Ecological Niche Modelling Approaches: Challenges and Applications in Vector-Borne Diseases.

Vector-borne diseases (VBDs) pose a major threat to human and animal health, with more than 80% of the global population being at risk of acquiring at least one major VBD. Being profoundly affected by the ongoing climate change and anthropogenic disturbances, modelling approaches become an essential tool to assess and compare multiple scenarios (past, present and future), and further the geographic risk of transmission of VBDs. Ecological niche modelling (ENM) is rapidly becoming the gold-standard method for this task. The purpose of this overview is to provide an insight of the use of ENM to assess the geographic risk of transmission of VBDs. We have summarised some fundamental concepts and common approaches to ENM of VBDS, and then focused with a critical view on a number of crucial issues which are often disregarded when modelling the niches of VBDs. Furthermore, we have briefly presented what we consider the most relevant uses of ENM when dealing with VBDs. Niche modelling of VBDs is far from being simple, and there is still a long way to improve. Therefore, this overview is expected to be a useful benchmark for niche modelling of VBDs in future research.

P-C, P-N, and M-N Bond Formation Processes in Reactions of Heterometallic Phosphinidene-Bridged MoMn and MoRe Complexes with Diazoalkanes and Organic Azides to Build Three- to Five-Membered Phosphametallacycles.

Reactions of the heterometallic MoRe complex [MoReCp(µ-PR*)(CO)6] and its MoMn analogue with some small molecules having N-N multiple bonds, such as diazoalkanes and organic azides, were investigated (R* = 2,4,6-C6H2tBu3). Reactions with excess ethyl diazoacetate proceeded slowly and with concomitant denitrogenation to give complexes [MoMCp(µ-η2P,C:κ2P,O-PR*CHCO2Et)(CO)5], which display a bridging phosphaalkene ligand in a novel µ-η2:κ2 coordination mode, while reactions with other diazoalkanes resulted only in the decomposition of the organic reagent. The MoRe complex reacted with benzyl- or p-tolyl azide at room temperature to give the green complexes [MoReCp(µ-η2P,N:κP,N'2-PR*N3R)(CO)6] [R = Bn, p-tol], which display bridging phosphatriazadiene ligands in a novel 6-electron donor coordination mode as a result of a formal [2 + 1] cycloaddition of the terminal N atom of the azide to the Mo-P double bond of the parent complex, followed by coordination of the distal NR nitrogen to the rhenium center. Denitrogenation was only observed for the p-tolyl azide derivative, which upon heating at 333 K yielded [MoReCp{µ-κP:κN-PR*N(p-tol)}(CO)6], a molecule displaying a bridging phosphaimine ligand in a rare κP:κN coordination mode. Analogous reactions of the MoMn phosphinidene complex proceeded similarly at 273 K to give the phosphatriazadiene-bridged derivatives [MoMnCp(µ-η2P,N:κ2P,N'-PR*N3R)(CO)6], but these were thermally unstable and degraded at room temperature to give the mononuclear triazenylphosphanyl complexes [Mn2(κP,N-PR*NHNNR)(CO)3] as major products, along with small amounts of the phosphaimine-bridged complex [MoMnCp{µ-κP:κN-PR*N(p-tol)}(CO)6] in the case of the p-tolyl azide derivative. The structure of the new complexes was analyzed in light of spectroscopic data and single-crystal diffraction studies on selected examples of each type of complex.

West Nile virus in Spain: Forecasting the geographical distribution of risky areas with an ecological niche modelling approach.

West Nile virus (WNV), a well-known emerging vector-borne arbovirus with a zoonotic life cycle, represents a threat to both public and animal health. Transmitted by ornithophilic mosquitoes, its transmission is difficult to predict and even more difficult to prevent. The massive and unprecedented number of human cases and equid outbreaks in Spain during 2020 interpellates for new approaches. For the first time, we present an integrate analysis from a niche perspective to provide an insight to the situation of West Nile disease (WND) in Spain. Our modelling approach benefits from the combined use of global occurrence records of outbreaks of WND in equids and of its two alleged main vectors in Spain, Culex pipiens and Cx. perexiguus. Maps of the climatic suitability for the presence of the two vectors species and for the circulation of WNV are provided. The main outcome of our study is a map delineating the areas under certain climatic risk of transmission. Our analyses indicate that the climatic risk of transmission of WND is medium in areas nearby the south Atlantic coastal area of the Cadiz Gulf and the Mediterranean coast, and high in southwestern Spain. The higher risk of transmission in the basins of the rivers Guadiana and Guadalquivir cannot be attributed exclusively to the local abundance of Cx. pipiens, but could be ascribed to the presence and abundance of Cx. perexiguus. Furthermore, this integrated analysis suggests that the WNV presents an ecological niche of its own, not fully overlapping the ones of its hosts or vector, and thus requiring particular environmental conditions to succeed in its infection cycle.

One Health initiative in the Bolivian Altiplano human fascioliasis hyperendemic area: Lymnaeid biology, population dynamics, microecology and climatic factor influences.

Fascioliasis is a freshwater snail-borne zoonotic disease. The Northern Bolivian Altiplano is a very high altitude endemic area where the highest human prevalences and intensities have been reported. Preventive chemotherapy by treatment campaigns is yearly applied. However, liver fluke infection of cattle, sheep, pigs and donkeys assures endemicity and consequent human infection and re-infection risks. A One Health action has therefore been implemented. Activity concerns lymnaeid vectors and environment diversity. Studies included growth, egg-laying and life span in laboratory-reared lymnaeids. Different habitat types and influencing factors were assessed. All populations proved to belong to Galba truncatula by rDNA sequencing. Analyses comprised physico-chemical characteristics and monthly follow-up of water temperature, pH and quantity, and lymnaeid abundance and density. Population dynamics in the transmission foci differed. Mean environmental temperature was lower than fluke development minimum temperature threshold, but water temperature was higher, except during winter. A two generations/year pattern appeared in permanent water habitats, and one generation/year pattern in habitats drying out for months. The multidisciplinary control measures can be extended from one part of the endemic area to another. These studies, made for the first time at very high altitude, constitute a baseline useful for fascioliasis control in other countries.

Lonomia envenomation in Brazil: an epidemiological overview for the period 2007-2018.

BACKGROUND: Among the Lepidoptera with medical importance in Brazil, larvae of Lonomia moth (Saturniidae: Hemileucinae) stand out by being the etiological agent of the lonomism, a form of erucism in which the most troubling symptoms include systemic hemorrhage that can lead to death. METHODS: This study provides an epidemiological overview of accident notifications with Lonomia registered by the Brazilian Reportable Disease Information System (SINAN) between 2007 and 2018. The categories of sociodemographic aspects of the victim, accident characteristics, and clinical data (6,636 records) were analysed by the chi-square test for goodness of fit (α=0.05). By the same test, accident frequencies by month, year, and state were also compared. To explore the spatial distribution of notifications and to identify significant space-time and purely spatial clusters, a spatial scan statistic (SaTScan) was used. RESULTS: The epidemiological profile of most of the victims had at least one of the following characteristics: male, >50 y of age, ethnically classified as white, and with a low level of education. Accidents in urban areas were as frequent as in rural areas. A higher frequency of non-work-related accidents was detected. Victims were mostly stung on the upper limbs. Most victims received medical care within the first 3 h after the accident. Most cases were classified as mild, although 12 deaths were reported. The south states of Brazil concentrate the highest frequencies of notifications. Summer was the season with the greatest number of cases, and the majority of the notifications occurred between 2017 and 2018. CONCLUSION: These results provide an overall and current situation assessment of the lonomism in Brazil, and they should enable health authorities to improve the management of this envenomation in states/regions that share the high epidemiological risk of exposure to Lonomia.

One Health initiative in the Bolivian Altiplano human fascioliasis hyperendemic area: Lymnaeid biology, population dynamics, microecology and climatic factor influences / Aplicação do conceito One Health na área hiperendêmica de fasciolíase humana do Altiplano Boliviano: biologia dos limneídeos, dinâmica populacional, microecologia e influência de fatores climáticos

Abstract Fascioliasis is a freshwater snail-borne zoonotic disease. The Northern Bolivian Altiplano is a very high altitude endemic area where the highest human prevalences and intensities have been reported. Preventive chemotherapy by treatment campaigns is yearly applied. However, liver fluke infection of cattle, sheep, pigs and donkeys assures endemicity and consequent human infection and re-infection risks. A One Health action has therefore been implemented. Activity concerns lymnaeid vectors and environment diversity. Studies included growth, egg-laying and life span in laboratory-reared lymnaeids. Different habitat types and influencing factors were assessed. All populations proved to belong to Galba truncatula by rDNA sequencing. Analyses comprised physico-chemical characteristics and monthly follow-up of water temperature, pH and quantity, and lymnaeid abundance and density. Population dynamics in the transmission foci differed. Mean environmental temperature was lower than fluke development minimum temperature threshold, but water temperature was higher, except during winter. A two generations/year pattern appeared in permanent water habitats, and one generation/year pattern in habitats drying out for months. The multidisciplinary control measures can be extended from one part of the endemic area to another. These studies, made for the first time at very high altitude, constitute a baseline useful for fascioliasis control in other countries.

Resumo A fasciolíase é uma doença zoonótica transmitida para os humanos por formas evolucionárias de Fasciola hepatica oriundas de limneídeos infectados. O Altiplano Boliviano Norte é uma área endêmica de altitude muito alta, onde foram relatadas as maiores prevalências e intensidades em infecções humanas. A quimioterapia preventiva por campanhas de tratamento é aplicada anualmente. No entanto, infecção por Fasciola hepatica em bovinos, ovelhas, suínos e asininos garante endemicidade e consequentes riscos de infecção e reinfecção humana. Portanto, ações norteadas no conceito "One Health" foram implementadas. As atividades envolveram os limneídeos e a avaliação da diversidade de ambientes. Os estudos incluíram o crescimento, postura de ovos e expectativa de vida de limneídeos criados em laboratório, bem como a avaliação da influência dos diferentes hábitats. Todas as populações foram identificadas como Galba truncatula por meio do sequenciamento de rDNA. As análises incluíram características físico-químicas e acompanhamento mensal da temperatura, pH, quantidade da água, abundância e densidade de limneídeos. A dinâmica populacional nos focos de transmissão diferiu. A temperatura ambiente média foi mais baixa do que o limite mínimo de temperatura do desenvolvimento do helminto, mas a temperatura da água foi mais alta, exceto durante o inverno. Um padrão de duas gerações/ano apareceu em hábitats com água permanente, enquanto um padrão de uma geração/ano foi observado em habitats que ficam secos durante meses. Os resultados permitem concluir que as medidas multidisciplinares de controle podem ser estendidas de uma parte da área endêmica para outra. Esses estudos, realizados pela primeira vez em altitudes muito elevadas, constituem uma base útil e extrapolável para o controle da fasciolíase.

Tasa de filtración glomerular estimada y mortalidad posterior al alta en una unidad geriátrica de agudos / Estimated glomerular filtration rate and post-hospital mortality after discharge from an acute care for the elderly unit

Objetivo: Determinar la asociación entre tasa de filtración glomerular estimada (TFGe) y mortalidad en una cohorte retrospectiva de adultos mayores hospitalizados en una unidad geriátrica de agudos (UGA). Materiales y métodos: Se incluyó a 1.678 pacientes de 60 años o más, en Cali, Colombia, de 2012 a 2015, en seguimiento hasta 2016. El desenlace primario fue mortalidad. La función renal se estimó empleando la ecuación del Modification of Diet in Renal Disease Study (MDRD-4). Se agrupó la función renal según la TFGe (ml/min/1,73m2) así: levemente disminuida (≥60), moderadamente disminuida (30-59) y severamente disminuida (<30). Se hicieron análisis de sobrevida bivariados y regresión de Cox multivariado. Resultados: En el análisis univariado, los pacientes con TFGe severamente disminuida presentaron una mortalidad significativamente mayor que aquellos con TFGe superiores (p=0,046). En el grupo con MDRD severamente disminuida, la sobrevida fue menor en el grupo dependiente (índice de Barthel [IB]<60) que en el independiente (IB≥60) (prueba log rank p=0,001). En el análisis multivariado, hay un aumento significativo del riesgo de morir en ancianos con MDRD severamente disminuida (<30) comparado con MDRD levemente disminuida (≥60) (hazard ratio [HR] 1,44; intervalo confianza [IC] 95%: 1,02-2,05; p=0,039). También hubo aumento significativo del riesgo de morir en ancianos dependientes comparados con los independientes (HR 1,72; IC 95%: 1,26-2,34; p=0,000), los que tenían a la vez morbilidad alta (≥4) con albúmina baja (<3,2g/dl) comparados con aquellos con morbilidad baja (0-3) y albúmina alta (≥3,2) (HR 1,77; IC 95%: 1,18-2,65; p=0,005) y en aquellos con PCR alta (16-102mg/dl) comparados con aquellos con PCR baja (0-15) (HR 1,42; IC 95%: 1,01-2,01; p=0,043). Conclusiones: El riesgo de mortalidad tiempo después de una hospitalización en una UGA es mayor en pacientes con TFGe<30. Las puntuaciones bajas en los índices del estado funcional, la comorbilidad alta, la hipoalbuminemia y los marcadores de inflamación son factores pronósticos adicionales a tener en cuenta. La mejoría en el estado funcional podría mejorar la sobrevida posterior a la hospitalización

Objective: To determine the relationship between estimated glomerular filtration rate (eGFR) and mortality in a retrospective cohort of older adults admitted to an acute care for the elderly (ACE) unit. Materials and methods: The study included 1,678 patients aged 60 years and over admitted to an AEC, in Cali, Colombia, from 2012 to 2015, and followed- up until 2016. The primary outcome was mortality. Renal function (eGFR) was estimated using Modification of Diet in Renal Disease Study (MDRD-4) equation. The renal function was grouped according to the eGFR (ml/min/1.73m2) as follows: slightly decreased (≥60), moderately decreased (30-59), and severely decreased (<30). Bivariate survival and multivariate Cox regression analyses were performed. Results: In the univariate analysis, patients with severely decreased eGFR had higher mortality than those with a higher eGFR (P=.046). In the group with severely decreased eGFR, survival was lower in the functionally dependent group (Barthel index [IB]<60) than in the independent group (IB≥60) (log rank test; P=.001). In the multivariate analysis, there was a significant increase in the risk of death in the elderly with severely decreased eGFR (<30) compared with slightly decreased eGFR (≥60) (hazard ratio [HR], 1.44; 95% confidence interval [CI]; 1.02-2.05, P=.039). There was also a significant increase in the risk of death in the dependent elderly compared to the independent ones [HR 1.72; 95% CI; 1.26-2.34, P=.000], those who had the high morbidity (≥4) with low albumin (<3.2g/dL) compared with those with low morbidity (0-3) and high albumin (≥3.2) [HR 1.77; 95% CI; 1.18-2.65, P=.005], and in those with a high (16-102mg/dL) C-reactive protein (CRP) compared with those with low CRP (0-15) [HR 1.42; 95% CI; 1.01-2.01, P=.043]. Conclusions: The risk of mortality after hospital admission to an AEC unit is greater in patients with eGFR<30. Poor functional status performance, high comorbidity, low plasma albumin, and increased inflammation markers are additional prognostic factors to be taken into account. The improvement in the functional status could improve the survival after hospitalisation

[Estimated glomerular filtration rate and post-hospital mortality after discharge from an acute care for the elderly unit]. / Tasa de filtración glomerular estimada y mortalidad posterior al alta en una unidad geriátrica de agudos.

OBJECTIVE: To determine the relationship between estimated glomerular filtration rate (eGFR) and mortality in a retrospective cohort of older adults admitted to an acute care for the elderly (ACE) unit. MATERIALS AND METHODS: The study included 1,678 patients aged 60 years and over admitted to an AEC, in Cali, Colombia, from 2012 to 2015, and followed- up until 2016. The primary outcome was mortality. Renal function (eGFR) was estimated using Modification of Diet in Renal Disease Study (MDRD-4) equation. The renal function was grouped according to the eGFR (ml/min/1.73m2) as follows: slightly decreased (≥60), moderately decreased (30-59), and severely decreased (<30). Bivariate survival and multivariate Cox regression analyses were performed. RESULTS: In the univariate analysis, patients with severely decreased eGFR had higher mortality than those with a higher eGFR (P=.046). In the group with severely decreased eGFR, survival was lower in the functionally dependent group (Barthel index [IB]<60) than in the independent group (IB≥60) (log rank test; P=.001). In the multivariate analysis, there was a significant increase in the risk of death in the elderly with severely decreased eGFR (<30) compared with slightly decreased eGFR (≥60) (hazard ratio [HR], 1.44; 95% confidence interval [CI]; 1.02-2.05, P=.039). There was also a significant increase in the risk of death in the dependent elderly compared to the independent ones [HR 1.72; 95% CI; 1.26-2.34, P=.000], those who had the high morbidity (≥4) with low albumin (<3.2g/dL) compared with those with low morbidity (0-3) and high albumin (≥3.2) [HR 1.77; 95% CI; 1.18-2.65, P=.005], and in those with a high (16-102mg/dL) C-reactive protein (CRP) compared with those with low CRP (0-15) [HR 1.42; 95% CI; 1.01-2.01, P=.043]. CONCLUSIONS: The risk of mortality after hospital admission to an AEC unit is greater in patients with eGFR<30. Poor functional status performance, high comorbidity, low plasma albumin, and increased inflammation markers are additional prognostic factors to be taken into account. The improvement in the functional status could improve the survival after hospitalisation.

Chronic exposure to environmental stressors enhances production of natural and specific antibodies in rats.

Although the immunosuppressive effect of chronic stress has been established, a stress response that downregulates the whole immune system does not make biological sense, especially if an animal has to endure difficult times in which there is also increased infection risk. At high animal densities, animals are faced simultaneously with food restriction (FR), social conflict (SC), and greater parasite-pathogen exposure. We hypothesized that the stress response to chronic stressors that covary with infection risk is not entirely immunosuppressive. Our prediction was that a chronically stressed animal would respond by enhancing innate defenses, while reducing investment in acquired immunity. In a laboratory setting, rats were exposed to prolonged FR and/or SC, and natural and specific antibody levels were repeatedly measured. Our prediction was fulfilled only partly, as FR and SC interacted to enhance natural antibodies, but rats exposed to either or both stressors also showed significantly higher levels of specific antibodies. These results suggest that, in the rat, chronic stress results in a prioritization of both innate and acquired humoral defenses, which makes biological sense provided the stressors examined usually signal an increased infection risk.

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.

Erythrocyte micronucleus cytome assay of 17 wild bird species from the central Monte desert, Argentina.

Birds have the potential to be considered valuable bioindicators of the quality of ecosystems and the environmental impact of pollutants. The aims of this study were to determine the micronuclei frequency and other nuclear abnormalities in erythrocytes by analyzing a wild bird community from central Monte desert (Argentina) and to clarify if there were any differences among certain species. Frequencies of nuclear abnormalities were determined in 73 wild birds belonging to 17 species and two orders (Passeriformes and Columbiformes). A high proportion of individuals, 90.4 and 80.9 %, had erythrocytes with micronuclei and nuclear buds, respectively. Notched nuclei, binucleated cells, nuclear tails, and nucleoplasmic bridges were also recorded. Certain species appeared to be more informative than others with regard to the possibility of being used as bioindicators of genetic damage. Saltator aurantiirostris and Columbina picui were the only species that showed significantly different frequencies of nuclear alterations, in comparison with the other species. The frequencies here presented are the first reported for these bird species from the orders Passeriformes and Columbiformes. This research supports the notion that the use of these biomarkers could be effectively applied to evaluate spontaneous or induced genetic instability in wild birds.

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.

Modeling the extrinsic incubation of Dirofilaria immitis in South America based on monthly and continuous climatic data.

The spread and recrudescence of dirofilariosis across several regions, either caused by Dirofilaria immitis or D. repens, responds to many factors. Building upon the temperature model by Slocombe et al. (1989), a number of studies have been performed to generate predictive models for dirofilariosis. These studies have demonstrated the length of transmission periods and the number of Dirofilaria generations supported throughout several regions of the world (either at large or at small-scale). The usual procedure have proved to be extremely time consuming, as it appears impractical when assessing potential transmission at large scale, such as at a country or large-scale level. Due to the increasing need to suggest standardized surveillance protocols and apply adequate preventive measures at national and regional levels, a model for calculation of Dirofilaria HDUs based on monthly data was adapted for large-scale regional use. The models proposed are based on both point data (meteorological stations) and interpolated climate data layers (WorldClim). Three different models (daily and monthly models based on point data, and monthly model based on continuous data) were developed and compared statistically. When compared with the results from the classical daily model, the monthly models proposed accurately predicted the locations were extrinsic incubation was possible. These models proved to be adequate for the regional analysis of the extrinsic incubation of D. immitis and, hence, the relative risk of transmission in South America. Further, these models confirm that favorable temperatures for heartworm transmission in South America are present in most of the countries. D. immitis extrinsic incubation follows a seasonal pattern in Argentina, Chile, Uruguay, eastern Paraguay and southeastern Brazil; while in northern half of South America (less than 25° S) transmission may occur year-round. Moreover, high risk areas suitable for dirofilariasis transmission are not geographically constant throughout the year. The validation procedures indicate that the predicted HDU and HG maps are good predictors of dirofilariosis potential distribution, but estimating dirofilariosis prevalences based on them might not be completely accurate. The resulting distribution and seasonal maps would be useful for heartworm prevention by chemoprophylaxis in different regions known to be endemic for canine dirofilariasis. The information here provided can be an important tool in veterinary public health, as well as a guide for future research.

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.

Sequence analysis of the internal transcribed spacer 2 (ITS2) from Philornis seguyi (García, 1952) and Philornis torquans (Nielsen, 1913) (Diptera: Muscidae).

Philornis Meinert, 1890 (Diptera: Muscidae) is a genus of Neotropical dipterans that parasitise birds. The currently used external morphological characters to distinguish between species within this genus present some limitations. We used the second internal transcribed spacer region (ITS2) of the rRNA gene as a molecular marker to differentiate adult specimens of Philornis identified morphologically as Philornis torquans and Philornis seguyi from different localities. Specimens identified as P. seguyi from Magdalena (Buenos Aires Province) showed an ITS2 sequence different from that for P. torquans, whereas all other specimens of P. seguyi had sequences identical to those for P. torquans. These findings do not necessarily confirm that specimens from Magdalena indeed belong to P. seguyi, nor that P. seguyi is a valid species. Instead, they alert us about the potential for species misidentification when using morphological characters alone. The use of molecular approaches to aid the identification of Philornis spp. will shed light on the systematics of this group. P. torquans is reported for the first time in Mendoza Province and Uruguay.

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.

Human fascioliasis in Argentina: retrospective overview, critical analysis and baseline for future research.

In Argentina, human fascioliasis has never been adequately analysed, although having a physiography, climate, animal prevalences and lymnaeids similar to those of countries where the disease is endemic such as Bolivia, Peru and Chile. We performed a literature search identifying 58 reports accounting for 619 cases, involving 13 provinces, their majority (97.7%) from high altitudes, in central mountainous areas and Andean valleys, concentrated in Cordoba (430 cases), Catamarca (73), San Luis (29) and Mendoza (28), the remaining provinces being rarely affected. This distribution does not fit that of animal fascioliasis. Certain aspects (higher prevalence in females in a local survey, although a trend non-significant throughout Argentina) but not others (patient's age 3-95 years, mean 37.1 years) resemble human endemics in Andean countries, although the lack of intensity studies and surveys in rural areas does not allow for an adequate evaluation. Human infection occurs mainly in January-April, when higher precipitation and temperatures interact with field activities during summer holidays. A second June peak may be related to Easter holidays. The main risk factor appears to be wild watercress ingestion (214) during recreational, weekend outings or holiday activities, explaining numerous family outbreaks involving 63 people and infection far away from their homes. Diagnosis mainly relied on egg finding (288), followed by serology (82), intradermal reaction (63), surgery (43), and erratic fluke observation (6). The number of fascioliasis-hydatidosis co-infected patients (14) is outstanding. Emetine appears as the drug most used (186), replaced by triclabendazole in recent years (21). Surgery reports are numerous (27.0%). A long delay in diagnosis (average almost 3.5 years) and high lithiasis proportion suggest that many patients are frequently overlooked and pose a question mark about fascioliasis detection in the country. High seroprevalences found in recent random surveys suggest human endemic situations. This analysis highlights that human fascioliasis may have been overlooked in the past and its real epidemiological situation in high risk rural, mainly altitudinal areas, may currently be underestimated. Results provide a valuable baseline on which to design appropriate multidisciplinary studies on humans, animals and lymnaeids to assess up to which level and in which areas, human fascioliasis may represent a health problem in Argentina.

Natural Fasciola hepatica infection in nutria (Myocastor coypus) in Uruguay.

Fascioliasis, the zoonotic disease caused by the trematode Fasciola hepatica, is expanding worldwide, with a 17 million people at risk. Rodents, often recognized as a major source of zoonotic diseases, are affected by F. hepatica, with some species playing important roles in the disease epidemiology. The case reported here in a nutria or kiyá (Myocastor coypus) is the first documented case of F. hepatica in this species in Uruguay. Parasitic burden and total egg production detected are markedly higher than reported previously for this species, confirming its potential role as an effective reservoir and disseminator of liver flukes. Although further research is needed, nutria should be considered when designing effective control programs for fascioliasis.