Introduction Entamoeba histolytica-caused amoebiasis is a major cause of mortality worldwide. E. histolytica is morphologically indistinguishable from nonpathogenic species like E. dispar, E. moshkovskii, and E. hartmanni. Polymerase chain reaction (PCR) is the approved method by World Health Organization for diagnosis and differentiation of amoebiasis. This study aims to molecularly differentiate the four Entamoeba spp. using conventional PCR and correlate their prevalence with the patients' sociodemographic data. Methods We collected fecal samples of 175 patients with gastrointestinal diseases at Damanhour General Hospital (El-Behira, Egypt). All microscopically positive samples were subjected to conventional PCR. ResultsThe overall prevalence of Entamoeba infection was 65.7% (115/175). The differentiation by PCR was successfully attained in 102 samples. The species distribution was as follows: E. histolytica (14.7%), E. dispar (61.8%), E. moshkovskii (11.8%); besides, 11.8% of samples revealed mixed infection. Of note, the infection rate was higher in men, patients from rural areas and patients who did not have sanitation facilities for sewage disposal. Conclusion This study demonstrates a high prevalence of infections caused by the nonpathogenic Entamoeba spp. E. dispar, E. moshkovskii, and E. hartmanni along with the pathogenic E. histolytica. Hence, we recommend PCR assay as an accurate, rapid, and effective diagnostic method for the detection and differentiation of the four morphologically indistinguishable Entamoeba spp. in both routine diagnosis of amoebiasis and epidemiological surveys.

Background: Giardiasis is one of the most important parasitic gastro-intestinal infections that affect humans worldwide. Children are the most affected age group either in developing or developed countries. Genotyping of Giardia lamblia by molecular techniques classified it into eight assemblages; of which, assemblages A and B are potentially zoonotic pathogens. This study was done to investigate the prevalence of different Giardia lamblia genotypes by conventional polymerse chain reaction (PCR), and to explore the environmental and patientsʼ sociodemographic factors that may affect the disease prevalence. Methods: Two hundreds fecal samples were collected at Damanhour General Hospital from patients with gastrointestinal diseases. All samples were examined microscopically, and the positive ones were investigated by conventional PCR. Results: Giardiasis was detected in 92 (46%) samples. Eighty-eight samples gave positive results by PCR, 18% of which were assemblage A, 70.5% were assemblage B, and 11.5% were mixed infection of both assemblages. The infection was more prevalent in males, rural patients and the highly educated ones. Conclusion:This study presents critical and demonstrative data regarding public health in Egypt. The results reveal that the prevalence of giardiasis is high among both rural and urban patients, particularly in children. It also prevails in patients of all education levels, and patients dealing and not dealing with animals. Moreover, we recommend PCR amplifying the triose phosphate isomerase (tpi) gene in fresh fecal samples as a very effective method for the diagnosis and genotyping.