Differential diagnosis of human Entamoeba infections: Morphological and molecular characterization of new isolates in Argentina.

Entamoeba infections occur worldwide, with higher frequency in countries of low socioeconomic status and poor public health. Since Entamoeba histolytica has long been recognized as the only pathogenic species, making a differential diagnosis of other morphologically identical Entamoeba is important. This study aimed to determine the prevalence of Entamoeba species in two populations from Argentina, make a differential diagnosis by PCR and characterize Entamoeba isolates at the SSU rRNA gene. A total of 493 serial fecal samples were obtained from individuals in the provinces of Buenos Aires (n=210) and Misiones (n=283). Samples were examined by conventional methods (formalin-ethyl acetate and Willis flotation) and specific PCRs to differentiate Entamoeba species. Entamoeba isolates were characterized by sequencing a fragment of the SSU rRNA gene. The overall prevalence of Entamoeba infection was 12.4%, being more prevalent in Buenos Aires than in Misiones (14.8% vs. 10.6%). A case of E. histolytica confirmed by PCR and sequence analysis was reported for the first time in Buenos Aires. Moreover, new genetic data on Entamoeba coli and Entamoeba dispar were recorded. The phylogenetic analysis revealed a congruence between morphological characteristics and SSU rRNA gene sequences. This study increases the amount of information on the distribution of these species in Argentina and the region of the Americas.

Phylogenetic relationship between Contracaecum spp. (Nematoda, Anisakidae) parasitizing cormorants (Aves, Phalacrocoracidae) in Argentina.

Species of the genus Contracaecum (Family Anisakidae) exhibit a broad host and geographical distribution, parasitizing aquatic organisms such as piscivorous birds and mammals as their definitive hosts. Several Contracaecum species have been reported parasitizing cormorants (Family: Phalacrocoracidae) in South America. The objective of this study was to highlight phylogenetic relationships between Contracaecum species parasitizing cormorants based on both molecular analyses and the papillae arrangement on the male tail. Some Contracaecum species parasitizing Red-legged cormorants from the Ría Deseado (RD), and other nematodes parasitizing eight Neotropic cormorants from San Miguel del Monte lagoon (SMML), Argentina, were collected and analyzed. Both morphological and phylogenetic analyses allowed us to recognize two species: Contracaecum chubutensis parasitizing Phalacrocorax gaimardi, and Contracaecum australe parasitic in Phalacrocorax brasilianus. According to the obtained sequences (mtDNA cox2, ITS1, ITS2, and SSrRNA), Contracaecum sp. parasitizing P. gaimardi exhibited concordance with the previously reported C. chubutensis parasitizing P. atriceps from Bahía Bustamante, Chubut province. Likewise, Contracaecum sp. isolates parasitizing P. brasilianus showed concordance with C. australe from Chile. Besides, the papillae arrangement on the male tail allowed us to understand the interspecific and genetic relationships between the Contracaecum species. The analyses confirm that C. chubutensis specimens parasitizing P. gaimardi from RD present a new host record for the species, whereas, those C. australe specimens parasitizing P. brasilianus from SMML provide a new geographical record for the species and the extension of its distribution range. Present results also confirm the inland and marine distribution of C. australe and C. chubutensis, respectively.

The genus Contracaecum Raillet & Henry (Nematoda: Anisakidae): host and geographical distribution on Neotropical and Antarctic species.

Nematodes of the genus Contracaecum Raillet & Henry, 1912 (Anisakidae, Contracaecinae) have a worldwide distribution. The taxonomy of the genus Contracaecum is well-known nowadays due to several morphometric studies, scanning electron microscopy, and molecular biology. The aim of this work was to review, clarify, and summarize the valid species of the genus Contracaecum parasitizing piscivorous sea birds and mammals from both the Neotropical and Antarctic regions reviewing all scientific available papers and electronic searching data up to date. A checklist on Neotropical and Antarctic Contracaecum spp. was organized through a revision of scientific papers and original descriptions. The systematic online search and the most updated papers were obtained through SCOPUS, Google Scholar, PubMed, Medline, World Register of Marine Species, etc. We provide information about hosts, Neotropical and Antarctic localities where worms were collected, references, molecular markers, and Genbank accession numbers. Twenty-five Neotropical and Antarctic Contracaecum species have been recorded up to date and checked out as valid ones according to the most updated data. Twenty-one species parasitize exclusively fish-eating birds, two species were reported only on marine mammals, and the other two parasitize both sea birds and mammals. A total of 20 Contracaecum species are exclusively reported for the Neotropical region, three only for Antarctic hosts, and two species were reported parasitizing both Neotropical and Antarctic hosts. Several Contracaecum species (10) have been corroborated by molecular analysis of different genetic markers. After reviewing all morphological descriptions of the Contracaecum species, and despite most of them have been characterized only by morphometric methods, we are convinced that all species listed in this work correspond to good and valid Contracaecum Neotropical and Antarctic species. Present results indicate that more taxonomic and molecular studies are needed to advance the understanding of the distribution and host specificity of the Contracaecum species.

Human hookworms from Argentina: Differential diagnosis of Necator americanus and Ancylostoma duodenale in endemic populations from Buenos Aires and Misiones / Ancylostomideos humanos de Argentina: Diagnóstico diferencial de Necatoramericanus y Ancylostoma duodenale en poblaciones endémicas de Buenos Aires yMisiones

Abstract Hookworm infection is endemic in many countries throughout the world; however,the information about the prevalence of each species, Necator americanus and Ancylostomaduodenale, is inaccurate in many South American countries. We aimed to determine the preva-lence of human hookworm species by combining the results of both microscopy and PCR amongendemic populations in Argentina, represented by natives and immigrants. A total of 140 serialfecal specimens were obtained from natives in the province of Misiones and an immigrantcommunity living in the province of Buenos Aires. Samples were examined using the formalin-ethyl acetate concentration technique (FECT) and one flotation technique (screening tests)and specific PCRs for N. americanus and A. duodenale. We characterized samples containingN. americanus by sequencing a fragment of the cytochrome b gene. The observed hookwormprevalence as assessed by the screening tests and PCR were 24.3% and 32.8%, respectively. PCRpositive samples were identified as N. americanus. PCR had 100% sensitivity compared with73.9% of screening tests. A total of 12 samples from individuals with hookworm-infected house-hold members were positive only by PCR. N. americanus sequences showed 90.5% identity, beingmore similar to each other than to any of the sequences obtained from GenBank. This is thefirst study that provides molecular data and characterization of N. americanus in Argentina.The complementary use of FECT and one flotation technique to screen hookworm infections,followed by PCR to differentiate the species contribute to produce better prevalence estimates.

Resumen La infección por Ancylostomideos es endémica en muchos países del mundo, pero la información sobre la prevalencia de las especies que la causan, Necator americanus y Ancylostoma duodenale, es inexacta en América del Sur. Nuestro objetivo fue determinar la prevalencia de especies de Ancylostomideos humanos en poblaciones de Argentina nativas o provenientes de áreas endémicas, combinando los resultados de microscopía y PCR. Un total de 140 muestras fecales seriadas fueron obtenidas de individuos nacidos en la provincia de Misiones con residencia en esta y de miembros de una comunidad oriunda del Paraguay establecida en la provincia de Buenos Aires. Las muestras fueron examinadas por la técnica de formol-acetato de etilo (FAE) y una técnica de flotación como pruebas de cribado, y se efectuaron PCR específicas para N. americanus y A. duodenale. Caracterizamos muestras que contienen N. americanus secuenciando un fragmento del gen del citocromo b. La prevalencia de Ancylostomideos según las pruebas de cribado y el método PCR fueron del 24,3 y 32,8%, respectivamente. Las muestras positivas por PCR se identificaron como N. americanus. La PCR tuvo una sensibilidad del 100,0% en comparación con el 73,9% de las pruebas de detección. Hubo 12 muestras de individuos con miembros de la familia infectados con anquilostomas que solo por PCR fueron positivas. Las secuencias de N. americanus mostraron un 90,5% de identidad y fueron más similares entre sí que a cualquiera de las secuencias obtenidas de GenBank. Este es el primer estudio que proporciona datos moleculares y la caracterización de N. americanus en Argentina. El uso complementario de FAE y una técnica de flotación para detectar infecciones por anquilostomas, seguido de PCR para diferenciar las especies, contribuye a producir mejores estimaciones de prevalencia.

Update of Dicrocoeliidae (Digenea) parasitizing rodents from the Americas with a description of a new Platynosomoides species from Argentina.

Digeneans are common parasites of small mammals. Dicrocoeliidae is a family with a cosmopolitan distribution, with 18 genera previously recorded from mammals in the Americas, six of them parasitizing rodents in Argentina. In this study, an updated compilation is provided of Dicrocoeliidae from rodents in the Americas. Also, a new Platynosomoides species is described parasitizing the cricetid rodent Akodon montensis of the Atlantic Forest in Argentina. Digital repositories were used to search for Dicrocoeliidae from rodents in the Americas. Rodents were collected in four localities of the Atlantic Forest, Argentina. Digeneans were removed from the rodent's bile duct, and conventional studies were used for the morphological description. A total of 15 Dicrocoeliidae species were found parasitizing 18 rodent species from eight countries in the Americas. The new species of Platynosomoides from Akodon montensis differs from the other two species of genus by the size of body, testes, ovary, cecum length and position and length of the vitelline bands. Dicrocoeliidae show growing diversity, and the compilation of species in a rodent host base allows a clearer comparison and identification of new taxa in the future.

Human hookworms from Argentina: Differential diagnosis of Necator americanus and Ancylostoma duodenale in endemic populations from Buenos Aires and Misiones.

Hookworm infection is endemic in many countries throughout the world; however, the information about the prevalence of each species, Necatoramericanus and Ancylostomaduodenale, is inaccurate in many South American countries. We aimed to determine the prevalence of human hookworm species by combining the results of both microscopy and PCR among endemic populations in Argentina, represented by natives and immigrants. A total of 140 serial fecal specimens were obtained from natives in the province of Misiones and an immigrant community living in the province of Buenos Aires. Samples were examined using the formalin-ethyl acetate concentration technique (FECT) and one flotation technique (screening tests) and specific PCRs for N. americanus and A. duodenale. We characterized samples containing N. americanus by sequencing a fragment of the cytochrome b gene. The observed hookworm prevalence as assessed by the screening tests and PCR were 24.3% and 32.8%, respectively. PCR positive samples were identified as N. americanus. PCR had 100% sensitivity compared with 73.9% of screening tests. A total of 12 samples from individuals with hookworm-infected household members were positive only by PCR. N. americanus sequences showed 90.5% identity, being more similar to each other than to any of the sequences obtained from GenBank. This is the first study that provides molecular data and characterization of N. americanus in Argentina. The complementary use of FECT and one flotation technique to screen hookworm infections, followed by PCR to differentiate the species contribute to produce better prevalence estimates.

Nutritional status, intestinal parasitic infections, and socio-environmental conditions in Mbyá-guaraní children: The current situation in communities in central Misiones, Argentina.

OBJECTIVES: Our previous research in Mbyá-guaraní communities of central Misiones showed high levels of growth stunting and intestinal parasites in children, as well as associations between these variables and deficient sanitary conditions. New studies were necessary to update the present health status of the previously studied Mbyá populations after around two decades. Therefore, we evaluated the current nutritional status, intestinal parasites, and socio-environmental conditions among Mbyá-guaraní children from these communities. METHODS: Body weight and height of 102 individuals (aged 2-14) were measured and nutritional status was estimated according to the World Health Organization criteria. Serial fecal samples and anal swabs were analyzed from 75 children (aged 1-14). Socio-environmental data were obtained from questionnaires. RESULTS: The prevalence of undernutrition was 31.4% and excess of weight was 10.8%. The prevalence of stunting and of overweight reached 30.4% and 8.8%, respectively. About 85% of the children were infected with at least one of the 14 species identified, and around 44% had multiple parasite infections. The most prevalent species were Enterobius vermicularis and hookworms. Among undernourished children, 88.2% were parasitized by at least one of the potentially pathogenic species detected. Most of the families lived in overcrowded conditions in precarious houses, defecated in latrines, and consumed well water. A higher risk of parasitosis was associated with the source of drinking water. CONCLUSIONS: Although the prevalence of undernutrition and intestinal parasites decreased compared with our previous studies, we still observed the coexistence of stunting, excess weight, and parasitic infections, in a context of socio-environmental vulnerability.

Cestode Parasites of Armadillos (Mammalia: Xenarthra) from Argentina: Two New Species of Mathevotaenia (Anoplocephalidae) in Tolypeutes matacus.

A total of 20 specimens of Tolypeutes matacus (Desmarest, 1804) from the Chaco Region in Argentina were examined. This study revealed the presence of 3 species of the genus Mathevotaenia Akumyan, 1946 (Cestoda Anoplocephalidae), two of them new for science. These species are described, illustrated, and compared with related species. Mathevotaenia chamicalensis n. sp. is characterized by having a small body with 45-65 proglottids; a globose scolex, longer than wide and well delimited from strobila; a long neck; mature and gravid proglottids longer than wide; and 20-35 testes located in a single field. Mathevotaenia yepesi n. sp. is characterized by having a small body with 86-128 proglottids; a rectangular scolex, wider than long and not well delimited from strobila; neck absent; mature and gravid proglottids wider than long; and 23-50 testes located in the medial portion of the proglottid. The finding of Mathevotaenia argentinensis Campbell et al., 2003 parasitizing T. matacus represents the first record in armadillos.

Intestinal parasitosis, undernutrition and socio-environmental factors in schoolchildren from Clorinda Formosa, Argentina / Parasitosis intestinal, desnutrición y factores socio-ambientales en niños escolares de Clorinda Formosa, Argentina

ABSTRACT Objective To evaluate intestinal parasitosis, undernutrition and socio-environmental factors in schoolchildren from Clorinda (Formosa, Argentina). Materials and Methods Serial fecal samples and anal swabs of 114 schoolchildren, canine feces and soil samples were analyzed. Body weight and height of 215 schoolchildren were measured and undernutrition was estimated according to the World Health Organization criteria. Socio-environmental variables were assessed by means of a semi-structured questionnaire. Results 78.1% of children were infected by at least one of the 12 species identified and 70.8% had multiple parasitic infections. Blastocystis sp., Giardia lamblia and Enterobius vermicularis were the most prevalent. Additionally, 17.5% of children were infected by at least one geohelminth (e.g. Ascarislumbricoides, Trichuris trichiura, hookworms). 64.3% of canine of canine feces were positive and six parasitic species were found; the most frequent were Ancylostoma caninum, Uncinaria stenocephala and G. lamblia. Furthermore, 37.5% of soil samples showed zoonotic parasites (i.e. Ascaris sp., Toxocara sp.). Finally, 10.0% of the children were undernourished and 85.7% of them had parasites. The risk for parasitosis was higher in children that lived in houses with inadequate solid waste disposal and whose parents were unemployed or had temporary jobs. Conclusions The lack of environmental sanitation, unstable employment of parents and the presence of zoonotic species were the most relevant factors observed. Consequently, these conditions result in an increase of parasitic infections and negatively influence the growth of children.(AU)

RESUMEN Objetivo Evaluar la parasitosis intestinal, la desnutrición y los factores socio-ambientales en escolares de Clorinda (Formosa, Argentina). Materiales y Métodos Se analizaron muestras fecales y escobillados anales seriados de 114 escolares, heces caninas y muestras de suelo. Se midió el peso corporal y la talla de 215 escolares y se evaluó la desnutrición según los criterios de la Organización Mundial de la Salud. Las variables socio-ambientales se evaluaron mediante una encuesta semiestructurada. Resultados El 78,1% de los niños estuvieron parasitados por al menos 1 de las 12 especies identificadas y el 70,8% presentó parasitosis múltiples. Blastocystis sp., Giardia lamblia y Enterobius vermicularis fueron las más prevalentes. Además, el 17,5% de los niños estaban infectados con al menos un geohelminto (e.g. Ascaris lumbricoides, Trichuris trichiura, ancylostomideos). El 64,3% de las heces caninas resultaron positivas y se encontraron seis especies parasitarias; las más frecuentes fueron Ancylostoma caninum, Uncinaria stenocephala y G. lamblia. Además, el 37,5% de las muestras de suelo mostraron parásitos zoonóticos (i.e. Ascaris sp., Toxocara sp.). Finalmente, el 10% de los niños estaban desnutridos y el 85,7% de ellos resultaron parasitados. El riesgo de parasitosis fue mayor en los niños que vivían en casas con eliminación inadecuada de desechos sólidos y cuyos padres estaban desempleados o tenían empleos temporales. Conclusiones La falta de saneamiento ambiental, el empleo inestable de los padres y la presencia de especies zoo-nóticas fueron los factores observados más relevantes. En consecuencia, estas condiciones resultan en un aumento de las infecciones parasitarias e influyen negativamente en el crecimiento de los niños.(AU)

Species of Contracaecum Parasitizing the Magellanic Penguin Spheniscus magellanicus (Spheniscidae) from the Argentinean Coast.

Anisakid nematodes have a worldwide distribution and are associated with fishes, birds, and marine mammals from freshwater, brackish, and marine systems. The aims of this work are to report for the first time Contracaecum mirounga parasitizing the Magellanic penguin Spheniscus magellanicus, to report another Contracaecum species in the same host species, and to discuss the validity of Contracaeceum spheniscus. Several dead chicks, juveniles, and adults of S. magellanicus were collected along the Argentinean coast from 2002 to 2009. Nematodes were removed from digestive tracts and studied using both light and scanning electron microscopy. Nematode prevalences were 2.38% for C. mirounga and 12.5% for Contracaecum sp. Contracaecum mirounga was found in 1 penguin from Península Valdés, Chubut. This species is known as a specific parasite of marine mammals such as Pinnipedia, thereby suggesting that this nematode is not as specific as believed. Another species of Contracaecum sp. was found parasitizing 1 penguin from the Río de la Plata coast. It possessed an unusual interlabial morphology and arrangement of male caudal papillae. Despite the low prevalence, the distinct morphological features are convincing and support the presence of a new Contracaecum species. However, a formal description is not presented because sufficient male specimens are lacking. Finally, C. spheniscus is considered a junior synonym of Contracaecum pelagicum. Future molecular studies might be helpful to determine the real diversity of Contracaecum species parasitizing S. magellanicus considering the number of sibling species recognized among the anisakids.

Intestinal parasitosis, undernutrition and socio-environmental factors in schoolchildren from Clorinda Formosa, Argentina.

OBJECTIVE: To evaluate intestinal parasitosis, undernutrition and socio-environmental factors in schoolchildren from Clorinda (Formosa, Argentina). MATERIALS AND METHODS: Serial fecal samples and anal swabs of 114 schoolchildren, canine feces and soil samples were analyzed. Body weight and height of 215 schoolchildren were measured and undernutrition was estimated according to the World Health Organization criteria. Socio-environmental variables were assessed by means of a semi-structured questionnaire. RESULTS: 78.1% of children were infected by at least one of the 12 species identified and 70.8% had multiple parasitic infections. Blastocystis sp., Giardia lamblia and Enterobius vermicularis were the most prevalent. Additionally, 17.5% of children were infected by at least one geohelminth (e.g. Ascarislumbricoides, Trichuris trichiura, hookworms). 64.3% of canine of canine feces were positive and six parasitic species were found; the most frequent were Ancylostoma caninum, Uncinaria stenocephala and G. lamblia. Furthermore, 37.5% of soil samples showed zoonotic parasites (i.e. Ascaris sp., Toxocara sp.). Finally, 10.0% of the children were undernourished and 85.7% of them had parasites. The risk for parasitosis was higher in children that lived in houses with inadequate solid waste disposal and whose parents were unemployed or had temporary jobs. CONCLUSIONS: The lack of environmental sanitation, unstable employment of parents and the presence of zoonotic species were the most relevant factors observed. Consequently, these conditions result in an increase of parasitic infections and negatively influence the growth of children.

A checklist of the helminth parasites of sympatric rodents from two Mayan villages in Yucatán, México.

In this survey, 19 species of helminths including Cestoda (Davaineidae, Hymenolepididae, and Taeniidae), Acanthocephala (Oligacanthorhynchidae), and Nematoda (Trichuridae, Ornithostrongylidae, Heligmonellidae, Oxyuridae, and Gongylonematidae) from Rattus rattus, Mus musculus, Sigmodon toltecus, Heteromys gaumeri, and Peromyscus yucatanicus in two Mayan villages in Yucatán, México, were recorded. Ten species of helminths were collected in both localities. The highest species richness was recorded in R. rattus from Xkalakdzonot (6 taxa). Twelve species are new records for Yucatán and two are registered for the first time in México. This survey constitutes the first checklist of helminth parasites in small rodents in the south-southeast of México.

Angiostrongylus spp. in the Americas: geographical and chronological distribution of definitive hosts versus disease reports

BACKGROUND Angiostrongyliasis is an infection caused by nematode worms of the genus Angiostrongylus. The adult worms inhabit the pulmonary arteries, heart, bronchioles of the lung, or mesenteric arteries of the caecum of definitive host. Of a total of 23 species of Angiostrongylus cited worldwide, only nine were registered in the American Continent. Two species, A. cantonensis and A. costaricensis, are considered zoonoses when the larvae accidentally parasitise man. OBJECTIVES In the present study, geographical and chronological distribution of definitive hosts of Angiostrongylus in the Americas is analysed in order to observe their relationship with disease reports. Moreover, the role of different definitive hosts as sentinels and dispersers of infective stages is discussed. METHODS The study area includes the Americas. First records of Angiostrongylus spp. in definitive or accidental hosts were compiled from the literature. Data were included in tables and figures and were matched to geographic information systems (GIS). FINDINGS Most geographical records of Angiostrongylus spp. both for definitive and accidental hosts belong to tropical areas, mainly equatorial zone. In relation to those species of human health importance, as A. cantonensis and A. costaricensis, most disease cases indicate a coincidence between the finding of definitive host and disease record. However, in some geographic site there are gaps between report of definitive host and disease record. In many areas, human populations have invaded natural environments and their socioeconomic conditions do not allow adequate medical care. MAIN CONCLUSIONS Consequently, many cases for angiostrongyliasis could have gone unreported or unrecognised throughout history and in the nowadays. Moreover, the population expansion and the climatic changes invite to make broader and more complete range of observation on the species that involve possible epidemiological risks. This paper integrates and shows the current distribution of Angiostrongylus species in America, being this information very relevant for establishing prevention, monitoring and contingency strategies in the region.

Angiostrongylus spp. in the Americas: geographical and chronological distribution of definitive hosts versus disease reports.

BACKGROUND: Angiostrongyliasis is an infection caused by nematode worms of the genus Angiostrongylus. The adult worms inhabit the pulmonary arteries, heart, bronchioles of the lung, or mesenteric arteries of the caecum of definitive host. Of a total of 23 species of Angiostrongylus cited worldwide, only nine were registered in the American Continent. Two species, A. cantonensis and A. costaricensis, are considered zoonoses when the larvae accidentally parasitise man. OBJECTIVES: In the present study, geographical and chronological distribution of definitive hosts of Angiostrongylus in the Americas is analysed in order to observe their relationship with disease reports. Moreover, the role of different definitive hosts as sentinels and dispersers of infective stages is discussed. METHODS: The study area includes the Americas. First records of Angiostrongylus spp. in definitive or accidental hosts were compiled from the literature. Data were included in tables and figures and were matched to geographic information systems (GIS). FINDINGS: Most geographical records of Angiostrongylus spp. both for definitive and accidental hosts belong to tropical areas, mainly equatorial zone. In relation to those species of human health importance, as A. cantonensis and A. costaricensis, most disease cases indicate a coincidence between the finding of definitive host and disease record. However, in some geographic site there are gaps between report of definitive host and disease record. In many areas, human populations have invaded natural environments and their socioeconomic conditions do not allow adequate medical care. MAIN CONCLUSIONS: Consequently, many cases for angiostrongyliasis could have gone unreported or unrecognised throughout history and in the nowadays. Moreover, the population expansion and the climatic changes invite to make broader and more complete range of observation on the species that involve possible epidemiological risks. This paper integrates and shows the current distribution of Angiostrongylus species in America, being this information very relevant for establishing prevention, monitoring and contingency strategies in the region.

A New Rictulariid (Nematoda: Spirurida) in Xenarthrans from Argentina and New Morphological Data of Pterygodermatites ( Paucipectines) Chaetophracti.

Pterygodermatites is a cosmopolitan genus of nematodes from mammals, and it is frequently encountered in the parasite fauna of armadillos (Mammalia, Xenarthra, Cingulata). In this work, a new species, Pterygodermatites ( Paucipectines) argentinensis, is described, and new morphometric data, new host records, and the geographical distribution of Pterygodermatites ( Paucipectines) chaetophracti are provided. We examined 109 hosts belonging to Chaetophractus vellerosus, Chaetophractus villosus, Cabassous chacoensis, Dasypus hybridus, Tolypeutes matacus, and Zaedyus pichiy, from several regions of Argentina. Pterygodermatites ( Paucipectines) argentinensis can be distinguished from P. ( P.) chaetophracti by the morphology and size of esophageal teeth of both sexes, by subequal and longer spicules, by having only 1 precloacal cuticular semicircular fan in males, and by a greater number of cuticular processes in females. Cabassous chacoensis and Zaedyus pichiy are new hosts for Pterygodermatites ( P.) chaetophracti.

Malnutrition and body composition in urban and rural schoolchildren: A cross-sectional study in San Rafael, Mendoza (Argentina).

OBJECTIVES: The aim of the present study was to analyze the nutritional status and body composition of children from San Rafael, Mendoza, avoiding urban and rural categorization by generating subpopulations as a function of their socio-environmental characteristics. METHODS: A cross-sectional study was performed in 3,596 schoolchildren from 4.0 to 13.9 years of age. Body weight, height, upper arm circumference, and triceps skinfold were measured. Body mass index, total muscle, and fat areas of the arm were calculated. To estimate nutritional status and body composition, the NHANES III reference was used. The socio-environmental variables were surveyed using a structured questionnaire. These variables were processed by categorical principal-component analysis (catPCA). RESULTS: The catPCA allowed the differentiation of four groups, three with urban characteristics (high urban, medium urban, impoverished urban), and a rural group. Stunting occurred at a higher rate in the impoverished urban group, and the occurrence of underweight children was higher in the rural group. The prevalence of excess weight varied in the range of 20-26%. The latter value corresponded to children of the high urban group, who also did not show reduced muscle mass. CONCLUSION: Children from San Rafael presented differences in nutritional condition and body composition associated with pronounced socio-environmental heterogeneity. Thus, we could observe a gradient from the "high urban" group, with better social, economic, and sanitation conditions and at the same time a more obesogenic environment to the "impoverished urban" and "rural" groups, whose vulnerability reflected a higher prevalence of child undernutrition and the association with excess weight and reduced muscle mass. Am. J. Hum. Biol. 28:796-803, 2016. © 2016Wiley Periodicals, Inc.

New host, geographic records, and histopathologic studies of Angiostrongylus spp (Nematoda: Angiostrongylidae) in rodents from Argentina with updated summary of records from rodent hosts and host specificity assessment.

To date, 21 species of the genus Angiostrongylus (Nematoda: Angiostrongylidae) have been reported around the world, 15 of which are parasites of rodents. In this study, new host, geographic records, and histopathologic studies of Angiostrongylus spp in sigmodontine rodents from Argentina, with an updated summary of records from rodent hosts and host specificity assessment, are provided. Records of Angiostrongylus costaricensis from Akodon montensis and Angiostrongylus morerai from six new hosts and geographical localities in Argentina are reported. The gross and histopathologic changes in the lungs of the host species due to angiostrongylosis are described. Published records of the genus Angiostrongylus from rodents and patterns of host specificity are presented. Individual Angiostrongylus species parasitise between one-19 different host species. The most frequent values of the specificity index (STD) were between 1-5.97. The elevated number of host species (n = 7) of A. morerai with a STD = 1.86 is a reflection of multiple systematic studies of parasites from sigmodontine rodents in the area of Cuenca del Plata, Argentina, showing that an increase in sampling effort can result in new findings. The combination of low host specificity and a wide geographic distribution of Angiostrongylus spp indicates a troubling epidemiological scenario although, as yet, no human cases have been reported.

New host, geographic records, and histopathologic studies ofAngiostrongylus spp (Nematoda: Angiostrongylidae) in rodents from Argentina with updated summary of records from rodent hosts and host specificity assessment

To date, 21 species of the genus Angiostrongylus (Nematoda: Angiostrongylidae) have been reported around the world, 15 of which are parasites of rodents. In this study, new host, geographic records, and histopathologic studies of Angiostrongylus spp in sigmodontine rodents from Argentina, with an updated summary of records from rodent hosts and host specificity assessment, are provided. Records of Angiostrongylus costaricensis from Akodon montensis andAngiostrongylus morerai from six new hosts and geographical localities in Argentina are reported. The gross and histopathologic changes in the lungs of the host species due to angiostrongylosis are described. Published records of the genus Angiostrongylus from rodents and patterns of host specificity are presented. Individual Angiostrongylusspecies parasitise between one-19 different host species. The most frequent values of the specificity index (STD) were between 1-5.97. The elevated number of host species (n = 7) of A. morerai with a STD = 1.86 is a reflection of multiple systematic studies of parasites from sigmodontine rodents in the area of Cuenca del Plata, Argentina, showing that an increase in sampling effort can result in new findings. The combination of low host specificity and a wide geographic distribution of Angiostrongylus spp indicates a troubling epidemiological scenario although, as yet, no human cases have been reported.

Rediscovery and New Morphological Data on Two Hassalstrongylus (Nematoda: Heligmonellidae) Coparasitic in the Marsh Rat Holochilus chacarius (Rodentia: Cricetidae) from Argentina.

Two species of Hassalstrongylus Durette-Desset, 1971, coparasitic in Holochilus chacarius Thomas (Rodentia, Cricetidae) and not recorded since their original description in 1937, were newly found in their type host and locality. Hassalstrongylus mazzai (Freitas, Lent and Almeida, 1937) and Hassalstrongylus argentinus (Freitas, Lent and Almeida, 1937) were obtained from Ho. chacarius from 2 different populations: one from Salta Province (northwest Argentina) and another from Chaco Province (northeast Argentina). The species described as Heligmonoides mazzai Freitas, Lent and Almeida, 1937 had been transferred to Hassalstrongylus even though its synlophe had never been studied. We provide the first descriptions and illustrations of the synlophe of males and females of Hassalstrongylus mazzai and the female of H. argentinus and account for morphological and metrical variability. We confirm, through the study of the synlophe, the placement of Hassalstrongylus mazzai in the genus Hassalstrongylus and designate neotypes for the species because the type material deposited by the authors could not be found. Females of both species were morphologically very similar, and a principal components analysis (PCA) performed on some morphometrical characters showed that the body length, uterus length, and an unexpected character as the number of eggs were useful characters in the discrimination of both species.

[Spatial distribution of intestinal parasites in the City of La Plata, Argentina]. / Distribución espacial de las parasitosis intestinales en la Ciudad de La Plata, Argentina.

Parasitosis analysis at regional levels is simplified by the use of the Geographic Information System (GIS), which enables the identification of areas with different degrees of vulnerability. We analyzed the spatial distribution of intestinal parasites in La Plata district and their relationship with socio-environmental conditions in order to identify areas with different degrees of epidemiological risk. An epidemiological survey was completed; stool samples were collected and analyzed by Ritchie's method. Levels of precariousness and vulnerability (Iv rate) were calculated and compared to the parasitological results. Parasitological and environmental analysis were carried out on a total of 653 individuals, of whom 585 (89.6%) were children and 68 (10.4%) adults. The analysis indicated that the most vulnerable (Iv = 3-4) were those located in areas with less access to urban infrastructure services. The Iv was strongly associated with the overall prevalence of intestinal parasitosis and the 4 pathogenic species related to the fecal contamination of the environment: Trichuris trichiura, Ascaris lumbricoides, Hymenolepis nana and Giardia lamblia (p < 0.01). On the other hand, Enterobius vermicularis, a parasite not related to the sanitary condition of its host, was not associated with the Iv. Statistical association between poverty and parasitosis was noted; the greater the Iv, higher the incidence of parasites (p < 0.01). GIS allowed zoning socio-environmental variables in an increasing gradient of unfavorable conditions and their relationship to the presence of pathogenic species. The continuity of these studies in different regions of Argentina contributes to the determination of health risk areas.