Serological tests exist for long-term infections. It is important to distinguish the E. histolytica cyst from the cysts of nonpathogenic intestinal protozoa by its appearance. Amebiasis is transmitted by fecal contamination of drinking water and foods, but also by direct contact with dirty hands or objects as well as by sexual contact. It is also frequently diagnosed among homosexual men. In fewer cases, the parasite invades the soft tissues, most commonly the liver.
Fatalities are infrequent.
E. histolytica cysts may be recovered from contaminated food by methods similar to those used for recovering Giardia lamblia cysts from feces. Filtration is probably the most practical method for recovery from drinking water and liquid foods. In recent times, food handlers are suspected of causing many scattered infections, but there has been no single large outbreak.