Diarrhea is an important public health problem worldwide, several causes associated with diarrhea especially in population live under poverty and unsafe water use. Different methods are available and use in diagnosis. This study was carried out to compare of various techniques for Giardia lamblia detection and study the association with E coil and Shigella in patients with diarrhea. A total of 100 children with diarrhoea were enrolled into the study, 57 were males and 43 were females, aged from 2 months -16 years were attendant to AL-Imamin AL-Kadhimin Medical City, during the period from May 2014 to February 2015. Stool samples were collected and analysed for Giardia lamblia presence by used light microscopy, enzyme linked immunosorbant assay and polymerase chain reaction as well as used bacterial culture and one-step colored chromatographic immunoassay for E coil and Shigella detection. Socio-demographic features of the study subjects were also included. Parasitic infection was the most common than bacterial infection. Most intestinal infection were recorded in age group 5-10 years and among males. Comparative analysis of various techniques for Giardia lamblia detection show that microscopy detected only 24 cases, while enzyme linked immunosorbant assay detected 32 cases. However, polymerase chain reaction assay detected 42 cases. Statistical analysis showed significant differences. The sensitivities was 57.14% for microscopy and 76.19% for enzyme linked immunosorbant assay, whereas polymerase chain reaction assay had sensitivity of 100% (42/42) and specificity was100%. Bacterial culture and immunochromatography assay show positive result for E. coli (12%), and Shigella (6%). Co-infection between three microorganisms which revealed that 5 patients with Giardia lamblia positive test had co-infection with E. coli and 4 patients with Giardia lamblia positive test had co-infection with Shigella. Polymerase chain reaction highly sensitive and specific than other methods for Giardia lamblia detection, direct examination exhibited many false positive and negative results with parasitic infection.
