Prevalence of parasites in selected captive bird species

Abstract Blood and fecal samples of chukar partridge (Alectoris chukar), albino pheasant (Phasianus colchicus), silver pheasant (Lophura nycthemera), rose-ringed parakeet (Psittacula krameri) and turkeys (Meleagris gallopavo) were analyzed to check parasitic prevalence. To record parasites these five avian species were placed kept in separate cages at Avian Conservation and Research Center, Department of Wildlife an Ecology, University of Veterinary and Animal Sciences, Lahore, Pakistan. 100 fecal and 100 blood samples for each bird species were inspected to analyze internal parasites. During present study, 17 species of endoparasites 14 from fecal samples and three from blood were examined. Two species of ectoparasites i.e. mite Dermanyssus gallinae 42% and fowl ticks Args persicus 41%were studied. Blood parasites included Plasmodium juxtanucleare 50%, Leucoctoyzoon simond having parasitic prevalence 40%, and Aegyptinella pullorum having parasitic prevalence of 40%. Parasitic species recorded from fecal samples included 6 species of nematodes viz. Allodpa suctoria 2%. Syngamus trachea with parasitic prevalence of 60%, Capillaria annulata 37.5%, Ascardia galli 24%, Capillaria anatis 40% and Heterakis gallinarum 28.3%. Similarly, two species of trematodes viz. Prosthogonimus ovatus having parasitic prevalence of 50% and Prosthogonimus macrorchis 21% were also documented from fecal avian samples . Single cestode species Raillietina echinobothrida having parasitic prevalence of 72% and 3 protozoan species i.e. Eimeria maxima having parasitic prevalence of 21%, Giardia lamblia 41% and Histomonas meleagridis 18% were documented during corpological analysis. In our recommendation, proper sanitation, medication and vaccination of birds enclousres are suggested to avoid parasites.

RESUMO Amostras de sangue e fezes de perdiz chukar (Alectoris chukar), faisão-albino (Phasianus colchicus), faisão-prateado (Lophura nycthemera), periquito-de-rosa (Psittacula krameri) e perus (Meleagris gallopavo) foram analisadas para verificar a prevalência de parasitas. Para registrar os parasitas, essas cinco espécies de aves foram colocadas em gaiolas separadas no Centro de Conservação e Pesquisa de Aves, Departamento de Vida Selvagem e Ecologia, Universidade de Veterinária e Ciências Animais, Lahore, Paquistão. Cem amostras fecais e 100 amostras de sangue para cada espécie de ave foram inspecionadas para analisar os parasitas internos. Durante o presente estudo, foram examinadas 17 espécies de endoparasitas, 14 de amostras fecais e 3 de sangue. Foram estudadas duas espécies de ectoparasitas, ou seja, o ácaro Dermanyssus gallinae 42% e o carrapato aviário Args persicus 41%. Os parasitas sanguíneos incluíram Plasmodium juxtanucleare 50%, Leucoctoyzoon simond com prevalência parasitária de 40% e Aegyptinella pullorum com prevalência parasitária de 40%. As espécies parasitas registradas em amostras fecais incluíram 6 espécies de nematoides viz. Allodpa suctoria 2%, Syngamus traqueia com prevalência parasitária de 60%, Capillaria annulata 37,5%, Ascardia galli 24%, Capillaria anatis 40% e Heterakis gallinarum 28,3%. Da mesma forma, duas espécies de trematódeos viz. Prosthogonimus ovatus com prevalência parasitária de 50% e Prosthogonimus macrorchis 21% também foram documentados em amostras fecais de aves. Espécies de cestoide único Raillietina echinobothrida com prevalência parasitária de 72% e 3 espécies de protozoários, isto é, Eimeria maxima com prevalência parasitária de 21%, Giardia lamblia 41% e Histomonas meleagridis 18% foram documentadas durante a análise corpológica. Em nossa recomendação, o saneamento adequado, medicação e vacinação de invólucros de pássaros são sugeridos para evitar parasitas.

Prevalence of parasites in selected captive bird species / Prevalência de parasitas em espécies de pássaros em cativeiro selecionados

Abstract Blood and fecal samples of chukar partridge (Alectoris chukar), albino pheasant (Phasianus colchicus), silver pheasant (Lophura nycthemera), rose-ringed parakeet (Psittacula krameri) and turkeys (Meleagris gallopavo) were analyzed to check parasitic prevalence. To record parasites these five avian species were placed kept in separate cages at Avian Conservation and Research Center, Department of Wildlife an Ecology, University of Veterinary and Animal Sciences, Lahore, Pakistan. 100 fecal and 100 blood samples for each bird species were inspected to analyze internal parasites. During present study, 17 species of endoparasites 14 from fecal samples and three from blood were examined. Two species of ectoparasites i.e. mite Dermanyssus gallinae 42% and fowl ticks Args persicus 41%were studied. Blood parasites included Plasmodium juxtanucleare 50%, Leucoctoyzoon simond having parasitic prevalence 40%, and Aegyptinella pullorum having parasitic prevalence of 40%. Parasitic species recorded from fecal samples included 6 species of nematodes viz. Allodpa suctoria 2%. Syngamus trachea with parasitic prevalence of 60%, Capillaria annulata 37.5%, Ascardia galli 24%, Capillaria anatis 40% and Heterakis gallinarum 28.3%. Similarly, two species of trematodes viz. Prosthogonimus ovatus having parasitic prevalence of 50% and Prosthogonimus macrorchis 21% were also documented from fecal avian samples . Single cestode species Raillietina echinobothrida having parasitic prevalence of 72% and 3 protozoan species i.e. Eimeria maxima having parasitic prevalence of 21%, Giardia lamblia 41% and Histomonas meleagridis 18% were documented during corpological analysis. In our recommendation, proper sanitation, medication and vaccination of bird's enclousres are suggested to avoid parasites.

RESUMO Amostras de sangue e fezes de perdiz chukar (Alectoris chukar), faisão-albino (Phasianus colchicus), faisão-prateado (Lophura nycthemera), periquito-de-rosa (Psittacula krameri) e perus (Meleagris gallopavo) foram analisadas para verificar a prevalência de parasitas. Para registrar os parasitas, essas cinco espécies de aves foram colocadas em gaiolas separadas no Centro de Conservação e Pesquisa de Aves, Departamento de Vida Selvagem e Ecologia, Universidade de Veterinária e Ciências Animais, Lahore, Paquistão. Cem amostras fecais e 100 amostras de sangue para cada espécie de ave foram inspecionadas para analisar os parasitas internos. Durante o presente estudo, foram examinadas 17 espécies de endoparasitas, 14 de amostras fecais e 3 de sangue. Foram estudadas duas espécies de ectoparasitas, ou seja, o ácaro Dermanyssus gallinae 42% e o carrapato aviário Args persicus 41%. Os parasitas sanguíneos incluíram Plasmodium juxtanucleare 50%, Leucoctoyzoon simond com prevalência parasitária de 40% e Aegyptinella pullorum com prevalência parasitária de 40%. As espécies parasitas registradas em amostras fecais incluíram 6 espécies de nematoides viz. Allodpa suctoria 2%, Syngamus traqueia com prevalência parasitária de 60%, Capillaria annulata 37,5%, Ascardia galli 24%, Capillaria anatis 40% e Heterakis gallinarum 28,3%. Da mesma forma, duas espécies de trematódeos viz. Prosthogonimus ovatus com prevalência parasitária de 50% e Prosthogonimus macrorchis 21% também foram documentados em amostras fecais de aves. Espécies de cestoide único Raillietina echinobothrida com prevalência parasitária de 72% e 3 espécies de protozoários, isto é, Eimeria maxima com prevalência parasitária de 21%, Giardia lamblia 41% e Histomonas meleagridis 18% foram documentadas durante a análise corpológica. Em nossa recomendação, o saneamento adequado, medicação e vacinação de invólucros de pássaros são sugeridos para evitar parasitas.

Prevalencia de Giardia lamblia por ecorregiones en preescolares y escolares peruanos: Propuesta de estratificación de riesgo

Introducción. La giardiasis es ocasionada por el protozoario intestinal Giardia lamblia, su transmisión tiene variabilidad geográfica y a pesar de ser muy frecuente, no existe una herramienta de estratificación de riesgo para priorizar las intervenciones. Objetivo. Estimar la prevalencia de G. lamblia en preescolares y escolares peruanos por ecorregiones entre 1990 a 2018. Métodos. A partir de un metaanálisis previo, se realizó un subanálisis por ecorregiones de la prevalencia de G. lamblia en 26 estudios en preescolares y escolares peruanos entre 1990 a 2018. Se extrajeron los datos por distrito y utilizando Google Earth fueron clasificados en ecorregiones. La heterogeneidad fue analizada mediante la prueba de Q de Cochrane y el sesgo de publicación mediante el método de Egger con StatsDirect versión 3.2.7. Se utilizó el método de riesgo absoluto para estratificar la prevalencia a nivel de distrito y se definió 4 estratos en base a los percentiles o arbitrariamente. Resultados. Se identificaron 43 datos de prevalencia a nivel de distrito que incluyeron 7606 participantes. Las prevalencias combinadas más altas por el método de efectos aleatorios de G. lamblia fueron de 47,0% intervalo de confianza (IC) 95%: 40,0 -54,0) en el desierto del Pacífico; 27,9% (IC95%: 22,8 - 33,2) en selva baja y 26,9% (IC95%: 22,5 -31,5) en la Puna. Conclusiones. De cada 100 preescolares y escolares que viven en las ecorregiones del desierto del Pacífico, selva baja y Puna, 47, 28 y 27 menores de edad, respectivamente, están infectados con G. lamblia. Asimismo, se propone 4 estratos de riesgo en función de la prevalencia: esporádico (0 a <1%), hipoendémico (1 a <25%), mesoendémico (≥ 25 a <50%) e hiperendémico (≥50%).

Introduction. Giardiasis is caused by an intestinal protozoan, Giardia lamblia. Despite its high prevalence and geographical transmission variability, there is no risk stratification tool available to prioritize interventions. Objective. To estimate the prevalence of G. lamblia in Peruvian preschoolers and schoolchildren by ecoregion from 1990 to 2018. Methods. Based on a previous meta-analysis, we conducted a G. lamblia prevalence sub-analysis by ecoregions from data of 26 studies in Peruvian preschoolers and school-aged children between 1990 and 2018. The data was extracted by district, a classification by ecoregions was made through Google Earth. Heterogeneity was analyzed using Cochrane Q test and publication bias applying the Egger method with StatsDirect version 3.2.7. The absolute risk method was performed to stratify the prevalence at district level, and 4 strata were defined based on percentiles or arbitrarily. Results. Forty-three district-level prevalence data was estimated, including 7,606 participants. The highest pooled prevalences by the random effects method of G. lamblia were 47.0% (95% CI: 40.0-54.0) in the Pacific desert, 27.9% (95% CI: 22.8-33.2) in the lowland forest and 26.9% (95% CI 22.5-31.5) in the Puna. Conclusions. Of every 100 preschoolers and school-aged children living in the Pacific desert, lowland forest, and in the Puna ecoregions, 47, 28, and 27 minors are infected with G. lamblia, respectively. Likewise, 4 risk strata are proposed based on prevalence: sporadic (0 to <1%), hypoendemic (1 to <25%), mesoendemic (≥25 to <50%) and hyperendemic (≥50%).

Establishment of duplex TaqMan RT-PCR method for detection of Entamoeba histolytica and Giardia lamblia in fecal sample / 中国热带医学

@#Abstract: Objective To establish the duplex TaqMan RT-PCR method for detection of Entamoeba histolytica and Giardia lamblia in fecal samples. Methods Primer pairs and probes for Entamoeba histolytica and Giardia lamblia were designed and duplex TaqMan RT-PCR amplification system was constructed. PCR products were inserted into the pUC57 plasmid, and the lower limit of detection of the method was determined. Clinical stool samples were tested in order to evaluated the efficacy of the method. Results The detection limits of duplex TaqMan RT-PCR were 31.6 copies/μL for Entamoeba histolytica and 32 copies/μL for Giardia lamblia, respectively. Of the total of 212 clinical stool samples tested, all 3 samples with E. histolytica-positive patients by microscopy were positive by PCR, while 1 from 209 samples with E. histolytica-negative patients by microscopy were positive by PCR, and the remaining samples were negative. For Giardia lamblia, all 8 samples positive by microscopy were positive by PCR, and 1 from 204 sample with a microscopy-negative patient was positive by PCR, and the remaining samples were negative. The amplification product sequencing and blast analysis were used to confirm that the amplified sequence in the specimen of a patient with negative microscopy but positive PCR belongs to the targeted pathogen, supported by clinical symptoms and laboratory test results. PCR results for other diarrhea-causing pathogens were negative, indicating no cross-reactivity. Conclusions The dual TaqMan RT-PCR method developed in this study can not only detect microscopy-positive samples of Entamoeba histolytica and Giardia lamblia but also can detect samples that were missed by microscopy, with higher sensitivity than the microscopy method. Further, this detection method does not cross-react with other diarrhea-causing pathogens, including cross-react with other diarrhea-causing pathogens including Iodamoeba butschlii, Blastocystis hominis, Plesiomonas, Aeromonas, Salmonella, Shigella, Sphaerozoum fuscum, and Entamoeba hartmani, thus has a good specificity.

Prevalence and genotyping of Cryptosporidium spp. and Giardia lamblia in dogs and cats from a pet hospital in Shanghai Municipality / 中国血吸虫病防治杂志

Objective To investigate the prevalence and genotypes of Cryptosporidium spp. and Giardia lamblia in dogs and cats from a pet hospital in Shanghai Municipality. Methods A total of 145 fresh fecal samples were collected from pet dogs and cats in a pet hospital in Shanghai Municipality during the period from November 2021 to June 2022, including 99 dog fecal samples and 46 cat fecal samples. The small subunit ribosomal ribonucleic acid (SSU rRNA) gene of Cryptosporidium and the triose phosphate isomerase (TPI) gene of G. lamblia were amplified using nested PCR assay, and the positive amplification products were sequenced from both directions. The sequence assembly was performed using the software Clustal X 2.1, and sequence alignment was conducted using BLAST. A phylogenetic tree was created with the Neighbor-Joining method using MEGA 11.0 to identify parasite species or genotype. Results The overall prevalence of Cryptosporidium and G. lamblia was 20.00% (29/145) in 145 pet dog and cat fecal samples, with the prevalence of 0.69% (1/145) and 19.31% (28/145) in Cryptosporidium and G. lamblia, respectively. G. lamblia was only detected in dog fecal samples, with prevalence of 18.18% (18/99), while the detection rates of Cryptosporidium and G. lamblia were 2.17% (1/46) and 21.74% (10/46) in cat fecal samples. Nucleotide sequence analysis showed that one Cryptosporidium positive sample was characterized as C. felis, and 28 G. lamblia positive samples were all characterized as Giardia assemblage A, which showed 100% sequence homology with human isolates of Giardia. Phylogenetic analysis revealed that the sequences obtained in this study belonged to the same branch with the reported Giardia assemblage A. Conclusions Cryptosporidium and G. lamblia infection was prevalent in pet dogs and cats from the study pet hospital in Shanghai Municipality, and there is a zoonotic risk for the species and genotype. Intensified surveillance of Cryptosporidium and Giardia infection is recommended in pets and their owners, and improved management of pet keeping is required.

Identification and verification of α-11 giardin-interacting protein / 中国血吸虫病防治杂志

Objective To identify and verify the interacting protein of α-11 giardin, so as provide the experimental evidence for studies on the α-11 giardin function. Methods The yeast two-hybrid cDNA library of the Giardia lambia C2 strain and the bait plasmid of α-11 giardin were constructed. All proteins interacting with α-11 giardin were screened using the yeast two-hybrid system. α-11 giardin and all screened potential interacting protein genes were constructed into pBiFc-Vc-155 and pBiFc-Vn-173 plasmids, and co-transfected into the breast cancer cell line MDA-MB-231. The interactions between α-11 giardin and interacting proteins were verified using bimolecular fluorescence complementation (BiFC). Results The yeast two-hybrid G. lambia cDNA library which was quantified at 2.715 × 107 colony-forming units (CFU) and the bait plasmid containing α-11 giardin gene without an autoactivation activity were constructed. Following two-round positive screening with the yeast two-hybrid system, two potential proteins interacting with α-11 giardin were screened, including eukaryotic translation initiation factor 5A (EIF5A), calmodulin-dependent protein kinase (CAMKL) and nicotinamide adenine dinucleotide phosphate-specific glutamate dehydrogenase (NADP-GDH), hypothetical protein 1 (GL50803_95880), hypothetical protein 2 (GL50803_87261) and a protein from Giardia canis virus. The α-11 giardin and EIF5A genes were transfected into the pBiFc-Vc-155 and pBiFc-Vn-173 plasmids using BiFC, and the recombinant plasmids pBiFc-Vc-155-α-11 and pBiFc-Vn-173-EIF5A were co-tranfected into MDA-MB-231 cells, which displayed green fluorescence under a microscope, indicating the interaction between α-11 giardin and EIF5A protein in cells. Conclusion The yeast two-hybrid cDNA library of the G. lambia C2 strain has been successfully constructed, and six potential protein interacting with α-11 giardin have been identified, including EIF5A that interacts with α-11 giardin in cells.

Giardia lamblia-infected preschoolers present growth delays independent of the assemblage A, B or E

BACKGROUND Intestinal parasite Giardia can affect children's physical development mainly stunting even in asymptomatic cases. The protozoa G. lamblia is divided into assemblages A-H. However, it is still unclear whether clinical manifestations and pathogenesis may vary according to the infecting assemblage. OBJECTIVES To investigate whether G. lamblia assemblages influence differently the physical development of preschoolers from a community of Rio de Janeiro, Brazil. METHODS Anthropometric parameters were analysed from children attending a daycare centre and stool samples were obtained for the G. lamblia diagnosis. G. lamblia isolates from positive samples were genotyped. Data were analysed in order to verify whether there is a relationship between G. lamblia infection and the physical development of children according to the assemblage. FINDINGS Herein we demonstrated that although eutrophic, G. lamblia-infected daycare preschoolers from a low-income community presented growth delay compared to non-infected ones. This effect was observed for the three assemblages (A, B or E) found infecting humans. MAIN CONCLUSION G. lamblia causes growth delays on children independent of infecting assemblage (A, B or E).

Zoonotic Giardia duodenalis assemblage A in northern sloth from Brazilian Amazon

BACKGROUND The parasite Giardia duodenalis infects a wide range of vertebrate hosts, including domestic and wild animals as well as humans. Giardia is genotyped into eight assemblages (A-H). Zoonotic assemblages A and B have already been identified in humans and wild and domestic animals (non-human primates and cats) from Brazilian Amazon and in the world. Due to its zoonotic/zooanthroponotic nature, surveillance initiatives and the definition of Giardia assemblages are important in order to characterise the epidemiological scenario and to implement further control measures. OBJECTIVES Determine assemblages of G. duodenalis in sloths from the Brazilian Amazon Region. METHODS Faecal parasitological examination of sloths from Amazonas State. Polymerase chain reaction (PCR) targeting the beta giardin (BG), and genes from multilocus sequence typing (MLST) scheme, amplicon sequencing and phylogenetic analysis. FINDINGS Here, we identified, by microscopy, Giardia in two northern sloths (Bradypus tridactylus). These two samples were submitted to molecular assays and it was revealed that both were infected by G. duodenalis assemblage A. Phylogenetic analysis showed that they belong to assemblage A within sequences from humans and wild and domestic animals. CONCLUSION Therefore, besides showing, by the first time, the current presence of this parasite in sloths, our findings reveals that this wild animal species would be part of the zoonotic/zooanthroponotic scenario of this parasite in the Brazilian Amazon.

Evaluación y caracterización de la sirtuina 2.3 de Giardia duodenalis (CdSir2.3)

La giardiasis es la enfermedad gastrointestinal de mayor incidencia mundial, causada por el protozoario Giardia duodenalis, para la cual no se cuenta con una vacuna o tratamiento eficiente. En aras de buscar nuevos blancos farmacológicos contra este parásito, se han estudiado las enzimas del metabolismo energético, como las sirtuinas, deacetilasas dependientes del dinucleótido de adenina y nicotinamida (NAD). Previamente se identificó a GdSir2.1 y GdSir2.2 como deacetilasas dependientes de NAD, con localizaciones subcelulares diferentes. En este trabajo se estudió otro candidato a sirtuina (GdSir2.3) mediante herramientas bioinformáticas para la identificación de características típicas de la familia sirtuina en la secuencia del candidato, y experimentales como la obtención de la proteína recombinante 6xHis-GdSir2.3 que demostró actividad deacetilasa dependiente de NAD y que sirvió como antígeno en la producción de los IgY - α -6xHis-GdSir2.3 para la localización subcelular de la proteína endógena en G. duodenalis. Lo anterior concuerda con otros estudios donde se señala a GdSir2.3 como un importante regulador de la enquistación, debido a su aumento de expresión durante esta etapa del ciclo de vida, constituyéndola como un blanco farmacológico promisorio para el control de esta parasitemia.

Giardiasis is the gastrointestinal disease with the highest incidence worldwide, caused by the protozoan Giardia duodenalis, for which there is no vaccine or efficient treatment. In order to find new pharmacological targets against this parasite, energy metabolism enzymes such as sirtuins, deacetylases dependent on the nicotinamide adenine dinucleotide (NAD), have been studied. GdSir2.1 and GdSir2.2 were previously identified as NAD-dependent deacetylases, with different subcellular locations. In this work, another candidate for sirtuin (GdSir2.3) was studied using bioinformatic tools for the identification of typical characteristics of the sirtuin family in the sequence of the candidate; and experimental ones such as obtaining the recombinant protein 6xHis-GdSir2.3 that demonstrated NAD-dependent deacetylase activity; and that it served as an antigen in the production of IgY - α - 6xHis-GdSir2.3 for the subcellular localization of the endogenous protein in G. duodenalis. The foregoing is consistent with other studies where GdSir2.3 is indicated as an important regulator of encyst due to its increased expression during this stage of the life cycle, constituting it as a promising drug target for the control of this parasitaemia.

A giardíase é a doença gastrointestinal de maior incidência no mundo, causada pelo protozoário Giardia duodenalis, para a qual não existe vacina ou tratamento eficaz. Com o objetivo de encontrar novos alvos farmacológicos contra esse parasita, têm sido estudadas enzimas do metabolismo energético, como as sirtuínas, desacetilases dependentes do dinucleotídeo adenina nicotinamida (NAD). GdSir2.1 e GdSir2.2 foram previamente identificados como desacetilases dependentes de NAD, com diferentes localizações subcelulares. Neste trabalho, outro candidato a sirtuin (GdSir2.3) foi estudado usando ferramentas de bioinformática para a identificação de características típicas da família sirtuin na sequência do candidato; e experimentais, como a obtenção da proteína recombinante 6xHis-GdSir2.3 que demonstrou atividade desacetilase dependente de NAD; e que serviu como antígeno na produção de IgY - α - 6xHis-GdSir2.3 para a localização subcelular da proteína endógena em G. duodenalis. O exposto é consistente com outros estudos em que o GdSir2.3 é apontado como um importante regulador de encisto devido à sua expressão aumentada durante esta fase do ciclo de vida, constituindo-se como um alvo promissor para o controle dessa parasitemia.

Evaluación de pruebas inmunológicas en el diagnóstico de Giardia duodenalis y Cryptosporidium spp, Honduras / Evaluation of immunologic tests in the diagnosis of Giardia duodenalis and Cryptosporidium spp., Honduras

Antecedentes: No conocemos datos sobre evaluación de pruebas inmunológicas para mejorar el diagnóstico de Giardia duodenalis y Cryptosporidium spp., agentes etiológicos de diarrea de importancia mundial, en Honduras. Objetivos: Comparar dos pruebas inmunológicas para el diagnóstico de Giardia y Cryptosporidium spp. con microscopía de rutina y determinar su aplicabilidad local. Métodos: Estudio descriptivo transversal. En 2013, 134 muestras de heces recibidas en el Servicio de Parasitología del Hospital Escuela (HE) y 67 muestras del Centro de Salud Alonso Suazo (CSAS) se analizaron con una Prueba Rápida Inmunocromatográfica (PDR). En 2019-2020, 60 muestras de heces del HE se analizaron con una prueba inmunoenzimática ELISA. El protocolo de rutina incluyó examen directo en solución salina y solución de Lugol, coloración tricrómica y coloración ácido resistente modificada (ARM) (HE) y examen directo en solución salina y solución de Lugol (CSAS). Resultados: Cada prueba inmunológica mostró mayor positividad que la microscopía: en 134 muestras del HE para Giardia (6.7% vs 4.5%) y Cryptosporidium (3.7% vs 0.7%), similar en 67 muestras del CSAS (14.9% vs 7.5% para Giardia; 0.7% para Cryptosporidium con la prueba inmunológica). De 60 muestras analizadas por ELISA en HE, 31.7% fue positiva por Giardia vs 18.3% en examen directo y 23.3% en coloración tricrómica; 6.7% positiva por Cryptosporidium spp. vs 3.3% por coloración ARM. Discusión: Pruebas inmunológicas aumentaron significativamente el diagnóstico de ambas parasitosis; sin embargo, publicaciones sobre pruebas similares ofrecieron resultados no concluyentes. Por costo elevado podrían reservarse para pacientes pediátricos, pacientes inmunocomprometidos en hospitales, complementando microscopía. Los laboratorios de salud deben fortalecer capacidad diagnóstica...(AU)

Use of laboratory methodologies to confirm an outbreak of acute diarrheal disease caused by multiple pathogens / Uso de metodologias laboratoriais para confirmação de surto de doença diarreica aguda causada por múltiplos patógenos

The aim of this study was to investigate an outbreak caused by protozoa, which occurred in a municipality in the Brazil southern region. The investigations were carried out analyzing 47 fresh stool samples and 26 water samples by parasitological and molecular methods, as well as, direct immunofluorescence. After the filtrations of water samples and purification of stool samples, the concentrates were evaluated microscopically for presence of parasites. Molecular analyses were performed by polymerase chain reaction (PCR) for DNA detection of Giardia spp., Cryptosporidium parvum, C. hominis and Cyclospora cayetanensis. Out of 26 water samples, 30.8% (8/26) had waterborne protozoa and C. cayetanensis was the most prevalent (15.5%). Out of the 47 stool samples, 23.4% (11/47) were infected with C. cayetanensis and Giardia spp. The results showed that backwash water samples from filters of the Water Treatment Station were contaminated with C. cayetanensis, C. hominis and Giardia spp., suggesting the contamination of water sources with human waste brought by sewage. These results show the importance of protozoa investigation in water and stool samples by laboratory methodologies principally in outbreaks causing acute diarrheal disease (AU).

O objetivo do presente estudo foi investigar um surto causado por protozoários, ocorrido em um município da região sul do Brasil. As investigações foram realizadas analisando 47 amostras de fezes frescas e 26 amostras de água por métodos parasitológicos, moleculares e de imunofluorscência direta. Após as filtrações das amostras de água e purificação das amostras de fezes, os concentrados foram avaliados microscopicamente a procura de parasitas. A seguir, foram analisadas, pela reação em cadeia da polimerase (PCR), a detecção de DNA de Giardia spp., Cryptosporidium parvum, C. hominis e Cyclospora cayetanensis. Das 26 amostras de água, 30,8% (8/26) apresentaram protozoários de veiculação hídrica, sendo que, C. cayetanensis foi o mais prevalente (15,5%). Das 47 amostras de fezes, 23,4% (11/47) estavam infectadas por C. cayetanensis e Giardia spp. Os resultados mostraram que as águas de retrolavagem dos filtros da Estação de Tratamento de Água estavam contaminadas com C. cayetanensis, C. hominis e Giardia spp. sugerindo a contaminação dos mananciais com dejetos humanos trazidos pelo esgoto. Estes resultados mostram a importância da investigação de protozoários em água e fezes por metodologias laboratoriais, principalmente em surtos que causam doença diarreica aguda (AU).

Prevalence and risk factors of Giardia lamblia infections among colorectal cancer patients in Henan Province / 中国血吸虫病防治杂志

Objective To investigate the epidemiological characteristics and identify the risk factors of Giardia lamblia infections among patients with colorectal cancer in Henan Province. Methods A cross-sectional study was performed for questionnaire surveys among colorectal cancer patients in Henan Cancer Hospital during the period from March to July, 2021. Patients’ stool samples were collected, and the triosephosphate isomerase (tpi) gene of G. lamblia was amplified in stool samples using nested PCR assay to characterize the parasite genotype. Univariate analysis and multivariate logistic regression analyses were employed to identify the risk factors of G. lamblia infections among colorectal cancer patients. Results A total of 307 colorectal cancer patients were investigated, including 176 males (57.3%) and 131 females (42.7%). PCR assay detected 8.1% [95% confidential interval (CI): (0.056, 0.117)] prevalence of G. lamblia infections among the study subjects, and there was no significant difference in the prevalence between men [9.1%, 95% CI: (0.057, 0.143)] and women [6.9%, 95% CI: (0.037, 0.125)] (χ2 = 0.495, P = 0.482). In addition, there was no age-specific prevalence of G. lamblia infections among the participants (χ2 = 1.534, P = 0.675). Multivariate logistic regression analysis identified use of septic tanks [odds ratio (OR) = 3.336, 95% CI: (1.201, 9.267)], daily use of well water [OR = 3.042, 95% CI: (1.093, 8.465)] and raising livestock [OR = 3.740, 95% CI: (1.154, 12.121)] as risk factors of G. lamblia infections among colorectal cancer patients, and the prevalence of abdominal pain was significantly greater in colorectal cancer patients with G. lamblia infections than in those without infections (P = 0.017). Among the 25 patients with G. lamblia infections, assemblage A was characterized in 24 (96.0%) cases and assemblage B in one case (4.0%). Conclusions The prevalence of G. lamblia is high among colorectal cancer patients in Henan Province, and assemblage A is the dominant genotype of G. lamblia. Use of septic tanks, daily use of well water and raising livestock are risk factors of G. lamblia infections among patients with colorectal cancer.

Caracterización físico-química y microbiológica del agua de un municipio del departamento de Boyacá (Colombia) / Physical Chemical and Microbiological Characterization of Water of a Municipality of the Department of Boyacá-Colombia / Caracterização físico-química e microbiológica da água de um município do departamento de Boyacá (Colômbia)

Introducción: El agua salubre y fácilmente accesible es importante para la salud pública, si se utiliza para beber, uso doméstico, producir alimentos o fines recreativos. El agua contaminada y el saneamiento deficiente están re-lacionados con la transmisión de enfermedades. Objetivo: Evaluar las características físico-químicas y microbiológicas de la red de distribución del acueducto urbano de un municipio de Boyacá. Materiales y métodos: Estudio cuantitativo descriptivo transversal. Se tomaron muestras de agua en 13 puntos, 7 concertados y materializados de la red de distribución, uno en la bocatoma de entrada de la planta, dos pozos y tres nacimientos, de donde se abastece la población. Se realizaron análisis físicos, químicos y microbiológicos de cada una de las muestras. Resultados: En las muestras sin tratamiento hubo concentraciones altas de unidades platino, cobalto y turbiedad. El cloro residual libre en dos muestras de agua tratada estaba por debajo de los límites establecidos. Se detecta-ron microorganismos heterótrofos y coliformes en las muestras de agua obtenidas de fuentes de abastecimiento. En dos puntos se encontraron quistes de Giardia y ooquistes de Cryptosporidium. De las 13 muestras estudiadas, tres arrojaron un índice de riesgo por calidad del agua inviable sanitariamente. Conclusiones: Se evidenció que el agua se encuentra en un nivel de riesgo inviable sanitariamente, lo cual demuestra que el sistema de tratamiento es insuficiente para garantizar el suministro de agua apta para el consumo humano.

Introduction: Safe and easily accessible water is important to public health, whether it is used for drinking, domestic use, food production, or recreational purposes. Contaminated water and poor sanitation are linked to disease transmission. Objective: Evaluate the physical chemical and microbiological characteristics of the distribution network of the urban aqueduct of a municipality of Boyacá. Materials and methods: Cross-sectional descriptive quantitative study, water samples were taken at thirteen points, seven points agreed and materialized from the distribution network, one at the entrance of the plant, one in a deep well and in three births, where it is supplied the population. Phy-sical, chemical and microbiological analyzes were performed. Results: The untreated samples showed high levels of cobalt platinum units and turbidity. The free residual chlorine in two samples of treated water was below the established limits. Heterotrophic and Coliform microorganisms were detected in water samples obtained from sources of supply. At two points, Giardia cysts and Cryptosporidium oocysts were found. Of the Thirteen samples studied, three showed a Risk Index for sanitary water quality. Conclusions: It is evident that the water is at a level of sanitary unfeasible risk, which demonstrates that the treatment system is not sufficient to guarantee the supply of water suitable for human consumption.

Introdução: Água segura e de fácil acesso é importante para a saúde pública, seja ela usada para beber, uso doméstico, produção de alimentos ou para fins recreativos. A água contaminada e o sa-neamento precário estão ligados à transmissão de doenças. Objetivos: Avaliar as características físico-químicas e microbiológicas da rede de distribuição do aque-duto urbano de um município de Boyacá. Materiais e métodos: Estudo quantitativo descritivo transversal. Foram coletadas amostras de água em 13 pontos, 7 concertados e materializados da rede de distribuição, um na entrada da planta, dois poços e três nascentes, dos quais a população é abastecida. Foram realizadas analises físicas, químicas e microbiológicas em cada uma das amostras. Resultados: Nas amostras não tratadas havia concentrações altas de unidades platina, cobalto e turbidez. O cloro residual livre em duas amostras de água tratada estava abaixo dos limites estabele-cidos. Microrganismos heterótrofos e coliformes foram detectados em amostras de água obtidas de fontes de abastecimento. Os cistos de Giardia e os oocistos de Cryptosporidium foram encontrados em dois pontos. Das 13 amostras estudadas, três apresentaram um índice de risco para a qualidade não higiénica da água. Conclusões: Ficou evidente que a água está em um nível de risco sanitário inviável, o que mostra que o sistema de tratamento é insuficiente para garantir o abastecimento da água adequada para o consumo humano.

Frecuencia de parasitismo intestinal en niños con diarrea persistente en el Área Sanitaria Sur de Sevilla

RESUMEN Introducción: La diarrea persistente está incluida en una gran categoría denominada síndrome de diarrea crónica, problema relativamente común de consulta médica en la edad pediátrica. La importancia y prevalencia de la diarrea persistente de etiología parasitaria es poco conocida en España. Objetivo: Determinar la prevalencia de parasitismo intestinal en niños con síndrome de diarrea persistente, así como las características clínicas asociadas a la etiología parasitaria en el Área Sanitaria Sur de Sevilla (España). Métodos: Estudio retrospectivo y de corte transversal realizado en un año (mayo de 2017-mayo de 2018). Se incluyeron a pacientes en edad pediátrica que consultaban por cuadro diarreico superior a 2 semanas y/o dolor abdominal. El estudio de laboratorio incluyó la determinación de sustancias reductoras, leucocitos fecales y grasas, además del estudio de la etiología infecciosa (bacterias, virus o parásitos). Resultados: De los 777 niños incluidos, 406 (52,3 %) correspondían al sexo masculino y 37 (147,7 %) al sexo femenino, con edades entre 1 mes y 14 años (mediana= 6 años). La presencia de parásitos fue detectada en el 6,9 % (54/777) de las muestras. Cuando se estratificaron los resultados por tipo de parasito, se observó que el 24,1% (13 casos) correspondía a Giardia sp., 14,8 % (8 casos) a Cryptosporidium sp., 55,6 % (30 casos) a Blastocystis sp., 3,6 % (2 casos) a Dientamoeba sp. y 1,9 % (1 caso) a Endolimax sp. Conclusiones: Los resultados revelan un escenario en el que la prevalencia de parásitos con valor clínico demostrado fue del 2,7 %. Esto lleva a considerar la conveniencia de incluir el estudio de parásitos en una segunda fase, después de descartar otras condiciones clínicas más prevalentes en niños con diarrea persistente, además de limitar el estudio de parásitos a la detección de Giardia sp. y Cryptosporidium sp.

ABSTRACT Introduction: Persistent diarrhea belongs in a large category known as chronic diarrhea syndrome, a relatively common concern in children's medical consultation. The importance and prevalence of persistent diarrhea of parasitic etiology are not sufficiently known in Spain. Objective: Determine the prevalence of intestinal parasite infection in children with persistent diarrhea syndrome and the clinical characteristics associated to its parasitic etiology in Seville South Health Area (Spain). Methods: A cross-sectional retrospective study was conducted during one year (May 2017 to May 2018) of patients in pediatric ages who attended consultation for a diarrhea picture of more than two weeks' evolution and/or abdominal pain. Laboratory testing included determination of reducing substances, fecal leukocytes and fats, as well as of the causative agents of the infection (bacteria, viruses or parasites). Results: Of the 777 children included in the study, 406 (52.3%) were male and 37 (147.7%) were female; mean age was six years (1 month to 14 years). Parasites were detected in 6.9% (54/777) of the samples. Stratification of results by parasite type showed that 24.1% (13 cases) corresponded to Giardia sp., 14.8 % (8 cases) to Cryptosporidium sp., 55.6 % (30 cases) to Blastocystis sp., 3.6 % (2 cases) to Dientamoeba sp. y 1.9 % (1 case) to Endolimax sp. Conclusions: According to the results obtained, the prevalence of parasites with demonstrated clinical value is 2.7%. It is therefore advisable to include the study of parasites in a second stage, after ruling out other clinical conditions which are more prevalent in children with persistent diarrhea, and limit the study to the detection of Giardia sp. and Cryptosporidium sp.

Factores asociados con la presencia de endoparásitos y ectoparásitos en perros domiciliados de la zona metropolitana de Toluca, México / Factors associated with endoparasites and ectoparasites in domiciled dogs in the metropolitan area of Toluca, México

Resumen | Introducción. Los endoparásitos y ectoparásitos en perros son de distribución mundial. La estrecha relación entre los perros y el hombre implica un riesgo de transmisión de parasitosis zoonóticas, por lo cual es necesario conocer las especies que parasitan a los perros de esta zona y determinar los factores asociados. Objetivos. Estimar la prevalencia de endoparásitos y ectoparásitos, identificarlos en perros domiciliados de la zona metropolitana de Toluca, México, y determinar la prevalencia de Dipyilidium caninum en pulgas del género Ctenocephalides spp. Materiales y métodos. Se recolectaron muestras de 402 perros que fueron llevados a consulta en cuatro hospitales de referencia de Toluca. En el diagnóstico de endoparásitos, se utilizaron las técnicas coproparasitoscópicas de frotis directo, flotación y sedimentación; además, se recolectaron ectoparásitos para su identificación taxonómica. Por último, la detección de D. caninum en pulgas se hizo mediante la reacción en cadena de la polimerasa (PCR). Resultados. El 37,2 % de los perros resultó positivo para endoparásitos. Los géneros o especies identificados fueron Toxocara spp., Giardia spp., Ancylostoma spp., Cystoisospora spp., D. caninum, Taenia spp. y Trichuris vulpis. Se determinó una prevalencia de ectoparásitos de 13,13 %. Se identificaron pulgas de las especies Ctenocephalides felis y C. canis, en tanto que solo un animal presentó parasitosis por Rhipicephalus sanguineus y otro por Trichodectes canis. La prevalencia de D. caninum en pulgas fue del 9,5 %. Conclusión. La prevalencia de endoparásitos fue de 37,2 % y, la de ectoparásitos, de 13,1 %. Por primera vez en México se hizo un análisis de endoparásitos y ectoparásitos en una misma población de perros, así como el diagnóstico molecular de D. caninum.

Abstract | Introduction: Endoparasites and ectoparasites in dogs are of global distribution. The close relationship between dogs and man implies a risk for the transmission of zoonotic parasites. Therefore, it is necessary to determine the parasites hosted by dogs in specific areas and the factors associated with their presence. Objectives: To identify and to estimate the prevalence of endoparasites and ectoparasites in domiciled dogs in the Metropolitan area of Toluca, México, and the prevalence of D. caninum in fleas of the genus Ctenocephalides spp. Materials and methods: We collected samples from 402 domiciled dogs in four reference hospitals in the area in Toluca. We diagnosed endoparasites using direct smear, flotation, and sedimentation techniques and we performed the taxonomic identification of ectoparasites. Finally, the molecular diagnosis of D. caninum in fleas was made using the polymerase chain reaction technique (PCR). Results: A total of 37.2% of dogs were positive for endoparasites; the genera or species identified were Toxocara spp., Giardia spp., Ancylostoma spp., Cystoisospora spp., D. caninum, Taenia spp., and Trichuris vulpis; the prevalence of ectoparasites was 13.13%. We identified fleas of the species Ctenocephalides felis, Ctenocephalides canis; only one animal was parasitized with Rhipicephalus sanguineus and another one with Trichodectes canis; the prevalence of D. caninum in fleas was 9.5%. Conclusion: The prevalence of endoparasites was 37.2% while that of ectoparasites was 13.1%; this is the first analysis of endoparasites and ectoparasites conducted in the same population of dogs in México together with the molecular diagnosis of D. caninum in fleas.

Risk to human health from protozoan (oo)cysts in water treatment plants / Risco à saúde humana por (oo)cistos de protozoários em estações de tratamento de água

ABSTRACT The presence of waterborne pathogens, when associated with the water supply system, poses risks to public health. This study investigated the occurrence of (oo)cysts of Cryptosporidium spp. and Giardia spp. in two Water Treatment Plants, with full-cycle technology, and assessed the microbiological risk to consumers' health. The membrane filtration technique was employed to identify the protozoan load in 24 samples of raw and filtered water. Physicochemical and bacteriological parameters were also analyzed. The Quantitative Microbial Risk Assessment model was used to determine the risk of daily and annual infection associated with the ingestion of filtered water. A total of 66.67% of raw water samples were positive for Cryptosporidium; and 33.33%, for Giardia. The maximum concentrations of 200 (oo)cysts/L and 50 cysts/L were detected in the Cerrado stream (located in Sanclerlândia, state of Goiás, Brazil), due to the predominance of grazing areas and intense agricultural activity. Water Treatment Plants did not completely remove the protozoa and the retention efficiency was lower than that recommended by the United States Environmental Protection Agency, with average values of 1.27 log for cysts and 1.04 log for oocysts. The probability of annual infection by cysts (100%) was higher than that of oocysts (86.61 - 98.32%) as for consumption of filtered water, and in the dry season, there was a higher risk of infection, due to the low performance of the Water Treatment Plants and higher concentration of pathogens. According to the results, the continuous intake of filtered water above the warning level can cause infectious diseases in the supplied population.

RESUMO A presença de patógenos de veiculação hídrica quando associados ao sistema de abastecimento de água causam risco à saúde pública. Esse estudo investigou a ocorrência de (oo)cistos de Cryptosporidium spp. e Giardia spp. em duas Estações de Tratamento de Água com tecnologia do tipo ciclo completo e avaliou o risco microbiológico à saúde dos consumidores. Utilizou-se a técnica de filtração em membranas para identificar a carga dos protozoários nas 24 amostras de água bruta e filtrada. Os parâmetros físico-químicos e bacteriológicos também foram analisados. O modelo de Avaliação Quantitativa de Risco Microbiológico foi empregado para determinar o risco de infecção diária e anual associada à ingestão de água filtrada. Um total de 66.67% das amostras de água bruta foram positivas para Cryptosporidium; e 33.33% para Giardia. As concentrações máximas de 200 oocistos/L e 50 cistos/L foram detectadas no ribeirão Cerrado (localizado em Sanclerlândia, Estado de Goiás, Brasil), devido ao predomínio de área de pastagens e à intensa atividade agropecuária. As Estações de Tratamento de Água não removeram completamente os protozoários e a eficiência de retenção foi inferior ao recomendado pela Agência de Proteção Ambiental dos Estados Unidos, com valores médios de 1,27 log para cistos e 1,04 log para oocistos. A probabilidade de infecção anual por cistos (100%) foi superior aos oocistos (86,61% a 98,32%) para o consumo da água filtrada, sendo que a estação seca, o risco de infecção foi maior, devido ao baixo desempenho das Estações de Tratamento de Água e à maior concentração de patógenos. Esses resultados indicam que a ingestão contínua de água filtrada acima do nível de alerta pode provocar doenças infecciosas na população abastecida.

Quantitative Microbial Risk Assessment of / 生物医学与环境科学（英文）

We aimed to assess the risks of

First report of Giardia lamblia in different animals in the United Arab Emirates

@#The aim of this study was to detect and characterize Giardia lamblia in animals in the UAE. Eighty-seven fecal samples were tested for G. lamblia using the conserved fragment of small subunit (SSU)-rRNA by nested PCR. Giardia-positive isolates were genotyped for assemblages A and B using assemblage specific primers of the triosephosphate isomerase (tpi) gene. Thirty samples (34.5%) were positive for G. lamblia. Conversely, neither genotype A nor B were detected using tpi genotyping on the studied samples. Further investigations are required using higher number of samples including both human and animals in the country taking into consideration the analysis of other genotypes to provide more detailed understanding about the zoonotic transmission of this parasite.

Occurrence and molecular characterization of Giardia duodenalis from naturally infected dogs in the municipality of Santa Maria, Rio Grande do Sul, Brazil

ABSTRACT: Giardiasis is an important and prevalent zoonosis in dogs and humans caused by Giardia spp. The close relationship between pets and humans has physical, emotional and social benefits. The dogs have an important role in Giardia duodenalis cycle and transmission. This study aimed to verify the occurrence of the parasite in dogs from Central Region, in Santa Maria, Rio Grande do Sul State, Brazil, from April to October 2018. Dog feces (230) were submitted to Faust coproparasitological and molecular analyses. The positive samples in the nested-PCR (-giardin gene) were sent for DNA sequencing and phylogenetic analyses (Neighbor-Joining). The occurrence of G. duodenalis, was 5.6% (13/230) and 4.3% (10/230) detected by coproparasitological technique and nested-PCR, respectively. There was no difference in the sensitivity of the tests used. From the faecal samples analyzed, there were no differences among the variables: diagnostic techniques, local, sex, and age of the animals (p>0.05). Only in the stool examination methodology a difference was observed between the ages (p 0.05). G. duodenalis assemblages were C and D, frequently reported in dogs. The close relationship between dogs and people may allow co-infections of circulating parasites in the population, including Giardia spp. and increasing the risk of transmission of zoonotic agents.

RESUMO: A giardíase é uma zoonose importante e prevalente em cães e humanos, sendo causada por Giardia spp. A estreita relação entre animais de estimação e seres humanos traz benefícios físicos, emocionais e sociais. Os cães têm um papel importante no ciclo e transmissão de Giardia duodenalis. Este estudo teve como objetivo verificar a ocorrência do parasita em cães da Região Central, em Santa Maria, RS, Brasil, de abril a outubro de 2018. As fezes de cães (230) foram submetidas a técnica coproparasitológica de Faust e análises moleculares. As amostras positivas no nested-PCR (gene -giardin) foram enviadas para sequenciamento de DNA e posterior análise filogenética (Neighbor-Joining). A ocorrência de G. duodenalis foi de 5,6% (13/230) e 4,3% (10/230) detectados pela técnica coproparasitológica e nested-PCR, respectivamente. Não houve diferença na sensibilidade dos testes utilizados. Das amostras fecais analisadas, não houve diferenças entre as variáveis: técnicas de diagnóstico, local, sexo e idade dos animais (p>0,05). Somente na metodologia de exame de fezes observou-se diferença entre as idades (p 0,05). As assemblages de G. duodenalis encontradas foram C e D, frequentemente relatadas em cães. A estreita relação entre cães e pessoas pode permitir co-infecções de parasitas circulantes na população, incluindo Giardia spp. e aumentando o risco de transmissão de agentes zoonóticos.

Occurrence and molecular characterization of Giardia duodenalis from naturally infected dogs in the municipality of Santa Maria, Rio Grande do Sul, Brazil / Ocorrência e caracterização molecular de Giardia duodenalis em cães naturalmente infectados no município de Santa Maria, Rio Grande do Sul, Brasil

Giardiasis is an important and prevalent zoonosis in dogs and humans caused by Giardia spp. The close relationship between pets and humans has physical, emotional and social benefits. The dogs have an important role in Giardia duodenalis cycle and transmission. This study aimed to verify the occurrence of the parasite in dogs from Central Region, in Santa Maria, Rio Grande do Sul State, Brazil, from April to October 2018. Dog feces (230) were submitted to Faust coproparasitological and molecular analyses. The positive samples in the nested-PCR (β-giardin gene) were sent for DNA sequencing and phylogenetic analyses (Neighbor-Joining). The occurrence of G. duodenalis, was 5.6% (13/230) and 4.3% (10/230) detected by coproparasitological technique and nested-PCR, respectively. There was no difference in the sensitivity of the tests used. From the faecal samples analyzed, there were no differences among the variables: diagnostic techniques, local, sex, and age of the animals (p>0.05). Only in the stool examination methodology a difference was observed between the ages (p<0.05). G. duodenalis assemblages were C and D, frequently reported in dogs. The close relationship between dogs and people may allow co-infections of circulating parasites in the population, including Giardia spp. and increasing the risk of transmission of zoonotic agents.(AU)

A giardíase é uma zoonose importante e prevalente em cães e humanos, sendo causada por Giardia spp. A estreita relação entre animais de estimação e seres humanos traz benefícios físicos, emocionais e sociais. Os cães têm um papel importante no ciclo e transmissão de Giardia duodenalis. Este estudo teve como objetivo verificar a ocorrência do parasita em cães da Região Central, em Santa Maria, RS, Brasil, de abril a outubro de 2018. As fezes de cães (230) foram submetidas a técnica coproparasitológica de Faust e análises moleculares. As amostras positivas no nested-PCR (gene β-giardin) foram enviadas para sequenciamento de DNA e posterior análise filogenética (Neighbor-Joining). A ocorrência de G. duodenalis foi de 5,6% (13/230) e 4,3% (10/230) detectados pela técnica coproparasitológica e nested-PCR, respectivamente. Não houve diferença na sensibilidade dos testes utilizados. Das amostras fecais analisadas, não houve diferenças entre as variáveis: técnicas de diagnóstico, local, sexo e idade dos animais (p>0,05). Somente na metodologia de exame de fezes observou-se diferença entre as idades (p<0,05). As assemblages de G. duodenalis encontradas foram C e D, frequentemente relatadas em cães. A estreita relação entre cães e pessoas pode permitir co-infecções de parasitas circulantes na população, incluindo Giardia spp. e aumentando o risco de transmissão de agentes zoonóticos.(AU)