Intestinal parasites in Los Angeles, California.

Because of an apparent increase in the number of parasitic infections in Los Angeles, California, a six-month retrospective analysis of data obtained from patient stool examinations for parasitic infections in out-patient populations from two county health facilities in Los Angeles County was compared with a survey published in 1936 and 1960. A significant increase in the incidence of pathogenic intestinal protozoal parasites was found to occur in the areas surveyed. Giardia lamblia and nonpathogenic Endolimax nana occurred with the greatest frequency.