Prevalence of intestinal parasites in Bursa Province of Turkey and assessment of enzyme-linked immunosorbent assays (ELISA) and three microscopic methods in the diagnosis of Entamoeba histolytica/Entamoeba dispar

Abstract

This study was designed to determine the prevalence of intestinal parasites in relation to personal and environmental risk factors in Bursa province of Turkey and to compare wet mount + Lugol's iodine, formalin ethyl acetate concentration, trichrome staining and enzyme-linked immunosorbent assays (ELISA) methods used in Entamoeba histolytica/Entamoeba dispar diagnosis. For this purpose a total of 176 faecal samples from people were randomly collected from regions of the Bursa City Centre, where crowded families of low socio-economic levels reside. All faecal samples were examined by wet mount + Lugol's iodine formalin ethyl acetate concentration, trichrome staining methods and ELISA. 66 faecal samples were infected with one or more parasite species and the overall prevalence rate was 37.5%. Nine species of intestinal parasites, including six protozoon and three helminth species were found. The most prevalent species was Blastocystis hominis (17.04%) and others were found with the following frequencies: 9.09% Enterobius vermicularis, 7.38% Giardia intestinalis, 5.68% Entamoeba coli, 2.27% E. histolytica/E. dispar, 1.13 % Entamoeba hartmani, 1.13% Taenia spp., 0.56% Hymenolepis nana. 6.2% of examined samples had mixed infections. Overall prevalence of the detected parasites did not differ significantly in different demographic groups. Except for B. hominis and G. intestinalis, there was no evidence for sex, age and other demographic-related differences in the prevalence of these parasites. Statistically, B. hominis and G. intestinalis were higher in 20 to 49 and in 1 to 19 year age groups, respectively than in any other age group. Microscopical examination and ELISA revealed that one sample (0.5%) was found to be positive using all 4 methods, and 162 samples (92%) were found to be negative with all 4 methods applied. E. histolytica/E. dispar complex was detected in 0.56% (1); in 0.56% (1), in 0.56% (1) and in 2.27% (4) of the fecal samples examined by wet mount + Lugol's iodine, formalin ethyl acetate concentration, with trichrome staining, and ELISA respectively. The wet mount + Lugol's iodine, formalin ethyl acetate and trichrome staining methods had a sensitivity of 25% each, a specificity of 94.1, 99.4 and 98.2%, compared to the results of the E. histolytica/E. dispar ELISA, respectively.