Ecoepidemiology of Ancylostoma spp. in Urban-Marginal and Rural Sectors of the Ecuadorian Coast and Prevalence of Cutaneous Larvae Migrans.

BACKGROUND Ancylostoma spp., including A. duodenale, A. braziliense, A. caninum, and A. ceylanicum, are hookworms that are transmitted from infected soil and by contact with domestic animals and rodent hosts, and can cause systemic disease and cutaneous larva migrans. The objective of this study was to describe the ecoepidemiology of Ancylostoma caninum and Ancylostoma spp. in urban-marginal sectors and in rural sectors located in Ecuador. MATERIAL AND METHODS Through addressed sampling, a total of 498 domestic dogs and 40 synanthropic rodents were analyzed via the following coproparasitic methods: direct, flotation, sedimentation with centrifugation using saline (egg identification), modified Baermann (larval identification), and morphometric methods (confirmation). A total of 236 people were surveyed, and a clinical analysis was performed via physical examination. The environmental variables were obtained through reports from the INAMHI of Ecuador and the use of online environmental programs. Through surveys, data related to social determinants were obtained. Epidemiological indicators (prevalence, morbidity, and mortality) were obtained through microbial analysis and surveys. RESULTS A total of 250 domestic dogs were diagnosed with Ancylostoma caninum (50, 20%), and 41 were diagnosed with Ancylostoma spp. (8.23%). One synanthropic rodent (2.5%) was positive for A. caninum. In the clinical analysis, 3 patients were identified as positive (1.27%) for cutaneous larva migrans (CLM). Likewise, environmental variables and social determinants influence the transmission, prevalence, and nature of parasitism by hookworm. CONCLUSIONS People, domestic dogs, and rodents were infected with these parasites. Consequently, there is a risk of ancylostomiasis and cutaneous larvae migrans spreading.

Zoonotic Transmission of Hepatic Hydatid Cyst from Domestic Dogs: A Case Report from an Urban-Marginal Area in Ecuador.

BACKGROUND Hepatic hydatidosis, or echinococcosis, is a zoonosis with worldwide prevalence and is potentially lethal in humans. This report presents a case of hydatidosis in a 40-year-old woman that was associated with a zoonotic transmission of Echinococcus granulosus from domestic dogs in an urban-marginal area of the city of Guayaquil, Ecuador. This report shows how early diagnosis and awareness favored the correct treatment of the disease. CASE REPORT A 40-year-old woman from the aforementioned sector presented the following symptoms: malaise, pain in the upper right hypochondrium, palpable mass, jaundice, and fever. Next, the patient's fecal samples were analyzed by direct coproparasitic methods, flotation, and sedimentation with centrifugation using saline solution, whereby the presence of Entamoeba histolytica eggs was determined. Likewise, she underwent an ultrasound, in which hepatic hydatid cysts were observed. Subsequently, the cysts were treated and surgically removed, and parasitic forms of E. granulosus were identified. Later, coproparasitic analysis of her 2 domestic dogs for coproantigen ELISA were performed, by which the presence of this cestode was also identified and confirmed. CONCLUSIONS Hydatidosis is a zoonosis that can affect the population, especially in endemic areas of developed and underdeveloped countries. In this case, hepatic hydatidosis was identified in a 40-year-old woman. Additionally, the presence of E. granulosus eggs was determined in the fecal matter of her dogs, which indicated that the patient's relatives and other people around them were exposed to this zoonosis.

A Case of Urbanorum spp. in a Woman from an Urban-Marginal Sector of Ecuador.

BACKGROUND Worldwide, there are few cases of Urbanorum spp. in humans; however, it is associated with gastrointestinal pathologies, where humans probably acquire the disease by fecal-oral transmission, by ingesting food or water with infective cysts. The main symptoms of the patients who have this presumed parasite are fever, vomiting, colic, dyspepsia, and watery diarrhea. Since the first case of Urbanorum spp. was reported in 1994 in Colombia, cases have subsequently been reported in Peru, Ecuador, Colombia, Brazil, and Mexico. In Ecuador, a prevalence of 1.16% has been reported, and the objective of this study was to record another case of Urbanorum spp. infection in Ecuador. CASE REPORT A female patient (mixed race; 40 years old; and thin, weighing 57 to 62 kg) requested help from the FCI Project approved and financed by the University of Guayaquil (Ecuador). She underwent routine tests, such as direct parasitology and sedimentation with centrifugation using saline solution. Samples were observed under an optical microscope with 10x and 40x objectives and stained with and without Lugol's solution. We detected a rounded structure with several filaments similar to light yellow pseudopods. CONCLUSIONS Herein, a case of Urbanorum spp. infection in Ecuador, where current environmental and sanitary conditions have contributed to new cases, is reported, indicating that the community was exposed to this probable parasite with importance in public health. Further studies are recommended to confirm its etiology, life cycle, and epidemiology, in order to create a national registry, in case it is defined as a protozoan.

Hymenolepiasis Caused by Hymenolepis nana in Humans and Natural Infection in Rodents in a Marginal Urban Sector of Guayaquil, Ecuador.

BACKGROUND Hymenolepiasis is a globally prevalent zoonosis of the monoxenic cycle. Humans acquire the disease through fecal-oral transmission by ingesting food or water with infective eggs from infected rodents. This report presents 3 cases of hymenolepiasis in children, due to zoonotic transmission from rodents and presumably associated with the consumption of powdered milk contaminated with infective eggs of Hymenolepis nana, and shows that awareness and early diagnosis contributed to timely treatment of the disease. CASE REPORT Three children, aged 9, 12, and 13 years, living in a marginal urban area of Guayaquil, Guayas province, Ecuador, presented symptoms of diarrhea, low body weight, abdominal discomfort, anorexia, paleness, and anal itching. Subsequently, their fecal samples were analyzed by direct coproparasitic methods, flotation and sedimentation with centrifugation using saline solution; the presence of H. nana eggs was determined. Blood biometry was performed. Further, 10 rodents were captured and necropsied to obtain intestinal contents. The powdered milk consumed by the children was analyzed, the same powder that contained rodent feces. Subsequently, these were studied with the above-mentioned coproparasitic methods. H. nana eggs were identified in the 6 trapped rodents, the powdered milk, and the feces of rodents found in the milk powder. CONCLUSIONS Hymenolepiasis can affect populations of endemic areas. In this case, the disease was identified in 3 children, who were diagnosed with eosinophilia and anemia. Additionally, the presence of H. nana eggs in captured rodents and in powdered milk was determined, indicating that the community was exposed to this zoonotic disease.

A New Species of Sprentascaris (Nematoda: Raphidascarididae) in Hypostomus commersoni (Pisces: Loricariidae) from Argentina.

PURPOSE: To report a new species: Sprentascaris pampayensis, a Raphidascarididae parasite from the Neotropical region. METHODS: During a parasitological survey, specimens were collected of a new species of Sprentascaris from Hypostomus commersoni Valenciennes from urban lakes in Santa Fe City, Santa Fe Province, in the Pampean region of Argentina. Morphological and morphometric descriptions, and molecular analyses were performed. RESULTS: The new species, S. pampayensis n. sp., is characterized by having slightly extended lateral wings in both sexes, oral structure with three well-developed lips with double papillae, ventrolateral lips with an amphidial pore. Triangular buccal opening with three well-developed lips with flattened extensions at their bases, which end in a pointed manner towards the back. Males have 17 pairs of preanal papillae, 1 pair of adanal papillae, 3 pairs of postanal papillae and 1odd median postanal papilla located between the first and second pairs, unusual shape of caudal papillae with the central tubular part conspicuously elevated. Females have pre-equatorial vulva, smooth-shelled eggs, and mature embryonated eggs. DISCUSSION: Sprentascaris pampayensis n. sp. differs morphologically and genetically from S. manherti Petter and Cassone, 1984, S. lanfrediae Melo, Santos, Giese, Santos and Santos, 2011 and S. andersoni Malta, Paiva, Elisei, Tavares and Pereira, 2018. Morphological and morphometric comparison also distinguishes it from S. pimelodi Petter and Cassone, 1984, S. hypostomi Petter and Cassone, 1984, S. marano Ramallo, 2009, and S. saltaensis Ailán-Choke, Ramallo and Davies, 2017. Sprentascaris pampayensis n. sp. is a new parasitic nematode of Hypostomus commersoni.

First records of parasitic nematodes in two species of river fish, San Juan Province, Argentina.

In rivers and other watercourses from San Juan Province specimens of Hatcheria macraei (Girard, 1855), Psalidodon eigenmanniorum (=Astyanax eigenmanniorum (Cope, 1894), Jenynsia lineata (Jenyns, 1842) and Trichomycterus corduvensis Weyenbergh 1877 were captured. Of these, H. macraei and P. eigenmanniorum were parasitized with the nematodes Rhabdochona acuminata and Contracaecum sp., respectively. The morphometric analysis of the identified nematodes is included. They are the first records of parasitic nematodes of fish from San Juan Province. In this way, the geographical distribution of both nematodes was extended and H. macraei and P. eigenmanniorum were registered as new hosts.

Rhabdias elegans (Nematoda: Rhabdiasidae) in the toad, Rhinella arenarum (Hensel, 1867) from Argentina.

This study describes the morphology of Rhabdias elegans Gutierrez, 1945, isolated from the lungs of the toad Rhinella arenarum (Hensel, 1867) from Lomas de Tafi Tucumán, Argentina. This is the first record of R. elegans in R. arenarum from northwestern Argentina as previously described Rhabdias truncata is a species inquirendae. The distribution of R. elegans is extended since it was previously recorded in Buenos Aires, Chaco and Corrientes Provinces, Argentina. Our light microscopical study of morphological details of R. elegans revealed a few previously unreported structures in the apical region including position of the excretory pore and lateral sessile papillae in the tail. In addition, morphometric variability was observed on comparing present specimens and those described in previous studies. Our study made it possible to validate the occurrence of three Rhabdias species occurring in Argentina: R. elegans, R. füelleborni and R. cf. sphaerocephala. The information presented in this study represents an important contribution to the parasitological knowledge of R. arenarum from northwestern Argentina.

Gastrointestinal nematodes of freshwater fish from Pilcomayo River, Argentina, including description of a new species of Procamallanus (Spirocamallanus).

Helminthological examination of viscera of six freshwater fish species, collected from Misión la Paz, Pilcomayo River, Province of Salta, Argentina, revealed the presence of five species of parasitic nematodes belonging to the Camallanidae, Cystidicolidae, Cucullanidae and Anisakidae  The material also contained one unknown species, Procamallanus (Spirocamallanus) tomsici sp. nov. collected from Pimelodus albicans, Pygocentrus nattereri and Hoplias misionera. This species is distinguished from its congeners all over de world by possessing six pores distinctly surrounding the mouth aperture, a buccal capsule with 3-4 spiral thickenings complete, females possessing a lateral cuticular ornamentation along the body, and two pairs of preanal and three pairs of postanal papillae in males. The findings represent new hosts and geographical records.

Checklist of nematode parasites of reptiles from Argentina.

A summary of the parasitic nematodes of reptiles from Argentina is presented. It is a compilation of 29 parasitological papers published between 1992 and May 2020. This review includes information about 40 species of reptiles (4 snakes, 3 turtles, 1 anfisbaenian and 32 lizards). Twenty-six nematodes species have been reported from reptiles. The present review provides data on hosts, geographical distribution and site of infection. A host/parasite list is also provided.

Histopathological study of Corydoras micracanthus (Siluriformes: Callichthyidae) parasitized by the nematode Procamallanus (Spirocamallanus) pintoi (Camallanidae) from Lesser River, northwestern Argentina, South America

The nematode parasites can cause mechanical injuries such as irritation or atrophy of tissue and occlusions of the digestive tract, blood vessels or other ducts in their hosts. Some species belonging to the family Camallanidae have been the focus of histopathological studies because they lacerate the host´s intestinal wall with their buccal capsule. In this study, we describe the histopathological effects produced by Procamallanus (Spirocamallanus) pintoi in the small fish Corydoras micracanthus from Lesser River, in the northwest of Argentina, South America. The samples were processed with routine histology techniques. At light microscopy, specimens of P. (S.) pintoi were observed occupying the lumen of the gut. The histopathological sections revealed damage to the host intestine with the total destruction of the mucosa and submucosa, observed mainly in the region which is surrounding the buccal capsule of parasites. Moreover, an inflammatory reaction was observed with lymphatic accumulations in the affected tissue. This kind of degenerative and necrotic changes in the mucosa could affect negatively the absorption function of the host intestine, which may have adverse effects of the health status of fish. The present study provides the firs data about the histopathological effects of P. (S.) pintoi in C. micracanthus.

Redescription of Hedruris mucronifer (Nematoda: Hedruridae) parasite of Telmatobius schreiteri (Anura, Telmatobiidae) from Tucumán, Argentina.

The species Hedruris mucronifer Schuurmans Stekhoven, 1952 parasite of Telmatobius schreiteri from Tafí del Valle, Tucumán, Argentina is herein redescribed. The main morphological characters used for its identification are illustrated. The lectotype and paralectotype are designated, respectively. The specific epithet of the host is rectified.

Pattern of infection with Parapharyngodon riojensis Ramallo, Bursey, Goldberg 2002 (Nematoda: Pharyngodonidae) in the lizard Phymaturus extrilidus from Puna region, Argentina

The pattern of infection with the nematode Parapharyngodon riojensis in the lizard Phymaturus extrilidus in a Puna area, central-west Argentina was studied. No significant prevalence differences were found between sexes or seasons sampled. However, there were differences in mean intensity between the summer (dry period) and autumn (wet period) seasons. Mean intensity was higher in the moistest season, associated with low body condition in P. extrilidus. The genus Parapharyngodon has a direct life cycle, and environmental moisture could favor higher intensity in the rainy period. The present study provides the first data on the parasitic ecology of P. extrilidus from Argentina.

Further study on Procamallanus (Spirocamallanus) pintoi (Kohn et Fernandes, 1988) (Nematoda: Camallanidae) in Corydoras paleatus and Corydoras micracanthus (Siluriformes: Callichthyidae) from Salta, Argentina, with a key to congeneric species from Neotropical Realm.

This study describes the morphology of Procamallanus (Spirocamallanus) pintoi (Kohn et Fernandes, 1988), isolated from the intestine of Corydoras micracanthus Regan, 1912 and C. paleatus (Jenyns, 1842) (both Callichthyidae, Siluriformes) from Bermejo and Juramento River basins, respectively, province of Salta, Argentina. This is the first record of P. (S.) pintoi in C. micracanthus from Northwestern Argentina. The light and scanning electron microscopy observations of P. (S.) pintoi, revealed a few previously unreported morphological details of the cephalic region, vulva and caudal region of males. In addition, morphometric variability was observed in, mainly body size, glandular oesophagus length and position of the vulva between present specimens and those described in previous studies. A key to the species of Procamallanus (Spirocamallanus) from the Neotropical Realm is proposed.

New species of Raphidascaris (Sprentascaris) (Nematoda: Anisakidae) in Rineloricaria steinbachi (Actinopterygii: Loricariidae) from Northwest Argentina.

During a parasitological survey, we reported specimens of a new species of Raphidascaris (Sprentascaris) in Rineloricaria steinbachi from La Caldera River, province of Salta, Northwest Argentina. The new species, R. (S.) saltaensis sp. nov., is characterized by possessing 16 pairs of preanal papillae, lips with lateral protrusions and membranous elevations, and mature eggs rough-shelled with striations. This is the sixth species of the genus described in the Neotropical Region, and the second from Argentina. Rineloricaria steinbachi is reported as host of this nematode genus for the first time. A key to the species of Raphidascaris (Sprentascaris) in the Neotropical realm is provided. Also, zoogeographical and host information of the species, belonging to the subgenus Sprentascaris, is summarized.

Thubunaea eleodori sp. nov. (Nematoda: Physalopteridae) from Liolaemus eleodori (Sauria: Liolaemidae) from Argentina.

Thubunaea eleodori sp. nov. is described from the stomach of Liolaemus eleodori (Sauria: Liolaemidae) from San Guillermo National Park, Province of San Juan, Argentina. T. eleodori is most similar to those species lacking spicules, T. cnemidophorus, T. fitsimonsi, T. parkeri, T. schukurovi, and T. smogorzhewskii. T. eleodori is separated from these species based on the papilla pattern. T. eleodori has 12 pedunculate papillae and 14 sessile papillae, T. smogorzhewskii lacks pedunculate papillae, T. fitsimonsi and T. parkeri lack sessile papillae, and T. cnemidophorus has14-16 pedunculate papillae and 12 sessile papillae. T. eleodori represents the first member of the genus to be reported from Argentina.

New species of Parapharyngodon (Nematoda: Pharyngodonidae) in Phymaturus spp. (Iguania: Liolaemidae) from Argentina.

Parapharyngodon sanjuanensis sp. nov. (Nematoda: Pharyngodonidae) from the large intestines of Phymaturus punae and Phymaturus williamsi (Squamata: Liolaemidae) from province of San Juan, Argentina, is described and illustrated. Parapharyngodon sanjuanensis sp. nov. is the 54th species assigned to the genus and the 8th from the Neotropical region. It differs from other species in the genus in that males possess 8 caudal papillae, 6 of which are large and pedunculate, 2 are small, almost inconspicuous; anterior lip echinate, posterior lip bilobate; females possess prominent vulva and short stiff tail spike.

A new species of Biacantha (Nematoda: Molineidae), a parasite of the common vampire bat from the Yungas, Argentina.

A new species of Biacantha Wolfgang, 1954 (Nematoda: Molineidae), is described from the common vampire bat, Desmodus rotundus Geoffroy and St. Hilaire, 1810, from northwest Argentina. Biacantha normaliae n. sp. Oviedo, Ramallo, and Claps, is characterized by the disposition and number of ridges of the synlophe, the excretory pore located on a knob, 2 lateral processes on the tail of females, the male caudal bursa morphology, and lack of gubernaculum. This is the first species of nematode described in a vampire bat from Argentina.

A new species of Cosmocercidae (Ascaridida) in the worm lizard, Amphisbaena bolivica (Squamata: Amphisbaenidae), from Argentina.

Aplectana tucumanensis n. sp., from the large intestine of Amphisbaena bolivica, is described and illustrated. Of the 43 nominal species of Aplectana, A. tucumanensis n. sp. represents the fourth species reported in Amphisbaena spp. These 4 species are separated on the basis of male characters: spicules of Aplectana alba approximately 60 micro in length, Aplectana pusilla and A. tucumanensis approximately 100 micro, Aplectana raillieti greater than 230 micro; papillae pattern of A. pusilla with 3 preanal pairs, 2 adanal pairs, 6 postanal pairs, and 1 median papilla compared to 9 preanal pairs, 1 adanal pair, 6 postanal, and no median papilla for A. tucumanensis.

New species of Aplectana (Ascaridida: Cosmocercidae) in the toads, Rhinella granulosa and Rhinella schneideri (Anura: Bufonidae) from northern Argentina.

Aplectana adaechevarriae n. sp., from the large intestine of Rhinella granulosa and Rhinella schneideri, is described and illustrated. Of the 43 nominal species of Aplectana, A. adaechevarriae n. sp. represents the 23rd Neotropical species and the third species reported from Argentina. Of the Neotropical species, only 4, Aplectana elenae, Aplectana hylambatis, Aplectana raillieti, and A. adaechevarriae n. sp., have 8 pairs of preanal papillae. Aplectana adaechevarriae lacks a median preanal papilla; the other 3 species possess a median preanal papilla.

Two new species of cosmocercids (Ascaridida) in the toad Chaunus arenarum (Anura: Bufonidae) from Argentina.

Aplectana tarija n. sp. and Cosmocercoides lilloi n. sp., intestinal parasites of the toad Chaunus arenarum, are described. Of the 41 nominal species of Aplectana, A. tarija n. sp. represents the 22nd Neotropical species and the second species reported from Argentina. Of the 14 nominal species of Cosmocercoides, C. lilloi n. sp. represents the 15th species and the first species reported from South America.