No abstract

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.

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an update of polycystic echinococcosis in the Eastern Brazilian Amazon, period from 1962 to 2003, including unpublished cases and those already published.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.

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.MethodsSixty-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.ConclusionsThese 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.

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 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.

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.

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.