Artigo Acesso aberto Produção Nacional Revisado por pares

Detection of a Giardia lamblia coproantigen by using a commercially available immunoenzymatic assay, in Belo Horizonte, Brazil

1999; UNIVERSIDADE DE SÃO PAULO; Volume: 41; Issue: 3 Linguagem: Inglês

10.1590/s0036-46651999000300003

ISSN

1678-9946

Autores

Miriam Rocha, Rômulo Teixeira de Mello, Tânia Mara Pinto Dabés Guimarães, Vicente de Paulo Coelho Peixoto de Toledo, Maria da Conceiçäo Carneiro Gonçalves Moreira, Carlos Alberto da Costa,

Tópico(s)

Parasitic infections in humans and animals

Resumo

It is known that fecal examination to detect Giardia lamblia cysts or trophozoites produces a high percentage of false-negative results. A commercially available immunoenzymatic assay (ProSpecT Giardia Microplate Assay, Alexon, Inc., BIOBRAS) to detect G. lamblia specific coproantigen was evaluated for the first time in Brazil. A total of 90 specimens were tested. Each specimen was first tested as unpreserved stool, and then it was preserved in 10% Formalin to be tested 2 months later. The assay was able to identify all the 30 positive patients (sensitivity = 100.0%) by visual or spectrophotometric examination in the unpreserved specimens and was negative in 57 of the 60 patients without G. lamblia (specificity = 95.0%). The assay identified 27 of the 30 positive patients (sensitivity = 90.0%) and was negative in 59 of the 60 negatives (specificity = 98.3%) in the preserved stools according to both readings. A marked difference was observed in the optical densities in both groups, preserved and unpreserved stools, when the G. lamblia-positive specimens were compared to the negative or positive for other intestinal parasites than G. lamblia. The assay seems a good alternative for giardiasis diagnosis, especially when the fecal examination was repeatedly negative and the patient presents giardiasislike symptoms.

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