each dose divided over 3 days (49, 50 and 51 days after infection). The data were analyzed using one-way analysis of variance (ANOVA). In regard to isolate R, no fecal eggs were observed with 250 mg/Kg and 500 mg/kg (p<0.05), whereas BH excretion reached zero with all doses. Mean worm burden reduction was significantly (p<0.05) higher at the two highest concentrations, regardless of isolate. At 62.5mg/kg, the percentage of immature eggs varied from 17% (isolate R) to 38% (isolate BH). At 125 mg/kg, the percentage of immature eggs varied from 20% (isolate R) to 16% (isolate BH). At 250 mg/kg, immature eggs dropped significantly to 1% (isolate R) and 4% (isolate BH). At 500 mg/kg, no immature eggs were found in isolate R, whereas in BH was 8%. No dosage significantly (p>0.05) affected the percentage of mature eggs, regardless of isolate. There was a large increase (p<0.001) in the percentages of dead eggs in all treated groups of 62% and 64% in groups 3 and 4, respectively (isolate R). The percentage of dead eggs rose from 34% (group 1) to 58% (group 3) in isolate BH. Although group 4 showed lowest increase in the percentage of dead eggs (46%), it was higher (p<0.001) compared to the 8% in the control. Our findings indicate that the wild isolate from N. squamipes is susceptible to PZQ., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Echinococcus vogeli is known to occur in the neotropics, causing polycystic echinococcosis (PE) in humans. The liver and lungs are the most commonly affected organs. In this paper, we report six cases of human PE in the mesenteries without primary liver involvement. All patients, four males and two females (median age 34 years; range 20-48 years), lived in a forested area (Acre, Brazil). Physical examination revealed abdominal masses. The patients were evaluated by abdominal CT scan, exploratory laparotomy and serology by immunoblot assay. CT scans revealed multiple and cystic lesions with calcified edges in the mesenteric segments. During exploratory laparotomy, polycystic lesions were excised from omentum, mesentery, pancreas and inferior vena cava. Positive serology identified 21 and 31 kDa subunits. We recommend that PE should be investigated in patients from tropical forests in northern Brazil exhibiting abdominal masses with no clearly defined diagnosis.

Angiostrongylus lenzii n. sp. (Nematoda: Metastrongyloidea) is described and illustrated from the pulmonary artery of the wild rodent Akodon montensis Thomas, 1913, collected in the municipality of Teresopólis, Rio de Janeiro State, Brazil. It represents the 17th species of the genus and the 2nd in South America as parasites in rodents. This new species is the most similar morphologically to Angiostrongylus vasorum, Angiostrongylus gubernaculatus, Angiostrongylus schmidti, and Angiostrongylus morerai. It can be distinguished from them by the morphology of the caudal bursa, ventral rays 2 and 3 with conspicuous knobs, differences in width and length of lateral and dorsal rays, presence of rays 8, and length of spicules.

Stilestrongylus lanfrediae n. sp. is described from the small intestine of Oligoryzomys nigripes (Cricetidae: Sigmodontinae) collected in the Atlantic Forest (Rio de Janeiro State, Teresópolis, Brazil). The new species shows some similarities to Stilestrongylus stilesi, Stilestrongylus freitasi, Stilestrongylus inexpectatus, Stilestrongylus moreli, and Stilestrongylus andalgala, but it can be distinguished from these species by the following combination of characters: 26 ridges in males and 25 in females at the mid-body, asymmetrical caudal bursa with a pattern of type 2-2-1, rays 6 markedly shorter than other lateral rays, rays 8 inserted asymmetrically on dorsal trunk and shorter than other species, and a proportion of spicule length in relation to body length (SpL/BL) of 25-29%. The new species is also distinguished from other species of Stilestrongylus by the asymmetry of the branches of the dorsal ray and by having the longest spicules.

Echinococcus vogeli has been reported to cause human polycystic echinococcosis. A 43-year-old Brazilian woman was admitted to hospital complaining of mild epigastric discomfort. Computed tomography (CT) revealed multiple cystic lesions with calcified edges in several hepatic segments. At exploratory laparotomy, polycystic lesions were excised from the liver, omentum and peritoneum. No remaining cysts were observed on a post-surgery CT scan. The patient was asymptomatic when discharged on Day 19 post-operatively. She was prescribed albendazole therapy for 6 months. Follow-up CT performed 11 months later revealed no evidence of recurrence. Surgery combined with chemotherapy may improve the quality of life of patients with polycystic echinococcosis.

Echinococcus granulosus infection is a problem of public health in livestock-rearing regions of Latin America, like in Peru. This species is characterized by the morphometry of the large and small rostellar hooks in both metacestodes and adult worms. The aim of this work was to study biometrical characteristics of rostellar hooks in hydatid cysts (lung and liver) from some Peruvian provinces (Arequipa, Cuzco, Huancavelica, Junin and Puno). The biometrical analysis was obtained in a digital system for image analysis. The following parameters were studied: area, perimeter, length and width total of the handle, the blade and the distance between the blade and the guard of large and small hooks. For statistical analysis Student's t-test and Analysis of Variance (ANOVA) with Pos-test of Tukey were used, considering the values of p< or =0.05 as of statistic significance. All morphometric characters of large and small hooks were highly significant (p<0.000), when data were compared among the samples from the different provinces. Rostellar hooks in specimens from Huancavelica presented smallest measurements, whereas hooks in specimens from Junin were bigger in relation to the total and blade measurements. Generally, samples from Arequipa presented the biggest large hooks in relation to the handle parameters. The rostellar hooks of cattle and sheep hosts varied depending on the geographic localization, host and organ. Hooks recovered from the lungs were larger than those collected in the liver. It was concluded that morphometry using computer image analysis allows the characterization of E. granulosus. The rostellar hooks presented morphometric polymorphism.

Cystic echinococcosis (CE) is a high prevalent zoonosis in the central and southern Peruvian Andes. Serum samples (n50)from patients presenting presumptive clinical and radiological diagnosis of CE (group 1), were tested for antibodies against Echinococcus granulosus metacestode using Arc-5 double diffusion assay (DD5), immunoelectrophoresis (IEF), and immunoelectrotransfer blot (EITB) techniques. Serum samples (n18) from patients presenting other parasite infections (paragonomiasis, cysticercosis, and fascioliasis) or healthy blood donors (n15), were designated as control groups. The overall sensitivity of the tests was of 94% (DD5 and IEF tests) or 96% (EITB test). Only patients from group 1 were seropositive for CE. Polypeptides of 21, 31, and 48 kDa were considered positive for CE. Based on these results, this study demonstrates that CE also occurs in other coastal departments (Piura, Ancash, Ica, Arequipa, and Tacna) besides Lima.

By means of epidemiological and clinical-laboratorial approaches was consolidated an update of polycystic echinococcosis in the Eastern Brazilian Amazon, period from 1962 to 2003, including unpublished cases and those already published. In that way, they were identified 40 cases of the disease in referred period, understanding cases coming from the States of Pará and Amapá, Brazil. The width of the ages went from 10 to 72 years and 47.5% belonged to the masculine sex. The liver was the attacked organ (82.5% of the cases). The Echinococcus vogeli (Rausch and Bernstein, 1972), comes as the main agent involved. Starting from the recognition of the importance and of the implications of the handling of the echinococcosis for the tropical area, it is believed that should happen an improvement of the diagnosis, appropriate treatment and of a better registration of the disease.

We report a case of human pulmonary dirofilariasis in a female patient 45-years-old, derived from Rio de Janeiro, Brazil. The chest radiologic finding consisted of single pulmonary nodule located on the left lower lobe that simulated lung tumor. Human pulmonary dirofilariasis might be investigated in nodules that are not malignants and require conclusive diagnosis.

Experiments were carried out to analyze the biological characteristics of two sympatric isolates of Schistosoma mansoni derived from humans and murines in a low endemic transmission area (Sumidouro county, state of Rio de Janeiro, Brazil). Sympatric reared-laboratory Biomphalaria glabrata and C3H/He mice were used as experimental hosts. Parameters assessed comprised: precercarial period, infectivity and mortality (snails), prepatent period, infectivity (percentage of cercariae maturation into adult worm) and intestinal egg count (mice). The murine isolate showed a shorter precercarial period and higher infectivity than human isolate (p<0.05). This biological heterogenicity did not correspond to the vertebrate data because any biological parameter presented significant difference (p>0.05). These data suggest that both isolates are local sub-populations, providing support for the hypotheses that in a same biotope mixed populations or sub-populations circulate among their main host (human beings) and/or rodent as an anfixenous infection.

Histopathologic and morphometric (area, perimeter, major and minor diameters) analysis of hepatic granulomas isolated from twelve naturally infected Nectomys squamipes were compared to four experimentally infected ones and six C3H/He mice. Liver paraffin sections were stained for cells and extracellular matrix. Both groups of N. squamipes presented peculiar granulomas consisting predominantly of large macrophages, full of schistosome pigment, characterizing an exudative-macrophage granuloma type, smaller than the equivalent granuloma type in mouse. Naturally infected animals exhibited granulomas in different stages of development, including large number of involutional types. Morphometric analysis showed that all measurements were smaller in naturally infected animals than in other groups. The results demonstrated that both N. squamipes groups reproduced, with small variations, the hepatic granuloma aspects already described in cricetidium (Calomys callosus), showing a genetic tendency to set up strong macrophage responses and small granulomas. Unexpectedly, natural infection did not engender distinguished histopathological characteristics distinct from those derived from experimental single infection, showing changes predominantly secondary to the duration of infection. It appears that the variability of the inocula (and the number of infections?) interfere more with the quantity than with the quality of the pathological changes, denoting some morpho-functional determinism in the response to schistosomal infection dependent on the animal species.

A comparative study was made between sympatric isolates of Schistosoma mansoni: one from a wild rodent (R) Nectomys squamipes and another one from humans (H) isolated from a low endemic schistosomiasis transmission area in Brazil. Our purpose was to detect differences between them concerning chaetotaxy (number and pattern of distribution of the argentophilic papillae) of the cercariae by means of silver impregnation. No significant difference (x > 0.05) between isolates was noted. Nevertheless, a significant difference (x < 0.05) was observed in the cercarial index (ratio of the distance between the first and the second preacetabular papillane and the distance between the first and the second dorsal preacetabular papillae) of male and female cercariae in both isolates. Males presented a greater cercarial index than females. By means of multivariate analysis, male cercariae were distinguished from female cercariae through the following characteristics: average number of dorsal papillae on the right quadrant, average number of ventral middle papillae on the right quadrant (H isolate) and average number of dorsal middle papillae on the left quadrant (R isolate). The results suggest that R and H isolates belong to the same population that could complete its life cycle in rodent-snail-rodent fashion.

The present case report refers to a patient from the State of Rondônia, North region of Brazil, attended with clinical suspicion of hepatic echinococcosis. Examination by imaging (ultrasonography and computerized tomography) revealed a conglomerate of cystic lesions, with mobile contents within the cyst. The serology (immunoblot) for Echinococcus sp. was positive (21 and 31 kDa bands). This case is the first reported in Rondônia, suggesting the need to investigate the polycystic echinococcosis in individuals with hepatic cysts from areas of tropical forest and hunting habits where wild life was present as wild dogs, cats and rodents, particularly Agouti paca (paca) and Dasyprocta aguti (agouti).

The objective of this study was to obtain a better characterization of Dirofilaria immitis (Leidy, 1856) Railliet & Henry, 1911, in Brazil, ratifying previous accounts and adding new data on the rugose area on the ventral surface of the spiralled posterior portion of males observed by scanning electron microscopy, which presents a different arrangement compared to other species of the genus, and differs also from the genera Litomosoides Chandler, 1931, and Wuchereria Silva Araújo, 1877, adding another taxonomic character to Dirofilariinae and Onchocercinae. Scanning electron microscopy studies also showed some aspects of the distribution of caudal papillae in D. immitis that have not been described before.

Prevalence of intestinal parasites was investigated in 1381 low-income children under five years of age from March 1990 to October 1991 in the city of Rio de Janeiro, Brazil. Stool tests were run using the Blagg et al. method. Observed prevalence of infection was 54.5%. The most frequent parasites were Giardia lamblia and Ascaris lumbricoides (25.0% of the children). A significant statistical difference (p<0.05) was demonstrated between age and infection according to the species of parasite studied. Infection rates demonstrated the need for control of parasites in these child.

The authors presented a detailed summary of the geographical distribution, clinical and pathological aspects of human pulmonary dirofilariasis. Although benign, this zoonosis, of which Dirofilaria immitis is the major etiological agent, represents a medical problem since it produces symptoms which may be confused with neoplasia and thus may subject patients to unnecessary thoracic surgery. Of 229 cases cited in the literature, only 17 were reported in Brazil, despite the existence of highly favorable conditions for the transmission of this infection in man. Thus it may well be that this parasitic infection remains underdiagnosed. Finally, the importance of a differential diagnosis between dirofilariasis and pulmonary neoplasia is emphasized in cases where there is a solitary subpleural nodule ("coin lesion") present. In addition, the development and improvement of modern immunological diagnostic techniques are essential to distinguish this benign disease from other pathological conditions and thus avoid unnecessary surgery. These techniques may reveal the true prevalence of this parasitic infection in our environment.