Comparison of modified ziehl–neelsen, auramine-phenol and immunofluorescence antibody test for the detection of cryptosporidium species at jimma university medical center, south west Ethiopia.

Abstract

Background: Cryptosporidium species infections cause severe diarrhea especially in children and immuno-compromised people worldwide. However, laboratory detection and identification of the Oocyst stage of these parasites seems overlooked with the routine saline wet mount stool examination. Objective: The objective of this study was to compare Modified Zeihl-Neelson (MZN), Auramine Phenol (AP) and Immunofluorescent Antibody test (IFAT) for the detection of Cryptosporidium species infections in under five years old children with diarrhea at Jimma University Medical Center (JUMC). Method: A cross-sectional study design was conducted from January 01, 2019 to March 30, 2019 enrolling a total of 221 children. Stool specimen was collected and examined by the direct saline wet mount, formol-ether oocyst concentration, MZN, AP and IFAT staining with a smear made both from direct and concentrated sediment. Comparison of diagnostic performances was evaluated in calculating for sensitivity, specificity, NPV and PPV, agreement compared with kappa values and level of significance at p-value of < 0.05 with the 95% confidence interval. Result: The overall prevalence of intestinal parasites was 91(41.2%). Intestinal coccidian parasites detected by MZN after formol-ether concentration was 34 (15.84%), of which Cryptosporidium spp. accounts for 23 (10.4%), C. cayatenensis 8 (3.6%), and C. belli 3 (1.4%). Whereas, 47(21.26%) was detected in AP staining after formal-ether Oocyst concentration technique. Of this, Cryptosporidium spp. accounts 39 (17.64%), C. cayatenensis 6 (2.7%), & C. belli 2 (0.9%). Cryptosporidium species detected by IFAT was 54 (24.4%). Generally, the sensitivity of MZN & AP against the Gold standard test was (42.6%) & (72.2%), respectively so that AP revealed a better NPV (92.0%) as compared to the MZN (84.34%). Conclusion and recommendation: the prevalence of Cryptosporidium species are still underestimated due to the low sensitivity of diagnostic methods used. Therefore, it is preferable to use the accessible, rapid, sensitive and specific method. According to findings in here, it is recommended to use Auramine phenol staining technique for the detection of intestinal Cryptosporidiosis in routine diagnostic in health facilities.