Fasciolasis Hepática, serie de casos reportados en Matanzas. Cuba / Hepatic fasciolosis, a series of cases reported in Matanzas, Cuba

RESUMEN Introducción: la fasciolasis hepática es una enfermedad parasitaria de difícil diagnóstico. La variada y múltiple sintomatología que caracteriza la enfermedad, la expulsión intermitente y tardía de los huevos del parasito, así como el difícil acceso a los estudios inmunológicos en las zonas rurales atenta contra la confirmación de parasitosis en casos esporádicos. En la provincia de Matanzas en los últimos años se constataron enfermos sospechosos de fasciolosis procedentes de Pedro Betancourt con diversos síntomas digestivos, fiebre y eosinofilia. Objetivo: caracterizar los aspectos clínicos y epidemiológicos de los pacientes diagnosticados de fasciolosis hepática. Materiales y Método: se realizó un estudio observacional, descriptivo a pacientes hospitalizados con el diagnóstico presuntivo de fasciolosis hepática en el Servicio de Medicina Interna del Hospital Faustino Pérez en el período enero del año 2011 a diciembre del 2013. La recolección de datos se realizó a través del interrogatorio, examen físico, Historia clínica y encuestas epidemiológicas. Resultados: se muestra la presencia de consumo de plantas acuáticas y consumo de agua sin hervir en los afectados. La fase aguda de la enfermedad en estos pacientes se caracterizó por fiebre, dolor abdominal, hepatomegalia y gran eosinofilia. Conclusiones: el diagnóstico de certeza se realizó a través de pruebas inmunológicas. Esto se debe a que a pesar de los múltiples exámenes parasitológicos de las heces fecales no se identificó huevos. Los pacientes del estudio fueron tratados con el triclabendazol y se logró mejoría clínica de los pacientes y pocas reacciones adversas (AU).

SUMMARY Introduction: the hepatic fasciolosis is a parasitic disease of difficult prognosis. The varied and multiple symptoms characterizing the disease, the intermittent and late ejection of the parasite eggs, and also the difficult access to immunological studies in the country areas sometimes attempts against the confirmation of parasitism. During the last years, in the province of Matanzas, several sick persons from Pedro Betancourt were suspicious of fasciolosis with different digestive symptoms, fever and eosinophilia. Objective: to characterize the clinical and epidemiological aspects of the patients diagnosed of hepatic fasciolosis. Materials and method: an observational, descriptive study was performed in in-patients of the Service of Internal Medicine of the Hospital Faustino Perez with the presumptive diagnosis of hepatic fascilosis in the period January 2011-December 2013. Data collection was made through questioning, physical examination, clinical record and epidemiological inquiries. Results: risk behaviors are evidenced given the water plants and un-boiled water consumption in affected persons. The acute `hase in these individuals is characterized by fever, abdominal pain, hepatomegaly and big eosinophilia. The diagnosis of certainty was made by immunologic tests. The patients were treated with triclabendazol with clinical improvement and little adverse reactions. Conclusions: health professionals when assisting a patient from a country area with eating habits of fresh vegetable consumption and suggestive clinical characteristics should carry out studies to confirm Fasciola hepatica infection (AU).

Molluscicidal potential of Heterorhabditis baujardi (Rhabditida: Heterorhabditidae), strain LPP7, on Lymnaea columella (Gastropoda: Pulmonata): An alternative for biological control of fasciolosis.

This study elucidated for the first time, under laboratory conditions, the susceptibility of Lymnaea columella to infective juveniles of Heterorhabditis baujardi LPP7. Exposure to the nematodes induced an average mortality rate of 66.66% in the population of L. columella, with the highest values attained from the second week after exposure onward. In addition, all the reproductive parameters analyzed (total number of eggs, number of egg masses, number of eggs laid/snail, embryo hatching rate and content of galactogen stored in the albumen gland) changed as a result of the infection. The results indicate the occurrence of the phenomenon of parasitic castration in L. columella infected by H. baujardi LPP7, probably through depletion of energy reserves such as galactogen, necessary to meet the intense metabolic demands of the nematode's larval stages. Finally, histopathological analysis demonstrated an intense process of cell disorganization, characterized by the occurrence of granulomatous inflammatory reactions in tissues of exposed snails, induced by the spoliative action of the bacteria/nematode. The results suggest the use of H. baujardi LPP7 as an alternative for biological control of the population of this intermediate host, and thus of the diseases in whose epidemiological chain it participates, especially fasciolosis, in line with the recommendations of the World Health Organization (WHO).

The role of evolutionary biology in research and control of liver flukes in Southeast Asia.

Stimulated largely by the availability of new technology, biomedical research at the molecular-level and chemical-based control approaches arguably dominate the field of infectious diseases. Along with this, the proximate view of disease etiology predominates to the exclusion of the ultimate, evolutionary biology-based, causation perspective. Yet, historically and up to today, research in evolutionary biology has provided much of the foundation for understanding the mechanisms underlying disease transmission dynamics, virulence, and the design of effective integrated control strategies. Here we review the state of knowledge regarding the biology of Asian liver Fluke-host relationship, parasitology, phylodynamics, drug-based interventions and liver Fluke-related cancer etiology from an evolutionary biology perspective. We consider how evolutionary principles, mechanisms and research methods could help refine our understanding of clinical disease associated with infection by Liver Flukes as well as their transmission dynamics. We identify a series of questions for an evolutionary biology research agenda for the liver Fluke that should contribute to an increased understanding of liver Fluke-associated diseases. Finally, we describe an integrative evolutionary medicine approach to liver Fluke prevention and control highlighting the need to better contextualize interventions within a broader human health and sustainable development framework.

Assessment of the FasciMol-ELISA in the detection of the trematode Fasciola hepatica in field-collected Galba cubensis: a novel tool for the malacological survey of fasciolosis transmission.

BACKGROUND: Fasciolosis is one of the food-borne neglected trematodioses that has reemerged as a human disease while its effects on domestic animal health remains of significant economic consideration. Being snail-borne disease, the accurate and time-saving epidemiological surveillance of the transmission foci where infected lymnaeid snails occur could be essential to effectively focus or redirect control strategies. For this purpose, the first monoclonal antibody-based immunoenzymatic assay to detect Fasciola hepatica-infected snails (FasciMol-ELISA) was recently developed and showed a high sensitivity and specificity when tested in an experimental F. hepatica - Galba cubensis system. METHODS: Here, we surveyed populations of G. cubensis occurring in western Cuba for the assessment of the FasciMol-ELISA in determining natural F. hepatica infection in this intermediate host. A multiplex PCR, previously developed to detect F. hepatica in G. cubensis, was used for sample classification. Snail dissection method was also employed as screening technique. A Χ(2) test and a Kappa index were calculated to evaluate the positivity and the level of agreement between the FasciMol-ELISA and the snail dissection methods with the multiplex PCR, respectively. RESULTS: Galba cubensis was found in nine out of 12 sampled localities of which four were positive for F. hepatica infection as detected by both immunoenzymatic and PCR-based assays. The overall prevalence was higher than the natural infection rates previously reported for Cuban G. cubensis (range from 4.1 to 7.42% depending on the screening method). No significant differences were found between FasciMol-ELISA and multiplex PCR when determining parasite positivity (Χ(2) = 6.283; P = 0.0981) whereas an excellent agreement was also noted (Kappa = 0.8224). CONCLUSIONS: Our results demonstrate the importance of malacological surveys in assessing parasite transmission risk and constitute an alert on the need of accurate measures to control fasciolosis in western Cuba. The sensitivity and specificity of the FasciMol-ELISA as well as its time-saving capacity and the easy of performing the determination of a large number of samples, point at this assay as a novel tool suitable for large-scale monitoring of natural snails populations. To our knowledge, this is the first study that explores natural infection by F. hepatica in field-occurring lymnaeid snails using an immunoenzymatic assay.

Fascioliasis: a worldwide parasitic disease of importance in travel medicine.

Fascioliasis is a foodborne zoonotic disease caused by the two parasite species Fasciola hepatica and Fasciola gigantica. This trematodiasis has never been claimed special relevance for travellers and migrants. However, the situation has drastically changed in the last two decades, in a way that fascioliasis should today be included in the list of diseases to be enhanced in Travel Medicine. Different kind of travellers have been involved in human infection reports: business travellers, tourists, migrants, expatriated workers, military personnel, religious missionaries, and refugees. Europe is the continent where more imported cases have been reported in many countries. More cases would have been probably reported in Europe if fascioliasis would be a reportable disease. In the Americas, most of the reports concern cases diagnosed in USA. Relative few patients have been diagnosed in studies on travellers performed in Asia. In Africa, most cases were reported in Maghreb countries. Blood eosinophilia and the ingestion of watercress or any other suggestive freshwater plant in anamnesis are extremely useful in guiding towards a fascioliasis diagnosis in a developed country, although may not be so in human endemic areas of developing countries. Several suggestive clinical presentation aspects may be useful, although the clinical polymorphism may be misleading in many cases. Non-invasive techniques are helpful for the diagnosis, although images may lead to confusion. Laparoscopic visualization should assist and facilitate procurement of an accurately guided biopsy. Endoscopic retrograde cholangiopancreatography (ERCP) is the first choice in patients in the chronic phase. ERCP and sphincterotomy are used to extract parasites from the biliary tree. Fluke egg finding continues to be the gold standard and enables for burden quantification and establishing of the drug dose. Many serological and stool antigen detection tests have been developed. Immunological techniques present the advantages of being applicable during all periods of the disease, but fundamentally during the invasive or acute period, as well as to other situations in which coprological techniques may present problems. Triclabendazole is the drug of choice at present, although the spread of resistance to this drug is challenging. Prevention mainly concerns measures to avoid individual infection by considering the different human infection sources.

Characterization of the molluscicidal activity of Bauhinia variegata and Mimusops elengi plant extracts against the fasciola vector lymnaea acuminata / Caracterização da atividade moluscicida dos extratos das plantas Bauhinia variegata e Mimusops elengi contra o vetor da Fasciola, Lymnaea acuminata

The molluscicidal activity of Bauhinia variegata leaf and Mimusops elengi bark was studied against vector snail Lymnaea acuminata. The toxicity of both plants was time and concentration-dependent. Among organic extracts, ethanol extracts of both plants were more toxic. Toxicity of B. variegata leaf ethanolic extract (96h LC50- 14.4 mg/L) was more pronounced than M. elengi bark ethanolic extract (96h LC50-15.0 mg/L). The 24h LC50 of column purified fraction of B. variegata and M. elengi bark were 20.3 mg/L and 18.3 mg/L, respectively. Saponin and quercetin were characterized and identified as active molluscicidal component. Co-migration of saponin (Rf 0.48) and quercetin (Rf 0.52) with column purified bark of M. elengi and leaf of B. variegata on thin layer chromatography demonstrate same Rf value i.e. 0.48 and 0.52, respectively. The present study clearly indicates the possibility of using M. elengi and/or B. variegata as potent molluscicide.

A atividade moluscicida das folhas da Bauhinia variegata e da casca do Mimusops elengi foi testada contra o vetor caracol, Limnaea acuminata. A toxicidade de ambas as plantas é dependente do tempo e da concentração. Entre os extratos orgânicos, os extratos de etanol de ambas as plantas foi mais tóxico. A toxicidade do extrato etanólico da folha da B. variegata (96 h LC50 - 14,4 mg/L) foi mais pronunciada do que o extrato etanólico da casca do M. elengi (96h - LC50 - 15,0 mg/L). As frações purificadas em coluna durante 24 h LC50 do B. variegata e da casca do M. elengi foram 20,3 mg/L e 18,3 mg/L, respectivamente. A saponina e a quercentina foram caracterizadas e identificadas como os componentes ativos moluscicidas. A co-migração da saponina (Rf 0,48) e da quercentina (Rf 0,52) com a casca purificada por coluna do M. elengi e as folhas da B. variegata na cromatografia demonstraram o mesmo valor Rf isto é, 0,48 e 0,52 respectivamente. O presente estudo indica claramente a possibilidade de usar M. elengi e/ou B. variegata como moluscicidas potentes.

DNA multigene sequencing of topotypic specimens of the fascioliasis vector Lymnaea diaphana and phylogenetic analysis of the genus Pectinidens (Gastropoda)

Freshwater lymnaeid snails are crucial in defining transmission and epidemiology of fascioliasis. In South America, human endemic areas are related to high altitudes in Andean regions. The species Lymnaea diaphana has, however, been involved in low altitude areas of Chile, Argentina and Peru where human infection also occurs. Complete nuclear ribosomal DNA 18S, internal transcribed spacer (ITS)-2 and ITS-1 and fragments of mitochondrial DNA 16S and cytochrome c oxidase (cox)1 genes of L. diaphana specimens from its type locality offered 1,848, 495, 520, 424 and 672 bp long sequences. Comparisons with New and Old World Galba/Fossaria, Palaearctic stagnicolines, Nearctic stagnicolines, Old World Radix and Pseudosuccinea allowed to conclude that (i) L. diaphana shows sequences very different from all other lymnaeids, (ii) each marker allows its differentiation, except cox1 amino acid sequence, and (iii) L. diaphana is not a fossarine lymnaeid, but rather an archaic relict form derived from the oldest North American stagnicoline ancestors. Phylogeny and large genetic distances support the genus Pectinidens as the first stagnicoline representative in the southern hemisphere, including colonization of extreme world regions, as most southern Patagonia, long time ago. The phylogenetic link of L. diaphana with the stagnicoline group may give light to the aforementioned peculiar low altitude epidemiological scenario of fascioliasis.

Fascioliasis hepática / Hepatic fascioliasis

La fascioliasis hepática es una enfermedad parasitaria infecciosa producida por el trematodo Fasciola hepática. El humano es infectado accidentalmente al ingerir vegetales (principalmente berros) contaminados con las formas enquistadas del parásito (metacercarias). Clínicamente se reconoce una fase hepática (fase aguda) que comprende desde la liberación de la larva en el duodeno hasta su llegada a la vía biliar, y una fase biliar (fase crónica), en donde la Fasciola se localiza en la vía biliar, madura a su forma adulta y produce huevos. El diagnóstico requiere un alto índice de sospecha dado el polimorfismo en la presentación y muchas veces el desconocimiento de antecedentes epidemiológicos. Las manifestaciones clínicas dependen del período en el cual se encuentra la enfermedad, sin embargo, lo más habitual es la presencia de dolor abdominal y eosinofilia. El diagnóstico definitivo requiere la demostración del parásito a través de métodos directos (visualización por medio de colangiografía retrógrada endoscópica o búsqueda de huevos en deposiciones o bilis) o a través de la demostración por métodos serológicos. El tratamiento actualmente disponible con triclabendazol es altamente efectivo.

The hepatic fascioliasis is a parasitic disease caused by infectious trematode fasciola hepática. Man is infected accidentally by ingesting vegetables (mainly watercress) contaminated with the parasite encysted forms (metacercariae). Clinically a hepatic phase (acute phase) is recognized, ranging from the release of the larvae in the duodenum to their arrival to the bile duct and a bile phase (chronic phase), where fasciola is located in the bile duct, and the parasite matures to the adult form and produces eggs. The diagnosis requires a high index of suspicion given the polymorphism in the presentation and the frequent lack of epidemiological history. The clinical manifestations depend on the current period of the disease is, however, the most common is the presence of abdominal pain and eosinophilia. Definitive diagnosis requires demonstration of the parasite through direct methods (visualization by ERCP or search for eggs in stool or bile), or through the demonstration by serological methods. The currently available treatment is highly effective with triclabendazole.

Distribution of Lymnaeidae (Mollusca: Pulmonata), intermediate snail hosts of Fasciola hepatica in Venezuela

An extensive malacological survey was carried out between 2005-2009 in order to clarify the exact number of lymnaeid species which may be intermediate hosts of Fasciola hepatica in Venezuela. Four species were discovered during this survey, including two local species: Lymnaea cubensis and Lymnaea cousini and two exotic species: Lymnaea truncatula and Lymnaea columella. The most common local species was L. cubensis which was found at 16 out of the 298 sampling sites. This species has a large distribution area throughout the Northern part of Venezuela and was encountered from sea level to an altitude of 1,802 m in state of Trujillo. The second local species L. cousini was collected at only two sites of the Andean Region at altitudes of 3,550 m and 4,040 m, respectively. The European L. truncatula was found at 24 sites all located in the states of Mérida and Táchira at an altitude varying between 1,540-4,000 m. The respective distribution areas of L. cubensis and L. truncatula do not appear to overlap, but more detailed malacological surveys are needed. The fourth lymnaeid species, L. columella was collected in a canal from Mérida at an altitude of 1,929 m and in an irrigation canal from the state of Guárico, at an altitude of 63 m. The role of these four lymnaeid species in the transmission of fascioliasis in Venezuela is discussed.

Prevalence of slaughter and liver condemnation due to Fasciola hepatica among sheep in the state of Rio Grande do Sul, Brazil 2000 and 2005

The aim of this study is to determine the prevalence of Fasciola hepßtica among sheep in the state of Rio Grande do Sul, Brazil, by reviewing slaughter and liver condemnation data obtained from the Federal Inspection Service, afflliated with the Brazilian Ministry of Agriculture, Animal Husbandry and Supply, for years 2000 to 2005. Liver condemnation amounted to 14.57 percent (18,072/ 124,078) in 2000,10.14 percent (11,998/118,332) in 2001,10.96 percent (11,372/103,762) in 2002, 9.96 percent (10,802/ 108,461) in 2003, 5.42 percent (6,245/114,596) in 2004, and 2.27 percent (2,750/121,172) in 2005. The overall prevalence of liver condemnation due to F. hepßtica corresponded to 8.87 percent (61.239/690.361). In conclusion, fascioliosis was found to be prevalent among sheep in the state of Rio Grande do Sul and to account for major economic losses to farmers, meat packing plants and to the government.

O objetivo deste trabalho foi determinar a prevalência de Fasciola hepática em ovinos no Estado do Rio Grande do Sul, Brasil, através de laudos de abate e condenação de fígados ovinos. Os dados de condenação de 2000 a 2005 foram obtidos do Servico de Inspeção Federal (SIF) do Ministerio da Agricultura, Pecuaria e Abastecimento (MAPA). No ano de 2000 foi de 14,57 por cento (18.072/124.078); em 2001 foi de 10,14 por cento (11.998/118.332); em 2002 foi de 10,96 por cento (11.372/103.762); em 2003 foi de 9,96 por cento (10.802/108.461); em 2004 foi de 5,42 por cento (6.245/ 114.596) e em 2005 foi de 2,27 por cento (2.750/ 121.172). A prevalência geral de condenação de fígados por F. hepática foi de 8,87 por cento (61.239/ 690.361). Conclui-se que a fasciolose ovina é prevalente no Rio Grande do Sul, acarretando perdas para os produtores, frigoríficos e para o Estado.

Effect of three dormant oils on schistosomiasis and fascioliasis vector snails and its relation with some non-target snails.

Three oils were tested for their molluscicidal activity, Caple-2, Kemasol and Super-max. Super-max had the strongest toxic effect on B. alexandrina and other snail species. Its LC50 was 0.53 ppm, meanwhile LC50 of Kemasol 3.2 ppm and 4.21 ppm for Caple 2. The LC50 & LC90 of the oils were lower in Lymneae natalensis as compared to B. alexandrina. The LC50 & LC90 of the oils against non-target snails (Physa acuta, Helisoma duryi, Planorbis planorbis and Melanoides tuberculata) were higher as compared to B. alexandrina. Hatchability of snails' eggs exposed to Super-max (3.0 & 5.0 ppm) was stopped completely and l.0 ppm showed the lower percent of egg hatchability 22.7 %. Caple 2 and Kemasol did not affect eggs hatchability. Supermax had the strongest harmful effect on both miracidia and cercariae of S. mansoni. 100% mortality values were obtained for both larval stages after 8 & 9 minutes respectively when maintained at LC50. 100% mortality of miracidia occurred after 35 & 155 minutes when maintained at LC50 of Kemasol & Caple 2 respectively. The infection rate of B. alexandrina with S. mansoni miracidia was greatly reduced by the sublethal concentrations of the oils. The reduction of infection rate was higher in snails treated with Supermax (42.9%). A highly significant reduction of total cercarial production per snail was in the experimental groups as compared with controls. The prepatent period of treated snails was prolonged compared to control. Moreover, Total protein content and enzyme activities of snails treated with LC10 of oils showed a significant reduction as compared with control in haemolymyph. There was an increase of protein contents in the tissue. AlkP enzyme activity was slightly increased in haemolymph of experimental groups than controls and was significantly higher in the tissues as compared to control. ALT enzyme activity in haemolymph of experimental groups was higher than control, but lower in tissue. AST enzyme activity was higher in haemolymph and tissue of experimental groups than controls. The SDS-PAGE pattern of tissue soluble proteins extracted from treated B. alexandrina and controls showed different oils effects on the synthesis of protein within snails yielded a complex pattern of polypeptides ranging in molecular weight between 13.775 to 156.7 kDa. Many bands were present in treated snails. At least, one band was detected for snails treated with each of the oils and not in controls. The difference in the similarity indices between treatment and control; for Kemasol was 0.86 & 0.64, for Caple 2 was 0.61 & 0.55 and for Supermax was 0.64 & 0.86. LC25 of Supermax did not cause any mortality to Daphnia after 6 hr. But, LC50 & LC90 caused lower mortality after 6 hr. Kemasol caused 100% mortality after 4 hr at LC50 and 2 hr in LC90. Caple 2 caused 50% mortality of Daphnia after 5 hr at LC25 &100% mortality after 30 minutes in LC50 & LC90.

Anatomical studies of sibling species within neotropical lymnaeids, snail intermediate hosts of fascioliasis

Several anatomical parameters of the reproductive system have been used to distinguish Lymnaea cubensis from L. viatrix, the snail hosts of fascioliasis in South America and the Caribbean area. Three samples have been collected in the type localities of L. cubensis (Cuba), L. viatrix var. A ventricosa (Argentina, Río Negro Lower Valley), and L. viatrix var. B elongata (Peru, Lima), respectively. Only one parameter, the relative lengths of the penis sheath and preputium, showed significant differences between L. viatrix var. ventricosa and the two other taxa. None of the studied parameters separated L. cubensis from L. viatrix var. elongata.

Fascioliasis in relatives of patients with Fasciola hepatica infection in Peru

Altas tasas de fasciolosis humana han sido descritas en varias regiones del Perú. Estudiamos 20 familias en una área endémica del Perú para determinar la proporción de infección con F. hepatica en los familiares de los sujetos diagnosticados y para identificar factores de riesgo asociados. El estudio incluyó un total de 93 sujetos, quienes contribuyeron con muestras de heces y sangre. Las edades comprendieron desde 1 a 53 años (media = 18.6; DS = 14.2). La prevalencia general de fasciolosis por exámenes de heces fue 33.3% (n = 83) y por serología, 51.9% (n = 86). La prevalencia en el grupo de edad I (< 19 años de edad) por pruebas coprológicas y serológicas fueron 61.4% y 75.9%, respectivamente; en el grupo II (> 19 años de edad) 15.4% y 37.5%. El principal factor de riesgo asociado con fasciolosis fue comer ensaladas (OR = 3.29, IC = 1.2-9.0, p = 0.02). En conclusión, la fasciolosis humana es altamente prevalente en familiares de los casos índices y el factor de riesgo más significante para adquirirla en la familia es comer ensaladas en las áreas endémicas.

Proposal of a geographic information system for modeling zoonotic fasciolosis transmission in the Andes

El presente estudio describe la base para el desarrollo de un Sistema de Información Geográfica (SIG) para dirigir un análisis epidemiológico de la fascioliosis humana y animal en los Andes. La metodología propone el uso de varias bases de datos - derivadas de estudios epidemiológicos multidisciplinarios y de datos medioambientales derivados de estaciones terrestres y de satélites.

Zoonotic potential of infection with Fasciola spp. by consumption of freshly prepared raw liver containing immature flukes.

Mice were successfully infected with metacercariae of the Japanese Fasciola sp., resulting in the recovery of a mean number of 110 live immature flukes per mouse 4-5 days after inoculation. Twenty-four mice were then inoculated orally, each with a mean number of 68 freshly recovered immature flukes. The livers of 7 of the 24 recipient mice showed migratory lesions of capsular and subcapsular granulomatous infiltration and 2 of those mice also had haemorrhagic lesions. The lesions were typical of those caused by active migration of early immature flukes. However, no flukes were found in the livers of the recipient mice at necropsy when the flukes were aged 14 weeks. In another experiment, 10 piglets were given fresh livers of mice harbouring approximately 2000 live immature flukes aged 3-7 days. Two additional piglets were inoculated with 2000 metacercariae of Fasciola. All pigs were killed when the flukes were 14 days old. Granulomatous lesions were present in all pigs, except in those that were given livers containing flukes aged 7 days. The lesions were localized, forming well-defined foci, different from the typical migratory lesions normally observed in mouse or sheep liver at the early stage of fluke migration. From the 10 pigs given livers, 65 live flukes were recovered at necropsy, 0.29% of the estimated number of immature flukes given. From the 2 pigs which received 2000 metacercariae each, a total of 198 flukes were recovered (5%). The results of the experiments suggest that humans consuming raw liver dishes prepared from fresh livers infected with immature Fasciola spp. could become infected with liver fluke.

[The fate of parasites of animal origin transmitted to humans]. / Devenir des parasites d'origine animale transmis à l'homme.

The fate of a parasite transmitted from an animal to man depends on the ability of the contaminating agent to reach a place where it can thrive, to find necessary nutrients, and to resist host defense mechanisms. The purpose of this study was to evaluate the incidence of transmission of parasites from animals to man and to determine to what extent transmission is followed by development. Stenoxenic parasites whose life cycle requires transmission from animals to man obviously develop in man and then return to animals. These parasites cause holozoonoses of the cyclozoonosis type. Some euryxenic parasites can develop as well in man as in animals. These parasites can cause holozoonoses of the amphixenoses type. Other presumably euryxenic parasites can be transmitted from animals to man but not vice versa. These parasites are hemizoonoses agents. Non-transmission back from man to animals can be observed under several circumstances: incomplete development in man with failure to reach the stage at which transmission back to animals is possible; full development but with immaturity or sterility of the elements of dissemination necessary for transmission back to animals; full development but no way of evacuating elements of dissemination; full development and evacuation but with failure of elements of dissemination to survive. In these four cases man constitutes a dead-end for the parasite. A fifth possibility is that the parasite reaches full development but transmission back to animals cannot occur because man is not preyed upon by a carnivorous animal. In this case parasites are potential agents of holozoonoses and man is a cul-de-sac for the involved parasites.

Fascioliasis en la República Oriental del Uruguay / Fasciolasis in Uruguay

Se realizó una revisión y puesta al día de la situación médica y veterinaria de la distomatosis en Uruguay. Se trata de una zoonosis parasitaria altamente prevalente, producida por el trematode Fasciola hepatica actuando como huésped intermediario el molusco Limnaea viatrix. Afectca a los rumiantes de importancia económica para el país y en forma accidental al ser humano. La prevalencia en el ganado bovino es de 57 por ciento, encontrándose focalmente distribuida en todos los departamentos del país. Los casos humanos han sido esporádicos, y en su mayoría relacionados con la ingestión de berro (Nasturtium officinale). El diagnóstico se hacía accidentalmente durante el acto quirúrgico o por examen coproparasitario. Desde 1991 se ha podido detectar mayor número de casos mediante la aplicación de pruebas serológicas sensibles y específicas. Las medidas de control implementadas para el ganado son la dosificación con fasciolicidas y prácticas de manejo. No existen aún fármacos específicos eficaces para casos humanos. Se revisan las bibliografías nacionales sobre el tema

[Fasciola hepatica infestation. Biopathology and new diagnostic and therapeutic aspects]. / Infestación por Fasciola hepatica. Biopatología y nuevos aspectos diagnósticos y terapéuticos.

We present here 6 patients with Fasciola hepatica infection, all from rural origin, and with the risk factors of eating wild watercress. The more common symptoms were: fever (83%), abdominal pain (100%), weight loss (83%) and generalized myalgia and joint pain (67%). All patients presented with an absolute eosinophil count above 1,000 cell/mm3. The diagnosis was established in five cases by means of serologic techniques (haemagglutination) and with direct visualization of adult worms while surgery in one case. A CT abdominal scan was performed in five patients, revealing specific lesions of tissue infiltration in four of them. Praziquantel was used in four patients, achieving clinical cure in three cases. In two patients, bithionol was used, with clinical cure in both cases. We review also some newer diagnostic and therapeutic approaches to this parasitic disease.