Avaliação da etiologia das infecções enteroparasitárias em diferentes grupos pediátricos e genotipagem de isolados de Giardia duodenalis

Parasitic infections occur most frequently in children and can lead to severe disease in patients with alterations in the immune system, such as those with malnutrition or cancer. Giardia duodenalis is the most frequent parasite in children, causing intestinal infections ranging from asymptomatic to the development of acute or chronic diarrhea, being essential the correct diagnosis of the parasite. However, the more sensitive diagnostic techniques are also the most expensive, requiring a detailed analysis of the cost-benefit of their use in clinical routine. In addition to the routine diagnosis, the molecular characterization of Giardia contributes to a better understanding of the taxonomy, epidemiology and zoonotic potential of transmission and clinical forms of infection associated to a specific genotype (A - H). This study aimed to evaluate the etiology of parasitic infections in pediatric groups, using different diagnostic techniques, and characterize the genotypes of Giardia duodenalis isolates from children attending day care centers. There were collected fecal samples from 824 children: 70 oncologic patients, 110 hospitalized with severe protein-energy malnutrition, 151 hospitalized due to diarrheic disease and 493 healthy day care children. The samples were subjected to the following diagnostic techniques: a) direct examination, b) Baermann-Moraes c) stool culture on agar plates d) Faust e) sedimentation by centrifugation; g) modified Ziehl-Nielsen staining h) search of coproantigens of Cryptosporidium sp., Giardia duodenalis and Entamoeba histolytica by ELISA. Seventy-one fecal samples positive for Giardia duodenalis from day care centers children were subjected to genotyping by polymerase chain reaction (PCR) of the target genes β-giardina and Gdh, followed by Analysis of Restriction Fragment Length Polymorphism (RFLP). Among the 824 children, 30.3% were infected with at least one parasite. Children with cancer had the highest frequency of intestinal parasites (47.1%), followed by the day care group (35.4%), children with diarrhea (16.6%), and those with malnutrition (15.5 %). The parasite Giardia duodenalis was the most frequent (18.4%) in stood of the population without diarrhea, while Cryptosporidium and E. histolytica were significantly associated with the diarrheic disease. Comparing the diagnostic techniques for Giardia using as reference standard the positivity in at least one technique, the ELISA was more highly sensitive than microscopy (97% versus 55%). Of the 71 isolates of G. duodenalis from day care children subjected to PCR, 51 (77.4%) had the DNAs amplified. There were identified genotypes IIA, BIII, BIV and E, with a predominance of the IIA, suggesting that the main route of transmission is anthroponotic, either by ingesting food or water contaminated with human feces, or through the contact person-to-person, since this subtype has been found only in humans.

Grantor

Faculdade de Farmácia

Year dc:date.issued

2017

Author dc:creator

• Silva, Renata Kelly Novais Rodrigues

Advisor dc:contributor.advisor

• Teixeira, Márcia Cristina Aquino

• Giardia
• Helmintos
• Parasitologia médica

Statement dc:rights

• Acesso Aberto

Language dc:language.iso

pt_BR

Repository record dc:identifier.uri

http://repositorio.ufba.br/ri/handle/ri/22680

OAI identifier oai:identifier

oai:repositorio.ufba.br:ri/22680