V. Evaluation of Cross-Immunity against Type 1 Dengue Fever in Human Subjects Convalescent from Subclinical Natural Japanese Encephalitis Virus Infection and Vaccinated with 17D Strain Yellow Fever Vaccine
A study of intestinal parasitism in the New Hope community of Jackson County, Tennessee, based on three fecal specimens examined from each individual, revealed the prevalence of Endamoeba histolytica to be 22.4 per cent. The prevalence of this parasite reached a maximum of 35 per cent in the 5- to 9-year age group and subsequently declined. Prevalence rates of the other intestinal protozoa were commensurately high, and a similar age distribution pattern was observed. Ascaris lumbricoides was the most frequent helminth parasite being found in 9.6 per cent of the population.
Compared with a previous study in 1930, amebae in general (except E. nana) are now much less prevalent. The difference in prevalence appears to be due primarily to a lower prevalence of parasitism in adults at the present time. The change in the age-prevalence relationship would indicate that spontaneous termination of parasitism is frequent.
Compared with a rural, negro population of West Tennessee, recently studied in a parallel investigation, the white New Hope community had much higher parasite prevalence rates, despite a higher level of sanitation and cleanliness.
Located at the Medical School of the University of Tennessee, 874 Union Avenue Memphis 3, Tennessee.