Giardiasis in children and dogs, and the first report of assemblage E in dogs from northeastern Brazil.

Diagnosis is crucial for controlling giardiasis. We determined the prevalence and genetically characterize isolates of Giardia duodenalis of children and dogs from rural communities in northeastern Brazil. G. duodenalis cysts were concentrated by centrifugal flotation/sedimentation. Molecular characterization was carried out using the loci ssu-rRNA, bg, tpi, and gdh. By parasitological techniques, Giardia spp. infection was detected in 72/192 children (37.5%; 95% CI: 30.6%-44.7%) and 24/139 dogs (17.3%; 95% CI: 11.4%-24.6%). By molecular analysis, infection was detected in 60/141 children (42.5%; 95% CI: 34.3%-51.2%) and 26/92 dogs (28.3%; 95% CI: 19.4%-38.6%). The total prevalence of giardiasis was 54.9% in children (106/193; 95% CI: 47.1%-61.6%) and 32.9% in dogs (47/143; 95% CI: 25.2%-41.2%). Zoonotic assemblages A and B of G. duodenalis were detected in children, and assemblage E of G. duodenalis was detected in one child and two dogs. Parallel use of parasitological and molecular techniques proved to be a more effective strategy for detecting giardiasis in children and dogs from endemic areas.

Giardiasis in children and dogs, and the first report of assemblage E in dogs from northeastern Brazil / Giardíase em crianças e cães, e o primeiro relato de infecção por assemblage E em cães do nordeste brasileiro

Diagnosis is crucial for controlling giardiasis. We determined the prevalence and genetically characterize isolates of Giardia duodenalis of children and dogs from rural communities in northeastern Brazil. G. duodenalis cysts were concentrated by centrifugal flotation/sedimentation. Molecular characterization was carried out using the loci ssu-rRNA, bg, tpi, and gdh. By parasitological techniques, Giardia spp. infection was detected in 72/192 children (37.5%; 95% CI: 30.6%-44.7%) and 24/139 dogs (17.3%; 95% CI: 11.4%-24.6%). By molecular analysis, infection was detected in 60/141 children (42.5%; 95% CI: 34.3%-51.2%) and 26/92 dogs (28.3%; 95% CI: 19.4%-38.6%). The total prevalence of giardiasis was 54.9% in children (106/193; 95% CI: 47.1%-61.6%) and 32.9% in dogs (47/143; 95% CI: 25.2%-41.2%). Zoonotic assemblages A and B of G. duodenalis were detected in children, and assemblage E of G. duodenalis was detected in one child and two dogs. Parallel use of parasitological and molecular techniques proved to be a more effective strategy for detecting giardiasis in children and dogs from endemic areas.(AU)

O diagnóstico é crucial para o controle da giardíase. Foram determinadas as prevalências e as características genéticas isoladas de Giardia duodenalis, em crianças e cães de comunidades rurais do nordeste brasileiro. Os cistos de G. duodenalis foram concentrados por centrífugo-flutuação/sedimentação. A caracterização molecular foi realizada utilizando-se os loci ssu-rRNA, bg, tpi e gdh. Pelas técnicas parasitológicas, a infecção por Giardia spp. foi detectada em 72/192 crianças (37,5%; IC 95%: 30,6%-44,7%) e 24/139 cães (17,3%; IC 95%: 11,4%-24,6%). Molecularmente, a infecção foi detectada em 60/141 crianças (42,5%; IC 95%: 34,3%-51,2%) e 26/92 cães (28,3%; IC 95%: 19,4%-38,6%). A prevalência total de giardíase foi de 54,9% em crianças (106/193; IC 95%: 47,1%-61,6%) e 32,9% em cães (47/143; IC 95%: 25,2%-41,2%). Os assemblages zoonóticos A e B de G. duodenalis foram detectados em crianças, e o assemblage E de G. duodenalis foi detectado nas duas populações. O uso paralelo de técnicas parasitológicas e moleculares mostra-se uma estratégia mais eficaz para detecção de giardíase em crianças e cães de áreas endêmicas.(AU)