A mechanical device, producing a permanent communication between the lumen of the cecum and the exterior, offers a satisfactory method of studying the course of amebic infection in guinea pigs. Such animals thrive normally with the tube in situ and when inoculated in the cecum with a 48-hour crude culture of Entamoeba histolytica acquire the infection within 12 days. The infection takes an acute fatal course without diarrheal manifestations. With early treatment the condition may be controlled, but it usually recurs, simulating chronic intestinal amebiasis, as observed in infected animals kept under observation for several months.
Necropsy showed amebic ulcers in the colon, a large number of amebae being demonstrated in the deeper tissue and crypts. The weight of the liver in relation to the body weight was significantly increased as observed in the relapsing animals as compared to normal ones. Cutaneous amebic ulcers due to local contamination developed in three infected guinea pigs; they were cleared up readily with local anti-amebic treatment.
While illustrating the utility of the mechanical device not only in observing the natural course of amebic infection in guinea pigs but also in assessing the effect of amebicidal drugs on the parasites in the colon, no conclusion was drawn as to the relative efficacy of the different drugs used in the present study.