A Survey of Human Intestinal Protozoa in Sweden and Finland. (A Preliminary Report)

Abstract

This survey records the intestinal protozoa found in 611 hospital cases in Sweden, 1244 mental asylum cases in Sweden, and 159 medical out-patients in Finland. Only one examination was made of each case.In each of these three groups the following protozoa were found: Entamoeba histolytica, E. coli, Endolimax nana, Iodamoeba bütschlii, Giardia intestinalis, and Chilomastix mesnili. In hospital and asylum cases in Sweden Dientamoeba fragilis was encountered, Trichomonas hominis and a small flagellate were found in the asylum group, and in this group as well as in the series in Finland, Balantidium coli was met with. In one case cysts of this protozoon were found.In a group of 46 cases, formed stools as well as loose stools obtained after administration of a purgative were examined. The loose samples revealed the presence of Trichomonas hominis, Balantidium coli, and a small flagellate, none of these having been found in the formed specimens. The percentage of Dientamoeba fragilis rose from 8·7 per cent, in the formed stools to 23·9 per cent. in the loose stools. All the other species were more abundantly present in the loose than in the formed samples.In Sweden, mental asylum cases show a much higher incidence of infections than do the hospital cases.Intestinal protozoa seem to be more common in Finland than in Sweden.Among hospital cases in Sweden the residents of Stockholm show a lower incidence of infections than do the people living in rural districts.At admission, asylum cases are not infected to a higher degree than are the general hospital cases. The rise in incidence of infection is directly proportional to the length of time spent in the institutions up to ten years, after which time no further increase occurs. The male patients show throughout considerably higher percentages of infections than the female patients. Chilomastix mesnili shows a very high incidence in the asylums, whereas the percentage of Giardia intestinalis remains practically the same throughout the time of confinement in the institution.