Microscopic overdiagnosis of intestinal amoebiasis.

To determine the misdiagnosis of intestinal amoebiasis associated to microscopic examination of faeces, 50 stool samples of patients infected with Entamoeba histolytica were collected from different Primary Health Care Centers, hospitals and private laboratories in Ismailia G. The samples were examined using Wheatley's trichrome staining technique to differrentiate E. histolytica E. dispar complex from other non-pathogenic intestinal amoebae and multiplex polymerase chain reaction (PCR). PCR differentiated between the two morphologic identical species (E. histolytica and E. dispar) and had the advantage to save time and resources. E. histolytica was detected in only 5 (10%) samples and in association with E. dispar in 8 (16%) samples. On the other hand, 20 samples (40%) were E. dispar. The other 17 samples were negative. E. coli, E. hartmanni and polymorphs were commonly misdiagnosed as E. histolytica.