Cockroaches (Periplaneta americana and Blattella germanica) as potential mechanical disseminators of Entamoeba histolytica

Since cockroaches feed on feces, they may disseminate infective agents with the fecal-oral route. A field survey and experiments were conducted to determine the role of cockroaches in the dissemination of Entamoeba histolytica. Periplaneta americana (n=299) and Blattella germanica (n=29) were collected from 11 primary schools in an urban area of South Taiwan. E. histolytica/E. dispar cysts were found on the cuticle and/or in the digestive tract of P. americana (25.4%) whereas cysts were only isolated from the digestive tract of B. germanica (10.3%). E. histolytica cysts were found on the cuticle and/or in the digestive tract of both species after exposure to 1000 or 100 cysts/g feces for 24 h. These findings indicate that cockroaches may harbor the E. histolytica cysts and play a role as potential mechanical disseminators.