Epidemiology of Giardia duodenalis assemblages in Brazil: there is still a long way to go

Giardia duodenalis infection is distributed worldwide and can achieve prevalence around 60%, especially in developing countries. This protozoan is divided into eight assemblages, in which A and B have high zoonotic potential, whereas C to H are host-specific. This scenario is changing as molecular studies progress, highlighting that knowledge on host-specificity still has a long way to go. Understanding the players involved in transmission routes enables rational designs of control strategies. Considering the high prevalence of giardiasis, this review aims to gather together the data on available studies on the distribution of G. duodenalis assemblages in Brazil until September 2020.

Cryptosporidium spp. e Giardia spp. em carnívoros silvestres do Estado do Pará Brasil / Cryptosporidium spp. and Giardia spp. in wild carnivorous animalsthe State of Pará – Brazil

O presente estudo investigou a ocorrência de Cryptosporidium spp. e Giardia spp. em diferentes espécimes silvestres da ordem Carnívora de vida livre e de cativeiro procedentes de municípios do Estado do Pará. Coletou-se amostras fecais de 37 animais distintos (quatro de vida livre e 33 de cativeiro). Para pesquisa de Cryptosporidium spp. e Giardia spp. foram utilizados métodos microscópicos (direto e Kinyoun) e imunológico (RIDA®QUICK Cryptosporidium/Giardia/Entamoeba Combi - N1722). Do total de amostras, 24,32% (9/37) foram positivas, correspondendo a 5,4% (2/37) para Cryptosporidium spp. e 18,91% (7/37) para Giardia spp., respectivamente. Nenhum animal apresentou infecção concomitante para os agentes. Cryptosporidium spp. e Giardia spp., são protozoários zoonóticos que representam um emergente problema de saúde pública. Esses parasitos podem apresentar elevada frequência em regiões em que as condições de saneamento básico são precárias, promovendo surtos de diarreia em animais domésticos, silvestres e no homen. Mamíferos silvestres, como os carnívoros, são susceptíveis à contaminação por enteroparasitas presentes tanto no habitat natural como em cativeiro. Portanto, a pesquisa comprova a presença desses protozoários em carnívoros silvestres, tanto mantidos em criatórios como nos de vida livre no Estado do Pará, considerando-se que esses animais podem atuar como fontes de infecção para o homem, para outros animais e para o meio ambiente.

The present survey has had the purpose to investigate the occurrence of Cryptosporidium spp. and Giardia spp. in free and under captivity carnivorous wild animals, from several counties in the State of Pará. Samples of feces from 37 distinct animals (four in their natural habitat and 33 raised in captivity). For the research of Cryptosporidium spp. and Giardia spp. microscopic immunological, direct and Kinyoun methods were used (RIDA®QUICK Cryptosporidium/Giardia/Entamoeba Combi - N1722). The samples gathered from wild animals have resulted in 24,32% of positive infection on the rate of (9/37), being. 5,4% (2/37) positive to Cryptosporidium spp. and 18,91% (7/37) positive to Giardia spp., what shows that no animals had both infections at the same time. Cryptosporidium spp. and Giardia spp., are zoonotic enteroparasites that have been taking place as an emerging problem to public health. These species of protozoa may reach high levels of frequency in regions where the basic sanitation conditions are precarious, promoting outbreaks of diarrhea to men, wild and domestic animals. Wild mammals, as the carnivorous, are susceptible to contamination by enteroparasites, being present at their natural habitat or captivity. So, the research strengthens the real presence of these protozoas in wild carnivorous in both conditions of life, free or under captivity, in the State of Pará, making us consider the possibility that the cited animals may be natural reservoirs for infections, not only to men but to other animals and also to environment.

Detection of zoonotic and livestock-specific assemblages of Giardia duodenalis in free-living wild lizards / Detecção de genótipos de Giardia duodenalis zoonóticos e específicos de ruminantes domésticos em lagartos selvagens

Abstract Giardia duodenalis is a zoonotic parasite that infects the gut of a wide range of vertebrates, including numerous wildlife species. However, little is known about this protozoan parasite in reptiles. Fecal samples from 31 wild lizards were collected in Galicia (northwest Spain) and screened for the presence of Giardia by PCR amplification and sequencing of the ITS1-5.8S-ITS2 region in the ribosomal unit. This allowed detection of the parasite in 5 samples (16.1%), and enabled identification of G. duodenalis assemblage A2 in two samples of Iberian rock lizard (Iberolacerta monticola), G. duodenalis assemblage B in other two samples of I. monticola, and G. duodenalis assemblage E in one sample of Bocage's wall lizard (Podarcis bocagei). The results obtained after PCR amplification and sequencing of the SSU-rDNA gene confirmed the presence of G. duodenalis assemblage A in two samples of I. monticola. This is the first report of G. duodenalis in free-living lizards, although further studies are needed to distinguish between actual infection and mechanical dissemination of cysts. The detection of zoonotic and livestock-specific assemblages of G. duodenalis demonstrates the wide environmental contamination by this parasite, possibly due to human activities.

Resumo Giardia duodenalis é um parasito zoonótico que infecta o intestino delgado de uma ampla gama de vertebrados, sendo detectado em numerosas espécies selvagens. No entanto, pouco se conhece sobre a presença deste parasito protozoário em répteis. Para estudar a presença de Giardia, foram obtidas amostras fecais provenientes de 31 lagartos e coletadas em diferentes localizações de Galicia (Noroeste da Espanha). Mediante a aplicação da técnica de PCR e posterior sequenciamento da região ITS1-5.8S-ITS2 da unidade ribossômica, detectou-se Giardia em 5 amostras (16,1%), identificando-se o genótipo A2 de G. duodenalis em 2 amostras de lagartos da montanha (Iberolacerta monticola), G. duodenalis genótipo B em outras 2 amostras de I. monticola e G. duodenalis genótipo E em outra amostra de lagarto de Bocage (Podarcis bocagei). Os resultados obtidos, após amplificação e sequenciamento de um fragmento do gene SSU-rDNA, confirmam a presença de G. duodenalis genótipo A em 2 amostras de I. monticola. Esta é a primeira vez que se descreve G. duodenalis em lagartos selvagens, embora sejam necessários outros estudos complementares para confirmar se estes animais sofrem uma infecção real ou se apenas atuam como disseminadores mecânicos da contaminação ambiental. Além disso, a detecção de genótipos zoonóticos e específicos de ruminantes domésticos demonstra a contaminação do ambiente selvagem por G. duodenalis, possivelmente devido à atividade humana.

Genotipos de Giardia duodenalis en muestras de niños de las guarderías del Instituto Colombiano de Bienestar Familiar y de perros en Ibagué, Colombia / Giardia duodenalis genotypes found in the Instituto Colombiano de Bienestar Familiar day care centers and dogs in Ibagué, Colombia

Introducción. Se han descrito ocho genotipos de Giardia duodenalis, del A al H. Los genotipos A y B se han aislado de humanos y de una gran variedad de mamíferos; sin embargo, los genotipos del C al H han mostrado mayor especificidad de huésped. Objetivo. Identificar los genotipos de G. duodenalis a partir de quistes obtenidos en heces de niños de las guarderías del Instituto Colombiano de Bienestar Familiar (ICBF) y de perros en Ibagué, mediante PCR-RFLP de los genes de la beta giardina y la glutamato deshidrogenasa. Materiales y métodos. Los quistes de las muestras positivas para G. duodenalis fueron sometidos a concentración; se extrajo su ADN y se efectuó el análisis de PCR-RFLP de los genes de la beta giardina y de la glutamato deshidrogenasa. Como control positivo se utilizó la cepa MHOM/CO/04/G40 procedente del Grupo de Parasitología del Instituto Nacional de Salud. Resultados. De las muestras tomadas de niños, 11/23 (48 %) correspondieron al genotipo A y, 12/23 (52 %), al genotipo B. Cuatro muestras de perros presentaron los genotipos C y D, específicos de este huésped. Conclusiones. En los niños solamente se encontraron los genotipos asociados a infecciones humanas (AII, BIII y BIV) y en los perros, los genotipos específicos para este huésped (C y D). Debido al reducido tamaño de las muestras analizadas provenientes de perros, y dado que estos no estuvieron en contacto con los niños de las guarderías del ICBF, no fue posible determinar una interacción entre el ciclo de transmisión de los humanos y el de los animales.

Introduction: Eight Giardia duodenalis genotypes (A-H) have been described to date. Genotypes A and B have been isolated from humans and a wide range of mammals; however, genotypes C-H have shown greater host specificity. Objective: Identifying G. duodenalis genotypes from cysts in faeces obtained from children attending the Instituto Colombiano de Bienestar Familiar (ICBF) day care centres and from dogs in Ibagué by PCR-RFLP targeting both the b -giardin and glutamate dehydrogenase genes. Materials and methods: Cysts from G. duodenalis positive samples were concentrated, DNA was extracted and the b -giardin and glutamate dehydrogenase genes were analysed by PCR-RFLP. The MHOM/CO/04/G40 strain was used as positive control (this was obtained from the Grupo de Parasitología at the Instituto Nacional de Salud ). Results: Of the total human samples, 11/23 (48%) were genotyped as A and 12/23 (52%) as B; PCR-RFLP revealed that four canine samples were genotypes C and D, these being host-specific. Conclusions: Only genotypes associated with human infection (AII, BIII and BIV) were found in the children and host-specific genotypes were observed in canines (C and D). No interaction could be established between animal and human transmission cycles due to the small canine sample size and as the former did not come into contact with children attending ICBF day-care centres.

MOLECULAR TYPING OF Giardia duodenalis ISOLATES FROM NONHUMAN PRIMATES HOUSED IN A BRAZILIAN ZOO / Genotipagem de isolados de Giardia duodenalis de primatas não humanos mantidos em zoológico do Brasil

Giardia infections in captive nonhuman primates (NHP) housed at a Brazilian zoo were investigated in order to address their zoonotic potential. Fresh fecal samples were collected from the floors of 22 enclosures where 47 primates of 18 different species were housed. The diagnosis of intestinal parasites after concentration by sedimentation and flotation methods revealed the following parasites and their frequencies: Giardia (18%); Entamoeba spp. (18%); Endolimax nana (4.5%); Iodamoeba spp. (4.5%); Oxyurid (4.5%) and Strongylid (4.5%). Genomic DNA extracted from all samples was processed by PCR methods in order to amplify fragments of gdh and tpi genes of Giardia. Amplicons were obtained from samples of Ateles belzebuth, Alouatta caraya, Alouatta fusca and Alouatta seniculus. Clear sequences were only obtained for the isolates from Ateles belzebuth (BA1), Alouatta fusca (BA2) and Alouatta caraya (BA3). According to the phenetic analyses of these sequences, all were classified as assemblage A. For the tpi gene, all three isolates were grouped into sub-assemblage AII (BA1, BA2 and BA3) whereas for the gdh gene, only BA3 was sub-assemblage AII, and the BA1 and BA2 were sub-assemblage AI. Considering the zoonotic potential of the assemblage A, and that the animals of the present study show no clinical signs of infection, the data obtained here stresses that regular coproparasitological surveys are necessary to implement preventive measures and safeguard the health of the captive animals, of their caretakers and of people visiting the zoological gardens.

A pesquisa de infecções por Giardia e a caracterização genotípica deste protozoário foi realizada em primatas não humanos (PNH) mantidos em Zoológico a fim de avaliar o seu potencial zoonótico. As amostras dos animais consistiram de fezes colhidas do piso de 22 baias onde eram mantidos 47 primatas de 18 diferentes espécies. Exames coproparasitológicos foram realizados pelos métodos de concentração por sedimentação e centrífugo-flutuação e revelaram a presença dos seguintes parasitas e suas respectivas frequências: Giardia (18%); Entamoeba spp. (18%); Endolimax nana (4.5%); Iodamoeba spp. (4.5%); oxiurídeos (4.5%) e estrongilídeos (4.5%). O DNA extraído de todas as amostras fecais foi submetido à técnica de PCR para a amplificação dos genes gdh e tpi de Giardia, porém, só foram obtidos amplicons das quatro amostras positivas provenientes de Ateles belzebuth, Alouatta caraya, Alouatta fusca and Alouatta seniculus. O seqüenciamento dos fragmentos amplificados foi possível apenas para as amostras oriundas de Ateles belzebuth (BA1), Alouatta fusca (BA2) e Alouatta caraya (BA3), cuja análise fenética de ambos os genes revelou pertencerem ao genótipo A. As análises das sequências de tpi revelaram que todas as amostras pertencem ao subgenótipo AII. No que se refere ao gene gdh as análises revelaram uma amostra pertencente ao subgenótipo AII (BA3) e duas ao subgenótipo A1 (BA1 e BA2). Considerando o potencial zoonótico do genótipo A e o fato de que os animais não apresentavam sintomas de infecção, os dados do presente trabalho salientam a importância de se realizar, periodicamente, exames coproparasitológicos dos animais de zoológico, para implementação de medidas preventivas para resguardar a saúde dos animais em cativeiro, a de seus tratadores e dos visitantes de parques zoológicos.

Prevalencia y factores de riesgo de Cryptosporidium spp. y Giardia spp. en terneros de ganado lechero de la zona noroccidental de la Sabana de Bogotá / Cryptosporidium spp. and Giardia spp. prevalence and risk factors in dairy calves of the north-western zone of the Bogota Savanna

Objetivo Estimar la prevalencia de Cryptosporidium spp. y Giardia spp. en terneros de 0 a 2 meses de ganado lechero de la zona noroccidental de la Sabana de Bogotá. Se estimaron los factores de riesgo de la producción lechera que puedan incurrir en la infección de personas y animales. Métodos Estudio de corte transversal, mediante la toma de materia fecal de terneros. Se determinó la prevalencia de punto para Giardia spp. y Cryptosporidium spp. a través los resultados de los coprológicos (Ritchie para Giardia spp. y Ziehl-Neelsen modificada para Cryptosporidium spp.). Se calcularon Odds Ratio para establecer los factores de riesgo asociados entre estos dos géneros de protozoarios y el manejo de las Buenas Prácticas Ganaderas. Resultados Se evaluaron 33 fincas dedicadas a la producción lechera, donde se muestrearon 308 terneros. La prevalencia para Giardia spp. fue de 37,3 %, 115 animales positivos y para Cryptosporidium spp. fue de 4,9 % 15, animales positivos. Conclusión Existe un foco de Giardia spp. y Cryptosporidium spp. en el noroccidente de la Sabana de Bogotá, del cual no se tenía conocimiento previo. La prevalencia de Giardia spp. para la región estudiada, está en el límite alto del rango reportado para Sudamérica. En el caso de Cryptosporidium spp. la situación es distinta, la prevalencia se encuentra en el limite bajo del rango reportado para Sudamérica. Los factores de riesgo asociados a Giardia spp. y Cryptosporidium spp. en las explotaciones lecheras del noroccidente de la Sabana de Bogotá, dependen de Buenas Prácticas Ganaderas.

Objective The present study was aimed to establishing Cryptosporidium spp. and Giardia spp. prevalence in 0 to 2 months old dairy calves of the north-western zone of the Bogota Savanna. In addition, associated factors related to a failure in Good Practices of Livestock could incur in human and animal infection. Methods This was a cross-sectional study; calves' fecal samples were used. Farms' Good Practices of Livestock were observed by means of an observation blank. Giardia spp. and Cryptosporidium spp. prevalence was determinate by means of laboratory results (Ritchie for Giardia spp. and modified Ziehl-Neelsen for Cryptosporidium spp.). Odds Ratios (OR) were calculated in association between this two genera of protozoa and Good Practices of Livestock. Results Thirty three dairy farms were evaluated, where fecal samples of 308 calves were taken. Giardia spp. prevalence was 37.7 %, 115 infected animals; Cryptosporidium spp. prevalence was 4.9 %, 15 infected animals. Conclusion There is an important Giardia spp. and Cryptosporidium foci in the north-western zone of the Bogota Savanna, without a previous knowledge. Giardia spp. prevalence for this zone is in the highest rank reported for South-America and Cryptosporidium spp. prevalence is in en the lowest one. Associated risk factors of Giardia spp. and Cryptosporidium spp. in dairy farms of the north-western zone of the Bogota Savanna depend of a Good Practices of Livestock performance.

Giardiasis as zoonosis: between proof of principle and paradigm in the Northwestern region of São Paulo State, Brazil

OBJECTIVE: In order to evaluate the potential zoonotic transmission of Giardia duodenalis, isolates from humans and dogs in the Northwestern region of the São Paulo State, Brazil were characterized based on the β-giardin gene. METHODS: The samples were analyzed by sequencing of the Nested-PCR products. RESULTS: The A1 and A2 subgenotypes were detected in human and dogs. Cysts of assemblage B, C and D have not been found in any isolates studied. CONCLUSIONS: These results are consistent with the view that giardiasis in the largest endemic region of the Brazil should not be seen as a single entity.

Giardia duodenalis: genotypic comparison between a human and a canine isolates / Giardia duodenalis: comparação genotípica entre isolados humano e canino

INTRODUCTION: Evidence suggests that giardiasis is a zoonotic disease. The present work aimed to evaluate the genetic identity of Giardia duodenalis isolated from human and dog fecal samples from Belo Horizonte. METHODS: Human and dog fecal samples were cultured for isolation of G. duodenalis. To determine the genotype of the isolates, primers that amplify a specific region in rRNA of the protozoan were used. RESULTS: Two G. duodenalis isolates were obtained, which belong to the subgroup A genotype. CONCLUSIONS: These findings suggest that the transmission of giardiasis follows a zoonotic pattern.

INTRODUÇÃO: Evidências sugerem que a giardíase é uma doença zoonótica. O presente trabalho tem como objetivo avaliar a identidade genética da Giardia duodenalis isolada de fezes humanas e de cães de Belo Horizonte. MÉTODOS: Amostras de fezes humanas e de cães foram cultivadas para isolamento de G. duodenalis. Para determinação do genótipo dos isolados, foram usados oligonuclotídeos que amplificam regiões específicas do gene para rRNA. RESULTADOS: Dois isolados de G. duodenalis foram obtidos, os quais apresentaram o genótipo do sub-grupo A. CONCLUSÕES: Estes dados sugerem que a transmissão da giardíase segue um padrão zoonótico.

Prevalence of Cryptosporidium spp. and Giardia spp., spatial clustering and patterns of shedding in dairy calves from Córdoba, Argentina / Prevalência de Cryptosporidium spp. e Giardia spp., distribuição espacial e padrões de eliminação em bezerros de propriedades leiteiras em Córdoba, Argentina

The objectives of this study were to estimate calf and herd prevalence of Cryptosporidium spp. and Giardia spp., the herd prevalence clustering, spatial distribution according to soil type and shedding patterns in dairy calves from Cordoba, Argentina. Six hundred twenty calves younger than 7 weeks of age from 43 dairy herds were sampled. Samples were processed with the formol-ether and modified Ziehl-Neelsen techniques. Univariate analysis and Kruskall-Wallis tests were used. Factors associated were subjected to multivariate analysis with calf shedding intensity as the response variable. Clustering of herd prevalence was assessed by a scan method, and spatial analysis was applied to explore the overlapping of high prevalence herds and soil type. Overall calf prevalence for Cryptosporidium spp. oocysts and Giardia spp. cysts were 19.35 percent (95 percent CI: 16.14; 22.54) and 34.50 percent (95 percent CI: 30.69; 38.34), respectively. Calves younger than two weeks of age were almost four times more likely to be infected with Cryptosporidium, in comparison to older ones (RR: 3.78, 95 percent CI: 2.27; 6.26). Giardia spp. shedding showed a similar age pattern (RR: 1.33, 95 percent CI: 1.02; 1.75). A primary cluster of high Cryptosporidium prevalence was found, and high prevalence herds were located in areas with poor drained soil.

Os objetivos deste estudo foram determinar a prevalência de Cryptosporidium spp. e Giardia spp., a presença de aglomerados, a distribuição espacial de acordo com o tipo de solo e padrões de eliminação de cistos e oocistos em bezerros de propriedades leiteiras em Córdoba, Argentina. Amostras fecais foram colhidas de 620 bezerros com menos de sete semanas de idade, provenientes de 43 propriedades leiteiras e examinadas pelas técnicas de formol-éter e Ziehl-Neelsen modificada. Foram realizadas uma análise univariada e o teste de Kruskal-Wallis e, em seguida, uma análise multivariada com a intensidade de eliminação de cistos e oocistos, como um evento. A presença de aglomerados foi determinada com o método de varredura e a análise espacial foi realizada para explorar a sobreposição de rebanhos com alta prevalência e tipo de solo. A prevalência de Cryptosporidium spp. e Giardia spp. foi de 19,35 por cento (IC 95 por cento: 16,14; 22,54) e 34,50 por cento (IC 95 por cento: 30,69; 38,34), respectivamente. A probabilidade de infecção por Cryptosporidium spp. foi quase quatro vezes maior para bezerros com menos de 2 semanas em comparação com os bezerros mais velhos (RR: 3,78, IC 95 por cento 2,27; 6,26). O mesmo padrão de infecção relacionada à idade foi observado para Giardia spp. (RR: 1,33, IC 95 por cento 1,02; 1,75). Foi encontrado um aglomerado primário com alta prevalência de Cryptosporidium spp., e rebanhos com alta prevalência foram localizados em solos mal drenados.

Comparação da infecção por protozoários em chinchila (Chinchilla lanigera) de uma criação comercial do município de Viamão-RS, Brasil, e de chinchilas no seu habitat natural, Chile / Comparison of protozoan infection between chinchillas chinchilla lanigera) from a commercial breeding facility in southern Brazil and chinchillas from a natural reserve in Chile

Chinchilla lanígera é um roedor proveniente do Chile e sua criação é com fins comerciais. As doencas parasitarias, principalmente giardíase podem causar problemas clínicos e sanitarios, causando perdas produtivas e económicas. Foram colhidas amostras de fezes de 220 chinchilas de urna criação comercial no sul do Brasil e 35 amostras de chinchilas da Reserva Nacional las Chinchillas no Chile, e submetidas ão método de Faust e colaboradores. O total de amostras positivas para cistos de Giardia sp. foi de 31,37 por cento (80/255); da criação comercial foi de 36,36 por cento(80/220). O número de amostras que apresentaram mais de 5 cistos/campo foi 4,55 por cento(10/220). Todas as amostras dos animáis da Reserva foram negativas. Não houve associação entre a positividade e a faixa etária dos animais analisados.

Chinchilla lanígera is a rodent native to Chile which is bred for commercial purposes. Parasitic diseases, mainly giardiasis, may cause clinical and sanitary problems and lead to production and economic losses. Fecal samples were collected from 220 chinchillas pertaining to a commercial breeding facility in southern Brazil and from 35 chinchillas from Las Chinchillas National Reserve in Chile. All samples were analyzed using the method proposed by Faust et al. Positive samples for Giardia cysts amounted to 31.37 percent (80/255); 36.36 percent (80/220) was recovered from the commercial breeding facility. The rate of samples with over 5 cysts/field was equivalent to 4.55 percent (10/220). All of the samples collected from the National Reserve were negative for Giardia sp. No association was found between positive rates for Giardia sp. and the age of chinchillas.

Study of giardia infection in cats

Giardiasis caused by the intestinal flagellate Giardia duodenalis. It is postulated that animals may be a reservoir for human infection and vice versa, thus, giardiasis classified as a zooanthroponotic disease. Therefore, accurate information about the Giardia infection in animals can help the control and prevention of disease in human. With respect to considerable population of cats in Iran and close relation to human, in the current study we tried to determine the infection rate of Giardia in stray, semi-stray and domestic cats. One hundred eighty one cat fecal specimens were collected and after formol-ether concentration, Giardia cysts were detected using light microscope. Twenty one samples [11.6%] out of 166 samples were Giardia cyst positive. The highest levels of infection with Giardia were in domestic cats [75%]. The findings prominence the necessity for cat owners to have knowledge about zoonotic transmission of Giardia

Distancia filogenética de aislados de Giardia intestinalis de niños sintomáticos y asintomáticos / Phylogenetic distance between Giardia intestinalis isolates from symptomatic and asymptomatic children

The purpose of the present investigation, was to analyze the sequences of 16S ribosomal genes partially amplified from 17 isolated Giardia intestinalis obtained from faces of 13 children with intestinal pathology and four symptoms-free children with intestinal pathology. Analysis was made also with Giardia Portland-I and four Giardias isolated from dogs. Children ages in both groups ranged from six to twelve years. Genomic DNA was isolated using the phenol-chloroform-isoamyl alcohol technique, and partial amplification of 16S rRNA ribosomal gene was carried out by the Polymerase Chain Reaction. Sequences of rDNA were compared with Portland-I by using CLUSTAL-W (1.81) and PHYLIP (3.6) software in order to determine phylogenic associations. Our results showed that only one isolate from symptoms-free children and three from the symptomatic children were associated with Portland I. The other isolated Giardias were associated between them and with two samples obtained from dogs that are phylogenetically distant from Portland-I. Two isolates from dog constituted a different group. These results suggest a zoonotic infection and presence of symptoms in children from the present investigation; probably it was associated with host or special characteristics of Giardia strains. The last two situations have a special epidemiological and public health interest.

Effect of a broad spectrum antiparasitic drug ivermectin in acute and chronic experimental giardiasis using different dose regimens

In this study, the maximal excretion of Giardia lamblia cysts was three weeks post infection [pi]. The administration of ivermectin subcutaneously proved to be effective in treating hamsters infected for two and three weeks, respectively. It was found that the dose of 300 mug/kg bw was much more efficient than 200 mg/kg bw. The cure rate was 99.1% in the former and 98.7% in the later. In chronic giardiasis where infection was kept for six weeks, the cure rate was 99.5% two weeks after treatment with 300 g/kg bw of ivermectin. An assessment of cure was performed also by histopathological examination of upper 2/3 of small intestine of the hamsters. Localization and counting of the parasite were carried out immunohistochemically

Giardia in dogs in Botucatu, Säo Paulo State, Brazil: a comparative study of canine and human species

Giardia sp foi encontrada em 30 (6,66%) de 450 cäes examinados. Devido à possível importância epidemiológica da infecçäo canina para o homen, cistos e trofozoitos originários de ambos os hospedeiros foram medidos, sendo as diferenças entre as médias de comprimento e largura testadas por análise de variância. Os resultados obtidos, näo significantes a nível de 0,05% permite-nos concluir näo haver diferenças de tamanho entre Giardia provenientes de homem e de cäo