Pseudocorynosoma enrietti (Molfi & Freitas Fernandes, 1953) (Acanthocephala: Polymorphidae) from Patagonia (Argentina): life cycle, localities, and new host records.

All Pseudocorynosoma species inhabit freshwater environments of the American continent, but little is known about their life cycles. We report Pseudocorynosoma enrietti (Molfi & Freitas Fernandes, 1953) from natural and experimental specimens in Patagonia and identify the intermediate and definitive hosts of its life cycle for the first time in South America. Adult worms were recovered from Anas platyrhynchos (Linnaeus) and from a new definitive host, Coscoroba coscoroba Molina. Naturally infected amphipods, Hyalella patagonica Ortmann, were collected to obtain cystacanths that were fed to Gallus gallus domesticus (Linnaeus) and Anas platyrhynchos. Specimens of P. enrietti are described in detail using light and scanning electron microscopy. A key to species of the genus Pseudocorynosoma is included. Worms are characterized in both sexes by fore-trunk spines, and genital spines in an isolated field. The proboscis has 19-20 hook rows; males have 9-11 (10) hooks per row and females 7-9 (8). Males with four cement glands similar in size. Eggs elongated, with filaments. Experimental male and female worms were recovered from A. platyrhynchos at seven and 14 days, post-infection.

Toxocariasis in Carnivora from Argentinean Patagonia: Species molecular identification, hosts, and geographical distribution.

Twenty four specimens of seven species belonging to the families Felidae, Mustelidae, and Canidae were obtained in Lanín and Nahuel Huapi National Parks from March 1996 to April 2016. Specimens were processed by necropsy in order to contribute to the knowledge of toxocariasis in wild carnivores of Argentinean Patagonia. The only Puma concolor and the seven Leopardus geoffroyi were positive for Toxocara cati. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of the ITS-1 region from larval and adult DNA was carried out to confirm parasite species identification. This is the first molecular determination of T. cati from wild felids in Argentina and the study also fill gaps about the spatial distribution and hosts for Toxocara cati.

Diphyllobothriidea in the north area of the Andean Patagonia: Epidemiology in urban dogs, morphometrical and molecular identification, with comments on wild carnivores.

Diphyllobothriidea are the principal agents of Diphyllobothriosis, a widespread food-borne cestodosis. Accurate identification of the species in samples is therefore crucial for diagnosis and epidemiology in wild and domestic animals, and also humans. We aim to identify at specific level the causative agent, and provide an observational, descriptive, and transversal study of the epidemiology of this zoonosis in urban dogs. Also data on wild carnivores from Northwestern Patagonia are presented. Dog feces were collected in thirteen neighborhoods of varying socioeconomic status, and stools were analyzed by two concentration methods. Adult worms were collected and identified by molecular methods. The population of free-roaming dogs in each neighborhood was estimated, and surveys were conducted at all veterinary clinics registered in the Veterinary Medical College of Bariloche city. A total of 36 wild carnivores road killed or found dead in three National Parks were analyzed. Molecular and morphometric analyses of proglottids and eggs from dogs indicate they are infected with D. latum. Twenty out of 118 dog feces were positive for Diphyllobothrium, from 9 out of 13 neighborhoods, with infection values between 10% and 66%. Percentage of infection was correlated positively with the number of free roaming dogs per block, and with Unsatisfied Basic Needs (UBN %), but not with distance to nearest water body. Infection by D. latum in dogs is widely distributed throughout the city. Not all local veterinarians know the occurrence of Diphyllobothriosis in the dogs of the city, and it is evident that this zoonosis is underdiagnosed in relation to the percentage of infection found in this study. None of the analyzed wild carnivores were positive for Diphyllobothrium.

Interactions among four parasite species in an amphipod population from Patagonia.

Parasites commonly share their hosts with specimens of the same or different parasite species, resulting in multiple parasites obtaining resources from the same host. This could potentially lead to conflicts between co-infecting parasites, especially at high infection intensities. In Pool Los Juncos (Patagonia, Argentina), the amphipod Hyalella patagonica is an intermediate host to three parasites that mature in birds (the acanthocephalan Pseudocorynosoma sp. and larval stages of two Cyclophyllidea cestodes), in addition to a microsporidian (Thelohania sp.), whose life cycle is unknown, but very likely to be monoxenous. The aim of this study was to describe interactions between these parasite species in their amphipod host population. Amphipods were collected monthly between June 2002 and January 2004 to assess parasite infection. Infection prevalence and mean intensity were greatest in larger male amphipods for all parasite species. We also found a positive association between Thelohania sp. and both Pseudocorynosoma sp. and Cyclophyllidea sp. 1 infections, though Pseudocorynosoma sp. and Cyclophyllidea sp. 1 were negatively associated with each other. We conclude that contrasting associations between parasite species may be associated with competition for both food intake and space in the haemocoel.

Do environmental differences between lakes in northwestern Argentinean Patagonia affect the infection of Philureter trigoniopsis (monogenea) in Galaxias maculatus (osmeriformes)?

Philureter trigoniopsis is the only parasite found in the ureters and urinary bladder of Galaxias maculatus in Patagonian Andean lakes. The dynamics of this endoparasitic monogenean were studied in Lake Gutiérrez, a body of water with scarce shoreline vegetation, where the host has an annual cycle of migration to the deep pelagic zone of the lake. To compare variations of the infection related to differences between lakes, G. maculatus specimens were sampled monthly with baited traps from September 1998 to November 1999 in Lake Moreno, which is an oligotrophic body of water with emergent shoreline vegetation and where the fish do not migrate to the deep pelagic areas of the lake. In addition, data for summer infections of P. trigoniopsis from 10 Andean Patagonian lakes that differ in aquatic vegetation, depth, and area were compared. In Lake Moreno prevalence of P. trigoniopsis showed a seasonal pattern, with 1-yr-old fish exhibiting the highest values of prevalence and mean intensity. Negative correlations between water temperature and prevalence and between age of fish and abundance were found. Our results suggest that age of fish may be the main factor structuring the distribution of P. trigoniosis in populations of G. maculatus. At the regional level the relationship between the infection and the characteristics of the lakes was also observed, with prevalence and mean intensity of P. trigoniopsis in G. maculatus higher in large deep lakes without macrophytes.

Factors related to the attraction of flies at a biosolids composting facility (Bariloche, Argentina).

The composting process is used to treat biosolids from the Wastewater Treatment Plant of Bariloche (NW Patagonia, Argentina). Since 1998, an odourless, innocuous and stable organic amendment has been produced at the Biosolids Composting Plant of Bariloche. However, volatile compounds produced during this process, attract different vectors, mainly insects belonging to the Order Diptera, particularly in summer. To evaluate factors associated with the attraction of Diptera to composting windrows, volatile compounds, wind velocity, ambient and windrow temperatures were measured and their relationships with the taxa of flies found were determined. Sampling was conducted several months on newly formed windrows during 3 weeks of the thermophilic composting period. Composite samples from each windrow were taken on the first day of each sampling week, from November 1999 to March 2000 to analyze volatile compounds using an 'electronic nose'. Windrow and ambient temperatures and wind velocity were recorded on three consecutive days of each week, from January to March 2000; also the capture of flies was performed in this period. A weekly mean value was calculated for each environmental variable. Canonical Correspondence Analysis was employed to determine relationships between taxa of flies and the studied factors. The electronic nose discriminated among odours emitted, differentiating windrows by the bulking agent employed and by week of the thermophilic composting period. Ambient temperatures increased slightly during the sampling weeks; the highest values of wind velocity were registered during the second sampling week while windrow temperatures were sustained approximately 60 degrees C. Canonical Correspondence Analysis showed that attraction of flies to composting windrows was related to minimum and maximum ambient temperatures and volatile compounds for Muscina stabulans, Fannia sp. and Acaliptratae and to wind velocity for Ophyra sp., Sarcophaga sp., Cochliomyia macellaria and Phaenicia sericata.

New cases of human diphyllobothriasis in Patagonia, Argentina.

The purpose of the paper is to describe 4 new cases of human diphyllobothriasis in Patagonia, Argentine. Adult parasites recovered were submitted to morphological and histological analyses for taxonomic identification. The etiological agent found was always Diphyllobothrium latum and all the cases were autochthonous. These data combined with previous information make the number of autochthonous human cases of diphyllobothriosis registered in Argentina increase to 18.

Acanthocephalus tumescens (Acanthocephala, Echinorhynchidae) in Galaxias maculatus (Pisces, Galaxiidae) of Lake Gutiérrez, Patagonia, Argentina.

The seasonal distribution of Acanthocephalus tumescens (Acanthocephala : Echinorhynchidae) among Galaxias maculatus (Pisces : Galaxiidae) in Lake Gutiérrez was studied from March 1994 to June 1996. Acanthocephalus tumescens always occurs in the intestine, has an overdispersed frequency distribution, a similar proportion of sexes, and females are larger than males. Mean intensity and prevalence are low and increase with host length. The pattern of the infection shows seasonality, with recruitment in winter and a reproductive period during spring-summer.

[Monitoring of parasites in domestic sewage]. / Monitoreo de parásitos en efluentes domiciliarios.

OBJECTIVE: The evaluation of the presence of parasites in semisolid and liquid sewage in Argentinian Patagonia in view of the fact that this is a restriction for its use. METHODS: The samples taken at 4 Domestic Sewage Plants were analyzed in accordance with Standard Methods for the Examination of Water and Wastewater, Environmental Protection Agency, World Health Organization and some other classifications. RESULTS: Only 2 of 6 semisolid samples analyzed had non-viable Ascaris lumbricoides eggs. Of the 10 liquid samples analyzed, only 2 did not contain eggs whereas the remaining ones had pathogens of categories I (Giardia sp., Hymenolepis nana and Enterobius vermicularis) and III (Ascaris lumbricoides, Ancylostoma duodenale and Trichuris trichiura). CONCLUSIONS: All semisolid samples turned out to be satisfactory for use as fertilizer as no viable Ascaris lumbricoides eggs were found in any of them. But only 6 of the liquid samples were satisfactory for use as they had no eggs or their concentrations was equal to or less than 1 egg per litre.

[Gastrointestinal human myiasis caused by Eristalis tenax]. / Myiasis gastrointestinal humana por Eristalis tenax.

The myiasis observed in Bariloche are characterized and the probable conditions under which the infestations took place established. The larvae obtained from faeces of 2 patients were identified as Eristalis tenax (Diptera: Syrphidae) according to Hartley (1961) and Organización Panamericana de la Salud keys (1962). These 2 cases of human gastrointestinal myiasis were the first to be registered in Bariloche (Patagonia, Argentina) and their characteristics were similar to those described for this species in other parts of the world. The lack of specific control measures in the domestic water supply system was the most probable cause of the infestation. This event extends the distribution of E. tenax and human gastrointestinal myiasis in South America to 41 degrees 03' S.

[Human diphyllobothriasis in Patagonia, Argentina]. / Difilobotriasis humana en la Patagonia, Argentina.

OBJECTIVE: In view of the amateur fishing practices and the importance of salmonids in the region the study sets out to detect human hosts in the Andean-Patagonian zone. MATERIAL AND METHOD: Information campaigns were carried out by Clinical Analysis Laboratories of Andean Patagonia between 1986 and 1995 to detect diphyllobothriasis more efficiently by means of coproparasitological analysis. RESULTS: Further, forms were prepared for the collection of information about infection, treatment and the characteristics of the human host. During this period 13 new cases were registered either through direct identification of the parasite or through the presence of eggs in the faeces. The characteristics of infection are similar to those described for the genus Diphyllobothrium. CONCLUSIONS: The favourite game fish in Andean Patagonia are salmonids. This fish, often infected with plerocercoids, when eaten insufficiently cooked or cold smoked, constitutes the main source of human infection.

[Helminth parasites of Larus dominicanus in Argentinian Patagonia]. / Helmintos parásitos de Larus dominicanus en la Patagonia Argentina.

The presence of 9 endohelminths was quoted for Larus dominicanus of which 6 were new citations in Patagonia (Argentina) for this host: Stephanoprora, Cryptocotyle, Anomotaenia, Polymorphus, Contracaecum and Capillaria. For the first time Cryptocotile is being cited in Argentina.

[Presence of glochidia of Diplodon chilensis Hass 1931 (Mollusca, Pelecypoda) in Patagonian freshwater fishes]. / Presencia de gloquidios de Diplodon chilensis Haas 1931 (Mollusca, Pelecypoda) en peces dulceacuícolas patagónicos.

The presence of glochidia of Diplodon chilensis Haas 1931 (Mollusca, Pelecypoda) has been reported in gills of wild freshwater fish in the Argentinian Patagonia. Death occurrences due to glochidiasis have not been observed either in wild fish or in cultured fish. The records of Oncorhynchus mykiss, Galaxias platei, Patagonia hatcheri and Percichtys trucha extend the number of known hosts for D. chilensis and add new localities, thus extending the distributions of the mollusc.

Pomphorhynchus patagonicus n. sp. (Acanthocephala: Pomphorhynchidae) from freshwater fishes of Patagonia, Argentina.

Pomphorhynchus patagonicus n. sp. is described from Lake Rosario, Chubut Province, Argentina. It is characterized by a long neck forming an asymmetrical bulb with 2 well differentiated dorsal protruberances and 14 alternating rows of 13 and 14 proboscis hooks, each row with a stout fourth hook. It most closely resembles Pomphorhynchus sebastichthydis Yamaguti, 1939, from Japan, but differs in the bulb protruberances and in having more rows of hooks and more hooks per row and in the shapes of the fourth and basal hooks. Among American species P. patagonicus shows some similarities to Pomphorhynchus yamagutii Schmidt and Hugghins, 1973, from Chile, but differs with respect to the longer neck, bulb protruberances, and proboscis armature. Pomphorhynchus patagonicus is endemic to Patagonia, where its definitive type host is the endemic fish Patagonina hatcheri (Atherinidae) and its intermediate host the endemic freshwater amphipod Hyalella patagonica. It has been found also in autochthonous fishes belonging to the families Galaxiidae and Percichthyidae and in introduced salmonid fishes.