Diagnosis of Giardia infections by PCR-based methods in children of an endemic area

The present study was designed to estimate the prevalence of giardia infection in preschool- and school-aged children living in an endemic area. fecal samples from 573 children were processed by zinc sulfate centrifugal flotation,centrifugal sedimentation (using a commercial device for fecal concentration - tf-test kit®) and polymerase chain reaction (pcr)-based methods. of the stool samples assessed,277 (48.3%) were positive for intestinal parasites and/or commensal protozoa. centrifugal flotation presented the highest diagnostic sensitivity for giardia infections. the kappa index revealed that both coproparasitological techniques closely agreed on the giardia diagnosis (86%) versus satisfactory (72%) and poor (35%) concordances for commensal protozoan and helminth infections,respectively. concerning giardia molecular diagnosis,from the 71 microscopy-positive samples,specific amplification of gdh and tpi fragments was noted in 68 (95.7%) and 64 (90%) samples,respectively. amplification of gdh and tpi genes was observed,respectively,in 95.7% and 90% of microscopy-positive giardia samples. for 144 microscopy-negative samples,gdh and tpi gene amplification products were obtained from 8.3% and 35.9% samples,respectively. the agreement between these genes was about 40%. the centrifuge-flotation based method was the most suitable means of giardia diagnosis assessed in the present study by combining accuracy and low cost. © cevap 2011.