The aim of this study was to describe the infection levels of helminths of Rattus rattus in Corrientes city, Corrientes Province, Argentina. In order to determine the role of rodents as potential reservoirs for zoonotic parasites, different indices of helminth infection were assessed with respect to sex, age, season and urban landscapes. A total of 107 individuals of R. rattus were examined. Seven species of helminths were found. The values of total prevalence, mean intensity and mean abundance were 68%, 20 and 13, respectively. Nippostrongylus brasiliensis was the species more prevalent and abundant. The results showed that the age of the rodents and the season of capture had effects on the helminth infection.

El objetivo del trabajo fue describir los niveles de infección de Rattus rattus en la ciudad de Corrientes, provincia de Corrientes, Argentina. Con el objetivo de determinar el rol de los roedores como reservorios potenciales de parásitos zoonóticos, se analizó la distribución de helmintos respecto al sexo, edad, estación del año y ambientes urbanos. Un total de 107 individuos de R. rattus fueron examinados. Se identificaron siete especies de helmintos. Los valores de prevalencia total, intensidad media y abundancia media fueron 68%, 20 y 13, respectivamente. Nippostrongylus brasiliensis fue la especie más prevalente y abundante. Los resultados demostraron que la edad de los roedores y la estación del año tuvieron efectos en la infección con helmintos.

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.

The main purpose of this study was to characterize the helmintological fauna of three commensal rodents from Argentina, with the final goal of finding Strobilocercus fasciolaris (Cestoda: Cyclophyllidea), discussing possible reasons of the maintenance of the cycle in the study areas. Strobilocercus fasciolaris was observed in all the studied rodent species, including Rattus rattus and Mus musculus, which constitute new host records in Argentina. Estimates of prevalence, mean abundance and mean intensity were provided, and the existing morphometric characterization of the parasite was supplemented. Significant differences of prevalence between R. norvegicus and M. musculus and among seasons were observed. The potential risk of zoonotic transmission of S. fasciolaris is suggested.

El objetivo de este estudio fue identificar la fauna helmintológica de las tres especies de roedores comensales de Argentina, con el fin de hallar Strobilocercus fasciolaris, y discutir las posibles razones del mantenimiento del ciclo de vida en las áreas involucradas. Strobilocercus fasciolaris fue observado en todas las especies de roedores, incluyendo Rattus rattus y Mus musculus, que constituyen nuevos registros hospedatorios en Argentina. Se brindan los valores de prevalencia, abundancia media e intensidad media y se complementa la caracterización morfométrica de la especie. Fueron observadas diferencias significativas entre la prevalencia y estaciones del año de captura de Rattus norvegicus y M. musculus. Se sugiere un riesgo potencial de transmisión zoonótica de S. fasciolaris.

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.

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.

El análisis de las parasitosis a diferentes escalas (regional, local) se facilita por el Geographic Information System (GIS), que permite identificar áreas con distinto grado de vulnerabilidad. El objetivo del trabajo fue analizar la distribución espacial de las parasitosis intestinales en el partido de La Plata, estableciendo su relación con las condiciones socio-ambientales para identificar áreas con diferente riesgo epidemiológico. Se completó una encuesta epidemiológica y se tomaron muestras seriadas de materia fecal, analizadas por la técnica de Ritchie. Se calcularon niveles de precariedad y vulnerabilidad (Iv), y se compararon con los resultados parasitológicos. Se analizaron parasitológica y ambientalmente 653 personas, de las cuales 585 (89.6%) eran niños y 68 (10.4%) adultos. El análisis indicó que los más vulnerables (Iv = 3-4) estaban en el sector con menor acceso a servicios de infraestructura urbana. El índice se encontró fuertemente asociado a la prevalencia total de parasitosis intestinales y a las 4 especies patógenas asociadas a la contaminación fecal del ambiente: Trichuris trichiura, Ascaris lumbricoides, Hymenolepis nana y Giardia lamblia (p < 0.01). Enterobius vermicularis, parásito no vinculado a la condición sanitaria de sus hospedadores, no se asoció al Iv. Hubo asociación estadística entre precariedad y parasitosis y se halló que a mayor Iv mayor frecuencia de parasitosis (p < 0.01). El uso de GIS permitió zonificar las variables socioambientales en un gradiente creciente de condiciones desfavorables y su relación con la presencia de especies patógenas. La continuidad de estos estudios en diferentes regiones de Argentina contribuye a la determinación de áreas en riesgo sanitario.

Las especies de Trichuris presentan una distribución cosmopolita y parasitan un amplio rango de hospedadores mamíferos. Aunque la prevalencia e intensidad parasitaria de estos nematodes dependen de diferentes factores, su ciclo de vida y las características del ambiente han sido los principales aspectos que explican su distribución geográfica. En este trabajo se brindan nuevos hospedadores y registros geográficos para las especies de Trichuris de roedores Sigmodontinae para la Argentina. Además, se presentan datos completos y organizados sobre previos registros del género en roedores del continente americano, y principalmente de Argentina. Un total de 563 especímenes incluidos en 25 especies de roedores procedentes de 12 provincias y 43 localidades del noreste y del sur de la Argentina fueron examinados con el fin de hallar especímenes de Trichuris. Se presentan seis especies de Trichuris incluyendo 9 nuevos hospedadores y 16 nuevos registros geográficos. La prevalencia de Trichuris en la provincia de Misiones es más alta que en otras áreas geográficas estudiadas. Este grupo de nematodes tropical-subtropical es registrado por primera vez por sobre los 40º S. De todos modos, son necesarios nuevos estudios para explicar si la escasez de infecciones de Trichuris en regiones de altas latitudes es debido a la ausencia de esfuerzo de muestreo o al resultado del efecto del ambiente sobre la supervivencia del estadio infectivo.

Species of Trichuris have a cosmopolitan distribution and parasitize a broad range of mammalian hosts. Although, the prevalence and intensity of this genus depends on many factors, the life cycles and characteristics of the environment have been the main aspect used to explain their geographical distribution. In this paper, we provide new host and geographical records for the species of Trichuris from Sigmodontinae rodents in Argentina. Moreover, we present comprehensive data about previous records of the genus from rodents in North and South America, and mainly in Argentina. A total of 563 specimens including in 25 species of rodents from 12 provinces and 43 localities from Northeast and Southern Argentina were sampled for Trichuris. Six species of Trichuris including 9 new hosts and 16 new geographical records were found. The prevalence of Trichuris in Misiones province is higher than in other geographical areas studied. This tropical-subtropical nematode group is recorded for the first time from the latitude 40º S. Nevertheless, more surveys are necessary to determine whether the scarcity of infections of Trichuris in regions of high latitude is due to the absence of sample effort or to environmental effects on the survival of infective stages.

The aim was to know and to analyse the prevalence of undernutrition and body composition and proportion in relationship to socio-environmental conditions of residence in children of two adjacent departments in the province of Mendoza: San Rafael (SR) and General Alvear (GA). A crosssectional anthropometrical study was performed in 5.118 children from 5 to 12 years old. Body weight, height, sitting height, arm circumference and triceps skinfold were measured and the sitting height ratio and muscle and body mass index, fat areas of the arm calculated. Prevalences of low weight-for-age (LW/A), low height-for-age (LH/A) and low weight-for-height (LW/H) were estimated using NHANES III. The socio-environmental variables were surveyed using semi-structured questioner. Prevalences of LH/A were similar in both populations and LW/A and LW/H higher in GA. The lower limb shortening was higher in SR, the deficits of muscle and adipose tissue in GA. It is concluded that whereas GA shows a higher prevalence of acute malnutrition associate to body composition changes as consequence of the social insecurity; in SR, is evident that nutritional status and life quality are better than GA surpassing those adverse conditions that affected the early stages of development as a mirror in body proportion change.

El objetivo fue conocer y analizar las prevalencias de desnutrición, composición y proporción corporales en relación con las condiciones socioambientales de residencia de niños de dos departamentos lindantes de la provincia de Mendoza: San Rafael (SR) y General Alvear (GA). Se realizó un estudio transversal en 5118 niños de 5 a 12 años. Se relevaron: peso; estatura total y sentado; perímetro braquial y pliegue tricipital, y se calcularon índices de masa corporal y de estatura sentado, áreas muscular y grasa del brazo. Las prevalencias de Bajo Peso/Edad (BP/E); Baja Talla/Edad (BT/E) y Bajo Peso/Talla (BP/T) se estimaron utilizando NHANES III. Las variables socioambientales se relevaron mediante encuestas semiestructuradas. La prevalencia de BT/E fue similar en ambas poblaciones y las de BP/E y BP/T, mayores en GA. El acortamiento de los miembros inferiores fue mayor en SR; y los déficits de tejido muscular y adiposo, en GA. Se concluye que GA muestra mayores prevalencias de desnutrición aguda con modificación de la composición corporal asociadas a la precarización socioambiental. En SR, el estado nutricional y la calidad de vida son mejores que en GA, ya que supera aquellas condiciones adversas que afectaron las primeras etapas de desarrollo, reflejadas en la proporción corporal.

In the present work, the nutritional status, intestinal parasitosis and socio-environmental conditions of children from the city centre and 11 localities of La Plata Department were characterized through a transversal study. Body weight and height were measured in 6.397 children aged 4.0 to 13.9 years old. Body mass index was calculated and the nutritional status estimated using NHANES III. A structured questionnaire was made to evaluate socio-environmental characteristics. Parasitological analyses were carried out in 729 children using fecal samples and implementing the Ritchie technique and anal brushes. The overall results indicated 22.1% of weight excess, 8.7% of undernutrition and 68.5% of parasitosis, being more prevalent Enterobius vermicularis (38.7%), Blastocystis hominis (36.1%), Giardia lamblia (19.1%), and commensal protozoa (26.1%). The worm burden showed a lower value (9.3%). La Plata Department presented great heterogeneity in the nutritional status and parasitic infection of children because they depend on the socio-environmental characteristics. Poor living conditions, low educational levels and lack of formal jobs would explain the co-occurrence of infant parasitic infection and undernutrition, being chronic the most prevalent type of undernutrition. On the other hand, the localities in which parents had a higher educational level and a formalized job -though less access to basic urban servicesshowed a greater prevalence of overweight.

En el presente trabajo se caracterizaron el estado nutricional, las enteroparasitosis y las condiciones socio-ambientales de niños residentes en el Casco urbano y 11 localidades del Partido de La Plata, provincia de Buenos Aires, mediante un estudio transversal. Se midieron peso y talla de 6.397 niños entre 4.0 y 13.9 años. Se calculó el índice de masa corporal y se estimó el estado nutricional utilizando NHANES III. Las variables socio-ambientales se relevaron mediante encuesta estructurada. El análisis parasitológico se realizó en 729 niños sobre muestras seriadas de materia fecal analizadas mediante la técnica de Ritchie y escobillado anal. Los resultados globales indicaron: 22.1% de exceso de peso, 8.7% de desnutrición y 68.5% de parasitosis, siendo más prevalentes Enterobius vermicularis (38.7%), Blastocystis hominis (36.1%), Giardia lamblia (19.1%) y protozoos comensales (26.1%). Los geohelmintos tuvieron valores inferiores (9.3%). El partido de La Plata presenta gran heterogeneidad en el estado nutricional y las infecciones parasitarias de los niños por cuanto resultan dependientes de las características socio-ambientales. Las deficientes condiciones ambientales, el bajo nivel educativo y la falta de trabajo formal de los padres explicarían la coexistencia de parasitosis y desnutrición infantil, prevaleciendo la de tipo crónico. Por otra parte, las localidades en las que hay menor grado de cobertura de servicios urbanos básicos, pero los padres poseen mayor nivel educativo y trabajo formalizado, presentan prevalencias más elevadas de exceso de peso.

Although three species of nematodes have been recorded from the spiny rat Euryzygomatomys spinosus in Brazil, no helminthes have been recorded from this host in Argentina. Three taxa of nematodes from E. spinosus from Misiones province, Argentina, were identified from the helminthological collection of Museo de La Plata. Host voucher specimens refered to this material were found in the Colección Elio Massoia. The present survey contributes to the knowledge of nematode species from Echimyidae and illustrates the importance of integrating data from helminth and mammal collections.

La rata espinosa Euryzygomatomys spinosus ha sido registrada como hospedador de tres especies de nematodes en Brasil. Hasta el momento, ningún helminto ha sido registrado parasitando a E. spinosus de Argentina. Nematodes no estudiados procedentes de la Provincia de Misiones, Argentina fueron hallados en la colección helmintológica del Museo de La Plata. En esta nota, esos nematodes fueron identificados y tres taxa fueron registrados. Los voucher de los hospedadores fueron encontrados en la Colección Elio Massoia. Este estudio contribuye al conocimiento sobre los nematodes de Echimyidae e invita a estudiar e integrar los datos registrados en las colecciones de helmintos y mamíferos.

Endoparasitic infections are common in nonhuman primates and important factors in regulating their natural populations. Primates are particularly vulnerable to the infections of directly transmitted parasites because they often live in close social groups that facilitate their transmission. The main objective of this study was to provide baseline data on gastrointestinal parasites of semi captive and wild howler monkeys Alouatta caraya troops from Argentina. We collected 110 fecal samples from 38 howler monkeys from four troops, two of them kept in semi-captivity at the CRMAN, Córdoba, and two wild troops from Las Lomas, Corrientes. We identified six species of parasites: four Protozoa, Giardia lamblia, Blastocystis hominis, Eimeria sp. and Entamoeba coli; one Cestoda, Bertiella mucronata and one Nematoda, Strongyloides sp. Of the individuals sampled, 86.8% harbored at least one type of gastrointestinal parasite. Protozoa were found in 78.9% of hosts and helminths in 21.1%. We found significant differences in the prevalence of three protozoan species between study sites; and howlers from Las Lomas showed the highest prevalence. The differences found may be related to environmental conditions, where warmer and wetter regions (Las Lomas) favor the survival of infectious stages of some parasitic species.

Las infecciones endo-parasíticas son frecuentes en los primates no humanos y factores importantes que regulan sus poblaciones naturales. Los primates son particularmente vulnerables a las infecciones por parásitos de transmisión directa debido a que usualmente éstos viven en grupos sociales que facilitan su transmisión. El principal objetivo del presente estudio fue proveer información de los parásitos gastrointestinales que albergan tropas de monos aulladores Alouatta caraya en semi-cautiverio y en vida silvestre en Argentina. Colectamos 110 muestras de materia fecal de 38 monos aulladores pertenecientes a cuatro tropas, dos de ellas mantenidas en semicautiverio en el CRMAN, Córdoba y dos tropas silvestres en campo Las Lomas, Corrientes. Identificamos seis especies de parásitos: cuatro protozoos: Giardia lamblia, Blastocystis hominis, Eimeria sp. y Entamoeba coli; un cestode, Bertiella mucronata y un nematode, Strongyloides sp. El 86.8% de los individuos muestreados presentaron al menos un tipo de parásito gastrointestinal. Se encontraron protozoos en el 78.9% de los animales y helmintos en el 21.1%. Hallamos diferencias significativas en la prevalencia de tres especies de protozoos entre los sitios de estudio, donde los aulladores de Las Lomas mostraron la mayor prevalencia. Las diferencias encontradas pueden estar relacionadas con las condiciones ambientales, donde regiones más cálidas y húmedas (Las Lomas), favorecen la supervivencia de estadios infecciosos de algunas especies de parásitos.

A total of 165 fecal samples were analyzed, using two sedimentation methods: Ritchie (R), Carles Barthelemy (CB), and one of flotation: Willis (W), in order to optimize intestinal parasites diagnosis and to determine the techniques effectiveness. Parasites were found in 119 (72,12%) of those analyzed. Significant differences were in protozoa recovery (p < 0,001), being observed 81.4% (R), 77.4% (CB), and 57.8% (W). Blastocystis hominis, Giardia lamblia, Ascaris lumbricoides and Trichuris trichiura were recovered more frequency by means of sedimentation, being Ritchie´s method the most effective one (p < 0.05)

Se analizaron 165 muestras fecales seriadas, utilizando dos métodos de sedimentación: Ritchie (R) y Carles Barthelemy (CB) y uno de flotación: Willis (W), con el fin de optimizar el diagnóstico de los parásitos intestinales y determinar la eficacia de las técnicas. Se hallaron parásitos en 119 (72,1%) de los analizados. Hubo diferencias significativas en la recuperación de protozoos (p < 0,001), observándose 81,4% (R), 77,4% (CB), y 57,8% (W). Blastocystis hominis, G.lamblia, Ascaris lumbricoides y Trichuris trichiura se recuperaron con mayor frecuencia mediante sedimentación, resultando más efectivo el método de Ritchie (p < 0,05)