To the Editor.
—During a period of about one year, covering parts of 1952 and 1953, the parasitology laboratory of the Veterans Administration Hospital, Long Beach, Calif., examined 5,031 stool specimens from 1,773 patients and staff members. The incidence of Endameba histolytica infection in this group was 1.3%, or 23 cases. This is quite low in comparison with the average incidence of 8.1% obtained by Craig and Faust (Clinical Parasitology, ed. 5, Philadelphia, Lea & Febiger, 1951, p. 72) in an analysis of 40 different American surveys covering the period from 1916 to 1942 and also in relation to a reported incidence of 3.3% in a group of 2,016 adults and children in the Los Angeles area (Kessel and Sinitsin: J. Parasitol.24:433, 1938).Although we have no accurate statistics covering the incidence of infection in previous years at this hospital, we believe that recently it has fallen off