Canine parasitoses in north Patagonia (Argentina): comparison between different social and environmental factors.

In many countries, urban areas are commonly contaminated with canine feces that spread parasites, a situation related to the natural and social environment. Dogs having free access to public areas therefore constitutes a health risk. Because in Patagonia there are no records of city comparisons that consider the number of free-roaming dogs and the local environmental and socioeconomic characteristics, in this study we analyse and compare canine parasitoses in two cities of Rio Negro province, Argentina. Canine feces were collected from public areas of El Bolsón and Cipolletti cities and examined using enrichment methods, Kinyoun stain and immunoassay (Copro-Elisa). The total percentage of positive feces in El Bolsón was 68.95% and 16 parasite taxa being identified, whereas in Cipolletti the total positive feces was 41.1%, with 11 taxa. Both cities presented more helminth species than protozoans. The variables that explained the occurrence of all parasites were rainfall and socioeconomic stratum with the highest values being found in low-income areas.Soil moisture is conditioned by rainfall. This study highlights the presence of the zoonotic Echinococcus sp. in dogs in urban areas of the Rio Negro province. The occurrence of this parasite in Cipolletti is unexpected, given that this city is not considered an endemic zone for this disease, which is not included in local monitoring and control plans.

A new species of hemiuroidean trematode from Hatcheria macraei (Siluriformes, Trichomycteridae) and Heleobia hatcheri (Gastropoda, Cochliopidae) in a Patagonian River.

A new hemiuroidean species, Genarchella pichileufuensis n. sp. (Derogenidae: Halipeginae), was found in the stomach of the siluriform freshwater fish, Hatcheria macraei (Girard, 1855), in the Pichileufu River, Patagonia, Argentina. Its rediae with immature cystophorous cercariae were found in the snail Heleobia hatcheri (Pilsbry, 1911) in the same site. The present new species is morphologically featured by having a cyclocoel in the hindbody unlike the other species of the genus. The characteristics of this species allowed us to amend the diagnosis of the genus Genarchella as follows: cyclocoel present or absent; testes symmetrical to tandem; ootype pouch present. In the phylogenetic analysis, G. pichileufuensis forms a well-supported clade with Genarchella spp. recovered from Mexican freshwater fishes. This clade is included in the cluster of representatives of the subfamily Halipeginae. So far, three hemiuroidean species, Thometrema patagonica (Szidat, 1956), Derogenes lacustris Tsuchida, Flores, Viozzi, Rauque et Urabe, 2021 and G. pichileufuensis n. sp., have been reported from freshwater fishes in Argentinean Patagonia.

Pathology associated with larval eustrongylides sp. (nematoda: Dioctophymatoidea) infection in galaxias maculatus (actinopterygii: Galaxiidae) from patagonia, Argentina.

Helminth infections within tissues tend to be subjected to a host response that can include encapsulation and melanization to isolate the parasite. The effectiveness of this response depends on the host species. During a survey of parasites of the native fish, Galaxias maculatus, we found conspicuous, strongly melanized exterior cysts located in the caudal peduncle of the fish. Dissection of these cysts exposed larval nematodes whose morphometrical features allowed their identification as Eustrongylides sp. Species of this genus are distributed worldwide. Galaxias maculatus was previously reported as second intermediate host to Eustrongylides sp. larvae, and the aquatic bird Podiceps major was cited as definitive host of Eustrongylides tubifex in Andean Patagonian lakes. The site of infection in the fish, and the host's response are unique among infections by larvae of Eustrongylides sp. in fishes, so the objective of this study was to describe the histological injury caused by larvae of the genus Eustrongylides parasitizing G. maculatus. Samples of fish were taken near the shore of Gutiérrez lake, in northwestern Patagonia. Some larval morphometric features were described to confirm the identity of larvae to generic level. Histopathological analysis (tissues sectioned at 5-7 µm, stained with Hematoxylin and Eosin, and Masson's Trichrome) of the caudal peduncle revealed almost complete disappearance of the epaxial musculature due to compressive atrophy and a chronic inflammatory response, associated mainly with a dense fibrotic capsule and an intense melanic deposit. This is the first description of the histopathology of an external cyst caused by Eustrongylides sp. larvae in fishes.

Echinococcosis and other parasitic infections in domestic dogs from urban areas of an Argentinean Patagonian city.

In urban populations of South America, dogs with free access to public areas represent a public health concern. The primary consequence of roaming dogs on human health is the transmission of infectious and parasitic diseases mainly through feces contamination. The main diseases likely to be transmitted are hydatidosis or echinococcosis, larva migrans, and giardiasis. In Argentina, hydatidosis ranks among the most prevalent zoonosis. Although it is considered a rural disease, the circulation of this parasite in urban areas has been documented. The aim of this work was to survey intestinal parasites in canine feces from two low-income urban neighborhoods of Bariloche city, Argentina, and to assess their seasonal variation. During 2016, 188 fresh dog feces were collected from sidewalks in 40 randomly selected blocks from the neighborhoods. Each sample was processed by Sheater flotation and tested for a coproantigen (CAg) by ELISA. The percentage of parasitized feces was 65.3% (95% CI: 55.9%-73.8%). Eleven parasite species were found, 3 protozoan, 3 cestodes, and 5 nematodes. Echinococcus sp. was present in 9.3% of the samples (95% CI: 4.7%-16.1%). Canine echinococcosis rates resulted similar to rates found previously in other neighborhoods of the city. The life cycle of Echinococcus sp. is sustained in urban areas by the entry of parasitized livestock, domiciliary slaughtering, and inadequate deposition of offal. The risk of Echinococcus sp. transmission to people in these neighborhoods is very high, due to high density of free-roaming dogs and high percentages of infected feces, similar to percentages observed in rural areas.

Echinococcosis and other parasitic infections in domestic dogs from urban areas of an argentinean Patagonian city

In urban populations of South America, dogs with free access to public areas represent a public health concern. The primary consequence of roaming dogs on human health is the transmission of infectious and parasitic diseases mainly through feces contamination. The main diseases likely to be transmitted are hydatidosis or echinococcosis, larva migrans, and giardiasis. In Argentina, hydatidosis ranks among the most prevalent zoonosis. Although it is considered a rural disease, the circulation of this parasite in urban areas has been documented. The aim of this work was to survey intestinal parasites in canine feces from two low-income urban neighborhoods of Bariloche city, Argentina, and to assess their seasonal variation. During 2016, 188 fresh dog feces were collected from sidewalks in 40 randomly selected blocks from the neighborhoods. Each sample was processed by Sheater flotation and tested for a coproantigen (CAg) by ELISA. The percentage of parasitized feces was 65.3% (95% CI: 55.9%-73.8%). Eleven parasite species were found, 3 protozoan, 3 cestodes, and 5 nematodes. Echinococcus sp. was present in 9.3% of the samples (95% CI: 4.7%-16.1%). Canine echinococcosis rates resulted similar to rates found previously in other neighborhoods of the city. The life cycle of Echinococcus sp. is sustained in urban areas by the entry of parasitized livestock, domiciliary slaughtering, and inadequate deposition of offal. The risk of Echinococcus sp. transmission to people in these neighborhoods is very high, due to high density of free-roaming dogs and high percentages of infected feces, similar to percentages observed in rural areas.

En las poblaciones urbanas de América del Sur, los perros con acceso libre a áreas públicas representan un problema de salud pública. La principal consecuencia es la transmisión de enfermedades infecciosas y parasitarias a través de la contaminación por heces. Las principales enfermedades que pueden transmitirse son hidatidosis, larva migrans y giardiasis. En Argentina, la hidatidosis es una de las zoonosis más prevalentes y aunque es considerada una enfermedad rural, algunos estudios muestran la circulación de este parásito en zonas urbanas. El objetivo fue registrar los parásitos intestinales en heces caninas de dos barrios de bajos ingresos de la ciudad de Bariloche, Argentina, y evaluar su variación estacional. Durante 2016, se recolectaron 188 heces frescas de perros en 40 manzanas seleccionados aleatoriamente. Las heces se procesaron mediante flotación de Sheater y una prueba ELISA de coproantigeno (CAg). El porcentaje de heces parasitadas fue del 65.3% (IC 95%: 55.9%-73.8%). Se encontraron 11 especies de parásitos, 3 protozoos, 3 cestodes y 5 nematodes. Echinococcus sp. estuvo presente en el 9.3% de las heces (IC 95%: 4.7% -16.1%). La equinococosis canina mostró valores similares a estudios previos en otros barrios de la ciudad. El ciclo de vida Echinococcus sp. se mantiene en las zonas urbanas por entrada de ganado parasitado, faena domiciliaria y deposición inadecuada de vísceras. El riesgo de transmisión de Echinococcus sp. en estos barrios es alto, debido a la alta densidad de perros sueltos y al alto porcentaje de heces infectadas, similar al de las zonas rurales.

Tenencia responsable de perros y salud humana en barrios de San Carlos de Bariloche, Argentina / Responsible ownership of dogs and human health in neighborhoods of San Carlos de Bariloche, Argentina

La relación entre el hombre y el perro se asocia a numerosos y variados beneficios sobre la salud humana; sin embargo también presenta importantes riesgos. El objetivo de este trabajo es describir parámetros demográficos y características de la tenencia de perros con implicancias sobre la salud humana y evaluar la prevalencia de mordeduras y accidentes de tránsito causados por perros. Se realizó una encuesta en los barrios Nuestras Malvinas y Nahuel Hue de San Carlos de Bariloche. Se estimó el porcentaje de viviendas con al menos un perro, la media de perros por vivienda, la prevalencia de mordeduras de perro y de accidentes de tránsito causados por perros y el conocimiento de la población sobre zoonosis transmitidas por perros. Respecto de la tenencia, se evaluó el grado de esterilización, vacunación y desparasitación y el porcentaje de perros con libre acceso a la calle. Se realizaron 141 entrevistas. En 87% de las viviendas había al menos un perro (promedio 2.2 perros/vivienda). En 26% de las viviendas alguien había sufrido un accidente de tránsito causado por perros y en 41% alguien había sido mordido. El 83% de los perros fueron desparasitados en los últimos 12 meses, en promedio 1.4 veces (óptimo: 6 veces/año), 51% estaban esterilizados, 55% tenían libre acceso a la calle. Este estudio muestra una situación preocupante respecto de la población canina de los barrios evaluados. El número de perros sueltos en la calle y el bajo nivel de desparasitación y esterilización proveen condiciones ideales para que se propaguen zoonosis.

Human relationship with dogs associates with numerous and varied benefits on human health; however, it also presents significant risks. The goal of this study was to describe demographic parameters and characteristics of dog ownership with possible implications on human health and to evaluate the prevalence of dog bites and traffic accidents due to dogs. Interviews were conducted in the neighborhoods of Nuestras Malvinas and Nahuel Hue in San Carlos de Bariloche. The percentage of homes with at least one dog, the average number of dogs per home, the prevalence of dog bites and traffic accidents due to dogs and the general awareness of the population on dog transmitted zoonoses were estimated. Regarding ownership characteristics, the degree of sterilization, vaccination and parasite control and the percentage of dogs allowed to roam freely in public places were evaluated. A total of 141 interviews were conducted; 87% of the households had at least one dog, with an average of 2.2 dogs. In 26% of the households someone had suffered a traffic accident caused by dogs and in 41% someone had been bitten. Antiparasite treatment was administered to 83% of the dogs in the last 12 months, on average 1.4 times (recommended 6 times), 51% were sterilized, 55% were allowed to roam freely. This study shows a disturbing situation regarding the canine population of the evaluated neighborhoods. The number of dogs allowed to roam freely and the low level of parasite control and sterilization provide suitable conditions for the spread of zoonoses.

Dermatitis cercarial en bañistas del norte de la Patagonia Argentina / Cercarial dermatitis of bathers in northern Argentine Patagonia

La dermatitis cercarial es una enfermedad cutánea, zoonótica y estival, causada por una larva nadadora de trematodes de la familia Schistosomatidae, llamada cercaria. Esta larva penetra accidentalmente la piel de personas que se encuentran en el agua, generando una reacción alérgica que generalmente no se informa en centros de salud, dificultando el registro de su incidencia. Se han informado casos en todo el mundo, incluyendo a la Argentina, aunque los estudios epidemiológicos se han realizado solamente en el Hemisferio Norte. En este trabajo se estudió la epidemiología de la dermatitis cercarial en tres balnearios patagónicos de los lagos Pellegrini, Mari Menuco y Puelo, donde se realizaron encuestas a visitantes durante los veranos de 2012-2013 y 2013-2014. Se analizaron los factores de riesgo, que fueron agrupados en “características personales”, “uso del recurso” y “medidas de prevención”. En el lago Pellegrini fue la sensibilización de la persona incluida en "características personales" el único factor determinante para la ocurrencia de esta zoonosis, mientras que en el lago Mari Menuco la ocurrencia se asoció con el tiempo y la distancia a la costa y el uso de cremas. En el lago Puelo no se registraron casos durante el período de estudio.

The cercarial dermatitis is a zoonotic, summer, skin-disease, caused by a swimming larva (cercaria) of a schistosomatid trematode. This larva accidentally penetrates the skin of people in the water, causing an allergic reaction, which is not always reported in health centers, so it is difficult to determine its incidence. Cases have been registered worldwide, including Argentina, although the epidemiological studies were performed only in the Northern Hemisphere. In this survey the epidemiology of cercarial dermatitis was studied in three Patagonian lakes watering places, Pellegrini, Mari Menuco, and Puelo, where surveys were conducted during summers of 2012-2013 and 2013-2014. The risk factors were analyzed and grouped in “personal characteristics”, “use of the recreational resource”, and “prevention measures”. At the Pellegrini Lake, the people´s sensitivity included in "personal characteristics" was the only determining factor for the occurrence of this zoonosis, mean while in Mari Menuco Lake, the bathing time and distance from the coast, and the use of lotions would affect the occurrence of swimmer’s itch. In Puelo Lake, no cases were recorded during the study period.

A new genus of Cystidicolid nematode from the stomach of Galaxias maculatus (Osmeriformes: Galaxiidae) in Patagonia (Argentina).

During a parasitological survey of Galaxias maculatus (Jenyns) from Patagonian Andean Lakes, specimens of a new species of nematode were collected from the stomach of fish and studied by light and scanning electron microscopy. This species is described as the only member of a newly proposed genus of Cystidicolidae by having oral opening dorsoventrally elongated, 2 lateral pseudolabia, 4 cephalic papillae, stoma (vestibule) elongated, esophagus divided into anterior muscular and posterior glandular sections, and caudal alae in males. Placonema n. gen. (Habronematoidea, Cystidicolidae) is characterized by the combination of the following features: oral opening dorsoventrally elongated demarcated by 4 sclerotized plates and 2 well-developed pseudolabia projected to the buccal cavity, each pseudolabium with conspicuous, conical, anterior protuberances. Four cephalic papillae and deirids simple. Male with caudal alae, area rugosa absent, 4 pairs of preanal papillae, unpaired papilla present on anterior cloacal lip, and 6 pairs of postanal papillae. Larvigerous eggs without filaments. Placonema pataguense n. gen. n. sp. infects the stomach of G. maculatus from Lake Patagua (Patagonia, Argentina) and is the first species of Cystidicolidae described from G. maculatus.

New cystidicolid species (Nematoda) from Galaxias platei (Osmeriformes: Galaxiidae) in Patagonian freshwater environments.

During a parasitological survey of Galaxias platei Steindachner, 1898, from Patagonian Andean Lakes, a new species of Cystidicolidae was found in the stomach of fish. The new species was described using light and scanning electron microscopy; the species has characteristics of Ascarophis and is distinguishable from other species by a combination of the following features: well-developed pseudolabia with T-shaped inner extensions, bifurcate deirids, small ratio GE:ME, small left spicule, small ratio LS:RS, and larvigerous eggs with thick and fine filaments in both poles. Intraspecific variation in the morphology of larvigerous eggs was studied. This is the first species of Ascarophis described from freshwater fishes.

Presencia de eustrongylides tubifex (nematoda: Dioctophymatoidea) en la Patagonia, Argentina / Presence of eustrongylides tubifex in argentinian patagonia

La presencia de una hembra ovígera de Eustrongylides tubifex en el proventrículo de un Podiceps major se describe por prímera vez en un ave de un lago andino de la Patagonia Argentina. En dos nuevas localidades el parásito en Galaxias maculatus. La prevalencia de infección es mayor en el lago Quillén que la reportada previamente en el lago Gutiérrez.

Monitoreo de parásitos en efluentes domiciliarios / Control of parasites in domestic sewage

Objetivo: Avaliar a presença de parasitas em efluentes semi-sólidos e líquidos, em diferentes localidades da Patagonia argentina, por ser fato uma das restriçöes para seu uso. Métodos: As amostras selecionadas de 4 Centros de Tratamento de Efluentes Domiciliários foram analisadas de acordo com as normas da "Environmental Protection Agenty", Organizaçäo Mundial da Saúde e do "Standard Methods for Examination of Water and Wastewater", além de algumas classificaçöes. Resultados: Somente 2 das 6 amostras de semi-sólidos analisadas continham ovos de Ascaris lumbricoides näo viáveis. Das 10 amostras líquidas, somente 2 näo continham ovos, enquanto as restantes continham patógenos das categorias I (Giardia sp., Hymenolepis diminuta e Enterobius vermicularis) e III (Ascaris lumbricoides, Ancylostoma duodenale e Trichuris trichiura). Conclusöes: Todas as amostras de semi-sólidos analisadas foram consideradas aptas para seu uso como fertilizantes porque näo se registrou em nenhuma delas a presença de ovos viáveis de Ascaris lumbricoides, e somente 6 das amostras líquidas foram consideradas aptas para rego, por carecer de ovos ou por ser sua concentraçäo igual ou inferior a 1 ovo por litro

Presencia de protozoos parásitos en peces autóctonos de Patagonia Argentina / Presence of protozoan parasites in autocthonous fishes from Argentine Patagonia

One species of trichodina, one of henneguya, one of myxidium, at least two species of myxobolus ans species of microsporidea of different autocthonous fish from Patagonia are cited