Background: Giardia lamblia, a flagellate protozoa, is a common causative agent of parasitic diarrhoeal diseases of humans. Laboratory diagnosis mainly consists of direct microscopic examination of stool specimen for trophozoite and cysts of Giardia. However, due to intermittent faecal excretion of parasite, the case may be miss diagnosed and the patient may continue excreting the parasite and infecting others. Therefore, other mode of diagnosis should be looked for, which overcome the above drawbacks of microscopy used alone for diagnosis.
Objectives: The present study was done to evaluate the efficacy of RIDASCREEN Giardia (ELISA) test in comparison to direct microscopy in the diagnosis of Giardia lamblia in stool specimens from patients with diarrhea and other gastrointestinal symptoms.
Materials and methods: A total of 1680 patients were included in the study and three faecal specimens were taken from each patient which was divided into two parts. One part was used for direct wet mount examination and second part was used to put ELISA by using RIDASCREEN Giardia test.
Results: Out of 1680 stool samples, 380 specimens (22.6%) were found to be positive for Giardia lamblia. Maximum cases were detected by RIDASCREEN Giardia (ELISA) test with sensitivity of 100% and specificity of 91.5%. Maximum cases of giardiasis were detected in children less than 10 y of age (12.8%).
Conclusion: RIDASCREEN Giardia test is a rapid and effective method with high sensitivity and specificity and detects Giardia antigens in stool specimens even when the count of parasite is low, thus reducing the chances of missing even the asymptomatic cases.
Keywords: Direct wet mount microscopy; Giardia lamblia; RIDASCREEN Giardia test; Stool concentration.