The Experts below are selected from a list of 573 Experts worldwide ranked by ideXlab platform
Wanchai Maleewong - One of the best experts on this subject based on the ideXlab platform.
-
an unusual case of gastric gnathostomiasis caused by Gnathostoma spinigerum confirmed by video gastroscopy and morphological and molecular identification
American Journal of Tropical Medicine and Hygiene, 2021Co-Authors: Kookwan Sawadpanich, Luxkhana Sadaow, Patcharaporn Boonroumkaew, Oranuch Sanpool, Rutchanee Rodpai, Penchom Janwan, Pewpan M. Intapan, Nitiwat Chansuk, Wanchai MaleewongAbstract:Human gnathostomiasis is a harmful foodborne parasitic infection caused by nematodes of the genus Gnathostoma. Here, we report an unusual case of gastric gnathostomiasis seen in a hospital in Thailand along with the clinical characteristics, treatment, and outcome. A 39-year-old man presented with complaints of epigastric pain, dizziness, and history of passing dark, tarry stools for 2 days. The patient had a history of consuming raw freshwater fish. Supplementary differential diagnosis was performed via rapid serological testing, and presence of the causative agent was confirmed based on video gastroscopy, morphology of the removed parasite, and molecular identification. After its surgical removal from the stomach, the parasite was morphologically identified as Gnathostoma species. Molecular identification was performed via DNA extraction from the recovered worm, and amplification and sequencing of the second internal transcribed spacer (ITS2) region and partial cytochrome c oxidase subunit I (cox1) gene. The ITS2 and cox1 sequences were consistent with those of Gnathostoma spinigerum. Clinicians in endemic areas should therefore be aware of the rare clinical manifestations and use of supplementary serological tests to facilitate early diagnosis and treatment of gastric gnathostomiasis.
-
A Recombinant Matrix Metalloproteinase Protein from Gnathostoma spinigerum for Serodiagnosis of
2016Co-Authors: Kittisak Sawanyawisuth, Yukifumi Nawa, Chaisiri Wongkham, Chatchai Tayapiwatana, Amnat Kitkhu, Viraphong Lulitanond, Wanchai MaleewongAbstract:Human gnathostomiasis is an important food-borne hel-minthic zoonosis caused by spirurid nematodes of the genus Gnathostoma and is endemic in Asia and the Americas [1-3]. Generally gnathostomiasis is not a life-threatening disease, fa-talities being recorded only occasionally among neurognathos-tomiasis patients [2,4]. Gnathostoma spinigerum has been report-ed as the only causative agent for neurognathostomiasis in Southeast Asia, particularly Thailand, the only region where this condition exists [4]. Human infection occurs by consum-ing raw or inadequately cooked foods, e.g. freshwater fishes, frogs, and chickens, which harbor Gnathostoma advanced third stage larvae (AL3). The larvae migrate to the CNS to cause ra-diculomyelitis or radiculoencephalomyelitis. Subarachnoid hemorrhage (SAH) can occur, sometimes leading to death [5-7]. Definitive diagnosis of helminthic CNS infections is diffi
-
molecular phylogenetic confirmation of Gnathostoma spinigerum owen 1836 nematoda Gnathostomatidae in laos and thailand
Folia Parasitologica, 2016Co-Authors: Jurairat Jongthawin, Luxkhana Sadaow, Oranuch Sanpool, Tongjit Thanchomnang, Sakhone Laymanivong, Penchom Janwan, Wanchai MaleewongAbstract:We report the molecular-phylogenetic identification of larvae of the nematode genus Gnathostoma Owen, 1836 collected from a snake, Ptyas koros Schlegel, in Laos and adult worms from the stomach of a dog in Thailand. DNA was extracted and amplified targeting the partial cox1 gene and the ITS-2 region of ribosomal DNA. Phylogenetic analyses indicated that all five advanced third-stage larvae and seven adult worms were Gnathostoma spinigerum Owen, 1836. This is also the first molecular evidence of infection with G. spinigerum in a snake from Laos.
-
Three Human Gnathostomiasis Cases in Thailand with Molecular Identification of Causative Parasite Species.
The American journal of tropical medicine and hygiene, 2015Co-Authors: Jurairat Jongthawin, Luxkhana Sadaow, Oranuch Sanpool, Tongjit Thanchomnang, Penchom Janwan, Pewpan M. Intapan, Apichat Sangchan, Siriraksa Visaetsilpanonta, Worasak Keawkong, Wanchai MaleewongAbstract:Abstract. Human gnathostomiasis is one of the important food-borne parasitic zoonoses. The disease is caused by a spirurid roundworm of the genus Gnathostoma. Here, we describe three parasitological confirmed cases of human gnathostomiasis, caused by Gnathostoma spinigerum, in a hospital in Thailand during 2004–2012. Clinical characteristics, treatment, and outcome of cases were revealed. Parasites were accidentally recovered from patients and morphologically identified as Gnathostoma species. Confirmed diagnosis and identification of causative parasite species was made by DNA extraction of the recovered worms, followed by a polymerase chain reaction (PCR) of the second internal transcribed spacer region (ITS2) of DNA and the partial cytochrome c oxidase subunit 1 (cox-1) gene. Sequences corresponding to ITS2 and cox-1 were similar to G. spinigerum. To our knowledge, this study represents the first molecular confirmation that recovered G. spinigerum is a causative agent of human infection in Thailand.
-
growth and development of Gnathostoma spinigerum nematoda Gnathostomatidae larvae in mesocyclops aspericornis cyclopoida cyclopidae
Parasites & Vectors, 2011Co-Authors: Penchom Janwan, Luxkhana Sadaow, Oranuch Sanpool, Tongjit Thanchomnang, Wanchai MaleewongAbstract:Background Gnathostoma spinigerum larva is pathogenic, causing gnathostomiasis in humans and certain animals, and is prevalent mainly in Asia. Growth and development of Gnathostoma spinigerum larvae in the cyclopoid copepod Mesocyclops aspericornis, the first intermediate host, were examined.
Virginia León-régagnon - One of the best experts on this subject based on the ideXlab platform.
-
Systematics of the genus Gnathostoma (Nematoda: Gnathostomatidae) in the Americas Sistemática del género Gnathostoma (Nematoda: Gnathostomatidae) en América
Universidad Nacional Autónoma de México, 2011Co-Authors: Florencia Bertoni-ruiz, Marcos Rafael Lamothe Y Argumedo, Luis García-prieto, David Osorio-sarabia, Virginia León-régagnonAbstract:To date, more than 20 species of the genus Gnathostoma have been described as parasites of mammals, 9 of them in the Americas. However, the taxonomic status of some of these species has been questioned. The main goal of this study is to clarify the validity of the American species included in the genus. In order to complete this objective, we analyze type and/or voucher specimens of all these species deposited in 6 scientific collections, through morphometric and ultrastructural studies. Based on diagnostic traits as host specificity, site of infection, body size, cuticular spines, presence of 1 or 2 bulges in the polar ends of eggs, as well as eggshell and caudal bursa morphology, we re-establish Gnathostoma socialis (Leidy, 1858) and confirm the validity of other 6 species: Gnathostoma turgidum Stossich, 1902, Gnathostoma americanum Travassos, 1925, Gnathostoma procyonis Chandler, 1942, Gnathostoma miyazakii Anderson, 1964, Gnathostoma binucleatum Almeyda-Artigas, 1991, and Gnathostoma lamothei Bertoni-Ruiz, García-Prieto, Osorio-Sarabia and León-Règagnon, 2005. Gnathostoma didelphis Chandler, 1932 and Gnathostoma brasiliensis Ruiz, 1952 are considered synonyms of G. turgidum. Finally, based on a wide revision of specimens deposited in 6 American collections, we conclude that records of Gnathostoma spinigerum Owen, 1836 in the Americas are invalid.A la fecha, se han descrito más de 20 especies del género Gnathostoma parásitas de mamíferos, 9 de ellas en America. Sin embargo, el estado taxonómico de algunas ha sido cuestionado. El objetivo de este estudio es aclarar la validez de las especies americanas incluidas en el género. Para ello, se analizaron ejemplares tipo o de referencia de todas las especies, depositados en 6 colecciones científicas, mediante estudios morfométricos y ultraestructurales. Con base en rasgos diagnósticos como especificidad hospedatoria, sitio de infección, dimensiones corporales, espinas cuticulares (número de puntas, densidad, forma y distribución), presencia de uno ó dos tapones polares en los huevos, así como morfología de la bursa, patrón papilar y de la cubierta de los huevos, se re-establece a Gnathostoma socialis (Leidy, 1858) y se confirma la validez de otras 6 especies: Gnathostoma turgidum Stossich, 1902, Gnathostoma americanum Travassos, 1925, Gnathostoma procyonis Chandler, 1942, Gnathostoma miyazakii Anderson, 1964, Gnathostoma binucleatum Almeyda-Artigas, 1991 y Gnathostoma lamothei Bertoni-Ruiz, García-Prieto, Osorio Sarabia y León-Règagnon, 2005. Gnathostoma didelphis Chandler, 1932 y Gnathostoma brasiliensis Ruiz, 1952 son consideradas sinónimos de G. turgidum. Basados en una amplia revisión de material depositado en 6 colecciones Americanas, se invalidan los registros de Gnathostoma spinigerum Owen, 1836 en America
-
Identification of estuarine fish Dormitator latifrons as an intermediate host and Eleotris picta as a paratenic host for Gnathostoma binucleatum in Sinaloa, Mexico
Parasitology Research, 2008Co-Authors: Sylvia Páz Díaz-camacho, Virginia León-régagnon, Francisco Delgado-vargas, Ma. Del Carmen Cruz-otero, Magda Luz Zazueta-ramos, Angel Bojórquez-contreras, Josefina Sicairos-félix, Samuel Campista-león, Roberto Guzmán-loreto, Yukifumi NawaAbstract:Gnathostomosis is a typical fish-borne zoonotic parasitosis and is currently a serious public health issue in Mexico. Among several Gnathostoma species present in wild animals in Mexico, Gnathostoma binucleatum is the only proven species responsible for human diseases, and the advanced third stage larvae (AL3) of G. binucleatum have been found in over 20 species of fish in this country. In Sinaloa State, two fish species, Dormitator latifrons and Eleotris picta , were heavily contaminated with G. binucleatum AL3. When we analyzed the relationship between the size of the fish and the density of infection with G. binucleatum AL3, the distribution patterns of AL3 were markedly different between these two fish species. Apparent size-dependent accumulation was observed in E. picta but not in D. latifrons , suggesting that E. picta is a paratenic host whereas D. latifrons is a second intermediate host.
-
Gnathostoma binucleatum (Spirurida: Gnathostomatidae) en peces dulceacuícolas de Tabasco, México
Vicerractoría Investigación, 2004Co-Authors: Teiji Kifune, Luis García-prieto, Rafael Lamothe-argumedo, Alejandro Oceguera-figueroa, Virginia León-régagnonAbstract:La gnatostomiasis humana se adquiere al ingerir pescado de agua dulce crudo o insuficientemente cocido, infectado con larvas de tercer estadio avanzado (L3A) de nemátodos del género Gnathostoma. En el sureste de Asia, este padecimiento tiene una importancia relativa; en México, se le considera un problema de salud pública emergente desde 1970, cuando fueron registrados los primeros casos. Hasta la fecha, no se han establecido con precisión los caracteres morfométricos para diferenciar las L3A de las tres especies del género distribuidas en este país. Recientemente, se registraron larvas del parásito en peces dulceacuícolas de los Pantanos de Centla, Tabasco, sin definir su identidad específica. El análisis de cuatro especies de peces de la misma localidad reveló que tres de ellos: Petenia splendida (n=58), Cichlasoma managuense (n=35) y Gobiomorus dormitor (n=9), resultaron positivas a la infección por Gnathostoma binucleatum. La identificación del parásito se obtuvo comparando la secuencia del espaciador interno 2 (ITS2) del ADN ribosomal del material de Tabasco, con secuencias disponibles en Genbank. Este trabajo constituye el primer registro de G. binucleatum en P. splendida y G. dormitor de Tabasco y la primera determinación a nivel específico del parásito en la localidadHuman gnathostomiasis is a food-born parasitic disease of relative importance in many countries in Southeast Asia. It is caused by several species of nematodes of the genus Gnathostoma. In Mexico is an emerging public health problem since 1970, when first cases were reported. Until today, larval morphometric characters that have been proposed to differentiate between the three species of Gnathostoma present in this country, are not satisfactory. Recently, the presence of advanced third-stage larvae AdvL 3 (infective form for humans) in freshwater fishes from Pantanos de Centla, Tabasco, was recorded but their specific identity was not clarified. Examination of four species of freshwater fishes from the same locality revealed that three of them: Petenia splendida (n=58), Cichlasoma managuense (n=35) and Gobiomorus dormitor (n=9) were infected by 15 AdvL 3 of Gnathostoma binucleatum. Specific identity was obtained comparing the internal transcribed spacer 2 (ITS2) of the ribosomal DNA with sequences reported in Genbank. This is the first record of G. binucleatum in P. splendida and G. dormitor from Tabasco and the first specific determination of the parasite in the localit
Yukifumi Nawa - One of the best experts on this subject based on the ideXlab platform.
-
A Recombinant Matrix Metalloproteinase Protein from Gnathostoma spinigerum for Serodiagnosis of
2016Co-Authors: Kittisak Sawanyawisuth, Yukifumi Nawa, Chaisiri Wongkham, Chatchai Tayapiwatana, Amnat Kitkhu, Viraphong Lulitanond, Wanchai MaleewongAbstract:Human gnathostomiasis is an important food-borne hel-minthic zoonosis caused by spirurid nematodes of the genus Gnathostoma and is endemic in Asia and the Americas [1-3]. Generally gnathostomiasis is not a life-threatening disease, fa-talities being recorded only occasionally among neurognathos-tomiasis patients [2,4]. Gnathostoma spinigerum has been report-ed as the only causative agent for neurognathostomiasis in Southeast Asia, particularly Thailand, the only region where this condition exists [4]. Human infection occurs by consum-ing raw or inadequately cooked foods, e.g. freshwater fishes, frogs, and chickens, which harbor Gnathostoma advanced third stage larvae (AL3). The larvae migrate to the CNS to cause ra-diculomyelitis or radiculoencephalomyelitis. Subarachnoid hemorrhage (SAH) can occur, sometimes leading to death [5-7]. Definitive diagnosis of helminthic CNS infections is diffi
-
Infection status of the estuarine turtles Kinosternon integrum and Trachemys scripta with Gnathostoma binucleatum in Sinaloa, Mexico Estado de la infección con Gnathostoma binucleatum de las tortugas estuarinas Kinosternon integrum y Trachemys scripta en Sinaloa, México
Universidad Nacional Autónoma de México, 2010Co-Authors: Sylvia Páz Díaz-camacho, María Del Carmen De La Cruz-otero, Edith Hilario Torres-montoya, Sergio Sánchez-gonzales, Francisco Delgado-vargas, Yukifumi NawaAbstract:Human gnathostomosis, a serious public health issue in Mexico, is endemic to Sinaloa. The disease is mainly caused by consumption of the raw meat of freshwater or estuarine fishes infected with the advanced third stage larvae (AL3) of Gnathostoma binucleatum. In the present study, we examined estuarine turtles with a sample consisting of 23 Trachemys scripta and 5 Kinosternon integrum from Sinaloa, Mexico for the presence of Gnathostoma larvae; such examination was made by the pressing method of skeletal muscles between 2 glass plates. The results showed that both turtles harbored G. binucleatum AL3; identification was achieved by morphology and also by PCR/sequencing of the ITS2 region of ribosomal DNA of the larvae. Infection prevalence was higher for K. integrum (80%) than for T. scripta (69.6%), but heavy infection (> 10 AL3/turtle) was observed in the larger sized individuals of T. scripta. Consumption of the raw meat of these turtles represents a risk to acquire the disease.La gnathostomosis humana, un serio problema de salud pública en México, es endémica de Sinaloa. La enfermedad es principalmente ocasionada por el consumo de carne cruda de pescado de agua dulce o salobre infectado con larvas del tercer estadio avanzado (AL3) de Gnathostoma binucleatum. En la presente investigación, se examinaron tortugas estuarinas, 23 Trachemys scripta y 5 Kinosternon integrum, de Sinaloa, México para identificar la presencia de larvas de Gnathostoma; para ello se utilizó el método de compresión del tejido muscular entre 2 placas de vidrio. Los resultados mostraron que ambas especies de tortugas son hospederas de larvas AL3 de G. binucleatum; la identificación específica se basó en la morfología y composición molecular (por PCR/secuenciación de la región ribosomal ITS2) del DNA de las larvas. La prevalencia de la infección fue mayor en K. integrum (80%) que en T. scripta (69.6%), pero la intensidad fue más alta (> 10 AL3/tortuga) en las tortugas de mayor tamaño, T. scripta. El consumo de carne cruda de estas tortugas representa un riesgo para adquirir la enfermedad
-
discovery of an endemic area of Gnathostoma turgidum infection among opossums didelphis virginiana in mexico
Journal of Parasitology, 2009Co-Authors: Sylvia Paz Diazcamacho, Virginia Leonregagnon, Kaethe Willms, Jose Guadalupe Rendonmaldonado, Maria Del Carmen De La Cruzotero, Francisco Delgadovargas, Lilia Robert, Silvia Antuna, Yukifumi NawaAbstract:Gnathostomosis, caused by Gnathostoma binucleatum, is a serious public health issue in Mexico. Although 2 other Gnathostoma spp., G. turgidum and G. lamothei, have been found in wild animals, their natural life cycle or their relation to human disease remains unclear. While we were conducting an epidemiological survey on Gnathostoma spp. in Sinaloa State, Mexico, we found an endemic area for G. turgidum in common opossums, Didelphis virginiana, located in Tecualilla, Sinaloa. The species identification was carried out by morphological and molecular biological methods. This is the first record of an endemic area for G. turgidum infection in opossums, D. virginiana, in the Americas.
-
Identification of estuarine fish Dormitator latifrons as an intermediate host and Eleotris picta as a paratenic host for Gnathostoma binucleatum in Sinaloa, Mexico
Parasitology Research, 2008Co-Authors: Sylvia Páz Díaz-camacho, Virginia León-régagnon, Francisco Delgado-vargas, Ma. Del Carmen Cruz-otero, Magda Luz Zazueta-ramos, Angel Bojórquez-contreras, Josefina Sicairos-félix, Samuel Campista-león, Roberto Guzmán-loreto, Yukifumi NawaAbstract:Gnathostomosis is a typical fish-borne zoonotic parasitosis and is currently a serious public health issue in Mexico. Among several Gnathostoma species present in wild animals in Mexico, Gnathostoma binucleatum is the only proven species responsible for human diseases, and the advanced third stage larvae (AL3) of G. binucleatum have been found in over 20 species of fish in this country. In Sinaloa State, two fish species, Dormitator latifrons and Eleotris picta , were heavily contaminated with G. binucleatum AL3. When we analyzed the relationship between the size of the fish and the density of infection with G. binucleatum AL3, the distribution patterns of AL3 were markedly different between these two fish species. Apparent size-dependent accumulation was observed in E. picta but not in D. latifrons , suggesting that E. picta is a paratenic host whereas D. latifrons is a second intermediate host.
-
evaluation of the antigenic similarities of adult worm extracts from three Gnathostoma species using sera from mexican and japanese patients with Gnathostoma infections
Annals of Tropical Medicine and Parasitology, 2003Co-Authors: Kenji Ishiwata, Katsumi Ogata, Sylvia Paz Diaz Camacho, Fukumi Nakamurauchiyama, Kenji Hiromatsu, Yukifumi NawaAbstract:The antigenic similarities of adult-worm extracts of Gnathostoma spinigerum, G. hispidum and G. doloresi, all of which are important food-borne parasites causing larva migrans in humans, were evaluated. The 40 sera used came from gnathostomiasis cases in Mexico, where G. binucleatum is endemic, or in Japan, where G. doloresi predominates. When used as the fixed antigens in microplate-ELISA, the adult-worm extracts from the three different species of Gnathostoma were found to have equal binding capacity to the Gnathostoma-specific IgG antibodies in the sera of the Mexican and Japanese patients. The correlation coefficients for the optical densities seen in the ELISA, between any two of the three Gnathostoma extracts, were all >0.900. The dose-response curves produced when four sera were tested, in the microplate-ELISA, against the three different Gnathostoma extracts were nearly identical, indicating that the antigens in each of the extracts had similar avidity. Furthermore, the results of competitive-inhibition ELISA indicated that the antigenic specificities of the three extracts were almost identical. An antigen of 40 kDa, which SDS-PAGE and immunoblot analysis revealed to be present in all three extracts, was recognized by the sera from the gnathostomiasis cases. When the sera were investigated by dot-blot ELISA, they also gave similar results whichever extract was used as the antigen source. It appears that, in the serodiagnosis of gnathostomiasis by microplate- or dot-ELISA, each of the three adult-worm extracts would be equally useful, regardless of the causative species of Gnathostoma.
Jiménez, Pedro J. - One of the best experts on this subject based on the ideXlab platform.
-
Infección por Gnathostoma (Spirurida: Gnathostomatidae) en Hoplias microlepis: prevalencia, correlación con la talla del pez, huéspedes e implicaciones para salud pública en Ecuador
'Instituto Nacional de Salud (Colombia)', 2009Co-Authors: Alava, Juan José, Jiménez, Pedro J.Abstract:Introduction. Human gnathostomiasis has been reported in Ecuador since the early 1980s, when natural infections by Gnathostoma third larval stages were found in muscles of the second intermediary host, Hoplias microlepis (tigerfish). In Ecuador, this zoonotic disease is occasionally detected in humans, and its monitoring and eco-epidemiological assessment is of particular interest for its detection and control.Objective. The most recent evidence is provided with respect to natural infections by Gnathostoma as it occurs in the tigerfish (Hoplias microlepis), including insights into its biological cycle.Materials and methods. A total of 74 fish were collected from two localities (rice fields-wetlands and local fish market) of Samborondón County (Guayas Province). Each was examined for the presence of Gnathostoma in muscle of Hoplias microlepis. The abundance intensity and prevalence of parasites was estimated. Statistical comparisons between the two sites and correlations of parasite load versus fish size were conducted.Results. The infection prevalence by Gnathostoma was 69% (95% CI: 57-78%). The overall abundance intensity of parasites averaging the 2 sites was 1.7 larvae per fish. The proportion of infected fish was higher in rice fields (77%) when compared to those from the local fish market (62%). No statistically significant differences between the abundance intensity and prevalence were found between the sites (p>0.05). Parasite load and fish length were significantly correlated (Spearman p<0.05).Conclusions. Gnathostomiasis is a prevalent zoonosis in coastal Ecuador, and its etiologic agent is commonly found in the second intermediary host. Several Neotropical mammals are candidates as definitive reservoir hosts in the Gnathostoma biological cycle.Introducción. La gnathostomiasis humana fue reportada en Ecuador en 1981 a partir del hallazgo del tercer estadio larvario de Gnathostoma en Hoplias microlepis. Debido a que esta zoonosis es transmisible a humanos, su vigilancia y estudio ecoepidemiológico en sus huéspedes silvestres son de particular importancia en salud pública y control sanitario en Ecuador.Objetivo. Contribuir con la evidencia más reciente de infección natural por Gnathostoma en el pez dulceacuícola Hoplias microlepis y su ciclo biológico en sistemas acuáticos de la provincia del Guayas, Ecuador.Materiales y métodos. Se examinaron 74 peces obtenidos en dos localidades (campo de arrozales y mercado de peces) del Cantón Samborondón, provincia del Guayas. La presencia de Gnathostoma fue investigada en músculos de Hoplias microlepis. Se estimaron la abundancia y la prevalencia parasitarias, así como la comparación estadística de la intensidad parasitaria en los dos sitios estudiados y correlaciones de la carga parasitaria versus la talla de los peces.Resultados. La prevalencia total de Gnathostoma fue de 69%, con una abundancia media de 1,70 larvas por pez. La prevalencia parasitaria fue relativamente mayor en los campos de cultivo de arroz (77%) en relación con el mercado local (62%). No se observaron diferencias significativas en las abundancias media de larvas y en las prevalencia entre los dos sitios de estudios (p>0,05). Se encontró una relación directa y significativa entre la carga parasitaria y la longitud del pez (Spearman p<0,05).Conclusiones. La gnathostomiasis sigue siendo prevalente en la zona costera de Ecuador y el agente patógeno es aún encontrado en el huésped intermediario. Diversos mamíferos neotropicales estarían actuando como huésped reservorio definitivo en el ciclo biológico de Gnathostoma en Ecuador
Pedro J. Jiménez - One of the best experts on this subject based on the ideXlab platform.
-
Infección por Gnathostoma (Spirurida: Gnathostomatidae) en Hoplias microlepis: prevalencia, correlación con la talla del pez, huéspedes e implicaciones para salud pública en Ecuador
Instituto Nacional de Salud, 2009Co-Authors: Juan José Alava, Pedro J. JiménezAbstract:Introducción. La gnathostomiasis humana fue reportada en Ecuador en 1981 a partir del hallazgo del tercer estadio larvario de Gnathostoma en Hoplias microlepis. Debido a que esta zoonosis es transmisible a humanos, su vigilancia y estudio ecoepidemiológico en sus huéspedes silvestres son de particular importancia en salud pública y control sanitario en Ecuador. Objetivo. Contribuir con la evidencia más reciente de infección natural por Gnathostoma en el pez dulceacuícola Hoplias microlepis y su ciclo biológico en sistemas acuáticos de la provincia del Guayas, Ecuador. Materiales y métodos. Se examinaron 74 peces obtenidos en dos localidades (campo de arrozales y mercado de peces) del Cantón Samborondón, provincia del Guayas. La presencia de Gnathostoma fue investigada en músculos de Hoplias microlepis. Se estimaron la abundancia y la prevalencia parasitarias, así como la comparación estadística de la intensidad parasitaria en los dos sitios estudiados y correlaciones de la carga parasitaria versus la talla de los peces. Resultados. La prevalencia total de Gnathostoma fue de 69%, con una abundancia media de 1,70 larvas por pez. La prevalencia parasitaria fue relativamente mayor en los campos de cultivo de arroz (77%) en relación con el mercado local (62%). No se observaron diferencias significativas en las abundancias media de larvas y en las prevalencia entre los dos sitios de estudios (p>0,05). Se encontró una relación directa y significativa entre la carga parasitaria y la longitud del pez (Spearman p
