Blood parameters and parasite burden in cattle with chronic fascioliasis.

Fascioliasis is a trematodiasis that affects domestic and wild animals as well as humans worldwide. It is a well-recognized disease in livestock, were it produces serious economic losses. Yet in cattle, there is limited information about the burden of liver flukes and its relation to the eggs per gram shed to the environment. There is also lack of knowledge on the effect of parasite load in blood parameters of infected animals, which is important to evaluate the severity and progression of the disease. The objective of this work was to gain insight in these aspects. Cattle from Mendoza province, Argentina, were inspected at a farm and at the abattoir determining the presence or absence of Fasciola hepatica. Each animal was sampled for blood and feces and in the slaughterhouse the livers were inspected. Hematology and blood chemistry parameters were determined, feces were examined for F. hepatica eggs by a quantitative sedimentation technique and livers were thoroughly inspected to determine the number of flukes. Infected cattle presented a mild burden of liver flukes per animal, strongly correlated (r = 0.72) to the number of eggs per gram of feces. The total number of eggs (X̄=35,100) shed per animal to the environment and the type of livestock management techniques in the region exacerbate the role of cattle as efficient reservoirs of this disease. Statistically significant lower red blood cell, lymphocyte and neutrophil counts were observed in infected compared to uninfected animals. All hepatic parameters tested showed highly statistically significant differences (p < 0.001) as well as proteins by cause of rise of globulins in infected cattle. The correlation between the amount of flukes in the liver and the number of eggs per gram of faces indicates coprology as a reliable and cost-effective method to infer parasite burden. The impact of fascioliasis on blood parameters can be of aid for the veterinary practitioner on the assessment of this disease on cattle.

Ozone Environmental Pollution: Relationship between the Intestine and Neurodegenerative Diseases.

Repeated exposure to environmental ozone causes a chronic state of oxidative stress. This state is present in chronic degenerative diseases and induces a loss of control of the inflammatory response. Redox system dysfunction and failures in control of inflammatory responses are involved in a vicious circle that maintains and increases the degenerative process. The intestine also responds to secondary reactive species formed by exposure to ozone doses, generating noxious stimuli that increase degenerative damage. This review aims to elucidate how environmental pollution, mainly by ozone, induces a state of chronic oxidative stress with the loss of regulation of the inflammatory response, both in the intestine and in the brain, where the functionality of both structures is altered and plays a determining role in some neurodegenerative and chronic degenerative diseases. For this purpose, we searched for information on sites such as the Cochrane Library Database, PubMed, Scopus, and Medscape. Reviewing the data published, we can conclude that environmental pollutants are a severe health problem. Ozone pollution has different pathways of action, both molecular and systemic, and participates in neurodegenerative diseases such as Parkinson's and Alzheimer's disease as well in bowel diseases as Inflammatory Bowel Disease, Crohn's Disease, and Irritable Bowel Syndrome.

A Single Nucleotide Polymorphism Translates into a Radical Amino Acid Substitution at the Ligand-Binding Site in Fasciola hepatica Carboxylesterase B.

Fasciola hepatica anthelmintic resistance may be associated with the catalytic activity of xenobiotic metabolizing enzymes. The gene expression of one of these enzymes, identified as carboxylesterase B (CestB), was previously described as inducible in adult parasites under anthelmintic treatment and exhibited a single nucleotide polymorphism at position 643 that translates into a radical amino acid substitution at position 215 from Glutamic acid to Lysine. Alphafold 3D models of both allelic sequences exhibited a significant affinity pocket rearrangement and different ligand-docking modeling results. Further bioinformatics analysis confirmed that the radical amino acid substitution is located at the ligand affinity site of the enzyme, affecting its affinity to serine hydrolase inhibitors and preferences for ester ligands. A field genotyping survey from parasite samples obtained from two developmental stages isolated from different host species from Argentina and Mexico exhibited a 37% allele distribution for 215E and a 29% allele distribution for 215K as well as a 34% E/K heterozygous distribution. No linkage to host species or geographic origin was found in any of the allele variants.

Detección de casos de infección crónica, asintomática por trypanosoma cruzi en estudiantes que ingresen a una universidad pública nacional / etection of chronic asymptomatic infection cases due to trypanosoma cruzi in incoming students of a public national university

INTRODUCCIÓN La OMS define al Chagas como una enfermedad desatendida y endémica en Latinoamérica, donde viven alrededor de 70 millones de personas en riesgo de contraer la infección, y estima que un 95 % de las personas infectadas desconocen su estado y, por ende, no han recibido tratamiento. En la provincia de Mendoza, la prevalencia estimada de infección por Trypanosoma cruzi en personas gestantes está entre el 2 % y el 40 % según la zona geográfica. OBJETIVOS Conocer la prevalencia de casos crónicos asintomáticos de infección por Trypanosoma cruzi, factibles de ser tratados, en ingresantes a la universidad pública de la provincia de Mendoza. El perfil de ingresantes está compuesto mayormente por mujeres y personas con capacidad de gestar de 21 años o menores. MÉTODOS Se realizó un estudio descriptivo cuantitativo transversal. Se utilizaron las técnicas de hemaglutinación indirecta y enzimoinmunoanálisis. Los casos discordantes fueron derivados para su confirmación al Departamento de Enfermedades Zoonóticas y Vectoriales del Ministerio de Salud de Mendoza. RESULTADOS Se estudió a 202 de un total de 371 (55 %) estudiantes del primer año de la Facultad de Ciencias Médicas de la Universidad Nacional de Cuyo (Medicina 143, Tecnicaturas 122, Enfermería 106). Se detectaron 2 casos crónicos asintomáticos en estudiantes mujeres en edad fértil, que accedieron al seguimiento médico y tratamiento etiológico de la infección. DISCUSIÓN Los datos obtenidos permitieron a las autoridades sanitarias provinciales decidir respecto de la necesidad de ampliar la búsqueda de casos de infección crónica asintomática por T. cruzi en este grupo poblacional. Se logró constituir una unidad de diagnóstico y tratamiento para la enfermedad de Chagas y así, a partir de 2024, recibir los insumos necesarios para realizar el diagnóstico y seguimiento de la patología.

Epidemiological link between canine monocytic ehrlichiosis caused by Ehrlichia canis and the presence of Rhipicephalus sanguineus sensu stricto in Argentina.

In this work, we analyze data that support an epidemiological link between cases of canine monocytic ehrlichiosis (CME) by Ehrlichia canis and the presence of Rhipicephalus sanguineus sensu stricto as vector in an endemic area for this tick in Argentina. In a blood sample of a 1-year-old toy poodle with CME compatible clinical signs, which showed CME typical morulae in monocytes in Giemsa-stained blood smear, DNA of E. canis was detected by PCR. Further, DNA of E. canis was also detected in a female of R. sanguineus s.s. collected on the infected dog. Rhipicephalus sanguineus s.s. is the only member of the R. sanguineus group that prevails in the study area. The results of this study suggest that R. sanguineus s.s. may play a more important role in the transmission of E. canis than it was assumed so far. The epidemiological link between CME cases and R. sanguineus s.s. as vector in temperate areas of Argentina described in this work contrast previous studies which found that R. sanguineus sensu lato "tropical lineage" (which is absent in the study area) is competent to transmit E. canis but not R. sanguineus s.s.

Vertical and horizontal dissemination of an IncC plasmid harbouring rmtB 16S rRNA methylase gene, conferring resistance to plazomicin, among invasive ST258 and ST16 KPC-producing Klebsiella pneumoniae.

OBJECTIVES: Carbapenem resistance in Klebsiella pneumoniae is a major clinical challenge. Aminoglycosides remain an important asset in the current therapeutic arsenal to treat these infections. We examined aminoglycoside resistance phenotypes and genomics in a collection of 100 invasive KPC-producing K. pneumoniae isolates sequentially collected in a Brazilian tertiary hospital between 2014 and 2016. METHODS: Aminoglycoside susceptibility testing was performed. We used a combined long-read (MinION) and short-read (Illumina) whole-genome sequencing strategy to provide a genomic picture of aminoglycoside resistance genes, with particular emphasis on 16S rRNA methyltransferases and related plasmids. RESULTS: 68% of the strains were resistant to gentamicin and 42% to amikacin, with 35% resistant to both of these commonly used aminoglycosides. We identified the 16S rRNA methyltransferase gene rmtB in 30% of these isolates: 97% (29/30) belonged to sequence type 258 (ST258) and a single isolate to the emergent ST16 clone. In ST258 and ST16 the rmtB gene was located on large IncC plasmids of 177 kb and 174 kb, respectively, highly similar to a plasmid previously identified in Proteus mirabilis in the same hospital. Moreover, 99% of the isolates remained susceptible to the veterinary-approved drug apramycin, currently under clinical development for human medicine. CONCLUSION: Such findings in geographically and temporally related isolates suggest a combination of vertical clonal spread as well as horizontal interspecies and intraspecies plasmid transfer. This broad rmtB dissemination in an endemic setting for KPC-producing clones is worrisome since it provides resistance to most clinically available aminoglycosides, including the novel aminoglycoside-modifying enzyme-resistant plazomicin.

Mortalidad en pacientes con enfermedad renal. Instituto de Nefrología. 2016 y 2017 / Mortality in patients with kidney disease. Institute of Nephrology, 2016 and 2017

Introducción: La Enfermedad Renal Crónica es un problema de salud mundial. Objetivo: Determinar el comportamiento de la mortalidad en pacientes con enfermedad renal en el Instituto de Nefrología durante 2016 y 2017. Material y Métodos: Estudio observacional descriptivo transversal de pacientes fallecidos con necropsia realizada. Se registraron variables demográficas, de laboratorio, las relacionadas con la terapia de reemplazo de la función renal y con el diagnóstico anatomo-patológico. Para cada una de las variables se calcularon frecuencias absolutas y relativas. En el caso de la variable presencia de sepsis en las defunciones, fue empleada la prueba de chi-cuadrado para la bondad del ajuste, para probar la hipótesis nula H0: de igualdad de la distribución de las tres categorías de la variable. Resultados: Se estudiaron 48 fallecidos con necropsia, 48,9 por ciento del total de fallecidos en el periodo. La correspondencia clínico patológica fue 80,1 por ciento. Predominó el sexo masculino, el grupo de edad superior a 60 años y la hipertensión arterial como antecedente. El método de terapia de reemplazo renal más documentado fue la hemodiálisis, mediante catéter venoso central un 87,8 por ciento. El 61,8 por ciento de los fallecidos recibieron tratamiento hemodialítico por 3 meses o menos. La sepsis fue la segunda causa de muerte precedida por eventos cardio y cerebrovasculares; no obstante, en el análisis de la totalidad de necropsias, la infección asociada directa o indirecta a la muerte tuvo una frecuencia mayor. Conclusiones: La infección directa o indirectamente asociada a la muerte, la hipoalbuminemia y el acceso vascular mediante catéter se relacionan con la mortalidad en el periodo(AU)

Introduction: Chronic kidney disease is a health problem worldwide. Objective: To determine the behavior of mortality in patients with kidney damage in the Nephrology Institute during the years between 2016 and 2017. Material and Method: A cross-sectional descriptive observational study was conducted in 48 deceased patients who underwent necropsy. Demographic and laboratory variables were recorded, as well as those related to the type of renal function replacement therapy and the anatomopathological diagnosis. Absolute and relative frequencies were calculated for each of the variables. In the case of the variable presence of sepsis in deaths, the Chi-Square Goodness-of-Fit Test was used to test the Null Hypothesis HO: uniformity of the distribution of the three categories of the variable. Results: A total of 48 deceased were studied at necropsy, representing 48.9 percent of the total number of deaths within the period. The clinical- pathological correlation was 80.1percent. The male sex, the group over the age of 60 years, and arterial hypertension as antecedent of the disease predominated in the study. The most documented method of renal function replacement therapy was hemodialysis which was performed through central venous catheter, 87.8 percent. The 61.8 percent of deceased patients received hemodialysis treatment for 3 months or less. Sepsis represented the second cause of death preceded by cardiovascular and cerebrovascular events. However, during the analysis of all the necropsies, the direct or indirect infection associated with the death had a greater frequency. Conclusions: Direct or indirect infections associated with death, hypoalbuminemia, and the vascular access with venous catheter was related to mortality during the observed period(AU)

Air Sac Nematode ( Serratospiculum tendo) Infection in an Austral Peregrine Falcon ( Falco peregrinus cassini) in Argentina.

We report a case of air sac nematode ( Serratospiculum tendo) infection in an adult male Austral Peregrine Falcon ( Falco peregrinus cassini) admitted to a rehabilitation center in Mendoza Province, Argentina, in September 2017. This case of air sac nematodes reported in an Argentine raptor is only the second report of S. tendo in South America. We recommend examination of all raptors, especially those falcon species that include insects in their diet and inhabit open lands and those in rehabilitation centers or kept for falconry, education, or captive breeding. Fecal analysis and microscopic examination of oral swabs for evidence of parasites are simple noninvasive diagnostic procedures that allow easy detection of these parasites under field and captive circumstances.

Report of Amblyomma parvitarsum infesting goats in Midwestern Argentina.

Adult ticks were collected from goats on September 2012 in the locality of Trintrica (35° 17' 19″ S - 68° 44' 6″ W, 1430 m.a.s.l.), Mendoza, Argentina. The specimens were identified as seven females and three males of Amblyomma parvitarsum Neumann, 1901. This record represents the new occurrence of A. parvitarsum in the province of Mendoza, as well as the first report of the parasitism in goats along the geographical range of A. parvitarsum.

Liver fluke (Fasciola hepatica) naturally infecting introduced European brown hare (Lepus europaeus) in northern Patagonia: phenotype, prevalence and potential risk.

Fascioliasis has recently been included in the WHO list of Neglected Zoonotic Diseases. Besides being a major veterinary health problem, fascioliasis has large underdeveloping effects on the human communities affected. Though scarcely considered in fascioliasis epidemiology, it is well recognized that both native and introduced wildlife species may play a significant role as reservoirs of the disease. The objectives are to study the morphological characteristics of Fasciola hepatica adults and eggs in a population of Lepus europaeus, to assess liver fluke prevalence, and to analyze the potential reservoir role of the European brown hare in northern Patagonia, Argentina, where fascioliasis is endemic. Measures of F. hepatica found in L. europaeus from northern Patagonia demonstrate that the liver fluke is able to fully develop in wild hares and to shed normal eggs through their faeces. Egg shedding to the environment is close to the lower limit obtained for pigs, a domestic animal whose epidemiological importance in endemic areas has already been highlighted. The former, combined with the high prevalence found (14.28%), suggest an even more important role in the transmission cycle than previously considered. The results obtained do not only remark the extraordinary plasticity and adaptability of this trematode species to different host species, but also highlight the role of the European brown hare, and other NIS, as reservoirs capable for parasite spillback to domestic and native cycle, representing a potentially important, but hitherto neglected, cause of disease emergence.

Detection of Dirofilaria immitis in mid-western arid Argentina.

Dirofilariosis, caused by Dirofilaria immitis and D. repens, is (re-) emerging worldwide. Dogs are the main reservoirs, while human infection has recently become an important focus of interest and attention. In Argentina, canine D. immitis infection has been described in eastern and northern subtropical and temperate humid regions, but never reported in mid-western arid regions so far. In this research note we report for the first time the occurrence of autochthonous human and canine D. immitis infection in the region.

Analysis of climate and extrinsic incubation of Dirofilaria immitis in southern South America.

Dirofilariosis, caused by Dirofilaria immitis and D. repens, is spreading in several geographic regions. The development of infective larvae in the mosquito vector (extrinsic incubation) needs an accumulated total of 130 degree-days above the 14 °C threshold, normally expressed as heartworm development units (HDUs). Based on this information, temperature- based models have been developed and applied to evaluate the distribution and spread of Dirofilaria infections in various countries and continents. Despite the confirmed presence of D. immitis in most South American countries, the available information about its epidemiology remains scarce. We analysed the temporal and spatial extrinsic incubation of this parasite in Argentina, Chile and Uruguay, taking into account daily temperatures from 49 meteorological stations during a 30-year period (1982-2012). The theoretically possible number of D. immitis generations was calculated based on the number of meteorological stations that reached the 130-HDUs threshold. The resulting information was spatially interpolated using the inverse weighted distance (IWD) model to produce thematic maps. The model shows that 41 of the meteorological stations reach the threshold needed and that D. immitis transmission is markedly seasonal with a peak in late spring (December), stable during summer (January to March) and declining in the autumn (April and May). Suitable temperatures exist in Uruguay and most of Argentina, whereas D. immitis transmission in Chile is only possible in the north and in the central inlands. The results suggest that the climatic impact on D. immitis transmission must have been minimal in the countries investigated since the annual meteorological records did not change much during the 30-year period analysed.

Fasciola hepatica infection and association with gastrointestinal parasites in Creole goats from western Argentina.

Goats, called "the cow of the poor", are the livestock species with the most significant population growth worldwide in recent years. Gastrointestinal parasitism constitutes one of the main constraints to its outdoor and extensive breeding in temperate and tropical countries. Despite a Creole goat population of nearly 4 million heads, local reports on parasitological prevalence are scarce, and while Fasciola hepatica infection is spread all over Argentina, the goat is usually neglected as a reservoir and economic losses are not considered. To evaluate gastrointestinal parasitism prevalence and associations between parasite genera and species, with emphasis on fascioliasis, Creole goats from the plateau and Andean regions from western Argentina were investigated by coprological techniques, and associations were statistically assessed. Eighty-five percent (85%) of the animals harbored one or more parasite types, while 46% showed mixed infections. Significant positive associations between F. hepatica + Strongyle eggs, Eimeria sp. + Nematodirus sp. and Nematodirus sp. + Trichuris ovis were detected. Further studies are required to define the causality of these associations and their relevance in epidemiology. F. hepatica is rarely considered as goat parasite in the country, but a 33% prevalence poses an interrogation on the role goats play on the transmission and dissemination of this zoonotic trematode.

Fasciola hepatica infection and association with gastrointestinal parasites in Creole goats from western Argentina / Fasciola hepatica infecção e associação com parasitas gastrintestinais em caprinos crioulos do oeste da Argentina

Goats, called "the cow of the poor", are the livestock species with the most significant population growth worldwide in recent years. Gastrointestinal parasitism constitutes one of the main constraints to its outdoor and extensive breeding in temperate and tropical countries. Despite a Creole goat population of nearly 4 million heads, local reports on parasitological prevalence are scarce, and while Fasciola hepatica infection is spread all over Argentina, the goat is usually neglected as a reservoir and economic losses are not considered. To evaluate gastrointestinal parasitism prevalence and associations between parasite genera and species, with emphasis on fascioliasis, Creole goats from the plateau and Andean regions from western Argentina were investigated by coprological techniques, and associations were statistically assessed. Eighty-five percent (85%) of the animals harbored one or more parasite types, while 46% showed mixed infections. Significant positive associations between F. hepatica + Strongyle eggs, Eimeria sp. + Nematodirus sp. andNematodirus sp. + Trichuris oviswere detected. Further studies are required to define the causality of these associations and their relevance in epidemiology. F. hepaticais rarely considered as goat parasite in the country, but a 33% prevalence poses an interrogation on the role goats play on the transmission and dissemination of this zoonotic trematode.

As cabras, nomeadas como "a vaca dos pobres", são as espécies de gado com o crescimento populacional mais significativo nos últimos anos em todo o mundo. O parasitismo gastrintestinal constitui uma das principais limitações à sua criação extensiva em clima temperado e tropical. Na Argentina, apesar de uma população de caprinos crioulos de cerca de quatro milhões de cabeças, são escassos os relatórios locais de prevalências parasitológicas. Embora a infecção por Fasciola hepatica esteja espalhada em todo o país, as cabras são geralmente negligenciadas como um reservatório, e as perdas econômicas não são consideradas. Para avaliar a prevalência do parasitismo gastrintestinal e associações entre os gêneros e espécies de parasitos, com ênfase na fasciolose, caprinos crioulos da região andina e do planalto do oeste de Argentina foram avaliados por meio de técnicas coprológicas. Oitenta e cinco por cento dos animais hospedaram um ou mais tipos de parasitos, enquanto 46% hospedaram infecções mistas. Foram encontradas associações significativas entre F. hepatica+ ovos de estrongilídeos, Eimeria sp. +Nematodirus sp. e Nematodirus sp. +Trichuris ovis. Mais estudos são necessários para definir a causalidade dessas associações e sua relevância na epidemiologia. Raramente F. hepatica é considerada como um parasito de cabra no país, mas uma prevalência de 33% suscita uma interrogação sobre o papel dos caprinos na transmissão e disseminação desse trematódeo zoonótico.

Fasciola hepatica infection and association with gastrointestinal parasites in Creole goats from western Argentina

Goats, called the cow of the poor, are the livestock species with the most significant population growth worldwide in recent years. Gastrointestinal parasitism constitutes one of the main constraints to its outdoor and extensive breeding in temperate and tropical countries. Despite a Creole goat population of nearly 4 million heads, local reports on parasitological prevalence are scarce, and while Fasciola hepatica infection is spread all over Argentina, the goat is usually neglected as a reservoir and economic losses are not considered. To evaluate gastrointestinal parasitism prevalence and associations between parasite genera and species, with emphasis on fascioliasis, Creole goats from the plateau and Andean regions from western Argentina were investigated by coprological techniques, and associations were statistically assessed. Eighty-five percent (85%) of the animals harbored one or more parasite types, while 46% showed mixed infections. Significant positive associations between F. hepatica + Strongyle eggs, Eimeria sp. + Nematodirus sp. andNematodirus sp. + Trichuris oviswere detected. Further studies are required to define the causality of these associations and their relevance in epidemiology. F. hepaticais rarely considered as goat parasite in the country, but a 33% prevalence poses an interrogation on the role goats play on the transmission and dissemination of this zoonotic trematode.

As cabras, nomeadas como a vaca dos pobres, são as espécies de gado com o crescimento populacional mais significativo nos últimos anos em todo o mundo. O parasitismo gastrintestinal constitui uma das principais limitações à sua criação extensiva em clima temperado e tropical. Na Argentina, apesar de uma população de caprinos crioulos de cerca de quatro milhões de cabeças, são escassos os relatórios locais de prevalências parasitológicas. Embora a infecção porFasciola hepatica esteja espalhada em todo o país, as cabras são geralmente negligenciadas como um reservatório, e as perdas econômicas não são consideradas. Para avaliar a prevalência do parasitismo gastrintestinal e associações entre os gêneros e espécies de parasitos, com ênfase na fasciolose, caprinos crioulos da região andina e do planalto do oeste de Argentina foram avaliados por meio de técnicas coprológicas. Oitenta e cinco por cento dos animais hospedaram um ou mais tipos de parasitos, enquanto 46% hospedaram infecções mistas. Foram encontradas associações significativas entre F. hepatica+ ovos de estrongilídeos, Eimeria sp. +Nematodirus sp. e Nematodirus sp. +Trichuris ovis. Mais estudos são necessários para definir a causalidade dessas associações e sua relevância na epidemiologia. Raramente F. hepaticaé considerada como um parasito de cabra no país, mas uma prevalência de 33% suscita uma interrogação sobre o papel dos caprinos na transmissão e disseminação desse trematódeo zoonótico.

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.

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.

Distribución y capacidad de transmisión de lymnaeidos vectores de fasciola hepática en zonas Andinas de la Región de Cuyo / Distribution and transmission capacity of lymnaeid vectors of fasciola hepatica in Andean Regions of Cuyo

INTRODUCCIÓN La fascioliasis animal es endémica en las provincias de Mendoza y San Juan, y existen reportes de casos humanos. Sin embargo, se desconoce la distribución y la capacidad vectorial de los lymnaeidos, OBJETIVOS Determinar la distribución y la capacidad de transmisión de fasciola hepática de las distintas poblaciones de lymnaeidos en zonas andinas de las provincias de San Juan y Mendoza. MÉTODOS Se investigó la presencia de lymnaeidos en las cuencas hidrográficas de las regiones andinas de Mendoza y San Juan. Se determinó la infección natural de lymnaeidos por fasciola hepática, observando y cuantificando la emisión de cercarias. En caracoles libres de infección, se realizó la infección experimental analizando la emisión de cercarias. RESULTADOS Se hallaron 42 poblaciones de lymnaeidos con una amplia distribución latitudinal en ambas provincias. El 73,81% se encontraban entre 1.000 y 2.000 metros sobre el nivel del mar. El 25% de las poblaciones estaban naturalmente parasitadas. La prevalencia de caracoles con fasciola hepática fue del 2,21%. En la infección experimental, se logró que eliminaran cercarias el 36,36% de los caracoles. La cantidad media de cercarias eliminadas por caracol con infección natural y experimental fue de 60 y 54, respectivamente. DISCUSIÓN La distribución de lymnaeidos en zonas andinas de las provincias de Mendoza y San Juan.

Characterisation of fascioliasis lymnaeid intermediate hosts from Chile by DNA sequencing, with emphasis on Lymnaea viator and Galba truncatula.

In South America, Fasciola hepatica infection poses serious health problems in both humans and livestock. In Chile, the medical impact appears yearly stable and mainly concentrated in central regions, where the veterinary problem is highlighted by higher animal prevalences. Studies were undertaken by rDNA ITS-2 and ITS-1 and mtDNA cox1 sequencing to clarify the specific status of the lymnaeids, their geographical distribution and fascioliasis transmission capacity in Chile, by comparison with other American countries and continents. Results change the lymnaeid scenario known so far. The lymnaeid fauna of mainland Chile shows to be poor, including only two authochthonous species, Lymnaea viator and Pectinidens diaphana, and a third introduced species of Palaearctic origin Galba truncatula. Both Lymnaea lebruni and Lymnaea patagonica proved to be synonyms of P. diaphana. G. truncatula appears to have always been confused with L. viator and seems distributed from Región VI to Región IX, overlapping with human endemic areas. DNA sequencing results suggest that the absence of correlation between remote sensing data and disease prevalences could be due to transmission capacity differences between L. viator and G. truncatula. Results furnish a new baseline on which to undertake future appropriate studies on transmission, epidemiology and control.