Comparison of Kato-Katz and Formol-Ether concentration methods for the diagnosis of intestinal helminthic infections among school children of Wonji Shoa town, Eastern Ethiopia: A school based cross-sectional study

Background: Intestinal helminthic infections are among the most common infections in the world and are responsible for considerable morbidity and mortality. The diagnosis of these infections commonly relies on the detection of helminth egg or larvae in stool. The objective of this study was to compare the diagnostic performance of kato-katz thick smear and formol-ether concentration methods for the diagnosis of helminthic infections among Wonji Shoa town primary school children. Method: Institution based cross-sectional study design was used. 669 primary school students were selected using simple random sampling technique. Stool samples were examined using formol-ether concentration and kato-katz thick smear techniques. Results were shown in tables, percent and prevalence rates. P<0.05 was considered as statistically significant. Result: The stool concentration method showed that the prevalence of S. mansoni was (28.3%), A. lumbricoides (15.2%), Hookworms (12.1%) and T. trichiura (12.1%) respectively. Both Taenia species and H. nana were equally prevalent (3.0%). However, Kato-katz method showed a prevalence of 20.2%, 8.1% and 5.8% for S. mansoni, A. lumbricoides and Hookworms respectively. The sensitivity of the two techniques was statistically significant (p=0.02). Conclusion: Even though the Kato-katz thick smear is the most recommended method for epidemiological study of S. mansoni, in this study, it has lower sensitivity than concentration technique in the diagnosis of each type of helminthes. Since human intestinal parasitic infections are high in the study area; mass treatment, snail control and health education were strongly recommended.